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Author Topic: trackday coilovers, what kg?  (Read 116 times)

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Offline Pingman

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trackday coilovers, what kg?
« on: November 17, 2017, 07:48:17 am »
Hey guys,

My tuned mk2 16v came with the budget Prosport coilovers but I find them a bit soft/body rolley on a track day. The BC racing adjustable damping units look good for their price point but unsure what spring kg to run and they come in so many options, any advice please? (I also already have eibach sway bars front and rear)

front/rear

5/4kg/mm
5/6kg/mm
6/4kg/mm
7/5kg/mm
7/9kg/mm
7/10kg/mm
8/10kg/mm
9/8Kg/mm
10/8kg/mm
11/9kg/mm
12/10kg/mm

help appreciated!

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Offline RobT

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Re: trackday coilovers, what kg?
« Reply #1 on: November 17, 2017, 09:02:22 am »
Hi - there are lots of views about this and many things affect it.

But to begin 1kg/mm = 56lb/in which are units something a lot more people are familiar with.

With a golf, the key to handling is to prevent loss of front negative camber in roll, and front nearside compression. This can be done in many ways - suspension geometry, anti-roll bars, reducing the weight of the car, spring rate, damper characteristics (primarily low speed bump).

Putting rock hard springs on is a simple way to achieve this but traction will suffer as the tyre wont be able to ride the bumps. If you drive on super smooth tracks then that's less of an issue.

If you use slicks, you will have more grip which will lead to more roll and correspondingly you will need more tactics to counteract that roll.

I cannot remember the exact figures but I will dig them out tonight for my sprint Ibiza - this ran on big sticky slicks and didn't roll much at all towards the end of development, but equally was not super stiff, rode the bumps well, and was a proper weapon in the rain.

Cheers

Rob
2008 Audi A6 2.0TDI S-Line
2004 Audi A4 Avant 1.8T Quattro S-Line
1996 Seat Ibiza 16V F1.5 Race car

Offline Pingman

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Re: trackday coilovers, what kg?
« Reply #2 on: November 18, 2017, 03:37:04 am »

Hi Rob,

Thanks for quick reply,
I'm good with kg/mm, though actually not good with the old lb/in lol
Your figures could well help and will give me a starting point, how much did the car weigh would help too.
I'm no on slicks, on 'semi slick' track day tyres - RSR595s

Here's the evident 'roll' at brands going through druid:






Offline RobT

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Re: trackday coilovers, what kg?
« Reply #3 on: November 19, 2017, 07:59:10 pm »
Info here

http://clubgti.com/showthread.php?263043-Advice-on-springs-please-ibiza-6k2-track-car

I've sold my Ibiza now but basically I ended up with about 400lb front springs, 250lb rears, 25mm Eibach rear ARB, and an adjustable front ARB which went from about 50-150% what a 28mm regular bar would do. About -2 front and -1.5 rear camber. Slight toe in at rear, parallel toe at front. Custom drop-pin in the upright to raise the front roll center. Car was set up on corner weight scales for even weight distribution. It drove lovely - plenty of traction, rode the curbs and bumps well, didn't roll much at all even on sticky slicks.

Think the car ended up around 900kg, would have been around 60% frint.

Cheers

Rob
2008 Audi A6 2.0TDI S-Line
2004 Audi A4 Avant 1.8T Quattro S-Line
1996 Seat Ibiza 16V F1.5 Race car

Offline Pingman

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Re: trackday coilovers, what kg?
« Reply #4 on: November 24, 2017, 07:22:33 pm »

Cheers Rob, that's some good info.

matches up near enough to BC Racing's 7kg front 5kg rear listed track spring rates.

Where did you get the adjustable front ARB? not seen on of those before!

Offline RobT

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Re: trackday coilovers, what kg?
« Reply #5 on: November 24, 2017, 08:49:10 pm »
I had it made.
2008 Audi A6 2.0TDI S-Line
2004 Audi A4 Avant 1.8T Quattro S-Line
1996 Seat Ibiza 16V F1.5 Race car

Offline Pingman

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Re: trackday coilovers, what kg?
« Reply #6 on: November 25, 2017, 01:58:14 pm »
I had it made.

Sounds very interesting, is it a rally 'blade' style in car adjustable one? or more a fixed one with different holes you can move too on the bar itself? would be interested to see photos of it if you have any.

 

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