I have a 1992 DA with Ground Controls and Konis and want to know if there is any kind of rule of thumb for height when lowering, but at the same time still have 100% functional suspension without sacraficing handing. I don't want to go too low because I know I will have less shock travel which will defeat the purpose of a good handling car. This is a daily driven car, which I want to start taking to autocross. All advice is welcome. Thanks.
------------------------- The Ground Control Topmounts relocates shock upward 24mm to allow extra suspension travel. ONLY FITS Ground Control coil-over kits. Includes custom bump stops, urethane stem bushings and grade 8.8 hardware with new Metric nuts and washers. Sold in pairs NOTE: These uppermounts require the reuse of some components that are included with your Ground Control coilover kit. These Hondamounts can ONLY be used in conjunction with a Ground Control kit.
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Also, if you do feel inclined to reach the potential of rideheight versus suspension travel, pick up a few racecar suspension dynamics books. I've thought about making the total ride height equal to the total vertical wheel displacement, thus making an equation that considers the static ride height as a function of maximum load transfer from lateral accelerations. In other words, ideally, the equation should spit out the minimum ride height, at any value plugged in for maximum acceleration. This way, the car will have the lowest center of gravity, without the chassis bottoming out.
By the way, I would be making this equation for my 1990 DA 2dr in SM. I bet I could get some of my mechanical engineering teachers to help me with this at Virginia Tech.
Current project: 275/45 Hoosier'd B20vtec DA, SCCA solo II SM car
Chris Fries - #117 H1 Prelude 2007 Midwest Honda Challenge H1 Champion Estrada Customs in Libertyville, IL Great place for custom / repair body work! Ask for Fabian.
A friend once told me the gap between the wheelwell and the tire should be half of the tires sidewall size.
Cosmetically, that would probably look best.
However, for best handling, it would be entirely dependent on tire grip and spring rate. As low as you can go without pushing into the bumpstops at all under normal driving conditions (so hitting them while curb hopping is fine) is generally best.
I have to run a good 1.5" higher than the other STS Integras in my region, because I run significantly softer spring rates (its my daily driver). When I tried to get down to their height, I couldn't get the car to turn in, as the shocks were already into the front bumpstops from braking, before I even started turning the wheel.
Because how much suspension compression you have is determined by track surface, tire grip, and spring rates, there is no "best ride height" for everyone. Trial and error, and a pack of zip ties, are your friends.
However, for best handling, it would be entirely dependent on tire grip and spring rate. As low as you can go without pushing into the bumpstops at all under normal driving conditions (so hitting them while curb hopping is fine) is generally best.
I have to run a good 1.5" higher than the other STS Integras in my region, because I run significantly softer spring rates (its my daily driver). When I tried to get down to their height, I couldn't get the car to turn in, as the shocks were already into the front bumpstops from braking, before I even started turning the wheel.
Because how much suspension compression you have is determined by track surface, tire grip, and spring rates, there is no "best ride height" for everyone. Trial and error, and a pack of zip ties, are your friends.
what spring rates do you run ? and any shots of your tegs height ?
2000 Integra GSR 400/400 on OTS Koni Yellows, GC extended upper mounts Uncut bumpstops that came with the GC upper mounts
No current pictures. "2 finger" front gap, "3 finger" rear gap. Or approximately 6.25" from the ground to the front side jack points (on correctly sized tires). The car is as high as I can get it with the extended upper mounts. The front springs are lightly preloaded.
When I first installed the suspension, I lowered the car to flushed tires front and back. This left the car sitting on the front bumpstops at rest. Ride was bouncy (front was underdamped for the additional spring rate the bumpstops added) and the car did not want to turn in (go figure).
At this height, I mostly stay off the front bumpstops during autocross conditions. Uneven surfaces, and I do find them from time to time, but I account for that when doing the course walk, and plan for the sudden understeer.
Rear is raised higher than the front to help induce a little more oversteer. This seems to a cheap hack instead of adding (a little) more rear bar or spring rate.
And my shock towers have dents from my SPC UCAs introducing themselves when driving over pot holes.
550/600 springs are sitting in my garage, awaiting install. Then I'll probably lower the car 3/4" and see how often I hear that gut wrenching "bang" driving to work.
*edit: Keep in mind that the front suspension of the G2 Integra is quite a bit different than the front suspension of the G3 Integra.
Trial and error, and a pack of zip ties, are your friends.
On my RSX, I've used zipties.
On my Miata, the dampers I got included shock shaft dust boots, and the Miata crowd seems to think running w/o dust boots on their Miata is the end of the world. I'm used to not having them from running track days for 2 years now in my RSX. I should be fine removing them from my Miata right? I wanted to use the ziptie trick as well to see the range of shock movement in the Miata.
Also, if you do feel inclined to reach the potential of rideheight versus suspension travel, pick up a few racecar suspension dynamics books. I've thought about making the total ride height equal to the total vertical wheel displacement, thus making an equation that considers the static ride height as a function of maximum load transfer from lateral accelerations. In other words, ideally, the equation should spit out the minimum ride height, at any value plugged in for maximum acceleration. This way, the car will have the lowest center of gravity, without the chassis bottoming out.
By the way, I would be making this equation for my 1990 DA 2dr in SM. I bet I could get some of my mechanical engineering teachers to help me with this at Virginia Tech.
total ride height equal to the total vertical wheel displacement, thus making an equation that considers the static ride height as a function of maximum load transfer from lateral accelerations.
Except lateral acceleration isn't the only thing affecting your suspension ride height. That might work okay for a billiard smooth skidpad, but for transitions and bump, you'll pound the bumpstops and give up grip.
Except lateral acceleration isn't the only thing affecting your suspension ride height. That might work okay for a billiard smooth skidpad, but for transitions and bump, you'll pound the bumpstops and give up grip.
Don't listen to this guy, he's unlucky.
Wait, don't listen to me...
Chris Fries - #117 H1 Prelude 2007 Midwest Honda Challenge H1 Champion Estrada Customs in Libertyville, IL Great place for custom / repair body work! Ask for Fabian.
as long as you have enough suspension travel (ie not hitting the bumpstops), you should be ok.
I've heard this comments for a while and I must say I disagree. While I agree that running on bumpstops is not good, hitting it occasionally won't hurt.
Ideally, if everything else is adjusted accordingly, for performance stand point, you will want to have your car as low as possible. There is no substitute to lower center of gravity.
Some people put zip ties on their shock shaft to ensure the shock will not bottom out. While this is a pretty good method, it really doesn't tell you much. It doesn't tell you where you are hitting the bumpstops, which part of the track. Hitting bumpstops at certain part of the track where it won't hurt the performance is fine. If running your car lower means improved speed through corner 1 through 10 and you are slower through corner 11 and 12. You are better off than raising the car and slower through corner 1 to 10 and faster through corner 11 and 12. Or maybe there is a big bump on the straight where it will hit the bumpstops, but who cares, it is on the straight, it won't hurt anything.
I've heard this comments for a while and I must say I disagree. While I agree that running on bumpstops is not good, hitting it occasionally won't hurt.
Ideally, if everything else is adjusted accordingly, for performance stand point, you will want to have your car as low as possible. There is no substitute to lower center of gravity.
Some people put zip ties on their shock shaft to ensure the shock will not bottom out. While this is a pretty good method, it really doesn't tell you much. It doesn't tell you where you are hitting the bumpstops, which part of the track. Hitting bumpstops at certain part of the track where it won't hurt the performance is fine. If running your car lower means improved speed through corner 1 through 10 and you are slower through corner 11 and 12. You are better off than raising the car and slower through corner 1 to 10 and faster through corner 11 and 12. Or maybe there is a big bump on the straight where it will hit the bumpstops, but who cares, it is on the straight, it won't hurt anything.
+1. And with proper bump rubber tuning, you can even let the car use the bump stop as extra spring. With modern bump rubber, keeping the car out of the bump stops isn't as critical as it once was.
