turbogarrett

iTrader: (1)

I have been tossing around the idea of getting a stiffer front sway bar before my next track event for a little less oversteer. Yes I know the tri point is best, but that is more than I want to spend right now. I ran across one made by tanabe, it is a hollow, chromoly bar w/ 30.4mm diameter. Just wondering if anyone has used it here who also tracks the car.

My car is a 94 touring with buddy club d1 coilovers (8/6 kg), widefoot sway bar mounts(stock bars), 4 point rollbar and 9" fronts/ 10" rears wrapped in 255/275 kuhmo mx.

tia-Garrett

WidefootRacing

iTrader: (3)

Hi Garrett,
I'm a little surprised you're getting oversteer with your setup - the big rear
tires should be giving you plenty of traction, to the point of understeer. And going
to a larger front bar will generally make things worse from an "ultimate traction"
standpoint (taking away some front traction to balance a loose rear).

You might want to check your alignment, making sure you have a little rear toe-in,
which will stabilize the back end. Play with tire pressures front and rear, perhaps
going a little lower pressure in the rear (not to the point of "roll over", of course).

Check the spring rates on the coilovers, as well as the damping settings. Going
a little softer on the rear settings may help.

These are just some "Qik 'n Dirty" thoughts, feel free to PM or email me
(widefoot@comcast.net) if you want to go over this some more, or if you can
tell me your current track setup (spring rates, shock settings, tire pressures,
alignment settings, etc). I don't consider myself a suspension expert, but I
know a bit about it, and will help if I can.

You may also want to PM Howard Coleman, he seems to know his stuff...

David

ptrhahn

iTrader: (9)

Wow, now that Dave says it, it is odd that that setup oversteers.

Where specifically are you getting oversteer? What types of or points in corners?

Howard Coleman

iTrader: (6)

hi Garrett,

i enjoyed talking w you at the MRR. i was going to be testing 20 psi today but it is raining so i thought i would spend a moment w you....

do you have a pyrometer? if you track your car it is essential. you don't need anything fancy, i actually still like the analog ones from the past though i have a digital Stock Car Products w memory. without tire temps you are almost flying blind. tire temps will allow you to optimise all 4 tire pressures (yes, all 4 will be different), suspension settings such as camber and toe, weight distribution and track compliance.

i spent this monday at Heartland Park topeka Kansas, the site of the 06 Runoffs. i helped a couple of specmiata racers dial in their suspensions. track record 2:01.3. initial laps for the two cars around 2:04-:05. final laps after a day of tweeking: 2:02.3. considering the track was 55 degrees w no rubber they were running under the record.

my tools? air pressure gauge and pyrometer.

adjustments were air pressure at all 4 corners, and toe. (we could have changed the camber on one of the cars at one of the corners RF and gone faster).

back to you:

as has been correctly posted, IF your car is loose it is better to fix the rear rather than de-tune the front for balance. ALL front engine rear drive cars are ultimately loose. they key is to really really work on more rear grip. Lower Lower rear air pressure. as low as you can drive the car. the lower it is the sooner you can get on the throttle. think of road racing as drag racing w another car. if you can get launched before the other guy you have the advantage. soft rear springs. soft rear bar. soft rear shocks.

so get a pyrometer, and work on the rear. the FD has such a nice bump camber gain that some roll won't hurt it a bit and you will be able to drive it right on the edge as it will be talking to you softly not yelling as really stiff cars do.

good luck,

howard coleman

DamonB

I'd be most interested in knowing where exactly in the corner the car goes loose.

WidefootRacing

iTrader: (3)

back to you:

as has been correctly posted, IF your car is loose it is better to fix the rear rather than de-tune the front for balance. ALL front engine rear drive cars are ultimately loose. they key is to really really work on more rear grip. Lower Lower rear air pressure. as low as you can drive the car. the lower it is the sooner you can get on the throttle. think of road racing as drag racing w another car. if you can get launched before the other guy you have the advantage. soft rear springs. soft rear bar. soft rear shocks.

so get a pyrometer, and work on the rear. the FD has such a nice bump camber gain that some roll won't hurt it a bit and you will be able to drive it right on the edge as it will be talking to you softly not yelling as really stiff cars do.

good luck,

howard coleman[/QUOTE]


Hi Howard,
Heh - good to know my initial impressions weren't off. So many people
think "stiff = fast", when it can be quite the opposite. Stiff chassis always good,
stiff swaybars, springs, shocks maybe not...

David

turbogarrett

iTrader: (1)

It usually happens at the beginning of the turn, once in awhile the back end will kick out. I am by no means an expert driver with only about 6 track days(road america) under my belt, so some of the problem may be a loose nut behind the wheel

I don't have a pyrometer, but will put that on my shopping list. I have the car aligned to pettit's long track specs and run 30# in the fronts and 28 in the rears. The car was corner weighted in spring after I installed the coilovers. At the track I usually turn the shocks to full hard, I will have to experiment more with that and tire pressures.

Howard, you know road america well. I can only go 75, 80 tops through the carousel before the rear starts to feel loose. It is a long, gradual maybe 140* right turn that other cars seem to catch me at. Would more bar in the front benefit me in a long, sweeping corner like this? Thanks for the help!

DamonB

If you're running all four shocks at full hard the first thing I'd try is softening the rears to say half of what you're running now. You want to make the change big enough to be sure its obvious in how it changes the car. Just as an example I run Koni yellows and at most tracks the front is typically 75%-100% fully stiff while the rear is typically 0%-50% of fully stiff.

Depends. If the car is loose around the entire corner once the outside suspension is fully loaded up most likely a stiffer front bar would help. If the car is only loose at entry this problem can be helped by softening the rear shocks. When the car is transitioning between manuevers you're feeling the shocks and when the car is at steady state you're feeling the springs and bars.

All that said I wouldn't bother adding a new front bar into the mix of things to play with until I'd finished playing with the tire pressures, shocks and alignment. You don't always have to throw parts at the car to solve a problem. IMO the softer front bar will make the car easier for a beginner to read and will inspire more confidence (softer cars in general will do this) and help prevent mistakes. Stiffer is faster in many cases but it's also much less forgiving. Since you haven't tried making any adjustments to fix the problem yet I wouldn't bother with a stiffer front bar.

Also make sure you're not trying to fix a driver induced problem by adjusting the car. An experienced person riding with you can be a huge help here. In my experience people who constantly have a lot of trouble at entry to different turns are consistently doing something that upsets the car, they just don't realize the cause and effect. If you're not driving some guy crazy by trying to pick his brain all the time decide on someone and start doing so

Howard Coleman

iTrader: (6)

i agree w most everything posted by Damon.

"usually happens at the beginning of a turn..."

i don't know how others drive but i drive a straight line into a turn and do almost all my braking going straight, turn the wheel at the same time i am on the gas. there is no time i am not on the brake or the gas. so if the car is loose it is probably under power application. you have a very powerful V8 powered lightish weight car. it is possible that you are on the gas just a bit much at a time when the tires are dealing w lateral forces. just a possibility. soften up the power application especially in lower speed corners... turn 5, canada corner, turn 6, etc. also soften up the rear tires by 2 pounds.

if your car ends up loose in the carousel you do need to do some chassis tuning. it could be any number of things, air pressure, toe, camber, shock settings... your springs are o k. what is your ride height measured to the top of the wheel wells? it is highly likely that you have a settings issue not a hardware issue. (pyrometer). as to the carousel, i would take 2 pounds of air out of the rear tires as a starter.

i would reset your shocks initially full soft in the rear and 30% from full soft in the front. then if you feel you want more shock raise each end a click at a time.

let me know the next time you are at RA and i will try to make it up w my tools and we will do a bit of dialing.

howard coleman