Spring rates for a race Clio

[Norfolknchance]

Hi guys we are building our second race Clio and we are struggling to agree on spring rates !

If you drive or have built one what did you use and how did it do

Thanks in advance

 

[BIGASH]

What dampers are you going to be running as that has an effect on the spring rates?

 

[Norfolknchance]

Gaz gold dampers

 

[BIGASH]

Ah okay well do you know about the motion ratio's for where the springs are mounted on the rears compared to running rear coilovers?

I think I am running 110nm front and 90/95nm rears hardly driven it but provided a massive reduction in lap time compared to my previous setup.

Sadly no one will like the same spring rates and while you can do a million and one calculations to work out the optimum in relation to pitch angle etc you are better off just giving it a try and go from there. I have got a couple of sets of springs so that I can have a fiddle if I'm not happy with it

 

[Norfolknchance]

Do you know what that equates to in lb's ?

 

[Ryan218]

Do you know what that equates to in lb's ?

Just used a conversion app on my phone

630 lb/in fronts
545 lb/in rears

 

[Ryan218]

Also one thing to bear in mind is James is using a coilover rear set up which gives a 1:1 leverage ratio, standard spring location gives a 2:1 leverage ratio so you will need to double the spring rate to give the same effective rate.

 

[Norfolknchance]

Thought it was about that,the last one we built had 800 rear and 700 front but we suffered with bad understeer so we dropped down to 550 on the front and it is bang on.
Just wondered as the one we are building now we are driving ourselves rather than building for someone else so we want to try and get it right first time.

Do you run spacers on the front for wider track ? If so do you think it helps ?

 

[Sam@NP]

James I have 100nm on the rear of my Trophy :rasp: Oversteer FTW.

 

[Dan519]

Ah okay well do you know about the motion ratio's for where the springs are mounted on the rears compared to running rear coilovers?

I think I am running 110nm front and 90/95nm rears hardly driven it but provided a massive reduction in lap time compared to my previous setup.

Sadly no one will like the same spring rates and while you can do a million and one calculations to work out the optimum in relation to pitch angle etc you are better off just giving it a try and go from there. I have got a couple of sets of springs so that I can have a fiddle if I'm not happy with it

are you sure those numbers are right? those are incredibly heavy springs. I'd expect about 60Nm on the rear for hard track use

 

[BIGASH]

Also one thing to bear in mind is James is using a coilover rear set up which gives a 1:1 leverage ratio, standard spring location gives a 2:1 leverage ratio so you will need to double the spring rate to give the same effective rate.

Yes this is what I was thinking but wasn't sure of the ratio on the back

Thought it was about that,the last one we built had 800 rear and 700 front but we suffered with bad understeer so we dropped down to 550 on the front and it is bang on.
Just wondered as the one we are building now we are driving ourselves rather than building for someone else so we want to try and get it right first time.

Do you run spacers on the front for wider track ? If so do you think it helps ?

What tyres were you running/ are you going to be running. Mine are based on 888's/DZ03's

I do run spacers at the moment although i'm afraid I put them on at the same time as different type of tyre, different tyre size and different suspension so wouldn't have a clue what was to thank for the improvements.

James I have 100nm on the rear of my Trophy :rasp: Oversteer FTW.

Haha nutter! I drove mine down the road the other day when I dropped it off with you guys and forgot just how bloody hard it is lol!

 

[BIGASH]

are you sure those numbers are right? those are incredibly heavy springs. I'd expect about 60Nm on the rear for hard track use

Just checked my setup sheet from Donington and the rear's I ran there are 550IB/in(96n/mm) but have a set of 500's incase but in all honesty the back felt very planted so was thinking to get a set of 600's just incase I can't dial out the understeer.

 

[Norfolknchance]

Federal 201's for dry and not sure for wet yet we tried 595 RSR's and they were good in the wet

 

[BIGASH]

Ahh similar tyre then!

I'm sure someone with more knowledge will come along and help more than I can but out of the box without any tweaking the rates i'm running felt 90%

 

[Norfolknchance]

BIGASH what size spacers do you run ?

 

[BIGASH]

15mm front on non cup hubs with ET37 offset
5mm rear with 18mm stub axle and ET37 offset

 

[NorthloopCup]

James I have 100nm on the rear of my Trophy :rasp: Oversteer FTW.

Do you keep a gum shield in the glove box Sam?! Lol! If you drive on the road with those on the back you are officially my new hero as well! Lol

 

[NorthloopCup]

James I have 100nm on the rear of my Trophy :rasp: Oversteer FTW.

Do you keep a gum shield in the glove box Sam?! Lol! If you drive on the road with those on the back you are officially my new hero as well! Lol

 

[Tony Hunter]

Very doubtful you will get it right first time, but you have to start from somewhere.

 

[p@blo]

Also one thing to bear in mind is James is using a coilover rear set up which gives a 1:1 leverage ratio, standard spring location gives a 2:1 leverage ratio so you will need to double the spring rate to give the same effective rate.

James I have 100nm on the rear of my Trophy :rasp: Oversteer FTW.

So thats comparable to James running a 50N? Doesnt really seem that stiff if the above is correct, or are you running rear coils on your trophy now?

 

[Ryan218]

So thats comparable to James running a 50N? Doesnt really seem that stiff if the above is correct, or are you running rear coils on your trophy now?

Yeah that's equivalent to running a 50 N/mm rear coilover spring if there sat in the standard location.

 

[NorthloopCup]

Gaz gold dampers

Am I right in assuming that your having these valved to suit the rear springs you'll be using? Iirc, they have quite a few clicks of adjustment on them so it should allow you quite a range of spring rates that you can use. +\- 50-100lb in most cases.

A mate of mine had them on a Clio trackcar, and despite their reputation on here they performed pretty well all things considered.

 

[Norfolknchance]

Do the Gaz Gold have a bad reputation on here then as I've only heard good reports ?

What is the main manufacturer used for race suspension on the clio then ?

 

[NorthloopCup]

Do the Gaz Gold have a bad reputation on here then as I've only heard good reports ?

What is the main manufacturer used for race suspension on the clio then ?

They leak mate. That's the main issue with them. The ones my mate had corroded really badly as well even though they're coated to protect them. The rear height adjuster collars seized and so did the adjustment knob.
It didn't help that they were out in all the salt and crap though tbh.

The main weapon of choice on here is ast's for racing. They use a rear coilover as well, but be warned - customer service is moderate to poor!
Josh Cook at Cooksport is your man to talk to if your after a set. He will go out of his way to help you out. Genuinely nice chap who's trying to improve their reputation as well.