Ground Control Coilover rates

ElectricEnergy · 05-14-2009, 07:30 PM

I'm looking at my options for the suspension setup in my mk1. I'm interested in the Ground Control sleeve/Koni Sport strut combination. Adjustability is good, and I like the idea of linear springs. I'm just not sure what spring rates to go with. What are other people doing? And does anyone have any first hand experience with these coilovers that they could share? I've been searching around and can't find the information I'm looking for.

This is a street car, but I'm building it to be fun, and it will see a lot of solo1&2.

Thanks in advance.
David

mach5mr2 · 05-17-2009, 10:34 AM

I ran 200/325 with ST sway bars for a while and it was a good setup for street, twisties, and so, so for auto-x. I switched to 400/450 with a stock front sway bar and no rear bar and it is much better for auto-x, but a bit stiff for the street. I don't daily drive it, so it is fine for me. It also has an aggressive auto-x alignment that includes a lot of toe out in the front.

John

ElectricEnergy · 05-17-2009, 01:51 PM

Is there a magic ratio for the front/back rates? I imagine going from 200/325 to 400/450 would change the balance of the car significantly. Should I maintain the same front/back ratio as stock, but just stiffer? Or is there room for improvement?

jaysgottavtec · 05-17-2009, 01:55 PM

Quote:

Originally Posted by ElectricEnergy

Is there a magic ratio for the front/back rates? I imagine going from 200/325 to 400/450 would change the balance of the car significantly. Should I maintain the same front/back ratio as stock, but just stiffer? Or is there room for improvement?

in for an answer to this

mach5mr2 · 05-18-2009, 02:00 PM

The magic ratio is related to the overall roll rate of the front to rear, based on the weight distribution. Hey, could I be more vague ? J/K Anyway, the springs and swaybars work together to give the car its roll rate. They are the main contributors. Alignment, strut settings, tire pressures, etc also contribute to the balance of the car.

With the 200/325 setup, I had ST sways with the front in the middle hole and the rear on the soft setting, although the ST rear bar is stiffer on the soft setting than the stock rear swaybar. I had to run the front Konis a little stiffer than the rears and it was very balanced.

I changed to the 400/450 setup with the stock front swaybar and no rear bar, and it is very balanced once again.

More spring and less swaybar is not as comfortable, but it does seem to respond more crisply. There is a long thread on the other board in the auto-x section hosted by XHead - Steve. He is a multi-time national champ and knows his stuff. What I have tried so far has made my car better.

The front roll rate needs to be higher than the rear on the MR2s, by 50% or so. If I ran with no swaybars, I would need something like 700 front, 450 rear. My alignment for auto-x makes the car rotate more than usual, so I need even more roll rate in the front to balance it out.

I have driven in a car that has 350/450 with just the stock front bar and it is balanced as well.

Before you pick the spring rates, you definitely need to determine what swaybars you want to run.

John

ElectricEnergy · 05-18-2009, 06:11 PM

Very informative post, thanks. I think I'll go with the ST swaybars and lighter spring rates since that should give me a little better ride quality than just having super stiff springs.

I'm pretty excited, I've never had a car with as much adjustability as this will have.

Tin_le004 · 09-08-2011, 10:35 PM

For street x 0.5

(Weight x weight dist. % x 0.5)/2 = lb/inch ratio

Soo without driver (2350 x 0.55(rear dist.) x 0.5)/2 = 325.125lb/ inch = 5.78kg/mm
Front : (2350 x .45(front dist.) x .5)/2 = 264.375lb/inch = 4.73kg/ mm

For track it is 0.75

Oops ive digged up the graveyard

05-14-2009, 07:30 PM	#1 (permalink)
ElectricEnergy No Skills Join Date: Apr 2009 Location: Saskatoon Posts: 20 Thanks: 1 Thanked 0 Times in 0 Posts My Google Map iTrader Rating: (0/0% )	Ground Control Coilover rates I'm looking at my options for the suspension setup in my mk1. I'm interested in the Ground Control sleeve/Koni Sport strut combination. Adjustability is good, and I like the idea of linear springs. I'm just not sure what spring rates to go with. What are other people doing? And does anyone have any first hand experience with these coilovers that they could share? I've been searching around and can't find the information I'm looking for. This is a street car, but I'm building it to be fun, and it will see a lot of solo1&2. Thanks in advance. David

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05-17-2009, 10:34 AM	#2 (permalink)
mach5mr2 93T, 88 SC Join Date: Apr 2008 Posts: 107 Thanks: 0 Thanked 10 Times in 9 Posts iTrader Rating: (2/100% )	I ran 200/325 with ST sway bars for a while and it was a good setup for street, twisties, and so, so for auto-x. I switched to 400/450 with a stock front sway bar and no rear bar and it is much better for auto-x, but a bit stiff for the street. I don't daily drive it, so it is fine for me. It also has an aggressive auto-x alignment that includes a lot of toe out in the front. John

05-17-2009, 01:51 PM	#3 (permalink)
ElectricEnergy No Skills Join Date: Apr 2009 Location: Saskatoon Posts: 20 Thanks: 1 Thanked 0 Times in 0 Posts My Google Map iTrader Rating: (0/0% )	Is there a magic ratio for the front/back rates? I imagine going from 200/325 to 400/450 would change the balance of the car significantly. Should I maintain the same front/back ratio as stock, but just stiffer? Or is there room for improvement?

05-18-2009, 02:00 PM	#5 (permalink)
mach5mr2 93T, 88 SC Join Date: Apr 2008 Posts: 107 Thanks: 0 Thanked 10 Times in 9 Posts iTrader Rating: (2/100% )	The magic ratio is related to the overall roll rate of the front to rear, based on the weight distribution. Hey, could I be more vague ? J/K Anyway, the springs and swaybars work together to give the car its roll rate. They are the main contributors. Alignment, strut settings, tire pressures, etc also contribute to the balance of the car. With the 200/325 setup, I had ST sways with the front in the middle hole and the rear on the soft setting, although the ST rear bar is stiffer on the soft setting than the stock rear swaybar. I had to run the front Konis a little stiffer than the rears and it was very balanced. I changed to the 400/450 setup with the stock front swaybar and no rear bar, and it is very balanced once again. More spring and less swaybar is not as comfortable, but it does seem to respond more crisply. There is a long thread on the other board in the auto-x section hosted by XHead - Steve. He is a multi-time national champ and knows his stuff. What I have tried so far has made my car better. The front roll rate needs to be higher than the rear on the MR2s, by 50% or so. If I ran with no swaybars, I would need something like 700 front, 450 rear. My alignment for auto-x makes the car rotate more than usual, so I need even more roll rate in the front to balance it out. I have driven in a car that has 350/450 with just the stock front bar and it is balanced as well. Before you pick the spring rates, you definitely need to determine what swaybars you want to run. John

05-18-2009, 06:11 PM	#6 (permalink)
ElectricEnergy No Skills Join Date: Apr 2009 Location: Saskatoon Posts: 20 Thanks: 1 Thanked 0 Times in 0 Posts My Google Map iTrader Rating: (0/0% )	Very informative post, thanks. I think I'll go with the ST swaybars and lighter spring rates since that should give me a little better ride quality than just having super stiff springs. I'm pretty excited, I've never had a car with as much adjustability as this will have.

09-08-2011, 10:35 PM	#7 (permalink)
Tin_le004 Clueless Join Date: Jul 2011 Location: San jose CA Posts: 131 Thanks: 8 Thanked 2 Times in 2 Posts iTrader Rating: (0/0% )	For street x 0.5 (Weight x weight dist. % x 0.5)/2 = lb/inch ratio Soo without driver (2350 x 0.55(rear dist.) x 0.5)/2 = 325.125lb/ inch = 5.78kg/mm Front : (2350 x .45(front dist.) x .5)/2 = 264.375lb/inch = 4.73kg/ mm For track it is 0.75 Oops ive digged up the graveyard