Auto-x setup questions
Thread Starter
Racer
Joined: Aug 2010
Posts: 344
Likes: 0
From: Lebbrownsville Indiana
Auto-x setup questions
OK, since my main release is auto-x'ing, and I know how to setup a FailWheelDriver, I am at a loss for this one. 88 Z51 4+3. I currently have 255/45/17's (wrong size, but they were new, might as well wear them out) up front and 275/40/17's Kumho SPT out back. What kind of tire pressures should I run? What type of alignment settings would you recommend?
This one will be an all-purpose star before it's over (track days as well), so nothing too auto-x specific. Something that translates to a good track day setting as well.
Any thoughts/recomendations would be appreciated.
This one will be an all-purpose star before it's over (track days as well), so nothing too auto-x specific. Something that translates to a good track day setting as well.
Any thoughts/recomendations would be appreciated.
Drifting
Joined: Feb 2008
Posts: 1,267
Likes: 27
From: Texas
I droped 2 seconds going to Hoosier R6s on a SHORT autox course. A6s would be even better.
As for alignment I Have it toed in 1 since its my daily driver. As for PSI I run 32 on the R6s. Im in south texas though and the temp was 95+ outside with NO CLOUDS. PSI will change depending on tired and track condition. I was also getting NO spin leaving at 1500rpm. (Auto 400rwhp 440tq)
As for alignment I Have it toed in 1 since its my daily driver. As for PSI I run 32 on the R6s. Im in south texas though and the temp was 95+ outside with NO CLOUDS. PSI will change depending on tired and track condition. I was also getting NO spin leaving at 1500rpm. (Auto 400rwhp 440tq)
Race Director
Joined: Jun 2004
Posts: 13,922
Likes: 700
From: WI
It's nice to be back to RWD isn't it? You will likely have a lot of under steer with that setup. Try to get as much camber as you can. With all the shims out you may only be able to get 1° or with some car much less. It varies per car!!! I can get 1.5° on one side of mine and only 1.1° on the other. I will probably machine the conical spacers down for a little more and do offset bushings.
For pressure I look at the tire after a run. You will be able to see the wear, lower the pressure till all the tread is getting worn. I would think 32 PSI hot would be the maximum you would ever want. Last event I think I was using 28 PSI hot.
Settings:
Front toe, 1/16" out per side.
Front camber, try to get 2° negative per side.
Front caster, as much as possible.
Rear camber, 1° negative or less depending on course.
Rear toe, 1/8" in, per side.
For pressure I look at the tire after a run. You will be able to see the wear, lower the pressure till all the tread is getting worn. I would think 32 PSI hot would be the maximum you would ever want. Last event I think I was using 28 PSI hot.
Settings:
Front toe, 1/16" out per side.
Front camber, try to get 2° negative per side.
Front caster, as much as possible.
Rear camber, 1° negative or less depending on course.
Rear toe, 1/8" in, per side.
Thread Starter
Racer
Joined: Aug 2010
Posts: 344
Likes: 0
From: Lebbrownsville Indiana
I had the car in here on the lift (work at an "Expensive" honda dealer, acura) and went over everything. Front bushing have some cracking but aren't loose yet Rears are about the same. It's one of my winter projects, new bushings all around. Also noticed that one of the previous owners replaced the Bilstiens with Monroes.... that explains why the *** isn't as controlled as I thought it should be.
Drifting
Joined: Feb 2008
Posts: 1,267
Likes: 27
From: Texas
R888s and NT05s are good for street and track tho
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Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Start out over at vette brakes and products. They have some alignment settings. Since you want to burn off the tires no worries there, a bit harder since you have two different types but you can figure it out.
Depending on the tires, usually you want to up the psi ~10 and go from there. You can pick up a cheap digital infared thermometer from Harbor Freight and immediately after a run pull back into the pits, crank the front wheels at an angle and take outside, middle, inside readings to look at the heat distribution. You want it even across the tire, that plus obviously feeling for tire roll over etc will help get you closer. Depending on your given alignment you may only get so close but it will be better than most.
Have fun, it is a great way not to get a ticket and it sounds like you know what you are doing. Save the R comps for later, once you have R's it is too painful to go back! (And it hides big driver flaws!)
Depending on the tires, usually you want to up the psi ~10 and go from there. You can pick up a cheap digital infared thermometer from Harbor Freight and immediately after a run pull back into the pits, crank the front wheels at an angle and take outside, middle, inside readings to look at the heat distribution. You want it even across the tire, that plus obviously feeling for tire roll over etc will help get you closer. Depending on your given alignment you may only get so close but it will be better than most.
Have fun, it is a great way not to get a ticket and it sounds like you know what you are doing. Save the R comps for later, once you have R's it is too painful to go back! (And it hides big driver flaws!)
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
It's nice to be back to RWD isn't it? You will likely have a lot of under steer with that setup. Try to get as much camber as you can. With all the shims out you may only be able to get 1° or with some car much less. It varies per car!!! I can get 1.5° on one side of mine and only 1.1° on the other. I will probably machine the conical spacers down for a little more and do offset bushings.
For pressure I look at the tire after a run. You will be able to see the wear, lower the pressure till all the tread is getting worn. I would think 32 PSI hot would be the maximum you would ever want. Last event I think I was using 28 PSI hot.
Settings:
Front toe, 1/16" out per side.
Front camber, try to get 2° negative per side.
Front caster, as much as possible.
Rear camber, 1° negative or less depending on course.
Rear toe, 1/8" in, per side.
For pressure I look at the tire after a run. You will be able to see the wear, lower the pressure till all the tread is getting worn. I would think 32 PSI hot would be the maximum you would ever want. Last event I think I was using 28 PSI hot.
Settings:
Front toe, 1/16" out per side.
Front camber, try to get 2° negative per side.
Front caster, as much as possible.
Rear camber, 1° negative or less depending on course.
Rear toe, 1/8" in, per side.
Only thing I think different would be tire pressure- street tires or extreme summer performance tires- 38/36psi frnt and 34/32psi rear. Then like Aardwolf said, look at your tires and see how much you are rolling over on the side wall. 
Team Owner
Joined: Mar 2001
Posts: 30,837
Likes: 289
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
I ran the 255f/285r setup for years
I pushed like a pig
Do yourself a favor and pickup another pair of 17x9.5 rims so you can run 275's up front, big improvement.
If you can' afford it, flip the tire pressure, run more in the back to loosen it up.
I pushed like a pig
Do yourself a favor and pickup another pair of 17x9.5 rims so you can run 275's up front, big improvement.
If you can' afford it, flip the tire pressure, run more in the back to loosen it up.
Thread Starter
Racer
Joined: Aug 2010
Posts: 344
Likes: 0
From: Lebbrownsville Indiana
Car was very neutral. Easy to step out, handled great. Very minimal push, easily changes into oversteer. Always undercontrol. The SPT's liked 31 up front and 29/30 outback. Ran into OTHER issues, like a stuck PCV Valve making the oil push out around the cap. ABS worked wonderfully... much better than I remember it working on Dad's 91 9C1.
Overall, I give it an 8 out of 10 with room for improvement.
edit: these are 17x9.5's on all 4 corners.
Overall, I give it an 8 out of 10 with room for improvement.
edit: these are 17x9.5's on all 4 corners.
Last edited by Bobzilla; Aug 30, 2010 at 12:27 PM.
Team Owner
Joined: Aug 2005
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From: Riverside County Southern California
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St. Jude Donor '09 thru '20
I had 255 in the front in my 95 and there were worthless. I run 285/40ZR17 all around and it handles great.
In my 96 I run 285/40ZR17 front and 315/35ZR17 rear.
In my 96 I run 285/40ZR17 front and 315/35ZR17 rear.
Thread Starter
Racer
Joined: Aug 2010
Posts: 344
Likes: 0
From: Lebbrownsville Indiana
I wouldn't call them worthless. They were generating more grip than the 275s on the rear were on Sunday.... 
Sure, if money were no option and I had everything else worked out, I'd run some 295's or larger....
Also, seat options for taller folks? Somethign that A.) holds my body in place, 2.) lets me wear a helmet with the top on and iii.) isn't uncomfortable to drive a few hours in.
Sure, if money were no option and I had everything else worked out, I'd run some 295's or larger.... Also, seat options for taller folks? Somethign that A.) holds my body in place, 2.) lets me wear a helmet with the top on and iii.) isn't uncomfortable to drive a few hours in.
Last edited by Bobzilla; Aug 31, 2010 at 04:03 PM.
