Suspension Set up for an SV

[TomGaval]

I have a 2000 S3 superlight with a K series that I built and everything is stock.  Had the car set up 17 years ago and it handles great, nice and neutral.

I bought an SV with a Cosworth 2.3L Duratec two years ago and it has almost every upgrade you can think of.  It's got Nitrons with the remote reservoirs, and the guy I bought it from was a bit bigger than me at 6'8" and a little over 300 lbs.  The car is running on Michelin radial slicks with 9.5 inch rims in the rear and 8 inch ones in the front. 

I put new slicks on this past year, but the car still doesn't feel as planted as my yellow superlight.   My lap times are still faster in the older car with the standard shocks and softer set up.

Can someone give me a few pointers as to setting up the car.  I know that I should only do one thing at a time.  But I feel like I should have the car corner weighted for me and Maybe soften up the suspension a bit as it seems not to roll as much as my S3.   This car is a lot quicker than my older car due to 100++ more HP, but it just doesn't seem to hold as well in the turns.  Where should I start?   Thanks   Tom

[Croc]

You left off that your K series S3 runs 10 inch slicks all round - its always going to be planted in corners.   

You could also get stuck into the pies and pile on...oh...another 35 odd pounds to take you to 300 pounds and then the car would handle perfectly as it did for Karl?    

All wisecracks and trolling aside my vote would be for a corner weight first with your weight in the drivers seat and nothing in the passenger seat.  Then give it a try on track to see where it is at and think next steps.  

What tyre pressures are you running in the SV slicks?

[Nigel Fox]

I would find out what spring rates you have, then discuss the issue with Simon Rogers at Meteor Motorsport.

Meteor are a Nitron agent and service centre as well as being a centre of expertise.

[TomGaval]

Thanks Croc,  I'd need to put on almost 100 lbs to get to 300, you cheeky bastard.     Yeah, I sorta forgot that 10 inch slick thing.       I set the Michelin slicks to 20 psi cold currently, and pretty much leave them at that.  They heat up to around 24psi hot with a 25 minute session.

On the bias ply Hooiser slicks the car just takes a set and holds it as long as I don't let off the throttle or upset the car.  On the Radial Michelins, it just feels like they have a lower grip level and the car never feels planted.  I'm definitely slower thru the bowl on Lightning.  

So how do I find out what spring rates I now have?  are there any markings or diameters I need to look for?

 

[ECR]

Hi Tom

I'd run the Slicks at 20psi HOT (or maybe a little less ......)

In my experience, cross ply tyres hold on hard but then the breakaway is relatively sudden. The cross ply Michelins tend to move sooner but more progressively. Perhaps you are feeling some of this.

Some springs are marked with their rate but most aren't. If they're not marked, It's a case of taking them off and finding a race shop with a test rig I'm afraid

[TomGaval]

Hi Rodger!  I hear you might be making a trip over for our 7s Gathering this year.  Maybe you can take it for a session and let me know what you think. 

The Hoosiers are Bias ply, and the Michelin are Radial.  I always heard that the Bias ply were more progressive in their slipping where as the Radials were abrupt in their release once the limit is reached. 

I may just do as Croc suggests first and have the car corner weighted with me in it.   and maybe have have the toe in and camber checked.   I'd love to fit the 10 inch Hoosiers all the way around like the yellow car, but with cycle wings they don't fit.  The yellow car has clams which provide plenty of room for the big slicks.  Might just have to take the wing stays off and give it a try to see if there is any improvement,

Hope to see you in July.   Tom

[ECR]

Ahh, a senior moment, I do believe you're right Tom ... (I'd still lower those pressures though)

My USA trip is still under consideration but the exchange rate is making it more unlikely ...

[Pendennis]

I will offer some advice, but there be plenty with differing views. You should bare in mind there is no guarantee the tyres are not passed their best.

Presuming your concentrating on slick use only and they are not shagged then you should go aggressive on the spring rate, obviously the front ARB needs to compliment the spring rate. Personally I would be looking 300-350 front & 150-180 rear.

If it is the same F3000 spec 13" Michelin slick that we all have used, they are a hard compound. They should be no higher than 21psi HOT, so start them at 16/17 cold and work them for 5/10 minutes before pushing hard. In my experience I never noticed any difference on the slippage between Radial/Crossply, if anything the Crossply bit more but hardly anything in it. Crossply certainly easier to get up to temperature.

The set up is very important to get the best from these tyres, front camber should be high circa 3.5 degrees and at least 2 degrees on the rear, Castor should be high to maintain camber on turn in, ride height low with rake set to suit corner weights. That is how I set it for you anyway, all the best and good luck.

 

 

[Simon.Rogers]

The spring rates may be a little heavy but if they are Nitron spec they are generally not to far from what I would specify.

What I would almost certainly say needs looking at is the valving.  This will be very significantly different to my own.

If you email me Tom I will let you have all the info needed.

I would suggest thy came to me for service but thats not really going to happen from the US is it?

They will also certainly need that service to regain optimum performance.

Maybe we can get the US Nitron agent to rebuild and service them to my spec?  Under some sort of licence?

Any way message me.

[TomGaval]

Hi, Simon,  Thanks for commenting,  Im just south of Philadelphia,Pa, on the East coast of the US.  I don't know who the US Nitron agent is off hand.

I have a pretty competant mechanic, so if there are no special tools or parts needed for the revalving, he might be able to accomplish it. 

Any suggestions or support would be great. 

Thanks  Tom Gaval    tgaval@comcast.net

[Simon.Rogers]

YHM  - FYI they are "very" special tools - I had most types of tool and I am forever buying and making even more tools with every new damper I service!

I doubt your man will have the specialist kit.

YHM