Best Suspension Setup For Max Grip

[lybker 26 2 Cars]

High power fwd is allways an issue to achive enough grip, and I am struggling. Any advice is therefor more than welcome.

 

Already fitted coilovers with 400lb springrate (to much, i know :-), quaiffe lsd and racing slicks.

 

Please help out with suggestions for suspension setup :-)

[Tom Fenton 1,536]

Plate LSD first of all.

[lybker 26 2 Cars]

Noted!

 

I am aiming for a good tracksetup with excellent grip - hence advice from other high powered 205s is welcome. Currently first 5 gears 6speed box) will, once boost kicks in, result in a loss of grip from the tires :-(

[allanallen 528 2 Cars]

So do you want a circuit set up or a drag car?

 

Put up the complete spec of your car and there'll be plenty of folk willing to help.

 

If you've got budget coilovers and 400lb springs with a standard bar'd beam it will never 'grip' or 'handle', in fact it'll be an utter dog.

And if you've got 500bhp you will never stop it wheelspinning.

[welshpug 1,646]

less boost!

[lybker 26 2 Cars]

Makes perfect sense....as this has been a long term project, i would need to go and meassure all arb and torsion bar dimensions. will post the details tomorrow. The aim is finding a solid compromise between trackday and drag.

 

Rwd /awd Would do the trick, but unfortunatly there seems to be no "good " solution for this available... :-)

[petert 578]

Depends on the tires. With A050's I run 500lb springs. You couldn't do that with any other semi-slick however. The side walls will be destroyed. I also run slicks with the same. Parry runs 600lb springs on slicks. All that is irrelevent if you don't have the back stiff enough. It will understeer like a dog. I also removed the front arb, which helped traction out of tight corners but may not be as good on faster corners. I'll never know however, as I have rose jointed wishbones now.

 

I'm surprised you have a 6 speed. Surely that's not sustainable?

Edited December 3, 2015 by petert

[mmt 15]

1. Plate diff will make a huge difference. Much more drivable.

 

2. Softer front.

 

3. Std rear end works for me. As you know I only have half the ponys.

Edited December 3, 2015 by mmt

[lybker 26 2 Cars]

Yes ....exaclty...was wondering how some seems to be fine with +500lb springs and others will go for 120lb - surely nomatter how stiff you make the rear....so stiff front end will have a tendency to bounce / loosing grip on the smallest of uneven surface during hard acceleration?

 

As my racing days are long over, i only need a fair setup for occasional trackday events - so instead of doing a great upgrade to current setup, maybe it makes sense to exchange front springs to best match my current rear setup. So i will post current details tomorrow and listen to advise :-)

 

Was thinking about getting a softer front arb or removing it, also in the hope it would allow for each front wheel to better grip the surface, as this seems to be working during racing in the wet

 

The 6 speed will be fine for the limited driving the car is exposed to. In case it fails, i have a 5 speed hdi gearbox as backup

[lybker 26 2 Cars]

Martin - what is your front setup, springrate, arp diameter etc?

[mmt 15]

Pm'd

[lybker 26 2 Cars]

Thx ;-)

[petert 578]

Yes ....exaclty...was wondering how some seems to be fine with +500lb springs and others will go for 120lb - surely nomatter how stiff you make the rear....so stiff front end will have a tendency to bounce / loosing grip on the smallest of uneven surface during hard acceleration?

 

No, if you're running slicks you need to be 500+ with the shocks valved to suit. The same in the rear. Make it as stiff as you can. I can assure you it's planted solid. You did ask for maximum grip? Watch the video:

 

http://forum.205gtidrivers.com/index.php?showtopic=165991

Edited December 3, 2015 by petert

[lybker 26 2 Cars]

Great race - 94 laps, phew :-)

[allanallen 528 2 Cars]

Sounds to me like a far more road biased set up would suite and perhaps look at using different tyres for the limited track day use the car will see?

[Tom Fenton 1,536]

What power/torque are we talking about? How is it delivered?

 

I recently finished Paul Higgs car at 252bhp, OK in the wet forget it, but in the dry its extremely driveable, 1st & 2nd you cannot apply the throttle like a chimp. but from 3rd upwards you can use full attack.

[lybker 26 2 Cars]

Ok, details are as follows:

 

Front:

400lb springrate 8"

Sachs race engineering coil overs

17mm anti roll bar

 

Rear:

Bilstein gas dampers

19mm torsionbars

24mm anti roll bar

 

Other:

235/610-17" racing

Quaiffe planetary diff lock

Output: 500hp/ 500nm +/-

 

Strange setup, maybe. What would be the right mod to balance cost and benefit.

 

First on the wishlist would be exchanging the planet diff lock to a plate diff. If any should have one up for sale, I am listening. in general suttle investment is required, as the funds unfortunalty are limited :-)

[B1ack_Mi16 67]

I think with that power you will wheelspin anyway.

 

Even mine non-turbo can sometimes wheelspin 3'rd if the tarmac surface is not very good and clutch operation is a bit brutal.

 

What about making the boost-pressure speed dependent to make it more driveable, of course in addition to optimizing grip.

[allanallen 528 2 Cars]

Your wheel/tyre size will be causing issues as they're too big.

 

Front dampers probably can't cope with the 400lb springs and as said the front is mismatched to rear very badly.

 

Either bigger bars are needed (25mm to match the front IMO) or softer springs, you'll struggle to get soft enough springs on coilovers so it may be better to go back to standard size springs and fixed height dampers.

 

With that power it's always going to wheelspin without drastic mods

[lybker 26 2 Cars]

That could be possible....could fit abs sensors and send the signal to the ecu for it to adjust boost accordingly. Then a value can be set for allowed wheelspin comparing front to front and front to rear. If this would work satisfactory in reality....is to be seen

[allanallen 528 2 Cars]

 

I personally think that'd detract from the driving experience but it's obviously an option.

Edited December 4, 2015 by allanallen

[Tom Fenton 1,536]

I would look more to use gear related power limiting. I have used this in an Emerald ECU to good effect, 250bhp 440kg Mini.

[lybker 26 2 Cars]

...problem is, it will, once on boost loose traction even at 130mph in 5th gear....would limit all gears then :-)

 

Part of this issue as rightfully mentioned must be down to a poor balanced setup. My first choice is to try improve this and see how far that will solve my problem.

 

At any time it is possible to reduce boost, but should really be the last resort ;-)

Edited December 4, 2015 by lybker

[welshpug 1,646]

most production high powered diesels and some big capacity petrol vehicles do this anyway, more to protect the transmission than retain traction

[lybker 26 2 Cars]

based on input, I will aim for a solution that is softer than full racesetup and try to match the rear by fitting softer front springs. Something in the region of 250-300lb and keep the rather thin 17mm front arb. Hopefully this will allow for the wheels to follow the surface better even it could increase roll a bit. Btw camber settings are currently 2degree front and 1,5 degree rear and very limited toe out.

 

More importantly swap the quaife for a true plate diff....i havent tried this, but word has it it makes a real difference...

 

In case above is insufficient, I might try to increase the thickness of the rear beams.

 

Is this way off?