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Discussion Starter #1 (Edited)
What ride height and where is it measuring it from (subframe,rocker panels)? I'm not asking for secrets just some baseline stuff (rake,etc.). Are there any tips for setting up coilovers for the first time? Most references are up and down a couple of inches but from what? My car is a b-13 and has 325/275 spring rates.
 

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sleeper
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Hmm.. I'd say as low as you can go without bottoming out. I'd dial in around -2.5 degrees of camber to start with on the front. Going too low though adds stress to the axles as it puts them at a severe angle.
 

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start high and go lower to dial it in. For reference, which shocks and coilovers do you have? That will make a difference in recommended ride height I think. Like Matt said, suspension travel is your friend.
 

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Discussion Starter #5 (Edited)
This is too simple of a question. The difference in height between front and rear. Height needs to be measured some where so it can be referrenced. Do you people use fingers or actual math. Nobody has yet to understand. I know travel is your friend but If don't know exactly where is was then "bad" changes can't be corrected. I'm 6 3/4 " in the back and 6 1/4" in the front, measured from the jack points on the rocker panels, which is a .5" of rake. My includes; GC's and shortened konis. Also if an enlightened one sees this, How much change in toe and camber through the travel range of the suspension front and rear.
 

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rex said:
Also if an enlightened one sees this, How much change in toe and camber through the travel range of the suspension front and rear.
Haha, we ignore bump steer and just put on springs so stiff it doesn't make a difference. 650/500 is a popular combo these days. In the SE-R Cup, there's not much you can do to change the bump steer curve, so we just try to limit travel and have had a fair amount of success with it.

If you get a bump gauge, let us know. :)

The more rake the better, but better isn't really that much. You're not going to get that much out of a lot of rake unless you have an aggressive front aero package. And then you are just lowering the front more closer to it lower limit on bottoming out and stressing axles. We run almost no rake in the Cup car. It is basically a brick- you're not going to gain that much by tipping a brick slightly into the wind.

But by all means get your car corner weighted after you adjust the height. That will make more difference than a change in ride height or rake in our cars.
 

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rex said:
I'm 6 3/4 " in the back and 6 1/4" in the front, measured from the jack points on the rocker panels, which is a .5" of rake.
Koni 8611s? Your rake is ok, but I'd experiment up to 1.5 or 2 inches lower, by driving and zip tieing the shock shaft. When you change the ride height, check the axle angle. Our axles are higher on the ouside, maybe at a 15 or 20 degree angle.

Rmember to corner weight after you get your ride height dialed in or you'll offset whatever gain you got with poor balance. That's where the real strength of the coil overs comes in- getting good balance.
 

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Discussion Starter #8
Thanks DriveNASA for the "meaty" info. The brick made me giggle. The rake just looked odd to me. I guess I should disregard slight variations to ride height when corner weighting and I'll go try the zip-tie method.
 

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Ironman
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You should measure at the rocker panels (not including the "pinch" where the panels are joined) IMHO. That is what the SCCA goes by for IT. It allows for plenty of consistency as well.

Be careful going too low with a B13. As Kheim said, if you go too low you will adversely stress the CV joints. We've lost two joints in our last two events and we are not even at the IT legal limit of 5".

We have not measured the bumpsteer or camber change, but the camber change on a lowered B13 is significant. It is in many cars. The Speed Touring Cars tend to run huge spring rates to control the camber change.

The 650/500 combo doesn't seem at all out of line for these cars, but only if you install a welded cage that ties into the rear suspension mounting points. The rear of these cars are flexi-fliers. The coachwork becomes the spring if you go too high on the rate w/o a good cage tied into the rear strut towers.

In fact, the best handling, most nimble SE-R I've ever driven, bar none, is Craig Damashi's. No cage. 450/275 with a suspension otherwise the same as our ITS race car. Bob Legere spec'd these because of the flexible rear end of the B13. Worked great on Craig's car. We didn't get around to trying it. Grover is now converting his car to an E Production car. That should be really interesting.
 

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Ironman
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DriveNASA said:
We run almost no rake in the Cup car. It is basically a brick- you're not going to gain that much by tipping a brick slightly into the wind.
Actually, the B13 SE-R has better aero than a C4 Vette. Yep.
 

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Ironman
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What is your applicaton?

Daily driver/track fun?

Autocross?

Dedicated track car?

Racing?
 
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