I'm not from the USA [from New Zealand] so I am not familiar with all your different road racing classes and regs.
I have followed with interest the debate of NA v's [JDM]Asia race setups with interest and have been thinking how this relates to our race integra.
Our rules are close to the FIA super touring regs .
we run 16x8 rims with 210x600x16 slicks all round , we have no minimum ride height. suspension is fully rose jointed and adjustable and brakes are as big as we can fit inside the control rims.
our setup is
front springs 700-900lbs with 180 helpers
koni 2 way adjustable shocks custom built short body
camber 3-4.5 neg
castor 3deg
toe out 3-5mm
front bar custom 30mm with longer arms than std - similar to mugen 26mm in rate
rear springs 600- 900lbs with 180 lb helpers
koni 2 way shocks custom built short body
toe 0m -1mm in
camber 2-3 deg neg
rear bar custom adjustable 21mm same mounting position as std.
we have to run front rates sufficiently high to keep off the bump stops and rear rates as high as possible, dictated by roughness of track surface.

We often suffer understeer coming off slow speed corners, but are unable to increase the rear rate due to circuit undulations causing the rear to get very loose!!

I am interested in any comments re our setup , and any information relating to optimum ride height in relation to bump steer, camber change etc.

 

can you put a bigger real sway bar on? have you tried to disconnect the front bar?

 

hi BigAl, can you share detailed pictures of the car?

i don't think honda really suffer from bump steer. and camber curve is pretty good. how is your race car in medium and high speed corners? ultimately it's how the car feels. as fast as the old BTCC cars were they were still considered momentum cars. as long as you can stay on the throttle, your setup is probably good. how much experiment with spring rates have you guys done?

 

we changed from the original front bar to our current bar and the times were slightly better, but no we have never run without it.
we are using a speedway style splined bar mounted above the steering rack in alloy bushes with alloy arms and drop links to the front bottom arms.


[Modified by BigAl, 8:57 AM 10/28/2002]


[Modified by BigAl, 9:06 AM 10/28/2002]

 

med. and high speed corners pretty good. any mild understeer can be tuned out with the rear bar and shock adjustments.
our high speed corners are probably not as fast as yours as we have no real banked tracks.
started with high front bias ,f1200lb and r 900lb and have tried many combinations, both by time and driver feel .800/900 f keeps us off the bump stops and 700r is getting hard in the back . if the tyres are not up to full heat it is easy to loose the back end on the first few laps!!
my ride height looks simlilar to the realtime cars, but realise they are on 17's.
What ride heights do you run ?
will get the camera out and post some shots


[Modified by BigAl, 9:02 AM 10/28/2002]


[Modified by BigAl, 9:05 AM 10/28/2002]

 

FWIW..you are running a LOT more camber than most other folks on the board. Given the low ride height and "touring car" set-up, that may make sense - it's all in what the car / tires like, but I thought I would pass it on. Most folks are running 2-3 degrees up fron and under 2 in the rear. That's on DOT R- compounds, though, not slicks.

 

though my expertise is autoX set-up, it does seem like you are running a really large front bar....maybe going to a smaller bar or setting the front bar on the softest setting will help you dial out your understeer...also if all your tracks are really that rough, maybe reset your rear toe to 0, should help not make your car dance and shimmy over all the undulations

 

This was my first thought when reading the problems and the setup, the front bar seems awfully large. This may be why you are having to run to your "maximum" rear rate. With the rates you have up front there shouldnt be much negative affect from a smaller bar.

One other thing to think about is the alignment settings in addition to what carlos posted. I am no alignment expert! But the toe out in front seems to be too much and may be hurting corner exit.

 

You have alot of trick stuff!!

Please post pictures

 

you have convinced me!
will try a smaller front bar around 26mm / nearest imperial size and report back after testing.
still working on the photos
Alan


[Modified by BigAl, 9:23 AM 10/29/2002]

 

Alan, do you have any data acq? What G's are you generating with the slicks? I guess you're hitting bump stops because the slicks grip so well even with fairly stiff front springs.

I don't think many of US Honda's have slick experience.

 

no data logging at the moment as the team is primarily funded by my cheque book!! Also dont have anyone on the team suitably experienced to analyse the data. The programable ecu is enough for us!
You have a valid point re slicks. whereas r type rubber is reasonably forgiving at the point of breakaway slicks are very hard to catch and give very little warning.
Once they let go its normally all over.particularly when running high spring rates- maybe a reason for the diffence between NA and JDM.
[I have spent a bit of time in Japan and some of the top guys can really drive.]

 

If you're not understeering until you start to accelerate out of the corner, shouldn't the car be transferring weight slightly to the rear making it less likely to ride the front bumpstops? It would be more likely to bottom out at turn in or under trail braking I think.

Just thinking out loud really.

 

Depending on how much straight line speed vs. turn in you need I might try less toe out in front. Also, I would try to reduce the amount of negative camber in the rear to help eliminate the understeer.

 

Does your cheque book want to fund the racing over here in the states??? My team needs sponsers!!!

 

Well, that depends on who you talk to. It is like people saying to run 40 hot on RA-1's & others saying it is too much. FWIW, those alignment specs are pretty much in line with some of the SVWC Touring cars.

 

Are you using a tire pyro. to determine camber? Off the top of my head, I would agree that a bigger rear bar (or smaller front) would be beneficial. I would not eliminate the front bar on an Integra. A little less toe out in front or more toe out in the rear might be helpful.