btaira

Does the size of the rear sway bar have any effect on the amount of off-throttle oversteer on the protege? That is, can I expect more off-throttle oversteer if I get a larger rear sway bar? I don't think I want any more than the car already has.

I went to an autocross practice on saturday - 18 laps (so much better for learning vs. three laps at a championship event). In any event, a BMW instructor (who drives a 1997 M3 with H&R Sport springs, Konis and Eibach sway bars) did a 360 in my car entering the slalom. He couldn't believe the amount of oversteer on a FWD car!

I'd like to get a little less understeer on the tighter turns, but I do not want any more off-throttle oversteer. Any input would be greatly appreciated.

carguycw

Yes, the rear swaybar does have a large effect on off-throttle oversteer. That's kind of the point.

How to fix it depends on the rest of your suspension setup, and whether you're trying to reduce oversteer all the time or only off-throttle. If you trying to reduce oversteer off-throttle only, here's what I would try:

1) More rear toe-in/ less toe-out. I've observed that rear toe makes a BIG difference in off-throttle handling in a BJ Protege, probably because of the rear-steer suspension geometry. I've found that ANY rear toe-out causes a BIG increase in off-throttle oversteer without really affecting the car's balance in offsets or sweepers.
2) Softer rear shocks or stiffer front shocks... to a point. I've found that too much front shock will make the car push in transitions, while too little shock in either end will make that end unstable in fast transitions. However, a lot of FWD Stock-class drivers swear by really stiff fronts and really soft rears; I've tried this setup before and I was generally unhappy with it, but it sure seems to work for them. However, my Pro does not have adjustable shocks so I can't really comment on this car. Try some adjustment and testing.

Good luck!

carguycw

Just to follow up this comment, a lot of lift-throttle oversteer is a common side effect of setting up a FWD car for autox, and you have to adjust your driving style to match. The reason the M3 instructor may have had trouble with your car is that it demands a different driving style than his RWD car. A lot of tightly-suspended, front-engined RWD cars (M3, my old Miata) respond really well to light trail-braking and slight throttle lifts to balance the car in sweepers. However, try this in a fast FWD SP car, like an 88 CRX, and you will be rewarded with a snap spin. In a fast FWD autox car, you often need to brake earlier and STAY ON THE THROTTLE through the entire turn.

However, I've obviously never driven your car, so YMMV.

btaira

"1) More rear toe-in/ less toe-out. I've observed that rear toe makes a BIG difference in off-throttle handling in a BJ Protege, probably because of the rear-steer suspension geometry. I've found that ANY rear toe-out causes a BIG increase in off-throttle oversteer without really affecting the car's balance in offsets or sweepers. "

I think I will try this. I currently have very slight toe out front (1/16?) and zero toe rear. I only want to decrease oversteer when lifting off the throttle. Does the BG platform give me more toe out in the rear when it is unloaded (i.e., off throttle)? Is this called bump steer? Jesse, I heard that the MR2 does this in the rear. Is it true? Also, regarding your comment - yes, I do tend to overcook the tight corners. I'm still working on .

Carguycw, thanks for the tips! Maybe my car isn't stiff enough, but I can't just STAY ON THE THROTTLE. It will push. I have to feather the throttle on both tight and medium turns. Then again, maybe I wouldn't have to if I had a little more front camber and toe out (and bigger tires - I'm currently on 195/60/14 azenis)!

carguycw

OK, a couple of my earlier remarks came out a little different b/c I was in a hurry while I was writing those posts...

When I said "STAY ON THE THROTTLE" what I meant is that it's important to maintain SOME throttle, not to lift off suddenly, and not to lift off *entirely* in mid-corner. Almost all FWD cars require you to feather the throttle in the tight stuff, it's the nature of the beast.

What I was referring to was lifting suddenly in mid-corner to break the rear tires loose and rotate the car, then getting back into the throttle. In an M3 or 99+ Miata, this works beautifully because you've got RWD and a really nice LSD to control traction in the rear. However, if you try this in a typical CSP CRX, the rear end will start coming around in a hurry, and you'd better get back on the throttle RIGHT NOW or you will (a) spin or (b) scrub off so much speed that the run will be ruined.

Basically, FWD cars that are set up to eliminate understeer always tend to be loose off-throttle. My point (and Jesse's too, I think) is that you have to be judicious with your throttle application, brake early, be precise with your corner entry, and don't try to make big corrections in your line in mid-corner. Front-engine, RWD cars will often tolerate big mid-corner adjustments. FWD SP cars (and mid- or rear-engine RWD cars) usually will not.

mazdaspeedwest

i went through a bit of the same thing when i went to stiffer springs and rear sway bar. I kinda changed my driving style to suit the car, rather than suiting the car to my driving style...more of a personal challenge than anything i guess, but ehhh

I started braking sooner and having "more throttle" for the corner, better excecution of trail braking seemed to help, as i used to tend to swing the *** end out too much...i actually started to brake less (harder bursts rather than longer grabs) but i found myslef braking way too much, way too early or late.....

So i started to focus on 2 things... be smooth and look ahead. All other things are gone, just those 2 things, and i'd say them to myself the whole run...even out loud, yelling....hey, it helped Once i learned those better i went faster and faster.

Barry,
if you can make it to Hollywood Park in LA on the 15th, your welcome to co-drive my car.

Davard

And take part in the SoCal Protege meet.

If you're there on the 14th (Sat), you can get a ride in my car too. Besides me driving, there will be a 2-time National champ practicing in it, too.

Jas00x

Yeah it sounds to me like it was just a driver mistake which sent you guys spinning.
Make sure you are looking ahead!!! When a part of the course surprises you, you won't be as smooth.
I, almost exclusively, brake in a straight line. I use slight lifts in sweepers to get the car to "come around" a little. I try not to trailbrake too much since it is using the brakes and will slow you down. When you get more comfortable with the rotation you get trailbraking you can brake later when you enter the turn.
Another thing I do, and seems to be more prevalent with FWD drivers - is Left foot braking. This helps trailbraking and getting back on the gas (or not lifting at all) much quicker. Its just another way to handle a FWD car.
Note- be sure to practice this on an empty road- the first time to mash the brake with your left foot, you realize how much more sensitive it is than the clutch (read: you may feel like you will fly through the windshield)!!

I'm not sure what model you have, and what mods you have done, but typically the Protege is fairly stable and predictable.
My main problems come from offset transitions!!! They frustrate the hell out of me and like every event in Florida is full of 'em.

btaira

Darryl or David,

Where can I get more information on this December 14/15 event? Is it a practice session? Or is it a championship event?

Davard

Here's the flyer for the Sunday championship. The Saturday practice at in the same location, but unfortunately is sold out (but you can still come out and get rides ).

mazdaspeedwest

without a harness and/or better seat, it's near impossible for me to left foot brake and feel comfortable doing it. My *** slides around too much as it is and i NEED my left leg pinned to the dead pedal and knee shoved into the door panel for stability

I don't really feel it untill i have a passenger. When i see them sliding around, i become conceous of myself sliding... kinda suprised i do as well as i do...it's really rather unpleaseant now that i'm thinking of it.....must add to christmas list....

Jas00x

I use a "Torso Harness". Jesse has used it while driving my car and I think he's used it when he had the Protege. It really helps alot. They only cost $15 from Racer Wholesale. Put it on your Christmas List!
http://www.racerwholesale.com/Mercha...ode=Restraints