whats up. im head n down to the track this weekend. last time i went to the track i had my tire pressure at around 25 psi and i ran a 60 ft time of 2.3 sec's. the tires on the car were bald at that time and i was run n on the stock steelies. i just got a new set of Dunlop sport 8000 tires on rota slipstreams. what tire pressure should i set the car too if i launch at around 4.5K?

 

20 psi should do ya good. Don't expect too much better than a 2.3, though, if you're still on stock bushings, stock engine mounts, no traction bars, stock open differential, or anything like that.

 

I'm still not certain that lowering tire pressure on modern tires does anything

 

this is the way I was tought...

start with 27psi
doo a quick launch stop
get off the car and check tire marks
in the first run you will see how much of the thread shows
for example if you see the outer threads only lower the press
try again untill you see the full marking of tire from left to right.
once you see this, it is the right pressure.

 

well i think my 60' times should be better. i ran that 2.3 sec with only Intake and exhaust. i was also run n on bald pirelli tires. i launched at 4K

This time at the track im gonna have I/E/H, MSD 6a and blaster 2 coil, new plugs/wires, no AC and PS, CROWER 62403 cams, SAFC (slightly tuned), SKUNK2 cam gears (slightly tuned), and new tires with lightweight rota slipstreams. I'll launch at around 4.5K this time. i'll try to run about mid 20 tire pressure. thats what i ran last time to pull off the 2.3 sec 60' time

 

since you have the 6al
you could add that 2 stage launching module to it
in wich it will control your first launch by setting the first
rev and then the second..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted k20 &raquo;</TD></TR><TR><TD CLASS="quote">well i think my 60' times should be better. i ran that 2.3 sec with only Intake and exhaust. i was also run n on bald pirelli tires. i launched at 4K

This time at the track im gonna have I/E/H, MSD 6a and blaster 2 coil, new plugs/wires, no AC and PS, CROWER 62403 cams, SAFC (slightly tuned), SKUNK2 cam gears (slightly tuned), and new tires with lightweight rota slipstreams. I'll launch at around 4.5K this time. i'll try to run about mid 20 tire pressure. thats what i ran last time to pull off the 2.3 sec 60' time</TD></TR></TABLE>

you should do a little better, but the mods you have are more likely to help up top.. and a lot fo the 60ft is how well you launch

so they will help, but your mods should really help with the top of each gear

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted k20 &raquo;</TD></TR><TR><TD CLASS="quote">well i think my 60' times should be better. i ran that 2.3 sec with only Intake and exhaust. i was also run n on bald pirelli tires. i launched at 4K

This time at the track im gonna have I/E/H, MSD 6a and blaster 2 coil, new plugs/wires, no AC and PS, CROWER 62403 cams, SAFC (slightly tuned), SKUNK2 cam gears (slightly tuned), and new tires with lightweight rota slipstreams. I'll launch at around 4.5K this time. i'll try to run about mid 20 tire pressure. thats what i ran last time to pull off the 2.3 sec 60' time</TD></TR></TABLE>

Just because you're putting down more power isn't necessarily going to improve the launch. When launching you're combating things like wheel spin and wheel hop. Stickier tires help with wheel spin, and things like suspenison bushings, engine mount inserts, and traction bars help keep the suspension rigid to reduce or prevent wheel hop. Whatever you can do to lessen weight transfer to the rear will also help the tires hook up on launch (stiffer rear suspension, etc.).

Also, tires with less tread will hook up better than new tires w/ deep tread (less tread squirm).

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mr.beeks &raquo;</TD></TR><TR><TD CLASS="quote">this is the way I was tought...

start with 27psi
doo a quick launch stop
get off the car and check tire marks
in the first run you will see how much of the thread shows
for example if you see the outer threads only lower the press
try again untill you see the full marking of tire from left to right.
once you see this, it is the right pressure.</TD></TR></TABLE>

If you only see the outer parts of the tire tread, that means the pressure is too LOW and the tires are cupping in the middle. So you would need to ADD air to the tires.

If you only see the center of the tread, then you should LOWER the pressure.

 

thanks for that info. damn i didnt know tires with less thread hook up better. now im think n on put n on my bald front tires on the car..... proabaly wont but hopefully i will hit a 2.1- 2.2 sec