Coilover springs: keeper springs

[crispy'86]

I did a search and didn't come up with anything conclusve with this. So.......Are keeper springs a hinderance or a help. I'm running some in my race car and suspect they maybe more of a nuisance than help, can anyone give me any advice of what length spring to use so the car still sits nice and low. Bear in mind my current setup is 225mm spring and about 75mm keeper spring. when i put my race wheels on the front has a 40-50mm gap between guard and tyre, this may npot be helping me in the handling deparment. SO what length spring would be best to give me enough adjustment both if i need to lower it or raise the car slightly. I know i'll probably need to machine my shocks if need be to make springs captive

[drift-monkey]

keeper springs are just to keep the springs captive at whatever height the sleeve is wound too, they are fully compressed when the weight of the car are on them so i dnt see how they could be too much of a bad thing, if u want it a tad lower and donbt mind shortening your shocks id just get rid of your keeper springs and thatd prob take 30mm out

[Distrb]

whats the compressed height of the keeper spring?

How far up your coil sleeve is your platform at full droop?

How high do you want the car to sit?

[Bazda]

If you take out the keeper springs you will have less droop.

As you will have less compression in the spring.

I dont run them in my car and I only got around 30mm droop front and rear.

If I run keepers I can double the droop and keep the same height.

The good thing about keepers is you can get them in different rates and say for the first xxmm of travel the car will feel like xxlbs then when you push the car further the spring will work more and the keeper will fully compress say, and the main spring will be doing the work.

[crispy'86]

Well i experimented with winding the coilover springs up to give a bit of pre-load on the keeper springs and that equalled understeer everywhere. Thats the main reason why i want to trial it without using keeper springs. Possibly cause the car sits too high would be more the reason it understees. Anyways, compressed height of keeper spring is about 50mm approx, (can't get accurate measurement) platform is wound right down to the bottom of the sleeve and want height to be pretty close to the rear at about 295-320mm from bottom of guard to sentre of wheel. I'm yet to actually measure exactly what the best height would be. At a rough guess maybe 250-280mm coilover springs and some machining of shocks would be best but. it's all about experimenting. Anyone got any springs i could borrow to try out?

[fivebob]

Anyways, compressed height of keeper spring is about 50mm approx

WTF are they made of and how many coils are they??

Most keeper springs are about 2-4mm max thick flat section and about 3-5 coils, so they wouldn't be more than 15-20mm when compressed. IIRC the ones on my Teins are about 12mm compressed.

If your ones are really 50mm compressed then they can't be proper keeper springs

[fivebob]

Here is what a keeper spring should look like.


They should be fully compressed with the static weight of the car on them, and pay no part in the suspension except to act as a thin spacer. Their job is to keep the springs tight on the seats, nothing else.

[ChaosAD]

The keeper springs are just to keep the main springs captive.

To need them you would obviously have no preload on the main springs.

You could remove the keeper springs and shorten the shocks to keep it captive, but then when you adjust the height you will also adjust the preload.

[85AW20v]

If your race car isn't road registered you don't need them at all as the weight of the car will keep the coil spring sitting in the right place - well it does on my AW anyway. If I jack up the rear the suspension goes to full droop and I've got about 30mm between the top of the spring and the ali hat it seats on. Playing about, I'd take the keepers out, adjust it to whatever height you're comfortable with and go from there.

I will say though, that I've got a 25mm difference from rear to front in the AW and when I lowered the rear to level the car, it understeered like a pig. Put the 25mm back into the rear and it came right. I've also made my swaybars adjustable by welding drilled tags along the top edge and playing with those can make a big difference too.

[crispy'86]

I haven't measured the compressed length of keeper spring with weight of car on ground

So what would be better. to leave shocks as is and have x amount of travel in them or shorten them a little so i have enough adjustability without affecting the preload on spring?

Might just do some trial and error with this one, anyone keen to lend me some different length springs to try?