STU: Understeer Understeer!! can you help ?
Try to lower the pressures for sure. The rule of thumb is you want as low of tire pressures as you can have without rolling the tire over too much. there are little arrows on the sidewalls that you shouldnt go much past. Now, without adding camber, you are most likely going to roll past those arrows no matter what, so It would be a really really good idea to run the "max" camber you can with the stock camber bolts.
As I see from the video, I couldnt tell what the car was doing at the turnaround. But I did see you doing a very common mistake. You werent "Backsiding" the slalom cones, or late-apexing them. heres a very quick illustration I threw together (dont laugh). moving from left to right, your path is o n the top, "backsiding" is on the bottom:
This also goes for those offsets in the video, you dont want to turn at the cone, you turn before it and pass by the back side of the cone (hence the name). If you dont use this technique, it is extremely easy to get behind with your turn-ins on a slalom and then you have to slow down, you scrub speed turning in harder, or you plow through cones alltogether. It is much faster and smoother to use this technique.
As I see from the video, I couldnt tell what the car was doing at the turnaround. But I did see you doing a very common mistake. You werent "Backsiding" the slalom cones, or late-apexing them. heres a very quick illustration I threw together (dont laugh). moving from left to right, your path is o n the top, "backsiding" is on the bottom:
This also goes for those offsets in the video, you dont want to turn at the cone, you turn before it and pass by the back side of the cone (hence the name). If you dont use this technique, it is extremely easy to get behind with your turn-ins on a slalom and then you have to slow down, you scrub speed turning in harder, or you plow through cones alltogether. It is much faster and smoother to use this technique.
never knew there was an actual term for it. that makes sense though, backsliding is exactly what you want to do.
but how would you do it? lift a little mid corner to load the front and lighten the rear or try to gently power slide the rear around?
when you draw it out like that I can clearly see how late apexing is much smoother. thanks for the detailed description, I can't wait to try it out next time.
that was the first time I ran pressures that high. usually im in the mid to higher 30's. Its good to know I can make the car very loose if I want to with just some psi. i'm going to bring shoe polish with me next time and I'll attempt to go as low as I can w/o rolling.
Backsiding relies on where you turn-in. the extremely good drivers (not me) basically turn-in when they can still see the cone, and aim basically at it. they have enough feel for thier cars movements they can determine how much the car will slide, thus missing the cone, just barely. I just think of backsiding as using the cone as the late-apex to a turn, and stringing it all together.
and dont forget to add in camber if you can, it com0pletely changes the way the car drives, for the better.
and dont forget to add in camber if you can, it com0pletely changes the way the car drives, for the better.
Last edited by RaNGVR-4; Jun 19, 2008 at 12:38 PM.
Well its the end of the season now and I appear to have it locked up the season with only one points event left. I found also that a very weak link was my alignment -2.0 i (or in my case 1.8/1.9 zero toe) isnt enough. Alignment is usually the second thing I change (tires first). The flipped bolts just werent enough. I decided on upper camber plates (in this case Cusco) to get the job done. I would have preferred Whitelines as I am told they are a better plate that also allows a bit of caster, but I didnt have the cash.
I set my alignment with me in the driver seat to take away any variance in my spec (actually made a .1-.2 difference when i would sit in the car and I am only 185lbs).
Since I DD my car I went as about as aggressive as I thought I could without making the car harder to driver and harder on tires. So I ended up with -2.6 and 1/8 out. This made an incredible improvement. The gap between me and the consistent 2nd place car opened from .3 to over 1 second, and allowed me to win 5 straight events. The plates also made the car bite sooner and just feel 'right'. I can still understeer if I overdrive it which unfortunately I still do way too much. But its a good feeling to know its now just my attitude.
I still have a pretty substantial amount of body roll. So:
I picked up a set of SSR-C's off a member and will be getting the kw-variants in the spring. Next year it looks like the direzza's will replace my bridgestones and maybe a few other minor changes but I am hoping to improve that much more in the gap to nationally ranked drivers. Time will tell
I set my alignment with me in the driver seat to take away any variance in my spec (actually made a .1-.2 difference when i would sit in the car and I am only 185lbs).
Since I DD my car I went as about as aggressive as I thought I could without making the car harder to driver and harder on tires. So I ended up with -2.6 and 1/8 out. This made an incredible improvement. The gap between me and the consistent 2nd place car opened from .3 to over 1 second, and allowed me to win 5 straight events. The plates also made the car bite sooner and just feel 'right'. I can still understeer if I overdrive it which unfortunately I still do way too much. But its a good feeling to know its now just my attitude.
I still have a pretty substantial amount of body roll. So:
I picked up a set of SSR-C's off a member and will be getting the kw-variants in the spring. Next year it looks like the direzza's will replace my bridgestones and maybe a few other minor changes but I am hoping to improve that much more in the gap to nationally ranked drivers. Time will tell
Since I DD my car I went as about as aggressive as I thought I could without making the car harder to driver and harder on tires. So I ended up with -2.6 and 1/8 out.
Thanks!
Backsiding relies on where you turn-in. the extremely good drivers (not me) basically turn-in when they can still see the cone, and aim basically at it. they have enough feel for thier cars movements they can determine how much the car will slide, thus missing the cone, just barely. I just think of backsiding as using the cone as the late-apex to a turn, and stringing it all together.
and dont forget to add in camber if you can, it com0pletely changes the way the car drives, for the better.
and dont forget to add in camber if you can, it com0pletely changes the way the car drives, for the better.
Here's a closeup showing how far his wheel is turned. Notice that the car is just past the centerline of the slalom and he's already turned for the next cone.
Here's to prove that he didn't actually hit the cone:
I still have a pretty substantial amount of body roll. So:
I picked up a set of SSR-C's off a member and will be getting the kw-variants in the spring. Next year it looks like the direzza's will replace my bridgestones and maybe a few other minor changes but I am hoping to improve that much more in the gap to nationally ranked drivers. Time will tell
I picked up a set of SSR-C's off a member and will be getting the kw-variants in the spring. Next year it looks like the direzza's will replace my bridgestones and maybe a few other minor changes but I am hoping to improve that much more in the gap to nationally ranked drivers. Time will tell
d
Bingo! Here's a set of photos from one of our region events. This series is Corey Ridgick coming through the last slalom into the finish.
Here's a closeup showing how far his wheel is turned. Notice that the car is just past the centerline of the slalom and he's already turned for the next cone.
Here's to prove that he didn't actually hit the cone:
Here's a closeup showing how far his wheel is turned. Notice that the car is just past the centerline of the slalom and he's already turned for the next cone.
Here's to prove that he didn't actually hit the cone:
I only expect tires to last one season and these are going to make to at the very least a couple of driving schools next years, so not really eating but I am sure they wouldnt go 2 full seasons.
Thats each side.
I'm still trying to figure out how to convert inches of toe into degrees of toe (since that's what the machines at the alignment shops display. I've come to figure out that it depends on the size of the car!
Of course, I run 0 toe out which happens to also be 0 degrees.
d
I budget replacing tires on all my cars at least once a year. The stock advans on the X only made it 6000 miles (about 6 months). Of course, they have a couple track days and 7-8 autocrosses on them (with a ham fisted driver at the helm).
I'm still trying to figure out how to convert inches of toe into degrees of toe (since that's what the machines at the alignment shops display. I've come to figure out that it depends on the size of the car!
I'm still trying to figure out how to convert inches of toe into degrees of toe (since that's what the machines at the alignment shops display. I've come to figure out that it depends on the size of the car!
http://www.smartracingproducts.com/p...ngs_manual.pdf
Look at page 10 of the PDF.
For those of you running 17" wheels, at 1/8" toe, that's like .43*?
That seems like a lot considering the stock toe is either 0 or like .04*!
Look at page 10 of the PDF.
For those of you running 17" wheels, at 1/8" toe, that's like .43*?
That seems like a lot considering the stock toe is either 0 or like .04*!
Last edited by goofygrin; Oct 1, 2008 at 10:25 AM.
http://www.smartracingproducts.com/p...ngs_manual.pdf
Look at page 10 of the PDF.
For those of you running 17" wheels, at 1/8" toe, that's like .43*?
That seems like a lot considering the stock toe is either 0 or like .04*!
Look at page 10 of the PDF.
For those of you running 17" wheels, at 1/8" toe, that's like .43*?
That seems like a lot considering the stock toe is either 0 or like .04*!
In any case 1/8th out is certainly outside of the factory spec, but so is the -2.5-3.5 degrees of camber that we run.
d
Evolving Member
Joined: Aug 2006
Posts: 130
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From: Adelaide, South Australia
I hate to point out the obvious with all of this great discussion going on, but the OP's posted photographs clearly show a huge amount of bodyroll.
If he's on the stock Bilstein's, then theyre probably a bit too soft for the tarmac autocross events.
you seriously need to have stiffer springs and much more dampening - keep that body roll in check.
I find maximum castor and some negative front and a little less negative rear about right.
I dont find understeer any kinda of problem in the evo. I use Tein SS and have it lowered slightly but I have the roll center well within a good range. Stiffened slightly and then each event is tuned for using tyre pressures and dampening settings. the rest I leave well alone.
Stock rear and front sway bars. I wouldnt stiffen the front bar on the AWD at all and I'd only slightly stiffen the rear if any. If you want a more rear-led car then put in the ralliart centre diff controller and increase your rear pressures while leaving the chassis balance of the car neutral.
Trav
If he's on the stock Bilstein's, then theyre probably a bit too soft for the tarmac autocross events.
you seriously need to have stiffer springs and much more dampening - keep that body roll in check.
I find maximum castor and some negative front and a little less negative rear about right.
I dont find understeer any kinda of problem in the evo. I use Tein SS and have it lowered slightly but I have the roll center well within a good range. Stiffened slightly and then each event is tuned for using tyre pressures and dampening settings. the rest I leave well alone.
Stock rear and front sway bars. I wouldnt stiffen the front bar on the AWD at all and I'd only slightly stiffen the rear if any. If you want a more rear-led car then put in the ralliart centre diff controller and increase your rear pressures while leaving the chassis balance of the car neutral.
Trav