# Trans cooler all fitted...



## charles charlie (May 3, 2008)

I've been tracking my GTR for 3 years and as many will know, the ruddy transmission temps drive you nuts.

So, I've been looking for a sensible solution and every one I looked at didnt suit me completely.

So I decided to pick the best bits from several key providers of colling solutions and put my own together.

My kit involved the following..

- SSP front mounted cooler, fan and hosing.

I liked the position of this cooler, it's large cooler core, and the twin fans. I also liked the gear pump as it should be more reliable than a diaphragm type. SSP produce a deep trans pan which requires cutting of the undertray and at over £1000 for that, I looked elsewhere.

- Japspeed trans sump

At £314 delivered it's as cheap as they come and has attached inputs/outputs for a trans cooler, as well as a 3rd hole for attaching a temp switch (like Forge do with theirs). It arrived with plenty of parts including sump plug/extension tube, attachments for the OEM magnets etc.

- Temp switch

This isnt a necessity but I wanted my cooler to come on when required so I found an M16 sized radiator switch (on at 95, off at 85) and attached this to the sump (with a bonded seal). The switch is earth type, normally open, so we will use it to earth the pump and cooler fans when it hits 95 deg c.

Here's the AN8 fittings and the temp sensor fitted to the sump










I was fortunate to have the guys at Vanquish fit me in today for the install and the quality of the install was flawless. I rolled up towards the end of the day and grabbed some snaps of the process..

Cooler core fitted nicely behind the bumper..

















Viewed from above, really neat place to put a cooler imho..










Pump attached to the front crash bar, really high quality connectors and hosing from SSP


















Fluid hoses covered in heat shield where necessary










The in/outs were attached to the sump, I would prefer the return to feed into the trans filler port but we're trying this setup first and it's easy to swap round. Paul has a rear mounted SSP cooler attached this way and it works great for him so we will see.



















The pump and cooler fans are set to turn on at 95 and off at 85 without any input from the driver but I also have an override switch in the cabin should I wish to turn it on sooner.

I cannot thank Paul and Lee enough for their hard work today as the install is as perfect as I could have wished for.


The best bit is the cost of the parts.

SSP cooler £960 delivered + £50 import duties

Japspeed Trans sump £314

OEM gasket £30

Wiring, switch, wiring tubing and heat shield £40

Parts therefore cost me around £1500.

Gotta get this mother on track now!


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## paul__k (Dec 8, 2007)

Looks like another CC quality job!
Get it round Spa that should test it...


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## SamboGrove (Jun 27, 2010)

My. My you have been a busy boy! This and a new zorst :thumbsup:

Looks like a quality set up. Hope it gives you good results


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## charles charlie (May 3, 2008)

Thanks for the kind words gentlemen.

The proof will be on track and that'll happen as soon as I can get the time.

Cant wait for Bruntingthorpe now!


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## Adamantium (Jun 24, 2002)

this looks like a small neat solution that wasn't a mammoth event to install.

Any idea why the forge option is so much larger and more time consuming to install, and why did you dismiss it?


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## sin (Dec 3, 2007)

Great write up CC.

I take it the house is finished.


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## charles charlie (May 3, 2008)

Good questions Adam.

The Forge unit is a well designed piece of kit with the added advantage of the temp switch and is very comprehensive in the bits and pieces supplied.

I dismissed it for several reasons.

1. Cost. Cheapest I could find was £1900.

2. The pump is a diaphragm type and I wanted a gear driven version.

3. Install was quoted at 10 hours which adds significantly to the cost.

4. Installation of the cooler core would prevent adding another oil cooler at a later date should I so wish.

5. No fans supplied and the area behind the cooler is obstructed by the washer bottle in particular.

6. The pump is mounted on the front sub frame and I wonder about longevity in this area and is close to the very hot downpipes/y-pipe junction.

The SSP version's install location I felt was superb and had the benefit of a top notch pump (Mocal gear driven which I couldnt find in the UK).
The supplied Setrab core is a dual pass version with 2 fans which means I can get the trans temp down without having to keep doing cool down laps (and hopefully bring temps back down faster during those laps)

SSP were happy to provide everything without the trans pan so I could find my own and design the wiring to suit my purpose, and only £950 delivered for the key components.

So to my mind I have the best of both worlds.

Great pump, gear driven, 10-12 litres per minute
Great cooler location
Cheaper sump
Still retaining a temp switch
Manual override in the cabin

I should also add that when I looked into getting the SSP parts separately I couldnt beat their combined price.

So all in all, it combined the well thought out part of the Forge idea (temp switch) combined with I believe, a better cooler location which also has fan assistance.

I may end up eating my words when I hit the track, but several NAGTROV guys have shown good results.


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## charles charlie (May 3, 2008)

sin said:


> Great write up CC.
> 
> I take it the house is finished.


Nope. This cooler and exhaust is instead of a bathroom.

Cool my car may be, smelly I certainly am!


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## mindlessoath (Nov 30, 2007)

great mod man! will u make the review at nagtroc also? i like this location alot. a long while back i remember ssp offered a custom lower sump pan. but i think the larger one gets more cooling due to air flow under the car (i dunno if there's data for that tho). the one you got and the setup with the temp sensor looks great tho!

the reviews showed great results only a few deg give or take differences from the hks and greddy kits. shows its a good kit. and ive read you can't hear the pump like some of the other kits.


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## SamboGrove (Jun 27, 2010)

What are the pros/cons of the geaer driven pump vs a diaphragm type?


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## nick the tubman (Jun 28, 2006)

great work CC.
cant wait to see the results. 
when you next going to Spa?

i assume you have had the pedestrian bumper mod done as well?


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## charles charlie (May 3, 2008)

Good question Sam.

I'd read a lot of opinion on the relative merits of each type of pump and there were strong views on the longevity of diaphragm pumps when they're pumping fluid at an elevated temp. The Mocal unit is rated to be able to run at a constant 130 so it may be fine but I felt the gear type seemed a more robust solution. I would doubt that a diaphragm type pump would be used in a Motorsport setting too.

Nick, pedestrian bumper thingies still intact. For now!! The guys at Vanquish can reset the bonnet ECU if it goes off so not overly concerned.

Should also add my sincere thanks to Kris and Jeremy at SSP whose service was extraordinary. They answered emails over their Memorial Weekend holiday within minutes and were happy to provide lots of info to my numerous questions. Great people to deal with.


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## Anders_R35 (Jul 20, 2011)

Nice install, I'm still interested in the AMS solution but will give this some thought also.

Anders


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## Anders_R35 (Jul 20, 2011)

Did some posts disappear from this thread? I made one that's vanished?

Anders


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## charles charlie (May 3, 2008)

You posted it in my exhaust thread where it's sitting all alone and looking out of place and odd....


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## TAZZMAXX (Mar 9, 2010)

As if by magic...............


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## Anders_R35 (Jul 20, 2011)

charles charlie said:


> You posted it in my exhaust thread where it's sitting all alone and looking out of place and odd....


User error, too many windows and tabs open :chairshot


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## R1Mark (Jul 7, 2003)

Do you get any noise or vibration from the pump when its running? I've a cooler pump that is really noticeable when its running.


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## charles charlie (May 3, 2008)

Nope cant hear it as the pump is on the crash beam in front of the radiator. The fans are the noisiest part and can only be heard if you stand outside in front of the car.

Nice and quiet!


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## R1Mark (Jul 7, 2003)

HHmmmmm maybe time for a change to my set-up.

Very impressed with your install. Looks the biz and the location of the cooler core looks spot on.


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## charles charlie (May 3, 2008)

R1Mark said:


> HHmmmmm maybe time for a change to my set-up.
> 
> Very impressed with your install. Looks the biz and the location of the cooler core looks spot on.


Hold your horses until I can get on track to prove the setup does what it should.

I'm expecting great things from this as the cooler is in the best place imho, and the pump is a well built gear type unit with great capacity.

My only weak link at the moment is the temp sensor I sourced as it has only been proven on my kitchen worktop with a multimeter and a pan of boiling water! It should all work as planned in which case it's just down to the cooling capacity of the setrab core which also looks great imho.

The fans are a plus point as I can pull into the pits and keep cooling the trans whilst stationary unlike the forge unit for instance.

As it stands I see no obvious weaknesses but the proof is in the use.


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## R1Mark (Jul 7, 2003)

Does that mean the temp switch is a bi-metallic type? Thats what I've got fitted but am not convinced they work very accurately especially when the temp is dropping and appears to stay on a bit longer than it should, but without spending a bit of time and effort researching the temp switch it'll do just now.


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## charles charlie (May 3, 2008)

R1Mark said:


> Does that mean the temp switch is a bi-metallic type? Thats what I've got fitted but am not convinced they work very accurately especially when the temp is dropping and appears to stay on a bit longer than it should, but without spending a bit of time and effort researching the temp switch it'll do just now.


All of these type of switches have a range of tolerance so 95 and 85 is not going to be exact.

When I was looking for a temp switch the actual ones available never quite had the ranges I wanted. I wanted 95 not 100 as I wanted it on earlier, and 85 is a little low given 85 is normal road temp but I took the view that on track I'll never get down to below 90-95 anyway whilst giving it some beans so the cooler will be running whenever I'm on it.

What cooler are you running at the moment and how do you find it?


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## R1Mark (Jul 7, 2003)

I'm running the GTC/SVM cooler. The last track day I did the tranny temp sat at about 110 if I recall correctly, however the noise from the pump is very noticeable as the design of the bracket to mount the pump is not great at all so all vibration and noise is transmitted to the body and chassis.


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## Taff1275 (Jan 25, 2012)

Fantastic comprehensive write up as usual CC, best of both worlds there!! my plan is to eventually hit the track and this cooler mod is on the list, like you mentioned elsewhere Vanquish are well experienced with the R35 and are more than capable of working on these cars


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## Adamantium (Jun 24, 2002)

110 with a cooler is it good enough IMHO.

Andy, do you now the core volume difference between yours and the forge?

For one reason it seems small to me.

Understand what you say about ideal placement, but there's not flow through the core if there's a pressure differential across it. Am thinking with the other heat exchangers and under bonnet area behind it, is it oing to allow enough air flow out the back?

Very much looking forward to hearing what happens on your next track., as so far I prefer your solution.


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## bobel (Jul 26, 2010)

Looks like a quality job, and quality parts too, just one question is there any fear that the placement of the core will increase your intake temperatures as looking at the pics i'm imagining the intake cones will be pulling the expelled hot air?


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## Arcam (Jun 30, 2009)

Unfortunately you won't get proper oil cooling with that setup as the oil is being retuned into the sump and not the fill port, what you will get is a false (low) oil temp reading, but I have already stated this before.

What is the flow rate of the pump?


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## charles charlie (May 3, 2008)

Arcam said:


> Unfortunately you won't get proper oil cooling with that setup as the oil is being retuned into the sump and not the fill port, what you will get is a false (low) oil temp reading, but I have already stated this before.
> 
> What is the flow rate of the pump?


Ed, we've discussed this previously and my preferred solution is filling back into the fill port on the front part of the casing and I may change things next week, but what I will say is this. Pump is rated at 9.5 litres per minute.

The OEM trans temp sensor is mounted to monitor the temp of the fluid in the sump itself so the MFD reading is in itself a "false" reading as it only monitors sump temp, not gearset temp. Also, my understanding is that the trans picks up fluid from the sump itself and pumps this up and over the gear set so if we have cooler fluid here, that must mean cooler fluid being delivered to the gearset.

So by drawing fluid from the sump (where it has fallen by gravity), cooling it and then returning it to the exact place where the trans picks it up from can only lead to lower temps inside the trans unit, which is the purpose of any cooler.

I'd appreciate your input on this as always, it is a work in progress and I have the bits there to change the fill point should the evidence suggest it is the better solution.

Adam, the Setrab core is not far off the size of the Mocal unit used by Forge but in a far better position to receive direct cool air and with space behind to allow, I hope, more air flow across the cooler itself. We know that airflow is the key, a large core with limited airflow is very inefficient by nature.
The HKS/Greddy/Forge cores are placed in that passenger side area which has a lot of stuff behind it (washer bottle for instance) which must impede airflow. They are also without any fans to aid airflow too when the car is stationary and as such rely almost 100% on the car moving to generate that airflow and cooling action. Those systems do work as advertised and that may have something to do with having as big a core as possible to overcome the inherent

Bobel, I'm not concerned about affects on intake temps as they take air front the side of the cooler core which itself expels air behind and into the path of the OEM radiator. As such I'd be surprised if there was an increase in intake air temps, but t is impossible for me to be sure without complicated measuring equipment.

I'm just converting some video which I'll have up in a few mins.


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## charles charlie (May 3, 2008)

Quick, boring video of temps dropping after a spirited road test. 

Note the quietness of the system inside the car, even though the fans make some noise outside when running. No vibrations from the pump when running which is good.

Got the trans up to 93 deg c then pulled over and switched the override on the pump/cooler.

Got a 19 deg drop in 9 minutes.

Obviously just a very unscientific test and not indicative of performance when we get to 110+ on track but that will come soon enough.


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## R1Mark (Jul 7, 2003)

Adamantium said:


> 110 with a cooler is it good enough IMHO.


What sort of temps should we ideally be looking at.

TBH I didn't really keep tabs on the temps during the day and the 110 was just what I noticed during a quick glance as I came of the track.


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## charles charlie (May 3, 2008)

mmm 110.

Nissan originally said that trans fluid temps of 110 deg c required a change within 3000 miles, then later rescinded that by altering the threshold to 120.

Original climbdown announced here.

So, what is a "safe temp" on track. IMHO that depends upon the type of fluid used and the life it has had.

The OEM GR6 fluid is regarded as being up to the job as long as its temp doesnt get too high. As for what that temp actually is is open to debate.

Many track users have swapped over to fluids with purportedly better high temp resistance with no obvious bad affects on trans longevity.

My own thoughts are that the cooler the fluid and trans components, the better. There are seals within the gearbox which will undoubtedly have shorter lifespans if they are exposed to higher temps for extended periods so anything we can do to limit that exposure the better.

My preferred temp for my trans fluid (regardless of what it is, GR6 OEM/FFL4/Willall) will be below 110, and hopefully around 100-105.

That way we are boiling off any water that's been absorbed by the fluid over time and keeping well within the operating limits of the fluid and trans components.

Strangely even after 4 years of tracking cars over in the US, we are no that much closer to answering that simple question. All we can theorise is that the higher the temps, the shorter the lifespan of components within the gearbox.


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## charles charlie (May 3, 2008)

Bit of an update.

I've spent the last 48 hours analysing the install and thinking about where the cooler fluid should be returned to the trans.

The OEM heat exchanger is mounted to return cooler fluid to the clutch compartment and after discussions with Jeremy at SSP, it does seem that most heat is generated by the clutches.

As such I'll be swapping the return feed so that it pushes the cooled fluid into the filler point of the clutch compartment.

That'll happen this weekend and I'll shoot some more video of how this affects the fluid temps after some more spirited driving.

More to follow.....


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## Adamantium (Jun 24, 2002)

Andy,

Sounds like a sensible plan to me.


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## charles charlie (May 3, 2008)

Thanks Adam, It's been occupying my mind ever since saturday's install.

Initially I wanted the return to be to the filler port as every other cooler does this (even the SSP one I have suggests this btw) but Paul at Vanquish was concerned about causing fluid starvation in the sump.

Some have suggested this was a bad idea as it would affect the monitored temp on the MFD given the location of the sump temp sensor but my thoughts were that fluid pick up form the sump and thus to the gearset was paramount.

However after careful analysis of fluid flow inside the trans casing it became clear that clutch temp is the key provider of heat inside the trans and as such be looking to coll these first.

I'll swap it over on saturday and see how we go.


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## Guy (Jun 27, 2001)

I certainly think that the coolest fluid should be introduced to the hottest part, to maximise the cooling effect. 

However I'm surprised that the clutch packs are what gets hottest. Clutches should only get hot when slipped and the GTR change is so quick they barely slip, which has been shown in lack of wear by any owners. Most heat is surely generated by frictional and shear-force stress generated by the gears themselves? In a 'normal' gearbox it's the gears that are cooled and the dry clutches are never cooled, nor do they get hot (or they'd slip).


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## charles charlie (May 3, 2008)

Thanks for your input Guy.

I have to say I'm caught in 2 minds at present as there are 2 scenarios which spring to mind.

Firstly the trans casing is actually 3 parts joined together as far as I can see..

Front casing is where the fill point is and contains the clutches as well as the OEM heat exchanger return

Middle casing contains the gear set assembly and is where the sump is and where the filters and pump is located to draw fluid from the sump up and back into the trans casing. The temp sensor for trans fluid is located here and is specifically placed here to measure sump fluid temp NOT gear set temp.

Back part which contains the rear diff (which of course has it's own fluid).

so, 2 options to play with

1. Return cooler fluid into the filler port at the front of the trans casing in a similar fashion to the OEM heat exchanger, which will flow cooler fluid over the clutches, then that passes into the gearset compartment and down to the the sump. Temp sensor should read the temp of the overall transmission as the fluid temp will be that of the gearset.

2. Return cooled fluid to the sump exactly where it is needed to be drawn up through the filter and onto the gearset. The temp sensor will show the temp of the fluid inside the sump and thus the temp of the fluid being pumped over the gearset, but not the actual temp on the gearset assembly.


So I am caught in 2 minds. 

Provide cooler fluid to the gearset or have the temp sensor display a more accurate indication of the trans temp.

Thoughts anyone?


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## Guy (Jun 27, 2001)

I think option 1 is 100% preferable. 

I didn't know it flows over the clutch then the gears, this makes sense I guess. My point was really that I didn't how the clutch got that hot. 

However flowing cooled oil to the sump makes no sense, since it means that the overall sump temps are reduced artificially which produces an artificial temp reading as well as reducing cooler efficiency, since the cooler is sourcing already cooled oil through it, rather than only oil that has been through the gearbox. You want the highest temp oil going into the cooler to maximise efficiency.


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## Jasper013 (Aug 16, 2011)

charles charlie said:


> Thanks for your input Guy.
> 
> I have to say I'm caught in 2 minds at present as there are 2 scenarios which spring to mind.
> 
> ...


Why not fit two sensors?

P


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## charles charlie (May 3, 2008)

Jasper013 said:


> Why not fit two sensors?
> 
> P


The sensor in question is the OEM one placed within the trans assembly itself. It would be almost impossible to fit another sensor inside the trans case and then pass that info to the MFD or another display.

Far easier just to refill the cooler fluid back into the clutch assembly compartment and let the OEM sensor read the overall temps within the transmission as it was designed.


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## Adamantium (Jun 24, 2002)

Let me get this straight,

how far from the cooler pick up point are you intending to reinstroduce the oil?


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## charles charlie (May 3, 2008)

Adamantium said:


> Let me get this straight,
> 
> how far from the cooler pick up point are you intending to reinstroduce the oil?


If you mean when I move the return from its current position to the filler point on the trans casing then the SSP pump draws fluid from the bottom of the sump










and the new location is the trans filler point which is at the fornt of the trans casing, in between the drive shafts










SO we would be re-introducing cooler fluid further away from the gearset but it should lead to the MFD temp sensor giving a better representation of the overall trans temp.


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## bobel (Jul 26, 2010)

Some really interesting ideas, really lookin forward to see how the setup fairs on the track, just out of interest whats the additional hold up volume with the setup? For what it's worth and not knowing the internal channels in the casings I just wonder given the flow rates from the new pump and returning further away from the sump pick up point will it as you've already said pose a problem of starvation for the OEM pump! be interesting to see how balanced the system is, but really like the look of this setup, well Done


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## Adamantium (Jun 24, 2002)

where is the OEM exchange feed?


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## Adamantium (Jun 24, 2002)

I have a few other questions.

Where is the OEM transmission pressure sender and how does the pressure in your return line compare with typical pressure readings from the gearbox

Does your return line have a suitably psitioned one way valve?


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## charles charlie (May 3, 2008)

Adamantium said:


> I have a few other questions.
> 
> Where is the OEM transmission pressure sender and how does the pressure in your return line compare with typical pressure readings from the gearbox
> 
> Does your return line have a suitably psitioned one way valve?


Weirdly I've just posted a reply and it's vanished..

OEM exchanger seen here, bi misleading as actually on clutch compartment casing, not so close to the sump









The trans pressure sensor is is in the valve body assembly which you can see above the sump when it's removed. This photo shows Willall's replacement sensor in situ and circled.









Pressure hasnt changed during pump/cooler usage as seen in the very firt part of the video above and no other aftermarket cooler has reported pressure issues.

I havent added any form of non-return valve as no other aftermarket kit uses one and my guess is that there is no need for one.


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## Adamantium (Jun 24, 2002)

I assume all the existing versions feed in and out of the sump, of course there's no need for a one way valve, but if you plan to feed in elsewhere, you need to know the pressure in that location to ensure that you don't get reverse flow through the pump.

That's why I asked where the pressure sender was.


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## paul__k (Dec 8, 2007)

Impressed with the amount of thought that has gone into this.

My thoughts are:

Is there any chance of pump cavitation due to the relative height of the pump to the fluid level?

The cooling effect due to the additional pipe length of fluid may be significant.
Wonder what the additional volume is?

Pressure drop due to adaptor (minimum orifice) constraint can significantly affect the flow rate and pressure drop.

Could there be any starvation due to high G cornering / braking?

I would put the return oil in the same place as the nissan heat exchanger.

Will be interested to hear how it pans out.:smokin:


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## charles charlie (May 3, 2008)

Adamantium said:


> I assume all the existing versions feed in and out of the sump, of course there's no need for a one way valve, but if you plan to feed in elsewhere, you need to know the pressure in that location to ensure that you don't get reverse flow through the pump.
> 
> That's why I asked where the pressure sender was.


Forge and SSP are the 2 systems which use their own sump and both take fluid from that, to the cooler then return to the filler port on the front of the trans assembly, rather than back to the sump itself.

Strangely my understanding of the trans is that it isnt completely full of fluid. I've come to that conclusion based on the fact that when you fill it back up you wait for drips to come from the filler tube which sticks up form the sump and into the gearset/valvebody area. This tube isnt very long so there must be an air void at the top of the trans itself above the gears. 

If that is the case then the pressure sensor may well be there to ensure that there is fluid inside the gearset casing and thus to warn of a blockage in the distribution system within the two casings (clutch and gears) and/or a loss of fluid from the trans itself.

The other systems HKS and Greddy take from the oem exchanger using a special fitment.


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## Guy (Jun 27, 2001)

Excuse the stupid question, but is this in addition to the stock trans-cooling system, or does it effectively replace the stock system?


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## charles charlie (May 3, 2008)

Guy said:


> Excuse the stupid question, but is this in addition to the stock trans-cooling system, or does it effectively replace the stock system?


It'll work in tandem with the stock cooling system (for what that is worth!) as that is left untouched. The oem system is important to actually heat up the trans fluid when starting from cold but one has to wonder what happens on track when coolant temp reaches 90+ degrees. That severely limits the capacity of the OEM coolant system to remove heat from the trans. 

The HKS and Greddy units use a thermostatically controlled valve attached to the OEM heat exchanger which closes off the feed from main radiator water when above a certain temp. They also utilise the OEM pump to push trans fluid to and back from their cooling cores.

There have been some reports of loud sounds from the oem pump when running these kits and also one has to question the longevity of that pump given it is being driven beyond what it was designed for.

Also HKS are proud to say their system prevented trans temps going above 127 degrees!

Not what I'd call value for money here


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## charles charlie (May 3, 2008)

paul__k said:


> Is there any chance of pump cavitation due to the relative height of the pump to the fluid level?
> 
> The cooling effect due to the additional pipe length of fluid may be significant.
> Wonder what the additional volume is?
> ...


The pump will always be pulling from the sump where the fluid level should always remain high enough to ensure only fluid and not air gets to the pump. The pump is a gear type so I'm too worried about cavitation as it can self prime anyway.

Additional volume should be around 1-2 litres.

Starvation at high G shouldnt happen as the position of the outlet is actuallu lower than the OEM filter within the sump. If lat G was an issue, we'd be losing trans pressure on track which afaik hasnt happened to anybody.

And yes, I'm swapping the return next Thursday when Paul from Vanquish is back from thrashing his own R35 around the 'Ring.


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## Adamantium (Jun 24, 2002)

Andy, the gearbox may not be full of oil but the clutches need to be. The wet clutches have annular control chambers which require oil pressure for actuation. As far as I can tell they must be completely immersed.

I don't personally agree with Guy that because they appear to bite immediately they generate no heat. There's always some slip and the faster that bite applies just means the clamping force is higher. That just means a shorter bite time over which the slip occurs but high friction due to high clamping will create a sudden heat spike.

I'm sure I've been told my Dodson that the temps in the clutch housing can reach 150+ degrees.


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## DRAGON (Nov 12, 2003)

charles charlie said:


> It'll work in tandem with the stock cooling system (for what that is worth!) as that is left untouched. The oem system is important to actually heat up the trans fluid when starting from cold but one has to wonder what happens on track when coolant temp reaches 90+ degrees. That severely limits the capacity of the OEM coolant system to remove heat from the trans.


Have you seen any results with people removing/blocking the standard cooling set-up?


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## charles charlie (May 3, 2008)

Adamantium said:


> Andy, the gearbox may not be full of oil but the clutches need to be. The wet clutches have annular control cameras which require oil pressure for actuation. As far as I can tell try must be completely immersed.
> 
> I don't personally agree with guy that if they appear to bad immediately tat they generate no heat. There's always some slip and the faster that bite applies just means e clamping force is higher. That just means a shorter bite tie over which the slip occurs but high friction due to high clamping will create a sudden heat spike.
> 
> I'm sure I've been told my Dodson that the temps in the clutch housing can reach 150+ degrees.


That would certainly make sense Adam (even if some of you ipad typing doesnt  ) and would explain why teh clutch compartment is separate from the gear set. It would also explain why the OEM system cools fluid from the clutch assembly rather than the trans sump itself.

The more I look into it, the better I am returning cooler fluid to that compartment.



DRAGON said:


> Have you seen any results with people removing/blocking the standard cooling set-up?


Nobody has ever mentioned removing the OEM coolant system but I'm sure Cobb or somebody similar have done so for their race prepped GTRs. I have seen some pics of some guys using a water/oil Laminova type cooler fitted in the boot with big fans cooling the cores themselves

Thread here










Not practical as a daily driver though.

imho I see no reason to complicate the installation by removing the oem coolant lines and they help warm the trans up from a cold start by providing heat from the engine coolant.


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## Adamantium (Jun 24, 2002)

What is the Problem with the oem modine? It accelerates stabilisation of the gearbox temperature to 90 degrees using the thermal rejection properties of the radiator. Isn't that a good thing in every way?

The danger is that if you increase power hounded the rad to have greater capacity but it's perfectly placed to cool really efficiently. It's far easier to upgrade the front radiator which is going to have a better shot of reducing the temp of the water than an aftermarket oil cooler has of cooling the transmission oil. The fact that the modine ties three two together is IMHO only a good thing. So long as you have capacity in the rad you have accelerated heating to operating temp combined with increased cooling capacity attempting to tie transmission and water temps to 90 degrees.


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## DRAGON (Nov 12, 2003)

Im just wondering why nissan decided to run it through the engine coolant system, to heat the trans temp up, or to cool it down?
I guess, that is was to speed up getting it up to temp, and can help lower the temp a little when the trans is getting very hot.
But the trans is getting up to temp on its own anyway, so I wonder how much it helps, also when the trans is at 110c for example, how much is it cooled by going through say 90 degree water?


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## digi (Dec 17, 2010)

here is my HKS oil pan (suppose to help with cooling etc. Not sure how well it works). Have cooler on the front bumper passenger side.










Quite useful in my climate.


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## charles charlie (May 3, 2008)

You will never know how useful a trans cooler is until you get on track.

That's where it earns its stripes.


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## Adamantium (Jun 24, 2002)

btw. the standard modines are there mostly to increase temps of fluids faster. This reduces their viscosity and thus reduces engine and transmission pumping losses giving a direct benefit to CO2 and MPG readings.


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## charles charlie (May 3, 2008)

Correct. The thermodynamics of the oem coolant system means that once up to track type temps, the coolant from the radiator is removing very little from the trans itself any may contribute to keeping trans temps higher when you use an aftermarket trans cooler. Even the best aftermarket radiators boast only a 30% increase in cooling capacity which in the overall scheme of things isnt a huge improvement given what the radiator is expected to do imho. Anyone who has tracked a GTR knows just how much heat is under that bonnet after a few laps. Even road driving generates tremendous amounts of engine bay heat.

AMS's solution also adds in a secondary oil cooler as they clearly cannot control engine coolant, trans temp and oil temp without addressing all 3 components at the same time.

For me I've never had coolant or engine oil temp issues on track (guys in the US struggle with these as their ambient temps are well above what we experience in the UK) yet trans temps always get beyind 110-115 within a few hard laps, almost regardless of the ambient temp.

Interestingly an updated radiator is next on my list (Koyorad probably) as it is a relatively cheap way to remove more heat from the engine and also it has to help the trans temps a little too.


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## Guy (Jun 27, 2001)

charles charlie said:


> For me I've never had coolant or engine oil temp issues on track (guys in the US struggle with these as their ambient temps are well above what we experience in the UK) yet trans temps always get beyind 110-115 within a few hard laps, almost regardless of the ambient temp.


Agreed.

The highest I ever got engine coolant to was 112c and that was hard driving alpine passes uphill, where the engine is on boost a lot and the air cooling is low due to low speeds. On track and at 180mph+ on road it was ok, though I guess modified big bhp cars may suffer more.

By contrast getting trans temps to 140c was easy at the ring and snetterton in the dry.


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## charles charlie (May 3, 2008)

GLOXN said:


> Great post.


Shame that one isn't.


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## charles charlie (May 3, 2008)

*UPDATE....*

Just a quick update after moving the return feed to the front of the trans casing as per previous discussions.

Same as before except ambient temp was 17 deg c, very similar results.

Track day booked at OP on 7th August so bigger test then...


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## Sinth (Sep 26, 2010)

How does it perform with the car moving? I assume the car isn't moving in the video


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## charles charlie (May 3, 2008)

Just got back from CATD day at Millbrook and the trans cooler was awesome. 5 fast laps on the handling circuit saw temps rise to over 100. Cooler kicked in on auto and temps dropped v fast back to 80.

Next set of 5 v fast laps I turned the cooler on before we started and temps never got above 89. 

Sin's temps reached 117 on an earlier exercise when my cooler again kicked in on auto at 100 and kept them at 90 for the rest of the exercise.

Yep different cars and drivers but gives you an idea of what we were putting the cars through.

Next test is Oulton Park a week Tuesday then Bruntingthorpe which is a huge test.

I'm very hopeful it'll work a treat.


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## SamboGrove (Jun 27, 2010)

charles charlie said:


> Just got back from CATD day at Millbrook and the trans cooler was awesome. 5 fast laps on the handling circuit saw temps rise to over 100. Cooler kicked in on auto and temps dropped v fast back to 80.
> 
> Next set of 5 v fast laps I turned the cooler on before we started and temps never got above 89.
> 
> ...


Sounds like great results. Can't imagine you hoped for much better than that?


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## charles charlie (May 3, 2008)

SamboGrove said:


> Sounds like great results. Can't imagine you hoped for much better than that?


Absolutely Sam.

It's always a slightly anxious feeling when you've put something together like this but a great feeling when it goes better than planned.

My only gripe is the thermal switch reads out by about 4-5 degrees over and under compared to the MFD so it's turning on at around 100-102 rather than 95, and off at around 80-81 not 85 as specced.

It's not an issue at present so I may end up tweaking the model of switch if I can be arsed but I'll wait until Brunters and OP are out of the way.


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## charles charlie (May 3, 2008)

*UPDATE...*

Well just had a great day at Oulton Park.

Ambient track temp was 20 deg c (scorchio!) and the trans cooler worked a treat. Came on at 100 or so, and my trans temps never got above 103 all day.

It meant that for the first time on track I could go out lap after lap after lap. I stayed out with my instructor for easily 15-20 laps in the afternoon in one stint and only came in when I ran low on fuel. I was pushing hard too.

Once into the pits, the cooler continued to work its magic and by the time I'd filled up, temps were down to 80 after around 10-15 mins.

I've now discovered other temp issues I've never known before.

Power steering fluid got rather hot, and oil temps rose to the highest I've seen in 3 years, and the RS29s are one hell of a pad.

Looks like I'm gonna have to add even more coolers at this rate!

I can now look forward to plenty of laps on Saturday.

Most happy!


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## andyg (Apr 1, 2012)

well done CC mission accomplished


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## SamboGrove (Jun 27, 2010)

charles charlie said:


> *UPDATE...*
> 
> Well just had a great day at Oulton Park.
> 
> ...


Awesome :bowdown1:

I think litcho are working on a aftermarket power steering fluid reservoir


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## Sinth (Sep 26, 2010)

Excellent work.


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## David.Yu (Jun 28, 2001)

What engine oil temps did you see?


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## charles charlie (May 3, 2008)

David.Yu said:


> What engine oil temps did you see?


That afternoon session saw oil temps get to 105-110 iirc, coolant got to 102 (ish) I think at one point.

I was so concerned about trans temps I didnt really pay much attention to other temps as they've never been an issue before as I always had to come in way before oil/coolant became an issue.

I'll be watching all of them on saturday that's for sure.

I'm gonna rig up some kind of video for saturday so I can record these temps. I'm still holding out for Cobb to add trans temp logging to the AP as that would mean I could have proper empirical data to fully demonstrate the efficacy of the SSP system.


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## CT17 (Mar 25, 2011)

Very interesting CC, I'm looking at getting a transmission cooler in the very near future.

How much would you think it cost overall?


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## charles charlie (May 3, 2008)

CT17 said:


> Very interesting CC, I'm looking at getting a transmission cooler in the very near future.
> 
> How much would you think it cost overall?


Quick costings..

SSP cooler, pump inc shipping and VAT/duties - £950

Japspeed sump - £314 inc shipping

OEM gasket - £30

M16 radiator switch - £10

Bonded seals for switch and sump in/out - £5

5m twin core wiring and plastic tubing - £20

Interior override switch - £10

Heatproof sheathing - £50


So say roughly £1400 for all the bits.

Vanquish charged me £400 for installing this and my exhaust as well.

Also you'll need an extra 2 litres of trans fluid. I just swapped out my FFL4 for 10 new litres, which I got for £130 delivered.


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## CT17 (Mar 25, 2011)

Blimey, that's still around £1000 cheaper then the Forge item installed, plus you have to add VAT!


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## Sinth (Sep 26, 2010)

charles charlie said:


> Quick costings..
> 
> SSP cooler, pump inc shipping and VAT/duties - £950
> 
> ...


absolute bargain, reckon its worth it for road use? I find myself looking at the transmission temps all the time. Getting too paranoid


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## charles charlie (May 3, 2008)

Road use is pointless tbh as trans temps should never reach 110.

Track use can see 110 very quickly and the key issue then is not just max temps (and changing trans fluid) but how slowly a GTR loses that heat.

I found the cycles of heating trans to 110, trying cooling laps to get down below 100, then 1-2 hot laps back into the red zone again utterly soul destroying and really took the shine off most track days.

Brunters yesterday I just kept going and going in the afternoon when we got the queuing issues resolved. 

My setup worked flawlessly, so I'm a very happy bunny.


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## gtrsam (Oct 27, 2005)

Some updates SSP does not seem to keen on Selling the kit without their super expensive pan ..... 
"You***8217;ll need the pan to accept the fittings/lines for our cooler, it wont work without our pan. 

Kind Regards,

Jeremy Rohrs"

So consider yourself lucky ......
Well all know that you dont need their trans pan  you have kind of prooved that.


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## charles charlie (May 3, 2008)

I'm disappointed to hear that as SSP were very helpful when I ordered mine.

Even if the design of the kit has changed, the cooler, bracket and pump take standard fittings and as such it would be possible to adapt them.


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## GTRCallum (Dec 6, 2010)

I have just received an SSP gearbox cooler kit without the oil pan.
I am going to retro-fit the cooler kit to my HKS oil pan - looks a quality kit and I am also going to add a temp switch and 30amp relay to allow fully automatic operation.
No issues with fittings.

Thanks to the Op for the inspiration as it's defo saved me quite a few $$$'s. :thumbsup:


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## Prindone (Oct 13, 2012)

I hear a lot of pepes in US dont us pomp, juste the pan, cooler and thats all... You think it will works correctly?


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## charles charlie (May 3, 2008)

Prindone said:


> I hear a lot of pepes in US dont us pomp, juste the pan, cooler and thats all... You think it will works correctly?


I've never heard if anyone in the US doing that. I think you are misunderstanding what they're talking about. You need a pump to move the fluid from the trans to whatever cooling core you fit.

That means either a separate dedicated pump, or using the internal oem pump of the trans, like HKS do with their kit. If you follow their route, it requires a specially adaptor which connects to the oem trans fluid/engine coolant heat exchanger.

This is the unique component of the HKS kit (and another manufacturer whose name escapes me at the moment...) and is important as at lower temps it is closed and allows the oem engine coolant to warm the trans fluid to a more protective temp, then at higher temps closes that off and diverts hot trans fluid to the cooler core. These kits do increase the noise of the oem pump though by some accounts.

Me I preferred an external pump which was temp activated (with manual override) and I have proven my setup on track numerous times.


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## Prindone (Oct 13, 2012)

Ok, what brand use this kind of pump that you can activate if needed!?


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## charles charlie (May 3, 2008)

Prindone said:


> Ok, what brand use this kind of pump that you can activate if needed!?


SSP, Forge. Motorsport, Willall racing etc etc etc.


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## goldgtr35 (Aug 15, 2012)

Very impressed with the install,
Great information as we'll,
Goldie


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## Firestarter (Mar 8, 2014)

CC
Great job and albeit 2 years ago!! I pretty much understand the concept, however where are the cooling fans fitted?

Cheers
Louie


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## Firestarter (Mar 8, 2014)

Firestarter said:


> CC
> Great job and albeit 2 years ago!! I pretty much understand the concept, however where are the cooling fans fitted?
> 
> Cheers
> Louie


Ah got it now....Their on the back of the cooler itself.


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## Firestarter (Mar 8, 2014)

*Bought One*

Well after a couple of weeks researching, talking to various people, and weighing up the Pro's and Cons I have decided to go for the SSP front mounted Tranny cooler. 
Despite considering the HKS cooler I wasn't convinced with the data provided that its going to keep the tranny cool enough and also it hasn't any back up fans, unlike the SSP which Andy - CC fitted albeit with a different sump and a thermostat. The fact that you can just flick a switch to invoke the fans, together with seeing how quickly Andy's cooled down after a good hoon made it the clear winner. It also sends the cooled oil to the trans filler which then gives the clutch basket a nice cold bath, hence cooling the area that I believe generates the most heat. I got so pissed off at Spa a few weeks ago having to constantly come in after 4-5 hard laps as temps were hitting 127c As I have several track days planned next year I've invested in the cooler so high temp transmission will be a thing of the past!!

Just need to get it fitted now.....LEE!!!!!!!:bowdown1:

Cheers
Louie


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## gtr mart (Mar 29, 2004)

Be interested in your findings and also the total costs and if they compare to those posted by CC.

I have a 2010 car and rarely saw temps above 100 even when pushed on the road. I did an event recently (Vmax) and was surprised how the trans temps rose (getting to 120 peak) and how sodding long it took for the temp to drop down to a reasonable level. 

I really liked this thread and is certainly a mod I would be interested in if I was to track my car.


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## Firestarter (Mar 8, 2014)

Hi bud
Yeah the tranny temps are a pain. Like you I never got the temps over 100 even pushing hard on the road....On track its a different matter!!
Will post up more details/pics once I get the kit from Kris @ SSP. Should be shipped out to me on Friday so hopefully have it next week. This cooler combined with Willall WR35TML will sort out any future tranny temp issues

Cheers
Louie


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