Track Suspension

[largeorangefont]

Originally Posted by Tamago

which is kind of unfortunate as it leaves you with 3/4 of your total grip..

There is no weight on that tire anyway in that situation. It will last longer if it is in the air. :)

[largeorangefont]

Originally Posted by Loren

If? This is a situation that anyone who's going this far with their suspension needs to PLAN on. The young guys working course at the BMW club autox I went to last weekend were calling me "tripod" at the end of the day!

The inside rear wheel will be in the air more than it's on the ground unless you're going straight.

You are right, how silly of me. It should look like an old GTI out there.

[Loren]

Originally Posted by largeorangefont

It is not that, it is dips at speed we are talking about. Potholes are a good example. At speed a softer, longer travel suspension would allow the wheel to drop into the hole and on hole exit the suspension would absorb the impact with bump travel.

Instead the entire weight on that wheel falls into the pothole, you feel the car drop into the hole. This takes weight off the opposite front tire and slams that weight back up and onto the opposite front again upon exit of the pothole. It would feel very jaring.

The solution to that would be a progressive spring, or a stack of springs designed to be progressive. I figured out how to do this on my Miata, but ultimately decided it was too expensive to bother with. You have to buy two springs instead of just one, and then you have to buy the couplers to go between them (unless you're really confident that your math is correct, then you could just weld them together).

For the back of the Yaris, if you did something like stacking a 6" 400# spring with a 2" 200# spring, the low rate spring would be mostly compressed under the weight of the car and as soon as you entered a turn, the outised spring would coil-bind and give you the 400# rate that you want for cornering. The inside spring would extend, giving you the full effect of the two springs, which nets a nice, soft 133# rate that would be in effect when that wheel came down to smooth things out.

Ground-Control sells the springs you'd need to do that if you wanted to go with 2.5" ID springs.

[Loren]

Originally Posted by Tamago

which is kind of unfortunate as it leaves you with 3/4 of your total grip..

Yes and no. You're optimizing the grip at the front of the car where you need it by taking weight off of the rear of the car. If you want that extra 1/4 of grip that you "lost", run wider tires in the front!

You're not really losing any grip, though. The overall cornering potential of the car goes up. You're taking grip away from the rear where it wasn't needed and transferring it to the front where it was.

[Tamago]

Originally Posted by Loren

Ground-Control sells the springs you'd need to do that if you wanted to go with 2.5" ID springs.

ground control utilizes eibach :) so you may be able to source them cheaper thru someone else?

[largeorangefont]

Originally Posted by Loren

The solution to that would be a progressive spring, or a stack of springs designed to be progressive. I figured out how to do this on my Miata, but ultimately decided it was too expensive to bother with. You have to buy two springs instead of just one, and then you have to buy the couplers to go between them (unless you're really confident that your math is correct, then you could just weld them together).

For the back of the Yaris, if you did something like stacking a 6" 400# spring with a 2" 200# spring, the low rate spring would be mostly compressed under the weight of the car and as soon as you entered a turn, the outised spring would coil-bind and give you the 400# rate that you want for cornering. The inside spring would extend, giving you the full effect of the two springs, which nets a nice, soft 133# rate that would be in effect when that wheel came down to smooth things out.

Ground-Control sells the springs you'd need to do that if you wanted to go with 2.5" ID springs.

I have not taken any measurments, but I dont think there is enough room to do that with 2.5 ID springs as we would need perches as well. I think the whole thing would coilbind over bumps, which is fixing one problem and creating another. I would rather have a droop issue than an compression issue. I have no problems living with the horrible street manners of a track spring and damper setup however.

That would absolutely solve the problem if there was room to make it to work.

[Loren]

Originally Posted by largeorangefont

That would absolutely solve the problem if there was room to make it to work.

Nah, I don't have much problem with it, either. :) I just run the rear shocks softer on the street and call it good.

I just wanted to throw that out there as an example of what can be done if a person were so motivated.

[largeorangefont]

Originally Posted by Tamago

ground control utilizes eibach :) so you may be able to source them cheaper thru someone else?

Hypercoils may be cheaper.

I used to know a place that sold lightly used springs from race cars, eibach and hypercoils for cheap. I'll see if i can dig it up. They wanted like $30 per pair.

[largeorangefont]

Originally Posted by Loren

Nah, I don't have much problem with it, either. :) I just run the rear shocks softer on the street and call it good.

I just wanted to throw that out there as an example of what can be done if a person were so motivated.

I dont have that kind of motivation.

[kngrsll]

wow, this thread really took off! Ok, ill read and contribute if i can, but i have a ton of work to do tonight!

[Tamago]

well, after having Steve at Ground control dick me around for 3 days like he was gonna actually be helpful, he gives me a canned-bullshit "we no longer carry an application for your vehicle" answer. i'm now stuck with Ksport rear perches/springs on special order, and nothing for the front of my car.

thanks again, ground control. you've dicked me over for the last time. i'm again reminded why i quit doing business with you back in 2003

[kngrsll]

Originally Posted by Tamago

well, after having Steve at Ground control dick me around for 3 days like he was gonna actually be helpful, he gives me a canned-bullshit "we no longer carry an application for your vehicle" answer. i'm now stuck with Ksport rear perches/springs on special order, and nothing for the front of my car.

thanks again, ground control. you've dicked me over for the last time. i'm again reminded why i quit doing business with you back in 2003

they wont even sell the front set (that had NO issues??)

[Tamago]

Originally Posted by kngrsll

they wont even sell the front set (that had NO issues??)

per Steve,

"we don't have the spec sheet on these parts"

what kind of fly by night company doesn't keep drawings for past products? simply retarded.

it looks like i'll be doing this:

http://qa1.thomasnet.com/item/motors...10&plpver=1001

[kngrsll]

Originally Posted by Tamago

per Steve,

"we don't have the spec sheet on these parts"

what kind of fly by night company doesn't keep drawings for past products? simply retarded.

it looks like i'll be doing this:

http://qa1.thomasnet.com/item/motors...10&plpver=1001

thats really suprising... oh well...