So this past weekend at Summit Shendoah, I experienced some really new, and odd things of how my car was re-acting. To give a little summary, the car is :

92 civic hatch
b18c
tein ra's (10kF/14kR)
spherical RTA bushings
Mugen compliance bushings, etc.
ITR 22mm Rear Sway
NO front sway
Tires are Azenis, pressures starting at 30F/32R cold.

Basically the car oversteered TOO much. The car has mostly felt nuetral at other tracks (summit main, VIR full) with a hint of oversteer either due to trailbraking, or all out spins b/c of lifting. But this weekend the car seemed to not find any grip, and I was fighting the steering wheel the whole day.

I then changed the rear tire pressures up to 38 PSI cold, and softened the rear dampening. This helped somewhat, but the car was still way too loose. What really puzzles me is how the car was still wanted to spin with the earlier tire pressures.

Basically, I'm gonna be going through the car and checking everything out. But if anyone had any advice where to start, Id appreciate it, or any tips on what to change.

And yes, a front sway is sitting in the garage waiting to go on.
This day left a pretty bad feeling for me, just glad the car is in one piece and in the garage.

 

my possible ideas..

1. tie-rods (needed replacement sooner or later)
2. alignment out of whack from offs at VIR - toe settings out of whack?
3. tires (yes, azenis suck... but never sucked this bad after 2-3 laps in nice weather)
4. there was a car whos motor blew earlier - would oil/coolant not have burned off?

<- clueless, and hating his car.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by navin &raquo;</TD></TR><TR><TD CLASS="quote">
I then changed the rear tire pressures up to 38 PSI cold, and softened the rear dampening. </TD></TR></TABLE>

the change in pressures seems backwards to me, and you should only make one change at a time so you can evaluate each one.

 

I started at 31/33 cold at first, then bumped the rear pressures.. Are you saying that is backwards?

After the bump in the rear pressure after the first session, the car felt a little more stable..

&lt;-

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by navin &raquo;</TD></TR><TR><TD CLASS="quote">I started at 31/33 cold at first, then bumped the rear pressures.. Are you saying that is backwards?

After the bump in the rear pressure after the first session, the car felt a little more stable..

&lt;- </TD></TR></TABLE>
I believe what he is saying is when the rear end is loose the "usual" remedy is to soften the the rear. You chose to make it firmer instead which would tend to make the problem worse. Thus backwards.

 

gotcha gotcha - i was told by a friend to try it out and see what happens. Has anyone ever started tire pressures under 30 psi cold for azenis?

 

From what I am reading above, I see massive oversteer just based on your specs. Those are closer to AutoX specs than RR specs... yes rotation ensues

 

Yeah a front swaybar install is def. in order - but the thing that worried me this weeekend is that the car never wanted to spin like this before.

 

for sure a front end bias with tire stagger will help reduce your oversteer tendencies. As said above you went the wrong way with pressures

 

on me.

 

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

1. tie-rods (needed replacement sooner or later)
2. alignment out of whack from offs at VIR - toe settings out of whack?
3. tires (yes, azenis suck... but never sucked this bad after 2-3 laps in nice weather)
4. there was a car whos motor blew earlier - would oil/coolant not have burned off?

&lt;- clueless, and hating his car.

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

I had this same problem, offs at Summit, caused MASSIVE oversteer at VIR, when I got back re-aligned the car and I had lots of toe out in the rear. Id check that before you go and replace anything.

 

As has been said, realign the car before changing/replacing any parts.

 

How old are the azenis?

 

1 track day.
1 weekend at VIR.

Other than that, they sat in the garage.

 

What rear upper arms do you use? Maybe bad bushing? You can get these little camber changes if there is a bad bushing making the car almost uncontrollable.

14k+R bar+ 32psi isn't going to cause massive oversteer

Also you have driven your car on other tracks and you know your car well enough to know something is wrong and it's probably not with your setup that you have to add bars etc



Modified by 89civicdx at 5:16 PM 8/19/2008

 

In the future, try these:

-Raise front tire pressure or decrease rear pressure (as has already been said)
-Disconnect rear swaybar
-Alignment

WHERE on the track were you oversteering? Just knowing that track, there are a few places that you're more likely to see that in your car. Any video?

Other than that, I don't know what would cause that. My car isn't too far off that setup other than a front bar, and if anything I had issues with understeer more than oversteer.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 89civicdx &raquo;</TD></TR><TR><TD CLASS="quote">What rear upper arms do you use? Maybe bad bushing? You can get these little camber changes if there is a bad bushing making the car almost uncontrollable.
</TD></TR></TABLE>
ding ding! thats a big possibility. especially if they are skunk2 rear arms

 

They are HardRace rear arms - I'll be inspecting those. I'm gonna see if a buddy can get it on a alignment machine just to see what the specs are now, and compare to my last alignment.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by navin &raquo;</TD></TR><TR><TD CLASS="quote">They are HardRace rear arms - </TD></TR></TABLE>
well there goes that idea. chacking the alignment is the first step for sure.

 

Just read in GRM that going very low will have the same effect as going high in air pressure, but with better progression. I'm going to try this out on Sunday. It pretty much goes against what I was told in my classes.

 

was the oversteer on braking/turn in? Mid corner? on/off camber corners? up/downhill corners?

never raced there but finding where the oversteer is can help determine how to eliminate it.

for my azenis i run 38F/R usually - dont quote me just that's what ive been used to.

 

Braking/turn in.
Off camber turns where it was mainly evident, but in some cases just regular 90 degree right turns, etc

 

yeah check your rear toe.... are the tires worn more/less front to rear?

 

I didnt even check - but i did rotate the tires at the event.

Previously the rear toe was at zero, so we shall see. Still gonna go about replacing the tie-rods, etc. They are the same ones that came with the car, so have about 90k on them.

Yes its a 92, and only has 90k on it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kusai.Nihonjin.Desu &raquo;</TD></TR><TR><TD CLASS="quote">Just read in GRM that going very low will have the same effect as going high in air pressure, but with better progression. I'm going to try this out on Sunday. It pretty much goes against what I was told in my classes.</TD></TR></TABLE>

Setting ideal tire pressure is to ensure maximum tire traction. Any pressure NOT ideal (above or below) will consequently provide less than ideal traction, felt/seen as tire slippage/sliding. The tire behavior will vary a bit though, as GRM said. Tire wear will also be different.