Sway Bars Gt-r

[Blackkers]

Hey everyone I'm looking to improve the cornering ability of the R32 GTR.

I had it at wakefield last week and a modified S2000 was catching me at the top of the hill at the end of the double right hander. This is unacceptable!

It was understeering heavily in the fish hook, turn 10 and turn 2. Not so much the double right hander but more grip would be nice anyway.

Is it worth getting some Cusco or Whiteline sway bars? Front and rear will cost about the same but the whiteline are adjustable and not as stiff.

Also should I upgrade the links or does it not really matter? Hardrace do some aftermarket links which are pretty good value.

I will be installing better coilovers, tyres and some subframe bush locking collars hopefully before the next track day. Should I wait until after then to see if I still need the sway bars or is it just a good idea to do it anyway?

I know sway bar stiffness need so somewhat match spring rates but I have no idea what's on there and I haven't decided which coilovers to go for.

any input is appreciated. Thanks

[GTSBoy]

No, ARB stiffness does not have to match the spring rates in the coilover so much as they must provide the right balance between front and rear end to either work with correctly matched coilovers (ie correctly matched front-rear) or to correct the imbalance between front&rear that poorly matched coilovers might have.

This is why adjustable ARBs are a good thing because they at least let you fiddle. But the real question becomes, assuming you choose a nice firm 24mm front bar (and I would), will you be better off with a 22 or a 24mm adjustable at the rear? Most will tell you that a 24 at the rear is far too stiff to go with a 24mm front. But if your main spring rates were biased stiff at the front, you might need more rear bar. This you can't know until you do the main springs.

Good strong end links are essential, especially if you plan to track it and nudge any kerbs. The high loadings and the sudden shock loadings can make a mess of the original links, or anything else that's not super strong.

[Blackkers]

okay sweet so I'm better off with adjustable items so it would seem. I should install some coilovers first though and my tyres were shocking and unroadworthy on the rear. I'm uploading some footage from the day so anyone can get an idea as to the understeer issues I had.

edit: also the cusco bars are 24mm front 30mm rear which seems super stiff

Edited March 21, 2015 by Blackkers

[GTRPSI]

I own both a R32 GTR and a S2000.

I can assure you, the S2000 will always out brake you and have a higher mid corner speed, stock for stock.

Mod for mod, same again.

Your only saving grace will be the ability to get on the power quicker and pull away on the straight sections.

Then watch the S2000 start pulling you in on the corners and twisties.

If it upsets you, stick to tracks with long straight sections, minimal corners or wet days......

[Blackkers]

I accept your challenge.

I gave MCA a call about some coilovers and he explained how they can set up the shock to suit your application before they ship it to you and you can choose whatever spring rate you desire. Though he recommended 12kg/10kg on the GTR for the best lap times. His test car had factory sway bars. Those spring rates seem unnecessarily high.

He also said they are about to release a new product line for in-betweeners who don't want the full on race gear but don't want the street gear either. the XR line is about to be released but they are waiting on a few cosmetic parts; he can sell them now if you specifically want them but the spring retainers will be the old colour scheme

[GTSBoy]

12/10 are really really high rates, but given the weight that GTRs carry, and the speeds they can carry, for smooth track only I would say that those rates are probably pretty right. For a bumpy goat track, forget about it. Too stiff - the car will jump off the first fast bumpy corner it enters.

As to the Cusco ARBs.....I refuse to believe that anyone would pair a 24mm front bar with a 30mm on the rear. I have 24 front and rear on a 32 GTSt and it is verging on being dangerously tail happy. Stiffness goes up with the 4th power of diameter, so a 30mm bar is 2.4 times the stiffness of a 24. That sounds unreasonably unbalanced. The only way you could justify it is if the rear springs were quite soft and the fronts quite hard.

[Blackkers]

apparently It's got to do with the 4WD system and correcting factory tuned understeer; but 2.4x stiffness doesn't even seem okay.

anyway here is some video from the other day:

https://youtu.be/R8ut82IIUOM

Keep in mind I'm on street tyres with shot rears. The Shock/spring combo is completely mismatched (springs are too low for the shock). And also the brake pads I ordered didn't come in time so I'm using some 80% worn Bendix Ulti-shits borrowed from my R33.

I couldn't lean on the brakes whatsoever. In fact you will see in the vid that I had to slow down and even put hazards on

[MrStabby]

IIRC Nismo did some equal rate front and rear spring setups for R32 GTRs to try to reduce understeer, but 30mm rear bar...wow. I'm running 7kg front, 6kg rear with whiteline adjustable ARBs set to soft front, hard rear. Still has understeer, but i quite like the setup now.

[Blackkers]

IIRC Nismo did some equal rate front and rear spring setups for R32 GTRs to try to reduce understeer, but 30mm rear bar...wow. I'm running 7kg front, 6kg rear with whiteline adjustable ARBs set to soft front, hard rear. Still has understeer, but i quite like the setup now.

Cool generally a bit of understeer is fast anyway; those spring rates are more attractive to me as I'm mostly on the street

What shocks are you running? Is it a coilover kit?

Edited March 21, 2015 by Blackkers

[MrStabby]

Just some old Tein NAs. Originally the front was 8kgs (and was the Oran Park setup for a track car), but i wanted less oversteer, hence the swap to the softer fronts.

[Trex]

Josh from mca is a great guy to deal with.

I am experiencing understeer and roll even with arb's. Arb's did help a considerable amount but I needed something more. Keep talking to josh and tell him everything that is done to the car, how it handles and exactly what you want to achieve.

[KiwiRS4T]

Get a Quaife front diff and beef up your transfer case and you will be able to get the power on earlier...

[Blackkers]

That's definitely on the cards Bob! The 26/30 will go in the car with a Quaife most likely but right now I've got a standard engine and 270rwkw.

Hopefully mid this year I can start making some power. I wanted to improve the handling and get a better feel for the car seeing as I've never really driven anything 4WD before.

I'm thinking MCA Blue coilovers (can't justify the $2600 for the reds) and spring rates in the 8/6 KG territory.

Wakefield is my favourite track and it gets pretty bumpy in places so as GTSboy said it won't even be advantageous using astronomical spring rates

Whiteline ARBs 22/24 with some adjust-ability there too.

I've got some locking collars for the rear subframe bushes too. Call me lazy but I don't really feel like spending 8 hours swearing at the rear subframe to install some solid items

[djr81]

For my ten cents worth.

The GTR is an understeering pig. You can bandaid it with bulk -ve camber at the front (start at 3.5 degrees and increase it from there) but its only a bandaid.

Don't bother with solid bushes.

The rear diff is more influential on cornering behaviour that the front. A 2 way or even a one way with a lot of preload will push the front end wide. So think about how much diff you want in it. The front only has any effect on corner exit which isn't usually the problem.

The Whiteline adjustability is illusory. You end up with the rear on full hard and the front on full soft. Chuck some suspension at it and then buy a Cusco rear bar and a Whiteline/Nismo front. Then adjust (Or not) the front bar, the camber and the rear diff for balance/taste.

[gtr jet]

My GTR is an understeering pig.

Atm I'm running some shitty old Tiens with unknown unknown spring rates, Roughly 3 degrees of camber in the front/ 1 in the rear.

WhiteLine adjustables set hard at the front and soft at the rear. Factory diffs and transfer case with a bit over 300kw. Rear subframe collars and a rear half cage.

Now the car has no issue pulling out of corners but it really doesn't like going through them. The quicker I try to push the car through the corner the more it under steers.

The only real fix I can think of at the moment is more front camber but for a car that still gets driven on the street I don't really want to go that route.

[GTSBoy]

My GTR is an understeering pig.

WhiteLine adjustables set hard at the front and soft at the rear. Factory diffs and transfer case with a bit over 300kw. Rear subframe collars and a rear half cage.

A stiff front bar makes the car more reactive to steering input so it can/will sharpen the feel you get at turn in, but if the overall balance of the ARBs favours the rear, then it will transition to understeer as soon as the tyres are all loaded up.

So soften the front and/or stiffen the rear to push the grip balance forward.

[gtr jet]

Cheers mate, I'll go a notch down on the front sway bars for the next track day and see what happens.

[djr81]

Cheers mate, I'll go a notch down on the front sway bars for the next track day and see what happens.

Just put the front full soft and the rear full hard.

[MrStabby]

Just put the front full soft and the rear full hard.

+1 Pretty sure everyone ends up doing that.

djr - So you're saying the cusco is stiffer than the rear whiteline adjustable on full stiff, right?

[djr81]

Reckon so. Its bigger on the od and hollow but given the relationship between stiffness and od basically yes. I did some rough calcs once based on assumed wall thickness and it came out fatter. Just wish it was adjustable. Found a big difference in the turn in behaviour with less preload on the Nismo LSD - changed by putting some friction modifier in the diff. To the extent that I am looking at putting some more -ve camber in the back to calm it down on old tyres.