I installed an HF front sway bar on my STS Civic and am trying to figure out why something has changed. First my setup: springrate is 400/450 f/r with OTS Koni's that have had the brake line bracket removed for extra travel. I have a 7/8 ST rear bar, no front, 3 degrees negative in the front, and 1.9 in the rear and I'm running 1/8" toe out in the front and 0 toe in the rear.

The car has always lifted the inside rear tire pretty significantly in turns but I've never had much problem with the front shocks bottoming before today. It usually only happened if there was a BIG bump midcorner. Watching the car today with my codriver competing it looks like the car is staying much flatter and keeping the inside rear either on the ground or a lot closer. The weird thing is that the front shocks seem to be bottoming a lot more. I'm figuring it's one of two things, either the site is a lot bumpier than I remembered, or the front suspension is being worked harder because the car is cornering flatter.

The good news is that the shocks go off next week to be shortened and revalved (SPSS3) so hopefully that will fix the problem. I'm just curious about what is going on and I figured the suspension gurus here might be able to help me out. TIA!

 

This will be interesting, I am wondering on wether or not adding a front sway from a 92 Si on my hatch (560/672 + 21mm rear sb)

 

WHat make you think the shock is now bottoming when it was not before? Maybe the wild card here is the lot but if the car is staying flatter and the fact that the inside rear is staying lower to the ground would mean that the loadside front is probably now travelling less than it was before, not more.

Was there a change in the handling? Did it get any understeer tendencies? If the surface was very bumpy, you may simply have had too much roll stiffness and you tire and surface grip could have been compromised as well.

 

When I say it is bottoming I'm not talking a minor incident. There were a couple of turns on course that had bumps that would get the car pogo-ing off the bump stops 2-3 times. I had never noticed this happening at this lot before but it's possible the course just happened to catch some bumps that we missed previously. I can think of two other places it has happened, both in Georgia. One was on the left course at the Atlanta Pro, and the other was one of the lots at Turner Field.

It just kind of threw me off since it was so noticeable today, plus I was paying more attention to what the car was doing today because we were testing new tires and the sway bar during a test and tune. If the shocks don't do the trick I'll probably look at raising the ride height a little to gain some travel or increasing spring rate. Guess I'll just have to wait and see, can't wait to get the shocks back.

 

Maybe try extended tophat mounts for more shock travel. That is...if you already haven't

 

well i'm sure the new shocks will at least lessen that effect,
I mean they are going to have stronger compression damping afterall.

but even if the problem is still there,
I'd say concern yourself with how the car actually feels, not so much what it looks like from the outside.

if it's performing like you want it to, adding more springrate might not be the best idea.

 

Your examples of running in atlanta. I know exactly where that has happened to you because it happens to every car. I don't think its actually bottoming out, but just a bumpy section of the course. I would guess the same thing might be happneing here but can't say for sure without driving the car.

 

i would have to say,with the extra spring rate from the bar, the shocks can no longer hold. that is the pogo effect. the revalve should fix that.

 

I agree. I have the same setup as you except 450-550 f/r and in gets bouncy in a rough corner because of the ots koni's. It also bottoms out because I didn't know to move the brake line bracket. When it bottoms out it doesn't hop any more, it just washes out mid corner and understeers.

Billy

 

My accord was definatly bouncing around a little today, but I dont think the suspension ever bottomed out. New stiffer setup for me too, I actually had to run lower pressures in the rear.

 

you probably never noticed the car bouncing before. i've watched pretty much every nationally run STS EF they all do it unless their ride height is pretty high. doesn't seem to matter if they have the HF front bar, no bar, or the stock bar. at the Peru Pro, jason noticed it too. kevin's car is the worst i've seen thus far. doesn't seem to be a factor in how fast the car is.

nate

 

Well things went better on Sunday so I'm thinking I was just catching some really big bumps at a bad time during the test and tune. The car seems to be much more predictable with the front sway bar. When the back steps out now it's a much smaller slide and it goes much more gradually.

Shocks are going out as soon as I can get them off the car, probably tomorrow night. I can't wait to get them back and see the difference. Thanks for all the replies!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STS_Underdog &raquo;</TD></TR><TR><TD CLASS="quote">Well things went better on Sunday so I'm thinking I was just catching some really big bumps at a bad time during the test and tune. The car seems to be much more predictable with the front sway bar. When the back steps out now it's a much smaller slide and it goes much more gradually.
</TD></TR></TABLE>

more predictable = slower

 

hf front bar= hottness. once you get your shocks back, try to get back to the lots where you felt it was bottoming out. also, try to pick up the ground control upper shock mounts.

-spenc

 

Ryan-
Time will tell. I've got a feeling that sometimes I was chasing the car too much and it was slowing me down. Part of it was my driving style. If I needed to go faster I would brake later, pitch it into turns, try to get away with a lift when I needed a touch of brake, etc. It looked really dramatic, but not very effective. I'm driving a lot more precisely and it's paying off so far. Guess we'll just have to wait until April to know for sure, eh?

 

drive it like its RWD and it'll work. Have to be very smooth inputs and you can set the car up loose. the harder my car is to drive the faster it seems to be. That is as long as I can control it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shakedown94 &raquo;</TD></TR><TR><TD CLASS="quote">i would have to say,with the extra spring rate from the bar, the shocks can no longer hold. that is the pogo effect. the revalve should fix that.</TD></TR></TABLE>

can you explain how this occurs? I was thinking once the car is back in a straight line it just has to dampen the same spring rates it's always been damping before the bar was put on right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by shakedown94 &raquo;</TD></TR><TR><TD CLASS="quote">i would have to say,with the extra spring rate from the bar, the shocks can no longer hold. that is the pogo effect. the revalve should fix that.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by azian21485 &raquo;</TD></TR><TR><TD CLASS="quote">

can you explain how this occurs? I was thinking once the car is back in a straight line it just has to dampen the same spring rates it's always been damping before the bar was put on right? </TD></TR></TABLE>

I have no idea what either of you guys are saying

 

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

I have no idea what either of you guys are saying</TD></TR></TABLE>

uh, the ots can not handle the extra spring rate from the bar when the car is in a corner. the shock does not have enough dampning force to keep from rebounding and pogoing? after rebound weight transfers back on that corner. and hense the effect. with the revalve,this should no longer be a problem.

 

Since the description was "pogoing", I'm expecting the motion to be primarily up-and-down -- not roll. Antisway bars can be thought of as invisible except in roll, so unless the oscillation you are seeing is primarily or significantly characterized as roll, the antisway bars are probably not the culprit, even if the "pogoing" occurs while the car is cornering.. (i.e. if you superimpose up-and-down bouncing on top of a steady state roll, the antisway bars are not really involved in the bouncing... even if the car is bouncing while it is exhibiting some roll... --assuming linear springs, and a few other things)

Sometimes I can't tell whether .RJ is being sarcastic or not..

 

I too really do not think that this is the result of having a swaybar,
or the koni's not being able to handle the "extra rate" of the swaybar.

first off, the hf bar is tiny,
and ots koni's can handle plenty of springrate without pogo'ing around.

Did you try turning up the damping on the front shocks?!?(would probably induce
some understeer but just for testing purposes).

even if a swaybar does function like a spring,
imo, this pogo'ing you're speaking of would actually DECREASE with the addition of a swaybar. No bar and the outside corner would just plumit to full compression on those bumps and recoil off the bumpstop.

maybe you dont have ENOUGH springrate?

 

I have just switched form the OTCs to shortened revaled, and I also switched back to the Azenis from the MX's. I'm not sure why but it dosent Pogo anymore. At the first event with the shocks on the car at a rough asphalt lot the hopped but that was due to a super rough section.

And Lee may chime in on this but this time of the year you will wait 4-6 weeks to get your shocks back and even longer the longer you wait. I'm on week 6 of the 4-5 week schedule for the CRX shocks and we sent them in back in Dec....

 

vbspec-

Fortunately I've been in line to have the shocks rebuilt for a while now and have stayed in touch with Lee so I've got a pretty good idea of my timetable.

As far as the pogo effect I'm pretty sure I was catching some big bumps when the car was already leaned over in a turn. Didn't have any problems at the same site on Sunday. At this point I'm going to wait until I get the revalves and then test from there.

Tad-

I'm actually thinking about trying some higher spring rates but I wanted to get the shocks worked on before I went higher than the 400/450 I'm running now. I'm just waiting to see how the car works with the SPSS3 valving.

 

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

I'm actually thinking about trying some higher spring rates but I wanted to get the shocks worked on before I went higher than the 400/450 I'm running now. I'm just waiting to see how the car works with the SPSS3 valving.</TD></TR></TABLE>

The shock revalve should get you a significant performance benefit, and lots of useful tunablity versus the OTS units. You will likely not see as big a return on investment in stiffer springs. You are in the ballpark already there. Last I talked with him, Kevin McCormick's car was relatively softly sprung (375/400) and I dare say he's done ok with it. Some of us who run on concrete regularly are a bit stiffer.

--Andy