RA1 Tire tech Qs

[berny2435]

RA1s questions here: I'm pretty much a noob (5 track days experience) and took my 95 Civic K20A2 swapped ride out to the track on some fresh, non shaved 225/45/15 RA1s. 2480 with driver and full tank. Camber a -2.5 front and -2 rear, NO LSD. New sus bushings and some spherical bearings hear and there. Koni Race with 650 fr and 850 rear.

 

?? How much does the RA1 cool down after one cool down lap??

 

I tend to not use the brakes but still take the corners with a good amount of speed.

 

?? What would be a sugested RANGE that I should stay within for HOT pressures??

 

?? If you've experience one tire gaining 3 psi more than the other tire around the course, did you start that tire out 3 psi lower or ??

 

?? On my FL, If I went from 31 cold PSI to 44 PSI, do you think I got that tire too hot???

 

I'm going back to the same track at the end of September so any info and suggestions is much appreciated.

 

Thanks

[ghettoracer]

you should get an LSD. excessive tire spin will create lot of heat and tire wear. if you are really concern about pressure, you can also measure tire temp to get better ideas on whats going on....

[lightningd]

oh my old accord (weighed 2750) i started pressures on the ra1's at 28, and they heated up to about 34-36. most people said that was ok, but i'm far from a tech with track setups.

 

at vir full, i started to put more air pressure in the right rear b/c it didn't heat up and gain as much pressure, which was causing me to push on the few left handers. i think i ended up at

 

LF: 28 LR:28

LR: 30 RR: 32

 

...cold before a run.

 

EDIT: they heated up to about 34-36 when measuring AFTER running around the paddock for a minute to cool the brakes.

[berny2435]

good stuff guys.

 

Yeah, I totally need to get a LSD, next year I'm just gonna buy an extra tranny. Mid America Motorplex is hard on Left front tires I guess. More righties than lefties. People typically do start the LF at a lower pressure.

 

I've talked to a few people about runnin RA1s and I have a good plan for the next event. I'll have a friend taking temps and pressures for me as well. I might be headin to the track this weekend again, well C what happens.

 

Cold pressures at LF 26, RF 28, rears at 29. Goal is hot pressures at 38 front and 35-36 rear

 

 

By looking at the track and remember where I was making the tires squal most of the time, MANY of the righties the tires are talkin to me.

 

Edited August 28, 2007 by Guest

[wm577]

My car is bit heavier than yours at 2700lbs, but I run cold pressures of:

 

25 PSI Front

28 PSI Rear

[berny2435]

My car is bit heavier than yours at 2700lbs, but I run cold pressures of:

 

25 PSI Front

28 PSI Rear

 

coo coo. I hear some FWD guys even like to be as low as 35 HOT in the front. I'll play around a bit and see where I like it.

 

I'm not runnin too much camber so I think 38 is gonna be good number for me.

[StealthTT]

If you can pull off into the hot pits and take measurements as soon as possible. MAM is set up fairly well for this as there are a couple good corners before the pit entrance.

 

Also, use tire chalk to see if your over or under inflated. Over inflated = you'll be riding on a crown and not using the whole tire. Underinflated = you'll be riding on the sidewalls.

[berny2435]

Also, use tire chalk to see if your over or under inflated. Over inflated = you'll be riding on a crown and not using the whole tire. Underinflated = you'll be riding on the sidewalls.

 

I actually saw significantly more inside wear on the fronts and slightly more outside wear on the rears.

 

I think from running too high of pressure I pushed more into corners, not rolling over the fronts enough and causing inside wear.. . I could be totally wrong though.

 

Maybe running zero toe caused the uneven wear durring braking?

 

I've replaced all bushings in the suspension within the last 6 months and had an alignment a couple weeks before going to the track.