# Rb26 500bhp mods??



## Danny86 (Feb 11, 2020)

Hi all

Recently bought a R32 Gtr and getting engine freshed up would like to get some decent power from it while im at it..

Car is fully stock at the moment

What do you guys recommend to get close to the 500bhp mark ?


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## Alex C (Aug 10, 2005)

What do I need for 500bhp?


This has probably been asked a thousand times but it would be good to see a few different takes on this. Between now and the end of february ( ish ) I'm hoping to gather together a shopping list to give to my tuner and for him to give me back a nice reliable 500bhp. My Car is stock at the...




www.gtr.co.uk


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## Bush (Jan 12, 2020)

My 32 put out about 470bhp at the flywheel with 13.5psi boost, and running very rich. As far as I know, all it has is some sort of Greddy hybrid turbos, full exhaust system, apexi induction kit, a hks boost controller and I think some sort of chipped ECU, as it revs to 8k, and still not reaching a limiter.

There has been no internal work done to the engine, that I know of. With a mappable ECU, the fellow in the garage thinks it will easily make 500.


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## gtr mart (Mar 29, 2004)

Welcome mate. When you say the engine is getting freshed up, is that stripped apart and rebuilt? 

If so, I'd be tempted to forge and have the oil return mods done. That will give you a lot more flexibility on future mods. 

As mentioned above there will be loads of info on here for what's worked and things to be aware of. Worth getting yourself a cuppa and having a good read through

Cheers
Martin


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## Danny86 (Feb 11, 2020)

gtr mart said:


> Welcome mate. When you say the engine is getting freshed up, is that stripped apart and rebuilt?
> 
> If so, I'd be tempted to forge and have the oil return mods done. That will give you a lot more flexibility on future mods.
> 
> ...


Yeah basicaly spun a bearing on the drive home so thinking of forging the engine when i have it getting done.
What turbo setup would you recommend?


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## gtr mart (Mar 29, 2004)

Twins or single? 

I'm out of date on skyline choices but deffo loads of info and opinions on here. 

Personally I'd be hitting up a single turbo. Either gt30x or a kit based on the new g series garret (g25). 

However I suspect just steel impellor / N1 turbos with enough boost thrown at them could probably hit 500bhp and be a pretty straight forward upgrade


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## Ares (Jul 9, 2013)

Yup, N1 turbos should be the go though they're old tech and not as spooly as newer options.
Garret Gen 2 and HKS *__* KAI turbos will also be in the mix but you need to make the call about singles or twins.

Also - 500hp is quite vague! I'm at 450hp with fuel system, intake, exhaust and tune - at the engine!
At the wheels would be a whole other thing 

The really important thing is to understand that these engines need to be tuned to take advantage of whatever you purchase for them engine wise. 
These ECU's are super touchy, so even just bolting on a new exhaust or changing an air-filter can cause issues if the vehicle isn't tuned to run them,
so find a tuning specialist you trust to work with is probably the most important thing you can do.


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## joshuaho96 (Jul 14, 2016)

An honest 500 whp is single turbo territory on pump gas. If you mean 500 crank hp or low 400 whp then maybe twin turbos still make sense.

Garrett 2860R-7 is broadly equivalent to a R34 N1 turbo. Garrett GT2859R-9 is the HKS GT-SS turbo. The GT-SS will give more power than the R34 N1 turbo, with a slight reduction in low RPM spool.

The wildcard option in that low 400 whp range is the HKS GT3-SS. It's a journal bearing turbo and I think online people have completely written it off as an overpriced option on the basis that it is a journal bearing turbo. But it's within a few hundred USD of the GT2859R-9 with all the bits that are included with the HKS kit like gaskets, oil lines, water lines, actuators, etc. From the dyno charts I've seen if you get the engine to flow enough at 2000 RPM using something like VCAM step 2 or maybe step 1 with 50 degree advance you can get the turbos to spool at 2500 RPM which isn't true of other turbos. Lends some credence to the marketing claim that it is based on modern direct injection turbos.

Edit:

Bolting on a catback exhaust should never cause problems. Same for a new air filter. The stock RB26 uses a MAF. If you change the backpressure of the exhaust and increase volumetric efficiency the ECU will automatically adapt. The important thing is to not damage the MAF with an oiled filter or a filter with poor dust filtration. Also avoid messing with the path leading up to and just after the MAF sensors. Downstream it doesn't matter as much.


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## Ares (Jul 9, 2013)

Um. Ok. I disagree mate. My two R34's (ER34 GT-t, RB25DET-Neo, BNR34 GT-r V-spec) both had irregularities in their rev range whilst running the
factory ECU once modifications to the exhaust and intake were done.
Flat spots and weird power peaks ARE WELL KNOWN AND DOCUMENTED - Nissan literally built failsafes into their ECU's so that if excess airflow
was detected the car would be put into a safe mode and will generally run richin an effort to protect the engine. In performance terms this means that
ANY modification installed on them needs to be tuned for to be optimized otherwise (as mentioned) flat spots and weird power curves will be encountered.
The older ECU's are somewhat more reliable BUT again, tuning your vehicle is literally the best performance mod you can do to the thing.
I'd tell you the story about my tuned gt-t vs my buddy's untuned A80 rz but it was over too quick to really be anything important - i had to wait at many
sets of lights for him to catch up. After going through stock ECU - to Apexi Power FC - to link G4 with MAP sensor with my GT-t and seeing the benefits
i went straight to the G4 with MAP with my GT-r.

YOU DO NOT NEED TO GO SINGLE TURBO for 500whp - if you'd prefer to that's cool but it's not NECESSARY. Hell even HKS 2530 Kai's will do
that and they aren't the biggest twins you can get.
You then contradict yourself by saying you can get that power with gt-ss turbos. Yep I'll agree that they're better than N1's but for the power he's wanting
gt-ss may be a bit small, especially if he gets the "i need more" bug, though they'd certainly spool faster and are better options than the N1, hence i
mentioned the HKS kai range above.

Just FYI I've attached my dyno in case JoshuaHo96 wants to dispute things.


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## joshuaho96 (Jul 14, 2016)

If you exceed the load scale of the stock tune yes you will need a retune, in practice a catback or an air filter as you have described will not do that. Maybe I just misunderstood what you said?

If you change the intake significantly and the exhaust to the point that you're overboosting the stock tune will run so rich that the mixture will be at the edge of being able to ignite which leads to flat spots and poor response. It's not really a failsafe, just very conservative values programmed into the tune. Even without modification the stock tune is way too rich, if you have a wideband O2 you can be more aggressive than the ~10.5:1 AFR that it will run at with high RPM boost, maybe 11.5:1 and only enrichening as you approach 3-5 psi boost.

If you run a Link with MAP sensor then yes you will need to retune the VE tables any time you make a substantial change to something like exhaust backpressure, cams, intake plenum, etc. An air filter will not affect the tune still though, a clogged filter will register as a lower intake manifold pressure and the ECU will be able to adjust, a freer flowing filter will just do the opposite. A MAF-based system can automatically adjust for these factors though because it is physically measuring airflow and can derive cylinder filling directly from that.


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## Ares (Jul 9, 2013)

Sigh.
A MAF based system SHOULD do that, but again Nissan specifically engineered their ECU's to NOT DO THAT VERY WELL.
That said, later model RB ECU's were more effected by the above and that's where my experience is.

A great example is how wrong Mighty Car Mods got their infamous Cold Air Intake video:





This came out shortly after I'd gone through massive issues with my own GT-t that were resolved by moving away from the factory ECU,
all because the previous owner took out the cat and threw on an exhaust (cat-back). This cause massive issues until it was tuned, none the least of 
which were some hefty fuel bills and fouled plugs. The issue i have with this video is that the R34's are well known for messing with timing to protect 
the engine, as mentioned above and thus, as it wasn't tuned for, this video proves literally nothing. So we're clear, if you install a cold air intake
without telling the ECU that's what you did it won't have the results you were hoping for.

All up, and back on topic, I'd advise the OP to really plan their build BEFORE DOING ANYTHING. At 500hp with an engine rebuild you should
consider forged pistons rods. Head studs, metal gaskets, many many options. PLAN IT ALL, find someone reputable to throw it together and
have an end result you're proud of!


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## Nzblackr32gtr (Sep 4, 2016)

Hi mate in answer to your question yes you can get 500hp atw stock engine.
I have a 1990 r32 gtr and bought it with veilside exhaust, hks intercooler, greddy hard pipe kit, hks bovs, hks pod filters. Car ran great and did 239kw atw or 320hp atw. My goal was 500 wheel horsepower stock engine so i bolted on two freshly rebuilt nismo rs580 ar60 turbos, did a dw300 fuel pump, injector dynamics id1050s, link g4 plug in ecu, NZ wiring custom cam trigger, gapped plugs to 0.8, and a link boost solenoid.

Then was dyno time and Chris from Prestige Tuning got my goal of 503 hp atw and car runs amazing. I then decided to do ARP head studs and a Tomei 1.2mm metal head gasket and full metal intake exhast kit for peace of mind and put car back on dyno and got 513 hp atw. Chris is an amazing tuner I highly recommend hom here in New Zealand. Car is running perfect with a safe tune and is now much more economical on gas and If I decide to put cams in we can squeeze a bit more out of it Chris said so may do that down the track.

Hope this helps answer your question and good luck with your build


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## Nzblackr32gtr (Sep 4, 2016)




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## Nzblackr32gtr (Sep 4, 2016)




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## Nzblackr32gtr (Sep 4, 2016)

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## Nzblackr32gtr (Sep 4, 2016)




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## Nzblackr32gtr (Sep 4, 2016)




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## Nzblackr32gtr (Sep 4, 2016)




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## Nzblackr32gtr (Sep 4, 2016)

Also to note im running pump gas BP ultimate 98 octane and car was tuned at sea level outside air temp was 18 degrees celcius and im running HKS 7.5w 45 engine oil.


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## Ares (Jul 9, 2013)

Nice results mate - though I'd recommend moving away from those awful mushroom pods - very bad for turbos!


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