# GTR and Toyos - track ability- disappointed !



## Radical1 (Feb 8, 2011)

First track day in GTR today at Silverstone and after 2nd run, discovered front left was through to the cord. Managed to order some 315 rear and 285 fronts from camskill and pick them up from toyo warehouse in northants, mission !
Anyway, having found the dunlops disappointing in the morning, I put it down to them being knackered, I could only just stay with a mates tuned 570bhp 997 turbo. On went the toyo's and after scrubbing them in one one run, I went out against my mate again and whilst the toyos were better, I am not happy with them and once again there was nothing in it between the 2 cars. Loads of grip on the rears but LOTS of understeer especially in fast corners........so......
I was running them at 33psi hot, is that correct ?
I had VDC off after finding it too intrusive in the morning. If I had the electrics switched on, would that have made the car behave more neutrally (doubt it) ?
Having come out of a radical sr3, am I just expecting too much of a near 2 tonne car ? So much hype about the gtr's ability but it really did not corner/brake any better than a 997 turbo on pilot sport cups and Alcon brakes.... So is the gtr really that good or am I missing something ?
Last gripe, what the **** were Nissan thinking when they built a so called super car that can't do more than 5, yes 5 laps before the tranny oil hit 125 degrees, my track day mates could not believe it when I told them this.
Sorry, last thing I wanted to do was slag the car off that we all own but I really expected more.........
Also, the road noise from the toys above 80 is pretty hideous and after 5 laps they started to go off, tied in nicely with the tranny oil....great !
Rant over, if anyone can advise me how to get more out of the car and the 1600 quid flipping toyos, I am all ears ?
Thanks


----------



## enshiu (Aug 20, 2010)

how soft are these tyres on the rubber?


----------



## David.Yu (Jun 28, 2001)

Not sure what you were expecting to be honest. As you said, they DO have more grip than the Dunlops, which are themselves pretty amazing tyres.

As I've said for a while now, I personally won't buy another pair of 315s for the rear as I think they induce too much understeer, with the rear simply refusing to let go, even with the 620lb.ft my car puts out.

So next time, it will be 285s all round.

Michelin Pilot Sport Cups are pretty extreme R compounds, generally rated above the R888 (and pretty much any other road tyre) in the dry, but completely hopeless in the wet.

As for trans temps, that is the single most widely reported issue with the R35, so should not have been a surprise, whilst hardly inexcusable.


----------



## Stevie76 (Dec 17, 2009)

Dont know anything about the tyres but a trans cooler seems to be a worthwhile investment if you are going to be regularly tracking the car....sure I have seen some posts where reported can't get to 120 with the cooler fitted even after a good number of laps


----------



## Chris956 (Apr 11, 2010)

You cannot compare the handling of a track orientated lightweight special to a heavy GTR however the car is marketed.

Understeer - Are you driving the car like a radical ? Cause that wont work. Slow in fast out. Also what geo settings do you have on the car ?

Tranny temps can get ridiculous depending on driving style and various options are open to you.

On a side note . How did the new brakes hold up ?

:thumbsup:


----------



## Arcam (Jun 30, 2009)

What geometry / alignment setting were you using on your suspension?

I still have a Forge tranny cooler available if you want one?

GT-Rs when correctly driven leave all standard Porsche machines in their wake


----------



## AlanN (Dec 10, 2007)

I have attempted to use R888's many (about 5 sets) times on my GT3RS, on track.
In my opinion they are not that great on a heavier car, for one thing I could never get the pressures to settle, they were forever ballooning up or diving too low.
Not tried them on the GTR (but then it's not a track car without lots of mods IMHO :flame and from past experience I wouldn't either. 
I would say the ultimate track tyre for the GTR would be the MPSC, if it's available in correct sizes.
Not cheap however. 

On the other hand, I wouldn't use anything BUT the R888's in my Megane R26.R, they are perfectly suited to the car.

Horses for courses.
:thumbsup:


----------



## bobel (Jul 26, 2010)

Radical, what mods are you running, whats your current bhp?


----------



## Radical1 (Feb 8, 2011)

Running custom tune cobb and y-pipe. I am not trying to compare it to a Radical but I think David is right, the car is not balanced on 315's at the rear, in the medium speed corners it washes wide too easily, 285's on the back would probably allow it to slide neutrally. 
BTW, if I went into the corners "slow in fast out" as suggested, that 997 turbo would have left me for dead - the GTR was (surprisingly better under braking - (AP's / Carbonetics very impressive) but the 997 had better traction out of the corners.
Is the car quicker with VDC in race or off, does anyone know ?
Also @ David; what pressures did you run on the toyo's, (hot) ?


----------



## Radical1 (Feb 8, 2011)

Arcam; running standard camber which I guess won't help. How easy is it to adjust the camber - I would want to adjust it back to standard after track days as I use the car every day and it would knacker the inside edges. I presume a decent mechanic can adjust it - what degree do you suggest on the fronts ?


----------



## Arcam (Jun 30, 2009)

Radical1 said:


> Arcam; running standard camber which I guess won't help. How easy is it to adjust the camber - I would want to adjust it back to standard after track days as I use the car every day and it would knacker the inside edges. I presume a decent mechanic can adjust it - what degree do you suggest on the fronts ?


I agree with you thoughts on the rear tyres being too wide, I do fancy trying an all square (285) setup.

I run just over 2 degrees of negative all round with 0.03in toe in on each wheel, I do my own alignment as I have access to some serious kit, I would suggest that any decent mechanic can adjust the camber/toe so long as the equipment used to measure/adjust the setting is decent and fully calibrated. This may seem odd but the number of places I have seen that don't have the alignment equipment calibrated is unreal!

As your car is a pre 2011 model you will not be able to get that much negative camber without modification, but I used to run 1.8 degrees neg all rounds with 0.04in toe in on my 2010 car and tyre wear was fine.

Funny enough even with the 2+ degrees on my 2011 car the inside wear is still pretty good, the main reason apart from wear that it would cause an issue with the tyres overheating which could lead to premature failure of the tyres :nervous:


----------



## David.Yu (Jun 28, 2001)

Ah, well there's your problem, right there. Road camber does not work on track and massively excacerbates the understeer. 

I've always run mine at max negative camber on road and track.
Admittedly I don't have to commute daily in it, so it's only brought out for spirited driving, but the wear on my R888s have been astoundingly even across the whole tread.

Of course being unidirectional, but not asymmetric, you can always pull the tyres off the wheels and swap them over to even out the wear should you notice either edge wearing more.

They are by no means the perfect tyre for the GT-R, but they do grip better than any other current option.


----------



## Chris956 (Apr 11, 2010)

With the geo settings you have I`m afraid slow in fast out is the only thing that will work to stop you understeering wide ( and wrecking tyres in the process ) regardless of how your mate in his 997 is doing.

In short - wrong setup and wrong tyres. Have you tried the OEM Dunlops by chance ? I find them spot on

I also prefer VDC off as it does interfere. The car is very stable and not tail happy like people expect and breakaway is very progressive ( on the Dunlops )

Its all a learning curve and glad to hear the brakes worked well :thumbsup:


----------



## David.Yu (Jun 28, 2001)

Holy cow, I've just re-read the original post (he was on Dunlops at first Chris), but "I could only just stay with a mates tuned 570bhp 997 turbo"!

Do you not think that is bloody impressive? A Turbo S is "only" 530hp and that is one of the fastest production cars available for any price! :runaway:

I forgot to say, that absolutely, all dry track driving should be done with VDC Off. It interferes too much, even in R mode, although it would have attempted to reduce the understeer, it would have been at the expense of exit speed and with high brake wear as the inside rear wheel would be braked to help turn-in.

R mode is great as a safety net, and borderline essential in the wet on either the OEM tyres or R888s!


----------



## Chris956 (Apr 11, 2010)

David.Yu said:


> Holy cow, I've just re-read the original post (he was on Dunlops at first Chris), but "I could only just stay with a mates tuned 570bhp 997 turbo"!
> 
> Do you not think that is bloody impressive? A Turbo S is "only" 530hp and that is one of the fastest production cars available for any price! :runaway:
> 
> ...


Yep me too 

Must have been serious understeer to go through a Dunlop so quick. Or driving style.


----------



## Radical1 (Feb 8, 2011)

Chris; my Dunlops were knackered anyway but I thought I could squeeze a track day out of them, very wrong. David; mine is probably 580bhp'ish so that is why I was surprised I could only just stay with the tuned 997 turbo. I thought dynamically, the GTR would be a better car than a 997 turbo with same power/brakes, etc. Seems not. I will get Litchfield to change the camber at my service next month and see if that helps.
Wish I had gone 285's all round now, far too much grip at the rear, although that will be a blessing for road driving, would rather have understeer for the road for one of those "once every few month momnents" !


----------



## sumo69 (Mar 31, 2008)

Whilst the bhp of the 2 cars is very similar, surely the Porsche has a distinct power/weight advantage? So the benefits of the GTR are acting to eliminate this advantage surely?


----------



## Radical1 (Feb 8, 2011)

Sumo; straight line speed was exactly the same, mine may have "just" had the edge but talking fractions. 997 is only about 90kgs lighter than the GTR.
As I said in my first post, maybe I was just expecting too much.....no other road car went past either of us all day and all cars have their limits I suppose.
Will adjust the camber and see if that helps negate the understeer.
BTW, driving to work today and those Toyo's even whine at 40mph,,,,let alone 80+ !


----------



## christer (Jul 16, 2010)

the camber will make a big difference imho.


----------



## Zed Ed (Oct 24, 2007)

Last time I went to Silverstone, the GTR drove like a dog.

Whilst I put this down to a problem with one of the front tyres, there was also a nagging doubt that I couldn't drive for toffee.

Clearly with this new information, I can sleep easy


----------



## sumo69 (Mar 31, 2008)

Radical - I understand what you say but 90kg is still 5% approx so a 25-30bhp "loss".

I think you may have expected a bit too much from your car as a track weapon, though Camber would laso have helped as has been said.

D


----------



## Radical1 (Feb 8, 2011)

Hi Sumo, as I mentioned earlier, there was no difference in straight line speed so power/weight ratio has no bearing on this. I was just surprised that the 997 turbo was easily as capable ad the GTR in every other area. Maybe all the hype of the GTR surrounds the fact that the GTR is half the price of a 997Turbo (and most other similar performing cars). In fact if you read Evo, you will see the standard GTR is only 0.1 of a second quicker than the 997 Turbo around Bedford (from memory) so that kind of suggest the performance is identical.


----------

