View Full Version : Harder rear springs
On a FWD car what effect does running rear springs that are harder than the front ones have on the handling?
Ultimatly, depending on which way your turning, the nearside or offside rear wheel can lift up causing massive amounts of sudden oversteer. Ala, welcome to lampost city.
/\ like i had the other night :( sideways flat out in 3rd :(
/\ like i had the other night :( sideways flat out in 3rd :(
Thats a worst case scenario, with average aftermarket poundage rates & average aftermarket tyres you'd have to be pushing very hard to do that before losing grip though.
need to get my coilovers refurbed asap and some decient tyres
Why do you want rock hard rear springs?
Theory being it prevents "squatting", keeping the weight over the front end, reducing understeer.
I've seen some of the track people run harder rear springs and apparently it reduces understeer so that got me wondering
Ive run mega hard rears on mine on track and i think it does help with understeer a little, but it made the rear end feel proper "twichy" and always on the verge of letting go. So i swapped back to softer springs.
thought it might be for that reason, the squatting that is.
Also helps with traction, for the same reason, keeps weight over the front.
Ive run mega hard rears on mine on track and i think it does help with understeer a little, but it made the rear end feel proper "twichy" and always on the verge of letting go. So i swapped back to softer springs.
That every thing happend to me doing about 13 or 18mph in the wet. Very nearly went through a wall on Wolverhampton ring road St George's. Spun right round facing on coming traffic.
C612DNM
18-10-10, 09:12 PM
It's all about a balancing act. Just bunging stiff springs on a car with factory or standard OEM type dampers is asking for trouble.
Stiffening the rear end will increase the tendency to oversteer, as mentioned. More so if lowered and stiffened without doing the same at the front.
To get it done properly, you need the dampers to be valved to match the springs. GAZ are probably the best people to do that for you as their kits appear to be bang on the money!
Simple rules, stiffen the front too far and it'll understeer. Stiffen the rear too far and it'll oversteer. To put that into laymans terms - Understeer is where you see the accident coming, oversteer is where you can't!
As an aside, when running my Nova GSi on road tyres (Super Road Saloon Racing), we calculated that the optimum spring rates were 325lb fronts, and 375lb rears. Now that seems odd when the rears are usually lower rate than the fronts. But remember that the Nova's beam / spring setup operated like a crank effect. The spring rate at the axle works out to be something like 275lb give or take some ounces!
Intresting.
I've went for 350 front and 250 rear (C20LET) and mcpherson rear setup
Theory being it prevents "squatting", keeping the weight over the front end, reducing understeer.
Slightly, more noticably though (unless you're on a drag strip) the back end is permitted to twist less, if you imagine it actually as the whole car twisting about it's centre, it keeps the front planted under corners, and less so the rear end, shifting the under/oversteer balance to oversteer more... it's best controlled with ARB's but nova owners are scared of front ARB's because they because OMGWTFDEATH lol
That every thing happend to me doing about 13 or 18mph in the wet. Very nearly went through a wall on Wolverhampton ring road St George's. Spun right round facing on coming traffic.
Dodgy as fook on the road, funny as fook on track :cool: lol lol
Meh, just keep the foot down on track and never let off mid bend, sorted :d
Dodgy as fook on the road, funny as fook on track :cool: lol lol
Meh, just keep the foot down on track and never let off mid bend, sorted :d
Was a hoot on the road, just a little brown panty in the rain sometimes. And that day was one of those times.
spanishfly
18-10-10, 09:27 PM
On the road it can cause that, on track once you get used to it you know you can maintain the speed. Me and Lee303 run 450lb rears, i run 350 in the wet/bumpy tracks. Clio cup race cars run 500lb rears.
spanish, what did you run on the front?
On the road it can cause that, on track once you get used to it you know you can maintain the speed. Me and Lee303 run 450lb rears, i run 350 in the wet/bumpy tracks. Clio cup race cars run 500lb rears.
Golf GTi cup cars run up to 1500 all round lol
C612DNM
18-10-10, 09:46 PM
Clio cup race cars run on slicks, which is a different ball game.
On slicks you can go up dramatically on the spring rates. Road tyres just can't handle that level of spring rate, and let loose.
For example, a slick setup (190 x 15" Dunlops) on my GSi was for between 600 and 750lb fronts, and 775 to 950 rears.
I wouldn't dare run those road tyres, it would be undriveable.
350's (coil-overs) with 225 x 16 Toyo888's would work.
Coupled with 375's at the front with a 1600 engine.
It's all conjecture, because to get the best setup, you need to test, tweak, try, test again, etc...
spanishfly
18-10-10, 09:54 PM
spanish, what did you run on the front?
280-90. Was under the 300 everyone says you need.
spanishfly
18-10-10, 09:57 PM
It's all conjecture, because to get the best setup, you need to test, tweak, try, test again, etc...
exactly, however if someone has a similar setup then you can steal ideas. Ultimately you need to play yourself as everyones idea of a good setup car is different.
I always say a good starting point on a trackday nova is around 300 front 350 rear and then go from there. Personally I liked 280-290 front and 450 rear, that was with dunlop direzzas.
BTW people I have a pair of brand new 1.9" 450lb springs for sale in the sales forum:D
C612DNM
18-10-10, 10:02 PM
Dunlop Direzza's - ahh sticky trackday tyres!
Softer fronts tend to make it turn in well, and with the 450's being coilovers, I reckon that's a good sounding setup.
What ARB are you using front/rear?
spanishfly
19-10-10, 06:45 AM
None front as was on full adjustable rosejointed setup. Castor was at +4.5. Rear was a GTE arb. Twas good.
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