What Have I Done? Understeer!?!
05-19-2009, 05:28 PM
#46
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Thread Starter
I started with 36 cold all round, raised em due to pushing, as high as 44 hot, then lowered the fronts to 38 hot. Cooled down to 34 cold. I typically ran the Pilot Sports at 36 cold all round with just the right amount of side wall scrubbing.
05-19-2009, 06:24 PM
#47
Rennlist Member
generally, too much pressure for a track day, regardless. try 30psi cold next time and you might be surprised. If it doesnt work, it will feel sqirmy, but street tires are tough to get to work right on the track anyway.
mk
mk
05-19-2009, 06:57 PM
#48
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05-19-2009, 07:16 PM
#49
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Don't the AX folks usually run more cold pressure than the DE folks? On a track you get a full warm-up lap to get the tires to operating pressures (and temperature) where as on an AX there's (usually) no warm-up so, too little pressure can pull the tire off the wheel. Yes? No?
05-19-2009, 07:27 PM
#50
Rennlist Member
this is true. the serious AX folks run AX type tires which are supposed to be softer and have stiffer sidewalls for this reason, but Ill leave it to them to chime in.
mk
mk
Don't the AX folks usually run more cold pressure than the DE folks? On a track you get a full warm-up lap to get the tires to operating pressures (and temperature) where as on an AX there's (usually) no warm-up so, too little pressure can pull the tire off the wheel. Yes? No?
08-10-2009, 09:31 AM
#51
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Thread Starter
Thought I would post and update.
Alignment!!! Those Dunlop Direnza Sport Star Spec are VERY sensitive to camber. Stock camber and toe produced understeer. At the low end of the stock ride height we maxed out the toe and put as much camber in as we could to get as close as possible to zero toe. Adding more camber made negative toe. Ended up with -1.6 in the front and -.7 in the rear. Made a huge difference at the limits. Went from massive understeer to very managable slight oversteer. Woo hoo!
Doing my favorite on ramp clover leaf it was 10mph faster. Went from 55mph to 65mph. Braking oversteer turn-in is now gone. I will need to soften the rear rebound to get some of that back. High speed esse turns the car now 4 wheel drifts through the apex instead of having to slow due to understeer.
Alignment!!! Those Dunlop Direnza Sport Star Spec are VERY sensitive to camber. Stock camber and toe produced understeer. At the low end of the stock ride height we maxed out the toe and put as much camber in as we could to get as close as possible to zero toe. Adding more camber made negative toe. Ended up with -1.6 in the front and -.7 in the rear. Made a huge difference at the limits. Went from massive understeer to very managable slight oversteer. Woo hoo!
Doing my favorite on ramp clover leaf it was 10mph faster. Went from 55mph to 65mph. Braking oversteer turn-in is now gone. I will need to soften the rear rebound to get some of that back. High speed esse turns the car now 4 wheel drifts through the apex instead of having to slow due to understeer.
08-10-2009, 11:10 AM
#52
Rennlist Member
yep, when I got hit in my race at sears at the beginning of the year, i had to run the entire race with about .5" toe in up front. it just wouldnt turn in as well and sweepers were bad too. wore the outside edge of the tire on the way home. 
. (not bad, toyos are tough!). then, at 0 toe, the handling came back. however, my car has a tendency to push anyway, at the extreme limits. Just under, its on rails with R compounds obviously.
. (not bad, toyos are tough!). then, at 0 toe, the handling came back. however, my car has a tendency to push anyway, at the extreme limits. Just under, its on rails with R compounds obviously.Thought I would post and update.
Alignment!!! Those Dunlop Direnza Sport Star Spec are VERY sensitive to camber. Stock camber and toe produced understeer. At the low end of the stock ride height we maxed out the toe and put as much camber in as we could to get as close as possible to zero toe. Adding more camber made negative toe. Ended up with -1.6 in the front and -.7 in the rear. Made a huge difference at the limits. Went from massive understeer to very managable slight oversteer. Woo hoo!
Doing my favorite on ramp clover leaf it was 10mph faster. Went from 55mph to 65mph. Braking oversteer turn-in is now gone. I will need to soften the rear rebound to get some of that back. High speed esse turns the car now 4 wheel drifts through the apex instead of having to slow due to understeer.
Alignment!!! Those Dunlop Direnza Sport Star Spec are VERY sensitive to camber. Stock camber and toe produced understeer. At the low end of the stock ride height we maxed out the toe and put as much camber in as we could to get as close as possible to zero toe. Adding more camber made negative toe. Ended up with -1.6 in the front and -.7 in the rear. Made a huge difference at the limits. Went from massive understeer to very managable slight oversteer. Woo hoo!
Doing my favorite on ramp clover leaf it was 10mph faster. Went from 55mph to 65mph. Braking oversteer turn-in is now gone. I will need to soften the rear rebound to get some of that back. High speed esse turns the car now 4 wheel drifts through the apex instead of having to slow due to understeer.
