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.

-justin

 

as long as you have enough suspension travel (ie not hitting the bumpstops), you should be ok.

 

GC top hats allows for more travel, at lower ride heights.

This is from http://www.weaksauceparts.com/...18820

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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.

 

drop it like it's hot!

 

A friend once told me the gap between the wheelwell and the tire should be half of the tires sidewall size.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mark D. Surface &raquo;</TD></TR><TR><TD CLASS="quote">A friend once told me the gap between the wheelwell and the tire should be half of the tires sidewall size. </TD></TR></TABLE>

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.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TunerN00b &raquo;</TD></TR><TR><TD CLASS="quote">

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.</TD></TR></TABLE>

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.


Modified by TunerN00b at 5:58 PM 5/6/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TunerN00b &raquo;</TD></TR><TR><TD CLASS="quote">Trial and error, and a pack of zip ties, are your friends.</TD></TR></TABLE>
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.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PseudoScience &raquo;</TD></TR><TR><TD CLASS="quote">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. </TD></TR></TABLE>

You need to join the Formula SAE team at your school. You'll learn alot! http://www.sewellphoto.com/vtsae/

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PseudoScience &raquo;</TD></TR><TR><TD CLASS="quote">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. </TD></TR></TABLE>

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.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WRXRacer111 &raquo;</TD></TR><TR><TD CLASS="quote">

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. </TD></TR></TABLE>

Don't listen to this guy, he's unlucky.

Wait, don't listen to me...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by verticle &raquo;</TD></TR><TR><TD CLASS="quote">as long as you have enough suspension travel (ie not hitting the bumpstops), you should be ok. </TD></TR></TABLE>

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.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Andrie Hartanto &raquo;</TD></TR><TR><TD CLASS="quote">

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.

</TD></TR></TABLE>

+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.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TunerN00b &raquo;</TD></TR><TR><TD CLASS="quote">

*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.


Modified by TunerN00b at 5:58 PM 5/6/2008</TD></TR></TABLE>

They are *slightly* different, but not as much as you think nor is it as important as you think.

 

ok, back from the dead, and a little bit of thread jacking; is there a control arm angle that works best for an ek hatch?

i know that with a mcphearson setup, you want your roll center to be as high as possible with your cg as low as possible. i would assume the same would apply for doublewishbones.

my idea is not to slam the car; use larger swaybars to reduce body roll while allowing softer spring rates for daily comfort.

edit: road course, not autocross.


Modified by white_r!ce at 7:58 PM 10/31/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Andrie Hartanto &raquo;</TD></TR><TR><TD CLASS="quote">

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.

</TD></TR></TABLE>

I agree, but only partially. The bumpstops are a tool for tuning for many cars, but you never want to clap them. Sharp increases in spring rate, especially when they reach close to infinite-- like bumpstops-- are likely not great for performance. I think the key point to avoid when dumping your car is to do it with hard enough, or progressive enough spring rate that the car eases onto the stops.

Am I right, or do I have the wrong idea. I learn these things by asking questions but everybody can be confused!

 

Here is a link to an old H&R article I like to provide learners on the nature of Bump Stops, read:


http://www.hrsprings.com/techn...mper/

 

Since this thread has already gone there
http://www.resuspension.com/Bu....html

Fine tune your bumpstops...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DB2-R81 &raquo;</TD></TR><TR><TD CLASS="quote">
</TD></TR></TABLE>

My bumpstops looked just like that before I cut the bottom 2/3ds off...

I prefer low, just to get thte CoG down. I am on relatively soft springs (500/600) and shocks with almost no compression damping (koni race). There are two places on my local track where I can bang the UCA against the shock tower really well if I try (its a transition from a banked surface to the flat), but I prefer to simply not drive over those transitions if I can avoid it (or at least drive over them where they are mild). So technically I have the car too low for those 2 places, but if I raised it up the car would handle worse in the other 13 turns.

I measure my ride height from the ground to the bottom of the body where the lower controll arms mount. I have 12.5cm in the rear and 13.5 cm in the front (this is on a '92 hatch).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MBellRacing &raquo;</TD></TR><TR><TD CLASS="quote">

I agree, but only partially. The bumpstops are a tool for tuning for many cars, but you never want to clap them. Sharp increases in spring rate, especially when they reach close to infinite-- like bumpstops-- are likely not great for performance. I think the key point to avoid when dumping your car is to do it with hard enough, or progressive enough spring rate that the car eases onto the stops.

Am I right, or do I have the wrong idea. I learn these things by asking questions but everybody can be confused!</TD></TR></TABLE>

I think you are right, but my bump stop is softer then my spring. I can compress it somewhat with my hands. I can stand on my front springs and they will only move around 1/8 to a 1/4 inch...

 

maybe an autoXer can chime in. Us roadracers have different needs, and this guy says he wants to autoX, not track.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gotocrx &raquo;</TD></TR><TR><TD CLASS="quote">maybe an autoXer can chime in. Us roadracers have different needs, and this guy says he wants to autoX, not track.</TD></TR></TABLE>

Already did, back with this thread was originally created.