Tractions Issues Gtr

[GT-R32]

I did a search and couldn't see anything on this.

My car is an R32 running HKS 2530 at 1.3 bar. I have a fairly choked exhaust with the stock dumps and front pipe. Power is basically unknown, it is pretty quick (I have a dyno of ~260awkw on the low reading mainline dyno in Canberra prior to replacing my cat). My car will come onto boost quite hard in 2nd and smoke the tyres up to high 7k rpm. Dramatic, but not the fastest way of forward movement. I drive like a Granny 98% of the time but I like to give it a hit now and then and wouldn't expect this in 2nd, nor is it especially legal.

I replaced the shit Nexens it had on it, with them the car would literally smoke all 4 at 100km/h. I figured it had to be the poor and balding tyres. I fitted 255/40/17 Toyo T1Rs to the TE37s all around which I've put several hundred kms on. It's slightly better but in second gear it's still hopeless, straight line is spins the wheels after 4500rpm.

Suspension is Bilstein shocks and unknown springs all around, with some changes to arms etc. as it came from Japan. The spring rates are of course stiff, but not overly so. The ride is quite compliant (certainly compared to a mate's WRX anyway). Camber is negative, but again nothing silly.

So my question is, WTF? How can a 4WD car with the same tyres struggle for grip when a mate's S8 RX7 (he runs a ported block + T04Z at 1.1 bar around 280rwkw) with the exact same tyres (basically the reason I bought them) have full grip?

Is there a certain set up that can cause this behaviour? It's got me beat.

[bnr#@]

Because I would guess that the rx7 would be making a fair whack less torque then your car

[Risking]

Im betting its not spinning all four wheels, I think it'd only be spinning the rears and there is something wrong with your ATTESSA or more likely your transfer case.

[GT-R32]

Im betting its not spinning all four wheels, I think it'd only be spinning the rears and there is something wrong with your ATTESSA or more likely your transfer case.

The clouds of tyre smoke out the rear when held at throttle says otherwise... so definitely rears (ie. you are correct). You can feel when the front comes in as it progressively transfers and regains grip (perhaps 'all 4 wheels' was a touch of exaggeration but it certainly felt like that on the old tyres - but just more wheelspin). Perhaps that regain of grip was just natural and at all the 4WD aid... Thanks for the thought, I'll look into it. But something doesn't seem right.

[GTRsean]

Shagged transfer case clutch pack, or the attessa system needs a full bleed...

[GT-R32]

Shagged transfer case clutch pack, or the attessa system needs a full bleed...

The more I think about it the more I think you and risking are correct. I'll look into.

Thanks fellas.

[Pezhead]

Yeah,

I'd be checking your transfer case. Firstly, they are tough but one good run at power where the rears slip but front doesn't will toast the clutch packs in the transfer case.

Try this, put the car on a jack (trolly jack with wheels) up until rears are just off the ground. Then slowly give it a little clutch to see if the fronts can pull the car forward. When my transfer case was stuffed it couldn't pull the car forward at all.

Also check the smell of the transfer case fluid. If it smells burned then that is a bad sign. Like others said, bleed and check the attessa system.

I did the plates in my transfer case which was expensive. Might be better off just swapping the whole transmission as I've seen a few for sale on the forums.

Best of luck.

[GT-R32]

Thanks so much Eric, I'll try to get to it tomorrow. Much appreciated.

[GT-R32]

The transfer case is working perfectly, it tried to pull itself off the jack LOL. WTF. I'll bleed the ATTESA, have my suspension set up looked at and go from there. Thanks everyone.

[some_cs_student]

Good luck, if your transfer case was really, dead, the car becomes un-drivable, when my one died, I could release the clutch and the car would not stall (clutch had 1-2mm left on it, transfer case was broken).

[GT-R32]

Nah it's definitely working, in 2nd I'm getting 10kg/m which results in wheelspin. Whereas in 1st I get the full 50 which is no wheelspin (obviously less power in 1st too). I'll have a shop look at my suspension set up and then decide if I need a ATTESA controller.

[djr81]

Nah it's definitely working, in 2nd I'm getting 10kg/m which results in wheelspin. Whereas in 1st I get the full 50 which is no wheelspin (obviously less power in 1st too). I'll have a shop look at my suspension set up and then decide if I need a ATTESA controller.

The guage doesn't understand how shagged your attessa system may or may not be. It assumes it is working perfectly & displays how much front torque you would have if the system was working properly & the motoro was standard.

What frequently happens with Gt-Rs is the clutches in the attessa system wear. This causes the clearances in the system to become out of tolerance & you get a slow reacting system - ie more rear wheel torque than it should have. Given the system is old, slow to react & calibrated for a stock motor it is quite easy to end up where you are ie with a GTR driving like a GTST.

[GT-R32]

I meant it's definitely working not because of the gauge, but because jacked up in the rear only it lurches forward just by letting the clutch out at idle. It may be slower or not as strong, but it's definitely 4WD still. I'll resist spending a bomb rebuilding the transfer case for now.

[MrStabby]

You've been subjective with spring rates and camber in your post - what are the numbers?

Have you tried pineapples in the "traction" configuration? Although IIRC SK reackoned on 32 GTRs the "neutral" config was better, so maybe try both.

[Risking]

Its the transfer case. Testing without load means nothing.

Get it put onto a 4wd dyno with torque split monitoring and id almost bet my race car's transfer case that yours is shot.

They become slow and end up with rear wheel spin. Eventually when its really rooted it wont drive off the jack. But at the moment its only slipping under load.

We re-build our cases with specially designed clutch plates every 48hours or so of use as this exact problem starts to occur on the circuit. Mines doing it atm and needs to be rebuilt.

On the road with genuine parts your transfer should last a very long time. Its not as an expensive excersise as some people think and in my opinion ANY R32 GTR which has not had it done should have it done.

[some_cs_student]

Risking, can you PM me where you got your transfer case(s) rebuilt?

I was quoted close to 1K or more for a rebuild, and even more if I wanted a stronger clutch pack in there.....

[GT-R32]

I guess it's time to work out where I can have these things rebuilt in ACT.

Thanks for ramming the point home. I get it now.

[GT-R32]

You've been subjective with spring rates and camber in your post - what are the numbers?

Have you tried pineapples in the "traction" configuration? Although IIRC SK reackoned on 32 GTRs the "neutral" config was better, so maybe try both.

Sorry it's running some camber - unsure how much. Spring rates again unknown . As per Japan basically... ie. no idea LOL.

Pretty sure it's the transfer case, like Risking said just slipping under load. Rebuilt for under $1k I would be happy, cs! I'll struggle here for that I reckon.

[some_cs_student]

I personally went down the path of second hand (R33 transfer case), and paid $400 for a second hand transfer case to be fitted, in my case I it wasn't the clutch pack that went, it was a shaft...

[GT-R32]

I personally went down the path of second hand (R33 transfer case), and paid $400 for a second hand transfer case to be fitted, in my case I it wasn't the clutch pack that went, it was a shaft...

It's gotta be clutches in mine. So rebuilt is preferred.