No rear sway bar= push
01-29-2010, 12:45 PM
#14
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When I was setting up the car for Stock, I spent more time changing rear alignment than I did shock settings getting the car to handle how I wanted.
You can also add some rear compression if the car is pushing on throttle.
You can also add some rear compression if the car is pushing on throttle.
01-29-2010, 10:36 PM
#17
Thread Starter
Well, I was having an issue with push and I couldn't believe that with the springs I was running, I was still having push.
Anyway, I measured the toe with some toe plates and I got about 7/16 of difference between the front and rear measuring points on the plates. I marked the rear camber bolts because I knew they were even since they were set on a professional rack. I then fooled around with it until I had abour 1/16 of difference in the measurements and went for a test spin.
All the push was gone. I was shocked.
Basically, the toe is an amazing way to settle the back end after you get your roll bias set. I love it.
Just make some marks, take your time and mess with it. you'll find that the toe is a great tuning tool. If the car gets too loose, just add toe.
Anyway, I measured the toe with some toe plates and I got about 7/16 of difference between the front and rear measuring points on the plates. I marked the rear camber bolts because I knew they were even since they were set on a professional rack. I then fooled around with it until I had abour 1/16 of difference in the measurements and went for a test spin.
All the push was gone. I was shocked.
Basically, the toe is an amazing way to settle the back end after you get your roll bias set. I love it.
Just make some marks, take your time and mess with it. you'll find that the toe is a great tuning tool. If the car gets too loose, just add toe.
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sigma2k (06-24-2018)
01-30-2010, 05:53 AM
#18
Matt - don't forget that you also changed your camber when you made the toe change.
Thats the one thing that I liked better about my ST car - toe and camber were independent - I could change one or the other and get a completely different handling change. On the S2000 - they both change at the same time and it can be a pain to only change toe and leave camber the same.
And I'm with Drew - I spent all my time on the ST car changing rear alignment to get the handling I wanted - I barely ever touched the shocks.
Matt - I told you I'd type this up via email but I'm in the mood to do this now.
Toe = transients. In a slalom or corner entry - the car never reaches terminal roll. The shape of the contact patch is still relatively longer than it is wide so the toe angle dictates how long it takes for the tire to shear and reach the point where the tire starts to slide. Toe will delay or expedite the transition point from grip to slide. Also - less camber will keep the car more stable at this phase of the corner.
Camber = steady state. At terminal/maximum roll the contact patch is wider than it is long. Camber thrust and angle dictate how grip is generated at this phase of the corner. Too much front camber will lead to bad corner entry grip, too much rear camber will lead to entry loose and mid corner push. Toe doesn't have nearly as much of an effect as camber because of the shape of the contact patch.
Also - remember that the phases of the corner run into each other very quickly in an autox - a steady state condition is a very rare occurance and autox'ing can be considered ALL transients for the most part. You aren't adding or reducing grip by changing front/rear camber (a common misnomer is that if you add camber you'll get more maximum grip) - you are just changing the phase of the corner where your maximum grip is generated.
Road race situations will be different than autox where they see very long sustained steady state conditions and keeping the outside tires at the optimal camber angle for a long period of time will be very important.
In my experience, there is absolutely no reason to run more than 2.5-2.6 deg of camber on either end of the car for autox. Doesn't matter if you are on Hoosier's or Street Tires.
I'm also running no rear bar and a total toe in of 1/4" to help it put power down. This also keeps the car stable under braking and turn in. I'm running 2 deg of camber.
Matt - I find it interesting that you didn't use rear camber/toe on the CRX much. I could tell a marked difference on my Civic. Lowering the rear 2 turns on the coilovers would get me another .25 deg of neg camber and 1/16" of total toe in. For low grip surfaces I would run lower, for high grip I'd run higher with less camber and toe. Baseline was 2.6deg and 1/8" total in. Shenefield told me once that the fastest FWD cars are going to be the ones that are still turning when you are on the gas. I know he wasn't running the shocks you were but I had my car very very close to that point. Hell I've heard rumors of people fun running the car (owned by a guy in VA now) and going faster than O'Maley at local events.
Thats the one thing that I liked better about my ST car - toe and camber were independent - I could change one or the other and get a completely different handling change. On the S2000 - they both change at the same time and it can be a pain to only change toe and leave camber the same.
And I'm with Drew - I spent all my time on the ST car changing rear alignment to get the handling I wanted - I barely ever touched the shocks.
Matt - I told you I'd type this up via email but I'm in the mood to do this now.
Toe = transients. In a slalom or corner entry - the car never reaches terminal roll. The shape of the contact patch is still relatively longer than it is wide so the toe angle dictates how long it takes for the tire to shear and reach the point where the tire starts to slide. Toe will delay or expedite the transition point from grip to slide. Also - less camber will keep the car more stable at this phase of the corner.
Camber = steady state. At terminal/maximum roll the contact patch is wider than it is long. Camber thrust and angle dictate how grip is generated at this phase of the corner. Too much front camber will lead to bad corner entry grip, too much rear camber will lead to entry loose and mid corner push. Toe doesn't have nearly as much of an effect as camber because of the shape of the contact patch.
Also - remember that the phases of the corner run into each other very quickly in an autox - a steady state condition is a very rare occurance and autox'ing can be considered ALL transients for the most part. You aren't adding or reducing grip by changing front/rear camber (a common misnomer is that if you add camber you'll get more maximum grip) - you are just changing the phase of the corner where your maximum grip is generated.
Road race situations will be different than autox where they see very long sustained steady state conditions and keeping the outside tires at the optimal camber angle for a long period of time will be very important.
In my experience, there is absolutely no reason to run more than 2.5-2.6 deg of camber on either end of the car for autox. Doesn't matter if you are on Hoosier's or Street Tires.
I'm also running no rear bar and a total toe in of 1/4" to help it put power down. This also keeps the car stable under braking and turn in. I'm running 2 deg of camber.
Matt - I find it interesting that you didn't use rear camber/toe on the CRX much. I could tell a marked difference on my Civic. Lowering the rear 2 turns on the coilovers would get me another .25 deg of neg camber and 1/16" of total toe in. For low grip surfaces I would run lower, for high grip I'd run higher with less camber and toe. Baseline was 2.6deg and 1/8" total in. Shenefield told me once that the fastest FWD cars are going to be the ones that are still turning when you are on the gas. I know he wasn't running the shocks you were but I had my car very very close to that point. Hell I've heard rumors of people fun running the car (owned by a guy in VA now) and going faster than O'Maley at local events.
