suspension issues when stripping out weight

[vRSy]

This is one for all the suspension track gurus

guys i have been reading with interest alot of the track day 172/182 cars in the projects sub forum.

I intend to make myself a trackday car.

with the plans of stripping weight out, coilovers, top mounts, Rear ARB, LSD, brakes

Ive had coilovers on my last few cars but they were never stripped out light weight hatches. They have all been 280HP+ salons, largre hatches so im kinda in a new area here now.

my thoughts are when you strip the weight out of the clio, 90% of that weight is going to be stripped from the rear of he car.

now i see a few potential problems with that.

1-Spring rates

surely all the colovers on the market will have been designed with the true weight of the clio in mind so once you strip out all the excess spag from the car, the spring rates will all be wrong as the weight distribution will be well out.

Also with all the weight off the back of the car would it not sit alot higher as well??

Are there other optionas avaialble for tailoring springs tp suit the weight of the car and how do you know what spring rate to ask for??

2- handling on the limit

obviously losing weight off the car is great for cornering and power to weight ratio, but will all the weight over the front of the car not cause a very skittish rear end on the limit. or maybe even understeer??

3-brake bias

with all the weight predominantly over the front axle will the front to back bias be off causing strange braking characteristic under harsh braking?


How do they handle on track stripped out???? I know my vRS is very predictable when trail braking and very easy to catch when the back steps out. but that is a heavy saloon, with a good weight distribution over both axles.

 

[vRSy]

how many guys on here have stripped interiors and ate there any good guides on th good stuff to take out??

 

[TimR26]

Have a browse through the projects section for some ideas.

 

[vRSy]

had a look through, but still have questions.

 

[edewer]

the car will sit a bit higher yes, but barely noticeable really.

braking wise i do find the back can float about a bit under heavy braking but thats as much due to having good front brakes as anything else

only thing i found handling wise is that you can get some epic lift-off oversteer too

possibly not the technical answers you were after but thats just my findings

ed

 

[Phil @ P5]

You're right, if you remove weight from any corner or axle you should revisit spring/ARB rates. When tuning a chassis this is where you start and from there you tune damper rates.

For maximum grip you are trying to achieve a [FONT=&quot]scenario[/FONT] where the front and rear tyres saturate grip at the same time. In reality you probably want a hint (5%) of understeer, so when grip goes you still have grip at the rear to get you in trouble rather than a comical cartoon-type dive into the hedgerow.

As for getting that package I'd say you'd need to look at bespoke or at least talk to someone who understands suspension dynamics.

Phil

 

[Munson]

IIRC Fred is into this s**t.

 

[Fred@BTM]

trial and error, you can spout as much theory as you like, go and try it and have a play

i'll try something and drive it, try something else and drive it, tweak here and there

my suspension setup "on paper" would look daft but it works for me! LOL

 

[Aron]

As Fred said is all depends on personal preferences.

I found when i removed the weight it really improved how the back felt. Lifted it about 10mm but just adjusted the front a little. Getting the car on scales is the best bet to try and even it out but at the same time you need to match it too how you want it too feel.(really need to redo mine)

The main problem i have found is the braking. Can be sorted slightly with a bias valve but will not completly cure it. The rear ARB made it feel a little more predictable and having the front setup correctly with camber and toe made it easily controlable. Just trial and error everything, not good for your wallet but well worth it.

There is a fair few people on here with full tracks so just browse and read everything and take advise as you need it.

 

[W17GLE]

Mine was stripped out but only running on eibach sportlines. I found the back end was rather lively but the car was riding higher than standard so that won't have helped. I think if you had coilovers and then got the car corner weighted you wouldn't have an issue.

 

[vRSy]

Apologies for all the questions. but i dont want to waste money this time. I rushed into purchases on my last car to get what i wanted and as i larnt the best methods/mods and tips from others and from personnel experience, i started to replace all my stuff with higher quality gear, so it cost me more in the long run. Dont want to rush into it this time.

Slow and steady wins the race

only thing i found handling wise is that you can get some epic lift-off oversteer too

nice!!, i can get that now, but its easy to catch with my ar cause of its size and weight. is it very snappy on the clio or is it easily caught?

As for getting that package I'd say you'd need to look at bespoke or at least talk to someone who understands suspension dynamics.

which companies can cater for this. Im no out and out racer. im just a keen track day entusiast. I dont like cutting corners but if i can use standard sets of coilovers with no issues after a strip out i would.

Im swaying towards the KW V2 coilovers when i get the car. Purely as ffrom experience they are at the head of the pack on the mk5 gti chassis, and seem to get good reviews on here.

how would the spring rate thing work though. Would having less weight on the rear mean softer springs, or maybe different length springs??

Also I think having adjustable damping on coilovers is a must when stripping weight as the damping rates on non adjustable coilovers will have been designed with the std clio kerb weight and distribution in mind.

trial and error, you can spout as much theory as you like, go and try it and have a play

i'll try something and drive it, try something else and drive it, tweak here and there. my suspension setup "on paper" would look daft but it works for me! LOL

Im keen to know what suspension setups you guys with stripped out cars are running. To Fred@BTM any chance you could divulge your setup or is not for the public forums! Do you have a build thread??

The main problem i have found is the braking. Can be sorted slightly with a bias valve but will not completly cure it.

are you taliking of increasing or decreasing the rear braking bias?

The rear ARB made it feel a little more predictable and having the front setup correctly with camber and toe made it easily controlable. Just trial and error everything, not good for your wallet but well worth it.

Im suprised whiteline are the only company that do an ARB for the clio, and only a rear one at that. its prob the best mod for my car by a long shot. Thestd bars must be really good!

As for adjusting for more negative camber on the front, i thought that would mean a higher likelyhood of the front outfripping the rear thus inducing oversteer. increasing rear negative camber is how i would have thought the oversteer could bre countered.

There is a fair few people on here with full tracks so just browse and read everything and take advise as you need it.

which usernames do i need to look out for. ive read burp speeds 2 build threads, Im thinking im only after about 80% of the strippage he went to on his, as it was insane the detail he went into lol.
read this one :Ben_Stevo172 - White Supercharged 172 and Ben_Stevo172 - White Supercharged 172

 

[Aron]

The KW V2's are very good and are what i am using. As i said the rear felt alot better once stripped with these. Just felt allot more solid.

I was on about reducing the brake bias.

Yes adjusting the rear camber will help but is allot more difficult then the front. I have found if the front is setup well then its allot easier to control the rear. Little bit of oversteer is eaily cureable.

 

[Fred@BTM]

give me a call anytime chap and i can bore you to death!

 

[vRSy]

give me a call anytime chap and i can bore you to death!

Haha, are you that bad, lol.

once i get the car fred ill look into taking the drive down to your workshop. see what you reccomend, prefer to talk face to face. Want to get this right first time on this project.


Now i need to find someone in the medway, kent area with a stripped clio to show me how it is.

Im one step closer to gettting a clio now. got my exhaust system, fuel pump and intake off my car today and gone from a 280Hp+ stage 3 remap, down to a 240hp stage 1 remap. god it feels slow. not going to switch back to the standard mao until i sell the car. i couldnt bare it.

 

[Fred@BTM]

depending on peoples technical knowledge and driving level i usually keep things as simple as i can otherwise i just end up getting blank looks hahaha!

 

[172Ben]

I have mine rock hard at the back, and the softest on the front. Seems to work good

 

[Fred@BTM]

^that's pretty much the way to go!

 

[172Ben]

Still need it corner weighting though