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

    • The old manifold was quite under the GTR strut brace.  The new manifold is quite [unknown] the GTR strut brace. The GTR strut brace was needed to clear the bonnet vents. The Old strut brace will almost certainly clear the new manifold, but not the bonnet vents. The old strut brace will almost certainly clear the new manifold, and the new bonnet without vents. But I am hoping the GTR strut brace clears the new manifold :p
    • On the bright side, at least you knew that it happened and remedied before anything happened. A friend of mine just took his Fiat 124 to a shop for an oil change and they didn't tighten the oil filter housing properly. 4.5 quarts spewed out and even after refilling + tightening the cap the engine has a tick now.
    • So, more pain. The FAST manifold is a little larger than the stocker. This is problematic because there really wasn't much clearance to begin with, so going from 'barely enough' well into 'no' is sad based on the external dimensions of the thing, even though where it bolts to the head is the same. Result is the fuel rails sit a good 25mm higher, and this is a bit of an issue with the wiring that runs behind the motor, and the fuel lines, and everything else. When pushing the manifold on, it required a huge amount of force to crush wiring looms to fit it, sensors like the MAP sensor are about 1mm from the firewall, and the FPR just has to bend ABS lines to be forced into place. After some brainstorming and some sad drinking, the loom for some reason ran from the grommet behind the ABS sensor, then to the driver side head, then back to the passenger side head. So all of this was pulled back and stripped, a few wires cut and rejoined, so that the 'branch' was now on the passenger side's head as below: Before you basically couldn't see anything behind the driver head. This is much improved! The MAP sensor is now pointing up (instead of at the firewall) Brackets have been made up for the rail. The rails are for a LS1, the manifold is designed around a LS2 as it's base. Which of course has slightly different bracketry and water pump clearance, hence the mods people need to do. Should be hopefully mounted tonight. I spent money on a new FPR that is slightly more compact than my Turbosmart FPR1200. The gauge has also been moved to the rail. There's also apparently an ORB to AN Union instead of the adapter, because the ~25mm of the current adapter is going to make the difference. Provided this all goes together and arrives today, it'll be the totally not stressful attempt to start it.
    • This seems like a pointless exercise. There is no E30 availability. Ongoing availability of E85 should not be assumed. Flex-fuel is the only sensible approach, so you can use E85 when and where you can get it, 98 when that's al you can get, and anything in between as you fill it up and drain it down. And if that means replacing the pumps, fitting a flex capable sensor/ECU/whatever has to be done to these Renault shitboxen, then.....so be it?
×
×
  • Create New...