BNR32 Not performing as expected on the Track -ATTESSA and Grip

[FarShark]

Hey Folks,

I took the car out to TMP for an opening lapping day. It was my first time with the GTR on the track and while it was fun and exciting it was also disappointing as I'll state below.

Some of the problems I may know answers to, however I am looking for personal experience from other members.



Some relevant info:
-300whp at the rears (dyno'd last year)
-Front upper strut bar
-Brand New (1000km already on road driving) Advan AD08 245/45/17s all around.
-No HICAS but no lockout bars (Do i need these?)
-No ABS
-V-Spec Brembo Calipers on front and Nissan OEMs on rear.
-Project Mu, two piece on fronts and OEM (unknown) pads on both and rear rotors.
-HKS Hypermax D suspension
-2.80 Negative Camber on rear - all other specs are factory recommended.

Problems:
Grip
As far as the straights go, I barely lost any noticeable grip. The tires held really well and the car accelerated great.

As for the Corners I took them all at multiple speeds, although the car held well, obviously I had oversteer as expected in the GTR. The issue with the oversteer was that it didn't step out enough for me to notice and adjust steering and throttle it leaped out way wide and even though I recovered... I had lost a lot of time. Perhaps my inexperience with the car is exaggerating my concern.

Brakes
Holy ....
I have good life on my rotors and pads but it seemed like my brakes weren't doing their job. I was pushing hard but the deceleration was slower compared to a prelude, integra and a corvette that I hopped in for a few laps. And yes, I know they are lighter cars.. but it seems like something is seriously wrong. I'm thinking about replacing rotors and pads however, I am concerned there is something else I'm missing here.

ATTESA
My biggest concern was my ATTESA. My ATTESA has worked and I have seen (via the torque gauge on the dash cluster) and felt it working .. I checked all my fuses midday and everything was in order.
But not once did my 4WD come alive. I tried quick turns with high Gs keeping all wheels aligned etc. But even on the straights.. my ATTESSA wouldnt come alive. What is a GTR without its 4WD advantage.. I was really disappointed, I tried everything but it seemed like my car didnt go into 4WD once.

So I've listed my issues and concerns above, I am looking for info from anyone that has encountered these issues and knows the fix.
Any other advice is appreciated as long as its kept on topic

Thanks All.
FS

[bobbo]

Hard to say what is up with your brakes. Could be the pad compound or type/age of brake fluid could make a difference. If you had boiled your fluid you may have air in the lines. Most people suggest changing your fluid before any track day.

As for your ATTESSA. You had no movement on the gauge in the dash at all? Even under hard excelleration in a straight line? With no "4WD" light on it seems strange. Where the gauge does move very quickly is it possible your eyes were on the track and didn't notice the movement? Have you tried any hard launches/cornering since?

Also depending on what the car has been through in the past the ATTESSA clutches can (and do) wear. Someone with a staggered tire set up would have caused excessive clutch wear and even though the gauge indicates function the xfer case can't engage properly.

I have an extremely TSC that has made a HUGE improvement in the cornering performace. I would highly suggest getting your hands on some sort of TSC if you plan on continuing with your track days.

Good luck, sorry I couldn't be of any more help!

[NismoS-tune]

Sounds like OEM brakes to me IF you had already done some laps. Once the factory brakes are heated, they don't perform as well. What kind of power you got?

The AWD thing, did your front torque gauge show anything? The GTR is AWD but it will still lose traction. What kind of sway bars you got?

If it were my guess, you're expecting a monster grip car but it takes time to get like that. GTRs don't mean floor it and beat everyone, you still have to brake for corners and throttle out and body roll will own you with oversteer. I'd say you're just not used to it....

[FarShark]

Bobbo - I didnt notice any flicker in the gauge at all, it is possible I didnt see it, but on the last few straights and corners of the day I tried to keep my eyes on it and didnt see anything.

NismoS-tune- Noted. and obviously.. if you read it all I did say I may be expecting too much and I do need to get used to the car. I didnt expect to floor it and the car would follow the rails down the track at max speed.
Im making 300whp at the rears (dyno'd last year before I put her away).
For Sway bars, all I have at the moment is the front upper strut bar.
My concern of 4WD still remains.

*Updated first thread with power and sway bar info.

Thanks again.

[hozer]

from track experience I can say without a doubt:

Brakes:
factory brakes after a few laps will become fairly useless. Get the best fluid you can afford and put it in, will help a lot. Also dunno what your experience is with non ABS, but that could be hurting you as well.

Cornering:
Until I put wicked tires on it seemed like the car wasn't performing well, unsure if this is your issue though. Diffs also made a huuuge difference as for cornering ability.

With time you'll get used to the oversteer.

Random: You have to much camber in the back IMO, would keep it above -2 (personal preference)... Think this could be contributing to the oversteer

[Skym]

From what I understand, R32GTR doesn't have preload (transfers a little bit of torque) to front wheels. R33GTR and R34GTR do have preload and is the reason you have to remove front halfshaft when dynoing in rwd. It's a good idea to fit a 4wd split controller with R32GTR. Group-A 4wd ECU has the 4wd ECU modified, so get 4wd at lower speeds, but rwd at higher speeds.

Project U are good rotors, but have to use Project-U brake pads and bed in rotors, brake pads to get good braking. I would say your rear brake pads are low temp street brake pads, so encountered brake fade on rear. You'll need high temp race spec rear brake pads. I also would suggest at least Dot 4 brake fluid, braided brake lines, brake master cylinder stopper, remove stone sheilds behind rotors, fit brake ducting.

What happens with brakes, is heat from hot rotors gets transfered to brake pads, then to brake fluid which overheats, creates bubbles and is how brake fade happens. Ducting to brake rotors helps to keep rotors in a certain temp range and high temp brake pads help to reduce heat transfer to brake fluid and high temp brake fluid helps to prevent brake fluid overheating and creating bubbles. Even on the street, I run race spec brake fluid in my car.

Understeer can be the transfer of torque to front wheels. GTR is naturally setup swaybar wise to oversteer as 4wd + throttle understeers to counteract the oversteer. No transfer of torque can be the G sensor is faulty (I think is mounted under centre console). Can be quite common, expensive problem to fix if you buy brand new. Some try mounting G sensor a different way on R32GTR to get the 4wd to work (that's if G sensor is ok) or buy a aftermarket 4wd controller to adjust the amount of torque to front wheels.

This article explains what happens with 4wd on R32GTR and creating a switch on dash setup to fix the transfer of torque problem -

http://autospeed.com.au/cms/title_Go...3/article.html

HICAS should be removed and locked off. But you could have a shimmed HICAS rack (so it won't move), disabled HICAS ECU, like the Tomei? HICAS lock kit.

[FarShark]

Thanks for the advice thus far folks.

hozer- The camber is temporary, my right rear coilover adjusting bolt is seized so right now the camber is maxed out at the current ride height. Once I can get the coilover adjusted I can drop the camber down between -1 and -2.

Skym- Ill try and swap out my pads to race spec pads and swap my fluid as well. I also purchased a brand new HKS Kansai Atessa controller yesterday, we'll see how that works once I have it installed. Although I would also prefer to have a fully functional G-sensor (which I was hoping was not the issue).
As for HICAS, the HICAS rack is present and I doubt its shimmed at least I dont know. Im pretty sure there isnt a ECU lockout. But also picked up a lockout bar yesterday and Ill likely get around to putting that on as well.

[Kras]

if your torque split gauge isn't moving at all I would suspect there is an issue with ATTESA.

R32 GTR's are pretty tail happy to be honest, fitting wider tires helps a lot (245 is pretty skinny IMO) also from what I hear torque split controllers work wonders.

[Marke]

Your transfer case might be tired. You may not be losing traction while you are cornering so 4wd doesn't engage.

Oversteer is most likely the driver pinching down on his turn exit.

To properly adjust camber you need adjustable upper links. Lowering your car just to get camber will cause other handling issues.

Up grade your brake pads, brake lines and brake fluid. A master cylinder stopper is a good investment. Use Motul 5.1 at the very least for brake fluid. Hawk HP+ will do well. Lots of companies make brake lines. I went with Endless.

[Skym]

Or fluid wasn't changed in transfer case???

Some use DOT 5.1 on racetrack. I run Super DOT 4 in my car that's rated to 600F+ (82F+ higher than DOT 5.1 fluid) for boiling point of fluid. Same brake fluid as used in GTR racecars, V8 supercars, etc.

Custom braided brake lines from a brake specialist are best, as you know they use quality parts and have teflon hose over the top to protect brake hoses from dust, rocks, etc (must have). Also precision made to exact tolerances. Some brands use cheap fittings and are not recommended for track use. So just be aware of this when buying braided brake hoses.