I have a Toyota Matrix XRS, specs are 2650 lbs, 1.8 NA Yamaha tuned 2zz rated at 180hp and 6 speed manual. What can i do to prevent or limit drive wheels from spinning in corners? An LSD is a wishlist item but fairly expensive so i was wondering what you guys do to set up FWD for autoX etc?
trucke
SuperDork
4/30/18 3:45 p.m.
You just answered your own question. LSD.
Short of that, you would need to work on your throttle application and steering application to find the limits of both of those variables combined. It will take awhile, but is a great skill that you will always have.
SVreX
MegaDork
4/30/18 3:54 p.m.
More serious answer...
I drive the same car as my daily. (The Pontiac variant)
Its traction challenged.
I know my first step is gonna be much better tires, then a rear anti-roll bar. I don't expect the bar to do much, so then I would stiffen then springs.
All this while I dream of an LSD.
SVreX
MegaDork
4/30/18 3:58 p.m.
For the autoXing part, I'd also get some R-comps MUCH wider then those 205's on the front.
Bigger, stickier tires.
Possibly more roll stiffness in the form of anti-roll bars to keep the tires in the good section of the camber curve.
Stefan
MegaDork
4/30/18 5:01 p.m.
Ditch the front sway bar, get used to turning in earlier, but allowing the springs to keep the tires in contact with the road helps quite a bit.
Swaybars can lift the inside wheel in a corner, especially if they are yuge as most are on FWD cars due to their very nature.
Ride won't suffer since the spring rate hasn't changed, it will roll more, but you could always leave it in place and disconnect one side before an autocross.
If you want to get some roll control back, you can up the spring rate, but you can quickly overwhelm the dampers and ruin the ride comfort. Improved dampers can help with this, but it can become a slippery slope leading towards a lot of money spent and very little street capabilities left.
Add a rear sway bar, especially a big, nasty one, and you can improve the rotation of the car at the exit of the corner so that you can straighten the steering wheel more quickly to allow the power to be applied more evenly. Stuff the biggest, stickiest tires you can under the front, leave the rear less wide and less sticky, some trial and error would be needed to find the right combo.
Bottom line? You'll always have inside wheelspin without some form of limited slip (whether electronic via the brakes or a mechanical via the differential), your best bet is to get the wheels pointed straight as soon as you can, which means you apex LAAAAAAAAATE as possible. To apex late, you may have to square off larger/longer corners.
As much as possible try not apply full throttle until the wheels are straight ahead.
More caster will help plant the inside wheel.
Wait, MORE body roll up front is good? Less in the back too? The rear is a torsion beam something or another so i helped it alot by straightening a trailer leaf spring with my tubing bender and bolting it to the rear twist beam thing with 3" muffler clamps. Works, um, well theres a LOT less body roll but i still have a way to go. I drive a ton for work and every day is an auto cross, rally cross, Gymkahna etc. I went through brand new Sumitomos in 7 months, will stickies last longer due to reduced wheel spin, or work better, but dissapear as quick or quicker than my All Seasons?
And thanks all
Stefan
MegaDork
4/30/18 7:52 p.m.
Its weird, and it makes it feel weird when cornering, but yes it can. The cars that run at the pointy end of the stock classes use no bars up front and really, really stiff dampers to slow the rate of suspension movement.
Remember, manufacturers want the cars to understeer, so big bars up front increase understeer, small or no bars in the rear increase understeer.
You'll be camber challenged no matter what without a lot of changes to the suspension that would ruin the ride.
Big rear bar is the first thing to try, I think. Low cost and little risk and sometimes, it's like a magic transformation.
+1 on the stock or no front sway bar. I have a fatty on my yaris and its always unloading the inside tire. But at higher speed stuff its lovely with my other modifications.
On my tercel I deleted the front sway bar when I installed my FortuneAuto coilovers and it's fantastic
As a general rule of thumb on a 2wd car, more bar on the non-drive end is good. Too much bar on the drive end leads to problems with unweighting the inside drive tire in corners and not putting down power well.
andy_b
New Reader
4/30/18 8:35 p.m.
I DD and autox an 04 Matrix XRS, and with a few changes, have been fairly happy with it. I'm in the same boat, where an LSD is a wishlist item, but pretty hard to justify when it costs nearly as much as I paid for the car. Instead, I've focused on replacing worn out stock parts with upgraded aftermarket options.
Here is what I've done so far to improve its handling, reduce wheel spin, and keep it reasonably comfortable for daily driving:
- Energy suspension engine mounts and control arm bushings (the original bushings were worn, so car had a ton of wheel hop at first. This turned the wheel hop into wheel spin).
- Tein S.Tech springs (134F/168R), part number SKL06-AUB00 (keep in mind, these put you into Street Touring)
- Progress 24mm rear sway bar, part number 62.2150 (REALLY helped cut down on understeer)
- Koni strut inserts up front (marketed for a 9th gen Corolla), part number 8610-1416 (turned almost all the way soft for autocross)
- Koni shocks in back (again, marketed for 9th gen Corolla), part number 80-2844 (I haven't actually installed these yet)
- Slotted strut mount holes towards the firewall to add caster. Stock is 2.8, currently at 3.9 degrees. (The additional stability, and the increased jacking of the inside wheel seemed to help quite a bit with wheelspin).
My first event this year was on pretty average summer tires, and with the above setup (minus the rear shocks), wheelspin is vastly reduced from stock. With just reasonably smooth throttle out of turns, I can keep traction on both front wheels. The cars biggest problem at this point is understeering, which is could largely be offset with proper autocross tires, instead of the 500 utqg tires I'm currently running. I'm not blowing anybodies minds with the Matrix, and I'm near the bottom of my class, but I am loosing to cars that honestly SHOULD be faster than me.
In reply to andy_b :
I screen shot your recipe and will be looking into those mods. Im with you though on putting a lot of money into mods. I paid $3200 for the whole car and if i have to pull the trans again im getting the FX Racing 10# flywheel and LSD. And if i do that the only limit for getting coilovers, RPF1s and some high end tires is my bank balance and my wife. Lol. Whats does SWMBO stand for anyway?
my only contribution here was an old 1988 Hyundai Excel I bought new. In wet conditions is absolutely did not want to turn. I put it up on a kerb in the rain doing just over walking speed as the car just went straight. (no damage done because I was going to so slow) and it was just a general pig due to lack of corning ability and only 62hp.
Several years into my ownership, one of the clips holding the swaybar to the driver's side control arm came loose and disappeared off the side of the road. As I could not get the part short of foing to the Junk yard and I was a poor college student, I just removed the bar. This transformed the car. While it still only had 62hp, it would run away from almost anything on the road through the twisties... even on tiny little 175/70/13 cheapo tyres. The front stayed planted and the rear got a bit loose, it was bliss
I dont know which is more helpful, front sway bar advice or SWMBO definition!
In my ZX2SR I had a device that went between the spider gear and applied pressure to give a some what limited slip effect. With very little body roll , more caster and this device I had very little inside wheel spin.
Forget the name.
Hey , it was cheaper and a LSD was not readily available.
iceracer - i think you must be talking about a Phantom Grip
I'd love to find my wife a ZX2SR and get her into autocrossing.