Spring rates

[breitlingboy]

I'm currently prepping another 320 for the MILTEK series. I've just sold my first one - that was running on Spax adjustables with their standard springs. The front runners in the series are running Leda coilovers.
My new car is going to be running coilovers but I've not got the first idea about what spring rates to go for. I've spoken to a few suppliers who all seem to give conflicting advice. Some have said go for an even spring rate on the front and rear. Others have suggested a 30% softer front compared to the stiffer rear and the latest one has suggested stiffer front and 30% softer rear.
I know the racers won't want to give away their closely guarded secrets but any advice would be great as I don't know which way to go.

[JimmyC]

that makes 2 of us then Mike

[breitlingboy]

Hi Jimmy,

I've ordered mine now but need to decide on spring rates. They'll do you a decent price - I managed to knock a bit extra off.
How's the car coming on?

[JimmyC]

I hate sound proofing and I hate sound proofing glue even more

Apart from that its coming along nicely, almost finished gutting the inside, got my bonnet pins on the other day to give me a break from the stripping

Got the added complication of having a water leak into the footwells at the moment- not sure where from?? sure all will become apparent when the dash comes out

what did you go for in the end? and hows yours going?

[breitlingboy]

Stripping is a pita - I found a heat gun softened it up nicely. Then cleaned the remnants off with petrol. A quick coat of spray paint and it looks good as new
Bet you didn't find as many fooking holes in the floor as I did - my welding is improving but still not v pretty.
Will u2u on Seloc re the dampers/etc.

[Taffy]

depends on what you like soft or hard set up, try out their recommended poundage & see how you get on.

[karlp]

The best person to ask about spring rates is Dave Kear - he prepares cars all the time.
If you are taking your car to him to get the cage done then simple question.

He has given me quite a bit of advice and even saved me a load of cash.

Karl

[breitlingboy]

Cheers Guys

[davemullender]

Water leak in the footwell is from the cooling matrix. Now's the time to fix it if you're going to bother because its behind the dash and once you put a rollcage in you're gonna have problems getting the dash out.

You might be lucky and it'll be just a pipe loose, or alternatively it could be the matrix itself.

[calder]

water leak could also be from sunroof - mine still does

[stappin]

water leak in the passenger foot well could be from the bulk head electrical rubber.

[JimmyC]

cheers guys, the car is bear now, so will be water testing once the cage is in, and hopefully find the leak

[Lloydie38]

I've just stripped out my 1988 E30 325i and both the two front footwells were rusty in the offside corners (near excelerator and left foot of passenger). I was able to easily remove the rust - straight through to see sunlight . The rust is from the outside coming in as the carpet and sound deadening material is not marked and does not show signs of water damage. Also a couple of holes in the drivers footwell the size of a 1p coin. I have just been to a local bodyshop I know and they have quoted Ԛ£120 to sort it for me which I'm with.

Apart from that the car is sound. In bodyshop on the 23rd so I need to get some work done on Brakes / suspension before then.

Any advice on which model of Bilsteins for Track use? Hard ride sir? YES PLEASE! I want it to handle not be comfy like a cardigan!

Cheers

[JimmyC]

I'm going for a GAZ coilover setup on mine, the feedback from a few people is very very positive and they are spitting didtance from where I work- quite good price from all acconts too

[lancelot]

Hello Guys, new to the forum, but an old hand at setting up cars for track use.

My e30 M3 runs Leda's for track and road. I use 550lb/225lb springs front to rear. stock ARB's and ususally run the dampers at about 21/19 for dry use (with R compounds). Bear in mind that mine is a road car so still has trim, with a lighter car those rights will effectively be higher as you have less weight to control.

HTH

[breitlingboy]

Thx for the info re spring rates etc. I take it your leda's are coilovers on the rear? How'd you find the understeer with running that stiff spring rate on the front?
Had to put the coilovers on hold until later in the year. Ended up with koni race dampers and old spax springs for the time being. Took it out to Oulton Park last week, performed really well when running soft ish, when stiffened up, the back was bouncing around. Got a race there on 24th, can't wait

[dazleeds]

breitlingboy

glad to hear you got car up n running mate

[lancelot]

Thx for the info re spring rates etc. I take it your leda's are coilovers on the rear? How'd you find the understeer with running that stiff spring rate on the front?

Very little understeer, the car is extremely neutral, I also run Kmac adjustable camber plates with 2 degrees neg dialled in. Without additional camber any e30 is going to suffer understeer, especially if you have that big straight 6 up front.

[breitlingboy]

breitlingboy

glad to hear you got car up n running mate

Complete with your lip spoiler and lower valance Cheers Daz

[Taffy]

550lb/225lb springs front to rear, wow i'm suprised you don't have shedloads of understeer, we run 425 on the front & 275 on the rear & i think the front is too stiff and we run -3deg camber & the ARB is set to soft

[breitlingboy]

I'm glad you said that Dom - I thought exactly the same but hey, I'm no expert.
Put the new car out at Oulton last week and it felt much better balanced when being run soft.

[Taffy]

Soft = more grip but too soft = too much roll and weight transfer which = less grip

[lancelot]

Very, very little understeer, especially if I start to wind the rear dampers up to close to the fronts. So as you get closer, the car goes more neutral, to bordering on oversteer. Ultimately, the car will understeer if you drive like a clown but basically it's pretty good.

[breitlingboy]

[quote= Ultimately, the car will understeer if you drive like a clown[/quote]

thats prolly a good description of me

[Taffy]

You can sleep in your car but you can't drive your house! Sorry, just wanted to add