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Question on twitchy handling

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Old 10-30-2009, 08:15 PM
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Default Question on twitchy handling

I've got a 1999 Civic hatch that I'm driving in Nasa HPDE-3 with the car being basically setup for Honda Challenge H2. Here's a link of the car at Thunderhill, I believe in turn 8 so high speed left turn:

http://i146.photobucket.com/albums/r...hill_Apr09.jpg

The car has Buddyclub 'Racing Spec Dampner' coilovers with I believe 7k and 8k springs front and rear. Most of the bushings are spherical. The sway bars are 24mm front and 22mm rear with both being non adjustable. The issue I'm having, is that the car sometimes seems kind of twitchy when turning left, but is fine when turning right. I found a loose right rear wheel bearing, so I replaced it, and it helped, but the car still sometimes seems a little twitchy when turning left. It was suggested maybe going to an adjustable rear sway bar, so I was looking into Comptech or ASR. Anyway, I just noticed that the rear sway bar left side endlink is approx vertical while the right side endlink is leaning almost 1 inch, so I'm wondering if maybe there is some binding of the right side endlink on the horizontal bolt. Here's a picture of the left endlink:



and one of the right side endlink that is leaning over:



I'm assuming that the sway bar length and the attachment holes in the lower control arms are correct. It looks like the rear sway bar has just slid over in the D ring collars. I'm assuming that I can just get some collars to put on the sway bar on either side of the D-ring bushings to keep the sway bar centered. It looks like if I do center the rear sway bar, that the end links will not be perfectly vertical, but should be a lot better than they are now. Any opinions if the right side endlink leaning over is causing any twitchiness?

Here's a picture of the current D-ring mounting brackets for the rear sway bar. I've read a lot about ASR or Comptech full brackets being good to prevent the subframe from getting torn apart. Are the brackets shown in the picture below good enough, I should I go with a full ASR sway bar kit with the full bracket? It looks like there is a 22mm ASR kit on the King Motorsport website, but there isn't any picture, so I can't tell if it is adjustable but most sites just list the 24mm and 32mm kits. Many websites list a 24mm ASR kit with it being adjustable, but I'm not sure how it would match with the current 24mm non adjustable front bar - if the 24mm ASR rear sway bar is set for full soft, then how stiff would it be compared to the current 22mm non adjustable bar? I checked ASR part website, and it didn't list much detail about the range of stiffness.



PS - the front sway bar has endlinks with the bushings being made of the D-ring material(polyurethane or ?) with the picture being below. The nut holding the bushings is quite snug, so the bushings are pretty well compressed. If the rear sway bar endlinks are using spherical bushings, then are the front sway bar bushings OK, or should I use something stiffer?



Thanks for any help or opinions!! - Jim
Old 10-30-2009, 10:20 PM
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Default Re: Question on twitchy handling

Have you tried and lubing those Polyurethane bushings they need regular maintance as well your spherical bushings prone to failing because they are expose to the environment. Good luck and replace the obvious and go from there.

Oh yeah try lifting the whole car on jack stands or one side at a time and then compressing the suspension with a jack with wheel off and seeing what happens and how the suspension reacts?

One more thing have you tried taking your car to a aligment specialist that deal with race car to get your car set up properly your car looks too low?
Next time try putting zip ties on all 4 shock pistons and trim the ends off like a little ring then go out for a run or two to see if you too see if the zip ties are still there and if they are not then your car is bottoming out and your car is too low.

Good luck and nice car.

Last edited by civichb20; 10-30-2009 at 10:32 PM.
Old 10-31-2009, 12:47 AM
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Default Re: Question on twitchy handling

Jim,

You should get a subframe brace.
It will hold the swaybar in place and keep your subframe from tearing out.
Check your rear suspension for a failed bearing. especially the lca's or the trailing arms.
Also do what Charles suggested with the zip ties.
Put on the bottom of the shafts and run the car.
If they are gone or at the top of the shaft your bottoming out.
Is turn 8 the only turn where this happens?
If so consider that you can not set up a car to run perfect on every part of a track.
Some turns are called "throw aways"
I learned this first hand a few weeks ago at buttonwillow.
Cotton corners will aways be bouncy no matter what i do to the car.

Hopefully some of the other seasoned racers will chime in.
They have a lot of knowledge.

Last edited by dirty19; 11-01-2009 at 02:47 PM.
Old 10-31-2009, 06:09 AM
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Default Re: Question on twitchy handling

First thing: get that rear swaybar re-aligned. I've had issues with weird handling resulting from exactly the same problem. Put it back in place, tighten it up, and try again. The fix could be as simple as that. Along that line, inspect those D-bushings, they might be worn out or deformed and could let the bar slip again.

I'd look over all your other bushings and bearings while you're at it. "Twitchy on one side" to me usually means something is out of whack or broken (cracked bushing, toasted bearing, something out of alignment, etc.). Stuff like that will tend to show up inconsistently as weird behavior. ("I'm snap-oversteering at the end of a braking zone, but only sometimes in T1 and occasionally in T5, wtf? ......Oh, my RTA bushings should've been replaced 3 years ago, I see...")

For your question on the front bar bushings, they seem fine to me, but I run OEM rubber everywhere and no sphericals.
Old 10-31-2009, 07:54 AM
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Default Re: Question on twitchy handling

Ah... so you bought James' EK.
Old 10-31-2009, 08:02 AM
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Default Re: Question on twitchy handling

The bar is way off-center.It looks like the bar is sliding left to right,and missing some clamps to keep the bar center.My progress bar had these clamps,some others weld a washer on the bar as well.

Can we see the whole bar from the rear of the car,then we can see more..The D brackets/bushing look to be for 24mm bar not 22mm.
I would center the bar,add clamps/washers for centering,get new bushings and you should be good.

Last edited by JW racing; 10-31-2009 at 08:08 AM. Reason: add on
Old 10-31-2009, 08:20 AM
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Default Re: Question on twitchy handling

Is your car corner balanced?
Old 10-31-2009, 12:40 PM
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Default Re: Question on twitchy handling

other than what people already suggested, wich makes a lot of sens btw, make sure the rear upper and compensator arm are in perfect shape on both sides.
Old 10-31-2009, 05:34 PM
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Default Re: Question on twitchy handling

Thanks for all of the responses. I stopped at Weaksos in San Jose today, and picked up an ASR subframe brace. Charleston Ong of ASR was there, and discussed the various options. He felt that my current sway bar would work OK, so I'll go with it, and may switch to their 24mm adjustable bar in the future. He did mention that the earlier civic sway bar lengths were approx 39", and the later (1996-2000) were 40", but that my bar should still work well enough if centered, so I'll look into getting some clamps and washers, or shaft collars, or washers welded on.

For the D-ring polyurethane bushings, they are right at 22mm at fit well on the bar without any slop. I lubed them earlier this year with some Mobil1 synthetic grease. One person suggested just some white lithium grease. How often do most people lube them, and is the Mobil1 grease OK, or something else? For the end links with spherical bushings, it was suggested to me to just occasionally lube them with some WD40. Do people use that, or something else? I haven't searched the forums for info on this. I know that I will need to check the bearings periodically to make sure that they aren't worn/sloppy. I haven't bothered lubing the front sway bar bushings, as they seem to pick up residual oil/lube from the engine and transaxle.

I moved the right rear wheel up and down, but no obvious binding or noise. Blacktrax had installed some of the suspension pieces (but not the sway bars), and had the car corner balanced. For ride height, the picture I posted was in a high speed left turn, so the right side suspension was pretty compressed. Graham took a quick look at the car at Thunderhill, and drove it for a session, and felt the ride height was OK. I believe he said that the jacking points should be say 4.5-5" off the ground. I measured them today,and they were 4 9/16" front left, 4 9/16" front right, 4 15/16" rear left, and 4 3/4" rear right. For the tie wrap method to check for bottoming, do I just snug a tie wrap on the piston shaft say 1" under the rubber stopper near the top of the shock?

At Thunderhill, the time the car felt twitchy was at turn 6, but I found the bad right rear bearing after one spin. It may also be that I'm braking too much, and then just not getting on the gas enough to get the car balanced before the apex. Hopefully the subframe brace and getting the rear sway bar centered will help. Thanks for everyone's help!!

- Jim
Old 11-01-2009, 12:25 AM
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Default Re: Question on twitchy handling

Originally Posted by Calif_Kid

For the D-ring polyurethane bushings, they are right at 22mm at fit well on the bar without any slop. I lubed them earlier this year with some Mobil1 synthetic grease. One person suggested just some white lithium grease. How often do most people lube them, and is the Mobil1 grease OK, or something else? For the end links with spherical bushings, it was suggested to me to just occasionally lube them with some WD40. Do people use that, or something else? I haven't searched the forums for info on this. I know that I will need to check the bearings periodically to make sure that they aren't worn/sloppy. I haven't bothered lubing the front sway bar bushings, as they seem to pick up residual oil/lube from the engine and transaxle.



- Jim
They make a special lube for poly bushings. You can get a tub for $20 that will last forever.
Old 11-01-2009, 12:35 AM
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Default Re: Question on twitchy handling

Originally Posted by ScottBell
They make a special lube for poly bushings. You can get a tub for $20 that will last forever.
Just wondering what the brand or name is, and where you suggest getting it. Thanks. - Jim
Old 11-01-2009, 06:57 AM
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Default Re: Question on twitchy handling

Energy suspension

http://www.amazon.com/Energy-Suspens...7091023&sr=8-1
Old 11-01-2009, 06:43 PM
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Default Re: Question on twitchy handling

zip tie you want to place them on the bottom snuggly and trim them and see if they last or disappear. Disappear means your bottoming out.
Old 11-01-2009, 06:57 PM
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Default Re: Question on twitchy handling

Just for reference:
Old 11-01-2009, 09:33 PM
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Default Re: Question on twitchy handling

Jim,

Is the twitchy-ness just in turn 6? Or is that were it is the most twitchy?

I have found turn6 to be a very pushy/understeer type corner and you see it as a lot of cars drive right off at track out.

Were are the poly bushings in the car?
Old 11-01-2009, 11:20 PM
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Default Re: Question on twitchy handling

Originally Posted by slammed_93_hatch
Jim,

Is the twitchy-ness just in turn 6? Or is that were it is the most twitchy?

I have found turn6 to be a very pushy/understeer type corner and you see it as a lot of cars drive right off at track out.

Were are the poly bushings in the car?
The twitchyness at Thunderhill was most noticeable to me in turn 6. Turn 10 (lower speed but more banked), turn 1 (high speed but I might have been back on the gas better), and turn 8 (high speed) seemed OK. I am thinking/hoping that the twitchyness was due a combination of the sway bar being shifted over plus the braking and accelerating (not getting back on the gas enough before the apex) I was doing along with the camber in turn 6. Some of it probably is that I just need to drive more smoothly plus to lube the rear sway bar bushings more often. So far, I've spun the car twice, and both have been at turn 6 at Thunderhill - one time in the rain and I later found the right rear bearing had a lot of slop/looseness and another time when some oil leaked from a car in front of me, so maybe I'm just just too nervous about that one turn.

I believe that the only poly bushing left are the D-rings for the sway bars, plus the end links for the front sway bar, with everything else being spherical bearings.

Originally Posted by Stinkycheezmonky
Just for reference:
Stinky - thanks for clarifying the zip tie attachment. I thought that the zip tie was just to be wound around the piston rod, but it looks like it just goes vertical alongside the piston rod, and inserted between the piston rod and the rubber bump stop if I understand correctly.

Anyway, I'm signed up for Infineon this next weekend, so I'll do the zip tie thing to check for bottoming, and will see how everything goes there. Thanks!! - Jim

Last edited by Calif_Kid; 11-01-2009 at 11:36 PM. Reason: Adding info
Old 11-02-2009, 05:53 AM
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Default Re: Question on twitchy handling

Originally Posted by Calif_Kid
but it looks like it just goes vertical alongside the piston rod, and inserted between the piston rod and the rubber bump stop if I understand correctly.
Correct. I guess you could wind it around the shaft, but I don't think it would work as well. Having it inserted between the bumpstop and piston has the bumpstop holding it in place. If it were wrapped around, I could see it moving down potentially, giving you false information.
Old 11-02-2009, 09:14 AM
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Default Re: Question on twitchy handling

A properly snugged zip tie fastened around the shaft will not slide down on its own. It will certainly be pushed up by the top of the shock body though. I have never seen that method before Stinkycheez. What would stop the zip tie from just bowing out under the push from the shock body with the top pressed against the bottom of the top hat?
Old 11-02-2009, 10:44 AM
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Default Re: Question on twitchy handling

Lets also look at tires and tire pressures too.

Jim what tires are you using and the cold pressure you are starting out with?
Old 11-02-2009, 11:07 AM
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Default Re: Question on twitchy handling

Jaker, not sure, that's how I've always seen it done. The couple times I tried it I had no issues. I could see what you're describing happening with a flimsier cheap ziptie though.
Old 11-02-2009, 11:19 AM
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Default Re: Question on twitchy handling

ya count me as some one else who has never done the zip ties that way...


The zip tie trick is good, but at thunderhill it is kinda point less.

Coming down the by pass that car WILL get into the bump stops, driving it 10/10th.

You should be able to tell if you are bottoming out though.

Getting into the bump stop isn't bad, getting the UCA into the body is bad. and that is very noticeable.

looking over the turns again, IMO it is something with that turn.

Turn 8 has a really good bump at the apex, as does turn 1. Turn one is ~20mph faster then turn6. and turn 8 is almost ~30-35mph faster then turn 6.

Also thinking back to when i drove a 'twichy car' were is the car twichy?

braking?
turn in?
corner entry?
mid corner?
corner exit?

I drove a car with full ES bushings and the thing felt really twitchy/unstable in braking and then less so through the rest of the turn.

I freaking suck/fail at turn6. Not sure why but i just NEVER feel like i got it "right".

Some of the other guys think its super easy, and it shows they would get good runs on me out of it.

I think Liam another who doesn't like 6.

BrianZ, Chris lock, Mike, all seem to have no problem with it..
Old 11-02-2009, 01:25 PM
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Default Re: Question on twitchy handling

Come to think of it Jimmy Turn 6 can be a handful if you dont exit 5a correctly Running too wide to the left) and set 6 up just right. (hence why people run off during track out)
There were times I was able to roll on the gas coming out of 5a and not lift going through 6 but you have to come out of 5a to the right and hit the apex of 6 just right.
I never felt twitchy though. I tend to use all the track to set 6 up though

As a very wise man once told me... "You paid to use the track, use all of it"!
Old 11-02-2009, 01:53 PM
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Default Re: Question on twitchy handling

Have you bothered to look at your alignment? More specifically Toe? If you're toe'd out too much your car will feel extremely unbalanced and twitchy.
Old 11-02-2009, 01:56 PM
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Default Re: Question on twitchy handling

Originally Posted by dirty19
Come to think of it Jimmy Turn 6 can be a handful if you dont exit 5a correctly Running too wide to the left) and set 6 up just right. (hence why people run off during track out)
There were times I was able to roll on the gas coming out of 5a and not lift going through 6 but you have to come out of 5a to the right and hit the apex of 6 just right.
I never felt twitchy though. I tend to use all the track to set 6 up though

As a very wise man once told me... "You paid to use the track, use all of it"!
nailing the by-pass helps greatly with getting the line into 6!

Although in the middle of the summer at the end of a race yep!!! you push way out there!!
Old 11-03-2009, 07:37 AM
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Default Re: Question on twitchy handling

it can be twitchy from toe.. if ur talking about initial turning in.. but if ur talking about oversteer then maybe sway bars coilovers settings camber.. many things.. but get a subframe brace. ASR and get those little rings im not sure what theey are called to keep the swaybar from sliding around.. has the car been corner weighted?


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