Building a S2 mk2 golf

[re2500]

Thanks for the info Andy, Yes I have KW V2's. You say 60N/mm up front, any idea about the rear? I can see the car doing a lot more track action so maybe springs is the way to go.




The driver of a Mitsubishi rally car came and had a word with me also, his excuse was "we're not allowed to use antilag here"

FYI My KW V2's have the same springs front and rear...

[re2500]

Sorry missed the prior posts, mine's a coupe, so the info above wont help you, sorry...

[Rusty]

Based on the coupe, the OE springs are about 5% stiffer at the rear. KW in their wisdom run 15% stiffer front springs on the high axle load setup What some have done is to swap the front and rear springs, so that the rear is then uprated

To keep the car supple, try to get it handling properly with stock or even smaller roll bars and then use the adjustable roll bar to fine tune the handling. Stiff bars are for road cars really, as they remove grip from an axle rather than add it, so there are better methods. There's also the suspension geometry that needs to be considered. Not sure how adjustable the rear of the avant is but the coupe is fully adjustable and suspension squat causes it to change a bit too.

[gnutz2]

*****, I'm confused

Stiffer springs, stiffer ARB's or both?

I'm thinking, upgrade the springs to 500lb front 550lb rear and fit adjustable blade ARB's so i can fine tune from there.

The car weighs 1160kg with no driver.

Camber is not a problem, i can adjust that.

Cheers Baz

[Rusty]

You'll need to find out what the original rear stiffness is before choosing the rear rate.

If you get stiff springs then you'll not be relying on the roll bars to keep the car flat, so they're more of a fine tuning device, so no need to go mental on them, like some do with road cars.

[gnutz2]

Right i've been reading a book (dangerous i know ).

First on the list to do is check my corner weights, figure out my sprung mass per corner and then figure out what wheel rate i have now. From a quick calculation i roughly guessed 500lb per front corners on 350lb front springs which works out at 157cpm. This does sound high so i'll have to stop guessing and get the car properly weighd.

I was thinking about 120cpm up front and 135cpm at the rear for a starting point.

[Amit]

Great big side intakes


Cheers Baz.

Have you tried this setup the other way round with the scoops sticking out but the openings facing the rear?

To me, you current setup looks like it will be pushing air under the car creating high pressure zone behind the rear wheels, where you want a low pressure zone to draw the air back and out creating more down force.

Other way round, and the fast moving air over the car will cause a vacuum behind the vent openings causing the air to be sucked through the rad.

Amit

[gnutz2]

Have you tried this setup the other way round with the scoops sticking out but the openings facing the rear?

To me, you current setup looks like it will be pushing air under the car creating high pressure zone behind the rear wheels, where you want a low pressure zone to draw the air back and out creating more down force.

Other way round, and the fast moving air over the car will cause a vacuum behind the vent openings causing the air to be sucked through the rad.

Amit

Hi Amit. One of the reasons for fitting the spoiler was to create low pressure behind the car and more air flow under the car, couple this with the high pressure from the submerged side scoops and it seems to be pretty efficient.

IMO the best exit for the rad would be the back of the car, massive low pressure zone (especially with the spoiler), this is confirmed with all the muck that sticks to it, but i want to keep the back of the car looking standard(ish).

The setup is yet to be tested in summer so watch this space.

[gnutz2]

Put the car on the weighbridge today, to try get some idea of corner weights and front to rear balance.

The car weighs 1160kg, 720kg of this is on the front axle meaning there is a 62/38 split front and rear. Unfortunately the weighbridge is only accurate to 20kg so when I did the the corner weights they worked out at 360/ 360 front and 200/200 rear. More resolution would be better but at least all 4 corners are within 20kg.

Next test is to get hold of some scales and measure unsprung mass on the corners, then I can work out the sprung mass and get some idea of what spring rates I need.

Anyone know the weight distribution of an audi s2?

Cheers Baz

[Rusty]

S2 is about 950kg front, 600kg rear.

[andy10v]

My 3b with some minor lightening was

Front 910
Rear 580
Gross 1490 (100kg driver)

[terrybullwon]

mine is

336 335

219 247

Thats with a 25kg drum of fuel

And i weigh 70kg the weight then ends up 20Kg heaver over the right front.
This is with the car set up

[gnutz2]

Thanks for the replies

That's a light coupe you have there James. It's the same weight as the s2 golf before i swapped polycarbonate for wind down glass in the front. What spring rates do you have on your coupe James?

[terrybullwon]

Afraid my spring rates won't help you as I am on a different type of damper.

But it's 120nm front and rear

[terrybullwon]

686lbs in English money