My R34 GTT Drift and now Grip Car

[25GTV]

Hi Guys,

Been using my R34 GTT Sedan for track stuff for years.  Slowly releasing the content and enjoying the great tracks in Aus.  Anyone have any tips on setup for a well balanced grip car?  I'll run semi slicks all round in the future.

Theres a few vids on my account, some drifting, a dyno run and some grip events.  https://www.youtube.com/watch?v=M1tEZWxhF0w

 

[Duncan]

What is your suspension setup and alignment?

[25GTV]

I have shockworks coilovers, 7kg 5kg. Adjustable rear upper arms.  Adj Front Caster Arms and extended front LCAs. Locked diff.  

[Duncan]

The springs seem like a reasonable start for track work, although you probably want adjustable sway bars as well.

The adjustable arms themselves are no use, you need to know the alignment. Generally you want a little toe in to 0 static at the rear for stability and at the front as much caster as you can get, camber you can decide by tyre wear but around 3-4o

From there, basically the more tyre grip you have, the less roll you want as the cornering forces increase. So best get the semis on (some are better than others, and new is always better than old) to see how the balance is front to rear.

Also, a locked diff is NFG for track work. You want a mechanical LSD, preferably 1 or 1.5 way

[GTSBoy]

On 8/5/2022 at 4:40 AM, Duncan said:

The adjustable arms themselves are no use

As an extension of that thought, if you do not also have adjustable front radius/traction arms, and if you have not had them properly** set up at the same time as any adjustments to the uppers (when camber is being set) then you  will likely have an excessive amount of bump steer and the rear end will actually be worse off.

**I built a bump steer measuring setup with a laser, mirror, etc and spent.....a whole day, and most of another day, getting both sides of my car to minimum bump steer. (Was a slow effort because I was designing/building the rig as I went, to start with). Then I had the rear camber adjusted a little at the next proper wheel alignment and had to set the bump steer rig up again to dial out the increased bump steer that it caused. Car's rear end behaviour was substantially nicer afterwards.

To get that done by a specialist would be.....near impossible in most places. Almost no chassis/wheel align shops would be willing to put up with the f**king around. And the fee would be horrendous. Racers and shops that cater pretty much only to racers would probably be set up to do it and do it reasonably efficiently, but it would still cost many hundreds of $$. My time should be worth even more than that, but fuddling about with the car is also therapy, so meh.

[GTSBoy]

I just realised that I made a small error of message above. When I said "adjustable front radius/traction arms" I was actually referring to the ones on the rear suspension. I said "front" because I meant they're at the front of the collection of arms on the rear of the car, only got halfway through the thought before full stopping. The message above is only relevant to the rear suspension, because the front radius rods don't really have that much (if any) effect on bump steer.

[25GTV]

Here it is at Eastern Creek on Tuesday night.

 

 

 

Had an absolute driving this track. The vibrations through the drivetrain at 200+ was scary and the rack bushes worsened over the sessions. Keen to make it faster.