Jump to content
SAU Community

Recommended Posts

Hi guys, I spent days researching spring rates for skylines (particularly GTT R34s) the general info was that 8/6kg setups were too stiff for the road and many said even too stiff for track...  

My car felt way too soft on the track and still too much body roll after doing a larger front swaybar.

I went from 8/5kg to 14/8kg and the car felt amazing and no where near too stiff on track.  The car was also lowered 20mm when the springs were changed.

Result was a 1.547 around Gardner Circuit at SMSP which is still slow.  If you watch my vids, the car is very slidy which is fun but slow and rear grip is the next step.

 

https://youtu.be/PjyTZ4dOq0M

 

Basic info:

Front Tyres 235 Zestine 07R

Rear Tyres Chinese 265s

220rwkw 12 psi

Locked Diff

Drift knuckles (ex drift car)

Shockworks coilovers

Whiteline 24mm F swaybar

Ext front LCAs, basic adj rear arms.

Stock brakes

Bucket Seat, Half Cage and still has climate control.

 

 

Edited by 25GTV
Trying to embed yt vid.
  • Like 1

went from 8/6 to MCA Red 13/10 (IIRC) and dropped a similar amount of time around barbagallo 

stops the weight transferring diagonally across and understeering  

set the ride height to the correct spec from mca website also makes a world of difference, it is a little higher than you would first suspect 

 

  • Like 3
18 minutes ago, 25GTV said:

168km/h on the gps into Turn 1.  Still not completely confident turning it in and I roll off the throttle after the finish line then coast turn 1.

wow that's pretty good!

I'm still a massive chicken shit and the fastest I've been was about 140km/h

  • Like 1
31 minutes ago, Dose Pipe Sutututu said:

wow that's pretty good!

I'm still a massive chicken shit and the fastest I've been was about 140km/h

It's a bit scary...  Especially with a locked diff and zero aero.

  • Like 2

Hi mate, glad you are enjoying your time at the track and looking to get your times down.

In my experience you will have more fun and way more lap time success changing things in the following order:

1. check wheel alignment

2. r spec tyres on spare set of rims

3. sway bars (stiffer springs are not the best way to reduce roll as they act in all compression conditions not just roll)

4. shocks and springs (lighter than you have)

5. mechanical diff

6. better pads and discs

7. replace sure all bushes, ball joints, rod ends etc 

8. more power

At the moment it is pretty clear from the video that it understeers mid corner (need more front end grip) and oversteers hugely under power on exit (needs more rear grip). Good tyres will make 200% difference to both of those and you won't really notice the effect of any change until you start with some grip.

Yes (comparably) stiff springs can be OK for track only use, as long as you stay off the ripple strips etc because they compromise the amount of time your tyres spend on the ground over bumps.

  • Like 3

You're probably right Duncan, thanks for the info.  Unfortunately the car budget has very little funds available, so...  

I have in the garage a spare s15 Helcial diff that I believe I can swap the centre and run s15 shafts.

Also, I can add some camber and toe in the rear for free.

The front tyres will have to wait for additional funds...

..... also get the rear swaybar. You would be stunned how much difference it makes with regards to turn in. I'm really surprised you didn't have one already from drift duties!

Anti roll bars are very hot topic, I'm personally not a fan of the super stiff setup. From my personal experience, I prefer upping the spring rate (I'm planning to myself, especially for SMSP).

Since Matt's car already understeers, I would not be adding a front ARB, however introducing a rear should aid in it clocking better, however with a slight compromise as the car would snap oversteer much easier.

7 minutes ago, Dose Pipe Sutututu said:

Since Matt's car already understeers, I would not be adding a front ARB

He has massive front spring rate AND a 24mm bar. It has a lot of roll stiffness in the front. It's really no wonder it wants to mid-corner understeer.

I suspect fixing the rear will come down more to getting rid of the welded diff and looking to the wheel alignment, and possibly bump steer geometry.

Plus tyres. The reason the V8 Supercars can get away with spooled diffs is the massively sticky slicks. Just watch how slidey they get on corner exit when the tyres go off.

1 minute ago, GTSBoy said:

He has massive front spring rate AND a 24mm bar

Totally missed that part!

I would set it on the softest setting to aid front end grip, waits for everyone to flame me for saying that LOL

1 minute ago, Dose Pipe Sutututu said:

I would set it on the softest setting to aid front end grip, waits for everyone to flame me for saying that LOL

If keeping the big springs, I would drop to a 22mm, or something. Maybe even a stocker.

Wow, your mid corner grip is terrible.

Put some toe on the back, get some cheap track tyres like AR1's and ditch the locker. If the car is super low you might want to consider changing the sub frame bushes to solids or zero height units at the back and raising the rear, same ride height but your rear geo will be closer to standard giving you better camber and toe curves.

  • Like 1

I urge you not to make any further setup changes until you put some proper tyres on it. There is no point trying to improve on a flawed foundation, you will likely find it handles totally differently (strengths/weaknesses) with new tyres.

  • Like 3

The mid corner understeer is probably majority linked to the Drift Knuckle geomerty (extra lock knuckles).  In general they destroy everything whilst giving big lock.

I will say it is great fun to drive like this, predictable when the low grip limit is pushed.

  • Like 1

I mean, I didn't drive your car and I am no expert track driver myself, but watching the video makes me think that car handles like an absolute uncontrollable bucket of shit.

I know you've drifted it, but if my 34 sedan started behaving like that it would have ended up on it's roof about five times trying to go around a corner with my hamfisted driving. That exit onto the main straight should absolutely not be a mission like that, in any car ever. It's not only rear grip being the issue there. This is an alarming set of tyres at the very least as mentioned.

  • Like 1
  • Haha 2

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


  • Latest Posts

    • Just a thought, how come you didn't use a 4D table? So you essentially run 2x fuel and 2x ignition tables, and the table/map switch is handled when there's enough WMI pressure detected. This is mine, but using the flex sensor as the 4th dimension, note the slider at the bottom. Between 0 to 70%, the timing is blended/interpolated , once it goes past 70% ethanol full send
    • Hi guys, after dreaming of owning a JDM legend for 20 years, I got the chance to buy a 1995 R33 GTR.  I live in a small country called the Solomon Islands which is in the pacific. There is no performance car scene here, however 90% of vehicles here are 2nd hand Japanese imports so there is a handful of JDM sports cars here, tucked away.  3 Evo VI’s, 1 180sx turbo, 2 GTO’s, 1 R32 GTR and 2 R33 GTR’s.    Only 1 Evo and a 33 (mine) are active. I’m hoping to set up a club to get these cars back in the road.    I’d known of my GTR for 9 years and always dreamed of owning it. At the start of this year I found it sitting outside a workshop waiting for a respray. It was in pretty bad shape, although running and driving perfectly apart from a big exhaust leak and worn out bushings. My brother in law who is a huge GTR guy came over for a holiday and I took him to see it, he got into my ear and I bought the car 2 weeks later as is.   I’ve had a pretty bad problem with alcohol and weed since 2020 and I really wanted to quit. So I used this as my motivation. I quit everything cold turkey and have been investing all my spare time into restoring this car. It’s honestly been the best experience and has been such a positive impact on my life.  There is no market for these cars here, no parts and no mechanics that can work on them, so if you wanted to sell one it would be pretty impossible unless you found the right buyer. After a bit of negotiating with the previous owner (a good friend) I got the car for $15,000 AUD ($85,000 SBD) which is insane.  I’ve almost finished doing a refresh on the engine, new turbos, spark plugs and split fire coil packs. Also new gaskets and seals, This car had no leaks to begin with, but it’s due now being 30 years old. . Next I’ll be working on the suspension, all new bushings, ball joints, king pins and new coil overs.  Then it will be body work, it has really bad rust in the boot floor, I have purchased a rear beaver cut from my bro which will replace the rusted out one. The car is originally KL0, but was burnt orange when it landed here, then it was resprayed toxic green and then Bayside Blue. I’m probably going to get it redone in Bayside Blue.  I’m super grateful to be able to enjoy this car and couldn’t have done it without my bro Chris from OG-JDM. Looking forward to the future with this car and hoping to get it on the runway at the airport here 😂  cheers fellas 
    • Also, it is just about triangularity. The less angle, the easier it physically is to do. Think of the amount of slip you're getting, as how hard you need to push an object. More slip, equals pushing way harder. Then the ramp is how steep the hill is. The Accel is less slip, which means it takes less pushing (less slip) to get it to be able to push apart. However, the steeper sides on the decell means it will take a lot more pushing (slip) to get it up the ramp.
    • It's the angle of the ramp from the vertical. You're measuring from the horizontal. To convert, take 90* minus your angle reference = Nismo Angle.
    • I agree, thus 45 degree is the *max* force one could apply to it. This is similar to what I've seen in uh... simulations... which allow you to play with diff ramp angles. Anything higher (or lower) than 45 degree would produce less force as 45 is the max... triangley.  I would state the 1 way is 90 degree, at least this is how my brain and other ways of explaining it refer to it. 90 degree also effectively acted completely open. I realise Nismo refer to it not as 90 (or 89) but "1". So I'm not understanding the angle on which these angles are based.
×
×
  • Create New...