Coilover spring rates for circuit racing

What coilover spring rates are other forum members using for circuit racing. I have just had my Zeal function springs tested and they are horribly soft 6.2kg/mm!!

 

I have the old slot car RE teins 8kg fronts /5.8kg .(wouldn't go any softer)

JP had 8kg/5kg but upgraded to firmer springs due to more down force of aero.

8kg / 6 kg is a good medium .

weight of car comes into play as well.. the lighter the car the firmer the springs will be.

 

Thanks for the replies. I have been looking at the Zeal coilover spring rates which quotes for Z32 street 10kg/mm and 7kg/mm with hard being 12kg and 9kg. I have Dunlop D11 slicks with front wheel camber set at 3.5.
I am trying to improve the car around corners as this is where I lose a lot of time against most other drivers

 

is that still too soft for street use only?

i'm considering a set of powertrix with spring rates 7/5 instead of 8/6

I take it when you say 'horribly soft' this is based on a good track setup only.

WZ

 

Yes, This car is only used for circuit racing, no street use at all. I'm just a 70year old with no experience and very little ability that relies on this forum to keep me on the tarmac. They are doing a great job, thanks guys.

 

and thanks for the info Rob260,

I appreciate it

 

8kg/6kg is a good combo for lakeside and QR as they are quite bumpy.

 

The MCA Proflex coilovers I got with my race car are 10kg / 8kg. These where custom made my Murray Coote so I expect they are pretty right for most circuits. He is a legend with many full on race and rally cars having suspensions made and tuned by him.

The issue is the firmer the spring rates on a circuit car the less sway bar you are likely to need, I expect I wont need a rear sway bar with these spring rates and maybe quite a small front one.

Most people on here have Commercially made ROAD coilovers which they choose to use on the track. When you make the transition to real race spec parts they are much firmer generally to minimize body roll without the use of large or any sway bars.

Want the best ? Look here.... http://mcasuspension.com/

 

My Tein flex's are 10/8,stiff but not unbearable. Car is still street driven at this point

Dave

 

^ did you change them? Even mono flex aren't that hard, normal flex is about 7/6, mono's 9/7. My hks hipermax 2's are 7/6 & I find them a good setup for street driving. Previous hiper-d's were about 10/8 & found them too stiff for daily duties, would skip over rough road surfaces.

 

Nope ordered direct from Japan that way, brand new

Mine doesn't skip or slide its stiff, but overall setup is key.

Dave

 

This should be interesting, I have gone with 12kg/10kg, I do not have a rear sway bar and as you say may have to reduce or remove front sway bar. Will let you know how it performs, aiming for a practice session in next couple of weeks.

 

When you're setting up a car for racing, (if your budget allows) you start with springs and dampers to get the overall balance of the car right, then use sway bars for fine tuning.

Bigger rear sway bar = more oversteer / less understeer.
Bigger front sway bar = more understeer / less oversteer.
And vice versa.

So depending on your spring/damper setup, you should still run sway bars, but they need to be balanced to get the overall turn characteristics that you prefer.

Of course choice of tyres is also a very big factor. A perfect setup on a set of tyres may not work if you change to a different set of tyres. Tyres are a very big part of your overall suspension/handling equation.

 

So what did you buy Martin?

 

I ordered my Tein Flex direct from Japan also with 8/6 spring rates.

 

Thanks

 

I got what I could at short notice Eibach on front Kings on rear, had my Zeal Function dampers overhauled to suit. If I find that the suspension is too stiff I will fit rear springs on front and purchase a set of 8kg/mm for rear. Its good fun experimenting

 

Hey martin apart from all that about coilovers, the thing about track racing is need turbos to come on way down the rev range, as for example at Eastern creek at 15psi boost a well tuned 240Z with triple webbers pulls away from me through the long continous corner like coming onto main straight but eat him when turbos come on strong and like turn 1 where can power all the way through, just saying