Spring rates - Mk2 Race Series

Hi all
How can I work out what spring rates to go for?
I'm new to this, I've got a E reg 16v which I will be stripping out to the regs limit i.e 1025kg IIRC

I will be getting a set of GAZ coilovers (using my/our discount)


Also can we use a windage rather than a baffled sump?

Any info would be good.
Thanks
Olly

 

As a hopefully new driver in the series I had the same question a while back and got a lot of good ideas

http://www.clubgti.co.uk/forum/showthread.php?t=131951

In the end I sort of copped out, most seem to recommend 350lb for the front which is what I went with and in the end I just went to sort of the mid point of all the recommendation and went for 350lb also on the rear. Bearing in mind you can buy just springs from Gaz at a later date if you want to.

My 16v has a windage tray as standard but it is an 89, but I think your should have one already?

Maybe someone else can confirm that..

 

Thanks for the reply, that was a good read. might try 350 front and 280/300 rear.
Anyone else got any views?

 

You wont be far out at that.

I would use as baffled sump instead, or aswell as a windage tray.

A windage tray only keeps the sump oil away from the crank to reduce drag/aeration, it doesn't stop the oil from running away from the oil pick up so you still risk running a bearing....especially at mallory!

 

If you need a windage tray pm me and I can bring one to Snett. I've got the longer bolts too. All brand new VW parts.

 

Does anyone have a drawing or information on where/what size/ shape baffle to fit?

 

Regarding baffled sumps

If you can provide the sump we can baffle it for you, we have done a few now-call it 20 to cover materials and we'll send it bk to you! We have a sump to copy from. Let me no if this of any interest.

Rich + the Bristol possy!!

 

Thanks for all the offers.

I only live in stroud so could drop it in one some time.
The car is not in my posetion at the mow (no MOT so can't get it home) but when it is i'll give you a call/PM


H5LRW I need to check if mine has one if not i'll give you a PM.

 

OK back to the springs.....
I'm just about to order mine and I've been talking to lots of people and am still getting mixed answers.
Now some people are saying i should run 500lb for the rear to make it realy stiff so it helps kick a wheel up and would make it drive like it has a big ARB on.
Any more views on the rear set up would be nice.
Olly

 

As far as I knew the windage trays come from GTD's and werent ever fitted to Gti's.

If you do go for one, get the Mk2 GTD one, it also has the built in gasket.

 

Got one in my shed begging to be fitted!

 

why so soft on the spring rates? that is like the very low end of the rates i ran on my mk1, and the rates ive seen run on mk2's are in the 600lb (fr) 450/500lb rear. currently i run 450/350 an intend to go up another 100#'s once i get some proper shocks.

 

Your spot on with your rates 600 fronts and 450/500 rears

 

I've just done some simple calcs and the 350 lb/in all round sounds about right.

But thats without taking ARB's into consideration and assuming a chassis frequency of 2 Hz (which may be a little on the low side for a track car).

 

Hi mate thats a bit on the low side and when using high poundage springs the roll bars dont come into play too much either and if your using slicks then then id go 100lbs higher all round.

 

I know mate thats why I said the calculations are with a chassis frequency of 2 Hz. And that was with R888's being used with an assumed K = 400 ib/in. Slicks are more like 600 lb/in.

I didn't know who if anyone would actually be interested in working this out mathematical, so I didn't state any of my assumptions.

With a frequency of 2.2 Hz the spring stiffness would be more like 500lb/in all round.

Where are you getting your figures from?

 

Hi Sean, my figures are just from spending a lot of time with people who specialise in chassis set and having a knowledge of FWD race cars.

Are you intending to put the same poundage springs all round.

 

I'd be interested to know how to calculate spring rates. Any pointers?

 

Baffled sumps on the cheap...

http://www.clubgti.com/forum/showthread.php?t=119894&highlight=baffled+sump