GT-R Track Report

[GTRjoe1]

Just took the GT-R to the (road) track. Until now, my track cars have been the C6 Z06 and 997 GT3.
Both the Vette and GT3 are outstanding track cars - in very different ways. The Vette is big, powerful, sticky and a lot of fun to throw around. The GT3 is equally fast, but achieves it speed from precision and amazing overall balance.

The GT-R did pretty well. On a dry track, it does tend to understeer (push) on corner entry, then rotate and drift out the rear end on power application mid-turn. One is very aware of its substantial weight, however overall it is very well balanced, and the 4 wheel drive system does a great job of pulling the car around the apex and to turn exit. You can essentially power your way out of the curve. I would say that corner entry speeds are a little slower than either the Vette or the GT3, (because of the understeer), but are comparable by corner exit because you can put the power down so well in the GT-R. Speed at the end of mid length straights was comparable to the Vette (The Vette would be faster at the end of a long straight).

Then it started to rain (hard). It was brilliant in the rain. Mine has the Bridgestone RE 070 tires, which look like dry tires, but they performed very well. By far the best car I have ever driven on a track in the wet. You can slide the rear out, but the stablity system catches it nicely, and continues to power it into the turn. Traction accelerating down the strights was as good as in the dry. My speed approaching the braking points were only slightly lower than in the dry!

So overall a great track car. Certainly does not have the finesse of the GT3 nor the ultimate pull of the Z06, but makes up for both with the terrific 4 wheel drive sytem and brilliant transmission (I should have mentioned that the gear shifts on a track environment are excellent - you can actually shift mid-turn, and the car does not get upset).

By the way, it is very thirsty on the track. My other cars get about 10 mpg on the track - the GT-R only got 5-6 mpg!!

[ATLsupra]

Thanks for the information. Can't wait to run one on the track

[GTRXLR8]

I would agree with all you said except about entry speeds into turns. I think the car gives the inpression it is slower then it is because of the push but I think we are both just going faster then we think! I ran the car at Lime Rock and my times were great at 1:01 on the Bridgestones. This is a great time compared to any other car in stock real street tire. I would be interested in knowing your lap times in the Vette,Porsche and GTR given same tires,temp. and conditions. I also hear the Dunlap tires offered are better and have less push. There is also a new compund on the Dunlaps coming out which were made for the Spec.V. I am going to wait for these as i really do not like the Bridgestones and never did on amy of my cars.

[sstevens06]

Originally Posted by GTRXLR8

...
I also hear the Dunlap tires offered are better and have less push. There is also a new compund on the Dunlaps coming out which were made for the Spec.V. I am going to wait for these as i really do not like the Bridgestones and never did on amy of my cars.

Very interesting -- first time I've heard that.

Always wondered about comparative performance between the Bridgestones and Dunlops. Do you have any further information, or links?

Thanks in advance!

[GTRXLR8]

No I do not but i do know that the Dunlaps were used at the Nurimburg Ring to get to the 7:29 lap time. And now they have a new compound for the Spec. V.
I also read somewhere I do not remember where that a tester said the Dunlap had less push.
I would love to see a Michelin Pilot Cup tire made to fit the car myself!

[john0990]

How was tire wear? Was it pretty even or does more negative camber need to be added?

John

[ted99]

I just had my first track weekend in my '09 and front tire wear was extreme. My car has the "track" allignment and there was pronounced wear from the inside to the outside. Another weekend, or two and I'll need new tires because of wearing down the inside of the fronts. All tires, including the rears, show the stress of track use. Wear was even across the tread of the rears, but very pronounced uneven from the negative camber on the fronts. Another GT-R driver at the same track has had his car realligned with the street settings to try to even out the tire wear on his new fronts. I'd say that tire life would be greatly increase for both street and track if the wear pattern could be evened out across the front treads. It's much better to replace all four tires as a set, but the track setting will wear out the fronts way before the rears.

[Norman]

follow your driving style,don't follow the service manual or fatory's "track" alignment.

when tyre tread wear outside, you need more negative camber. or opposite.
more toe out will cause more inner wear out too. or opposite.
few times later,your will get your own best track alignment.

still can't having an even wear? then change a harder suspension.

Btw, forget the 4wd system, drive it smoother,faster,outer the edge(out in out),rounder as GT3 before the apex,step on gas you will get a balance 4 wheels sway instead under steer.(most EVO drivers do so)

[ted99]

Thanks for the tips, especially getting on the throttle before the apex. This is my first AWD car, and the old RWD techniques don't work as well. We have one decreasing radius corkscrew turn and I'm wondering if the "Scandanavian flick" to induce oversteer will work.

[Norman]

suspension upgrade is very important for track use. oem's complicate absorber system comes with a smaller valve, it cause overheat. on a larger track, OEM sus can hold 3 to 4 hot laps only. after that, you will notice that you are off the best racing line. our brake system too... longer and longer braking distants just after 2~3 laps.

[john0990]

Out of curiousity, what are the "street" and "track" alignment settings for the GTR from Nissan? Is there a wide range of adjustment, especially with camber?

ted99 - I see that you're in Houston - are you taking the GTR to TWS? I was just there this past weekend. No GTR's there, though. :-(

John

[ted99]

John 0990. Yes, TWS. There were three there, including mine, on May 30,31. My settings at the 1200 mile check were -1.6 degrees camber. no value listed for toe in. No info on the "street" settings. I'll get that info when I go in for the reset at Baker-Jackson Northwest.

[john0990]

Norman - your comments on the OEM suspension and brakes have me worried. I would hope that if I do scrape together the money for a GTR I wouldn't have to spend too much more to make it track-ready.

Regarding brakes overheating, the most effective fix is usually brake ducting, with hose routed directly to the inside of the wheel hub/rotor, so air blows out through the rotor vanes. On the GTR is there room to install this kind of ducting & hose? I haven't seen any aftermarket kits for it yet...

My other concerns for tracking a GTR would be fluids overheating (tranny, diff, oil, coolant). Haven't heard from anyone yet though that complains about this.

And.... of course, the whole disabling stability control issue. Will disabling the stability control while at the track completely void the GTR warranty? Or only if I do it in conjunction with launch control?

John

[ATLsupra]

Originally Posted by john0990

Norman - your comments on the OEM suspension and brakes have me worried. I would hope that if I do scrape together the money for a GTR I wouldn't have to spend too much more to make it track-ready.

It is ready for track use, then again, like most OEM cars, bushings aren't make up to what the race cars are, especially with the weight of a GT-R. So, there will be more soft than the race/track cars causing the inconsistency after many laps. Auto Select makes good replacement bushings if you want your car to be stiff and race use only.

Regarding brakes overheating, the most effective fix is usually brake ducting, with hose routed directly to the inside of the wheel hub/rotor, so air blows out through the rotor vanes. On the GTR is there room to install this kind of ducting & hose? I haven't seen any aftermarket kits for it yet...

Yup, brake ducting is the best solution to fix brake fading. I guess you can fit the hoses, but I don't think anyone is willing to cut holes on the under panels. Another solution is to get Auto Select front lip, which has build in holes just for brake ductings.

My other concerns for tracking a GTR would be fluids overheating (tranny, diff, oil, coolant). Haven't heard from anyone yet though that complains about this.

And.... of course, the whole disabling stability control issue. Will disabling the stability control while at the track completely void the GTR warranty? Or only if I do it in conjunction with launch control?

John

There are several incidents that trans fluid will get very hot and cause the car go into limp mode after many hot laps. Adding a trans cooler will definitely help, but that will probably void the warranty on the tranny when you take the GT-R to Nissan for service.
Regarding the disabling VDC, I believe Nissan will not warranty anything unless you are stuck in mud to have the VDC off.

[Norman]

Thanks! Chinchi^^

[ted99]

John--One does not disable the stability control for our kind of track use. One puts it in "Race" mode and this does not void the warranty. If you have a full race ready (no street use) GT-R, one may do something else, but I have never been tempted to go to "off" for the stability control.

[john0990]

So what exactly does VDC do on the GTR?

Is it a "no-fun" nanny like my M3's DSC (Dynamic Stability Control)? Basically BMW DSC prevents any kind of loss of traction by cutting throttle and applying brakes. I would have *no* fun at the track if it remained on.

Or, does GTR VDC do something more advanced, like detecting loss of traction and changing amount of power sent to each of the 4 wheels, but still allowing you to slide the car around corners? Would it ever cut power or apply brakes in a loss-of-traction situation?

Thanks guys for all the info...
John

[ATLsupra]

Well, remember GT-R also has a VDC-R mode, which provide very little assistant. In normal mode, it won't let you slide. In R mode, you will able to slide unless you are way oversteering/understeering. This has been discussed before, and you can find it at the thread below.

http://www.nissangtrclub.com/showthread.php?p=10816

[john0990]

Thanks Chinchi! That is a very nice explanation of VDC and VDC-R indeed!
John

[Norman]

when i goes crazy will off it^^
R is best for dry condition.

[godspeedr35]

nice.