Jump to content
SAU Community

Recommended Posts

Hey, I have been slowly building up an R33 Gtst track car over the past 5 or so years. I feel that the car is just about where it needs to be in terms of upgraded/strengthened/adjustable parts now but i am having trouble dropping my lap times mostly due to oversteer.

I am hoping there is some knowledge out there that you might be able to share with me.

Here is a video of how the car goes at the moment which also should give you an idea of its handling characteristics.

https://www.youtube.com/watch?v=PeUwsz22pOU

and here is a basic rundown on the car and setup.

It is a 96 S2 Gtst with a steel wheel holset core and about 240kw

Interior

- Stripped interior about 180kgs removed

- 8 point roll cage

Handling

- Bilstein shocks valved for track work

- Springs 350 front 550 rear

- Ikeya formula front upper (front set to 3.2 negative)

- Ikeya formula rear upper (rear set to 1.6 negative)

- Ikeya formula rear toe (pretty sure toe was set to neutral)

- Alloy subframe bushes

- Polly bushes just about everywhere else

- Nismo 2way LSD

- Hicas Lock bar

- Height adjustment set to about stock

- 20mm spacers

- Federal FZ201 semi slicks (about 34psi hot in front and 32psi in rear)

There are other RWD cars running similar setups and power to weight lapping 3-4 seconds faster, now obviously the driver is going to have a big impact here, but looking at there videos they seem to have a lot more corner grip and stability.

Link to comment
https://www.sau.com.au/forums/topic/444856-r33-gtst-handling-advice/
Share on other sites

either im blind or you dont mention sway bars.

these are a must.,

if you do have them, soften the front sway a little, it will correct the oversteer.

just my little 2c on the limited knowledge i have.

The initial understeer is what worries me,,,gts-t's don't usually suffer from that. It's certainly not the tyres,,, FZ's are great but your tyre pressures are way different than me,,,I use on a hot day 38 all round and constantly adjust them till I get it. Zebra's on drugs,,,no way is your diff contributing,,,no way. I'm running close to 0 camber on the rears and about 4.5 on the fronts from memory. Artz is right she needs to be lowered,,,big time.

Just do little changes,,,or you will never know what fixed it.

Cheers

Neil.

The initial understeer is what worries me,,,gts-t's don't usually suffer from that.

Yeah hard to recommend changing swaybars when the car is exhibiting both under and over steer.

I found this interesting camber vs tyre pressure info that I will have a go at next track day http://www.turnfast.com/tech_handling/handling_pressure3

I will also lower it a couple of centimetres just a pain for road driving.

I am going to peg rear camber back to about 1 degree if this fixes the rear end grip then maybe i can adjust sway bars to reduce understeer (softer in the front or harder in the back although the links on the whiteline kit seem to only fit in some positions)

You stated the tyre size, but size wheels are you running front and rear? If you're running narrower front wheels and tyres, try running the same front and rear. I think you'll find it makes the handling

a lot more neutral. Also, a bit of toe out on the front will help with turn in and that corner entry understeer. Goodluck, and keep us posted.

You stated the tyre size, but size wheels are you running front and rear? If you're running narrower front wheels and tyres, try running the same front and rear. I think you'll find it makes the handling

a lot more neutral. Also, a bit of toe out on the front will help with turn in and that corner entry understeer. Goodluck, and keep us posted.

You are correct on rim size im running 8" on the front and 9" on the rear.

Interesting I need to get some lighter rims current are about 9ks a piece, will take this into account when i upgrade.

What do you reckon 9" front and rear running 255s?

this counters understeer not oversteer.

Nope, softening a front sway bar will correct understeer..so I just figured stiffening it will help with oversteer...

ED*

though if you look at the graphs below ther eis no clearcut solution really as softening and stiffening can fix it, depending on situation

I have been reading up on this all week man cause the cressy is understeering mid corner, been looking for a solution :P

Hey, I have been slowly building up an R33 Gtst track car over the past 5 or so years. I feel that the car is just about where it needs to be in terms of upgraded/strengthened/adjustable parts now but i am having trouble dropping my lap times mostly due to oversteer.

That's what I would be doing. And then, if it still has mid corner understeer, soften the front sway bar one notch.

thats what i read it as.....why are we all talking understeer now?

Also i dont think rim size is going to make alot of difference, mine felt perfectly stable with 8s and 9s..dont get me worng it will help, but i dont think it is something to really be concerned with.....

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Seat of the pants assessment of the new intake: The car is way less "doughy" when hitting the loud pedal, especially off idle when stopped or in traffic, I did use a cheapo lazer thermal thingo to measure the temp around where the pod filter got its air, it was between 55 - 60°C, in saying this the car was shut off and not moving, so the OEM intake pipe was not supplying any fresh air to where the pod was when the car was at least moving A weird bonus was induction noise on the throttle in the cabin increased a bit,  I was worried that I was actually going to lose some of that induction noise I love so much, outside though, when I got the daughter to do a WOT drive by pass for me, the induction noise has increased alot when on the throttle, not quite ITB doort, but well up there I'm extremely happy with the results and have been exploring the country roads in the region  As for house mods: 1.New front fence is up and is awesome, it really upgraded how the joint looks from the street, and the added security is nice 2. Electricians have replace some interior lights, and with more lighting in the garage, a few new motion detecting lights out the front above the garage, front room, and at the front door, which I have already found heaps helpful coming and going, also now has fancy pants CCTV all round the house The only hold point for power though is the solar and batteries due to supply issues, although this will happen over the next few weeks 3. I have done a heap of landscaping out the front and I'm almost ready to do a new small retaining wall with some nice blocks to replace the brick and cemented in rocks around the raised garden beds cemented in river stone "was the fashion at the time" the house was built. I currently have a pallet of retaining wall blocks and 2 bulka bags of 20mm blue metal to replace the wood chip that is in the raised garden beds around the house 4. I now have 3 big raised garden beds for out the back to grow some vegetables, about 70cm high, 200cm long and 100cm wide 5. My 2 compost bins are already pretty full with brown, green and kitchen waste from the landscaping I'vedone so far, but they will probably take a few months to break down, so anything else that gets chopped, trimmed, and kitchen waste will just start filling the base of the raised garden beds to about 30cm before I start throwing 40cm of good compost, and stuff, for the vegetables to grow in, I'll need a few ton of compost and soil, but the local supplier can sent me bulka bags of the stuff Basically the logs, wood chips and a few strategically placed rocks for drainage, will give the beds some good organic materials down low to break down over time, and they will hold moisture during the warmer months to save the water in my big arse water tank if we don't get alot of rain So, all in all, the car and house mods are going well, and I'm really enjoying being retired, I sleep in too 0700 and slowly plod around inside until I feel like actually doing anything, and only work in the yard for as long as want, which has actually been alot over the last few weeks,  although when you look at it, it seems that not a huge amount of work has been done,  until I look at the before I started the work pics Happy days and good times indeed 
    • hahaha yeah. Plan is to get side skirts and probably just rear pods. But going to do them one-by-one. I've got a set that I really like from RHDJapen, but that one isn't shipped to AU. So need to find someone who can get it for me
    • Here's an idea, answer the questions I asked you as they are trying to work out WHY the LSD will be binding up in a straight line.
    • You haven't driven many modern cars then have you? Most of them have sfa steering feel with their stupid electric bullshit steering systems.
×
×
  • Create New...