Ideal tire pressure for the track?

[2543arvin]

What tire pressure are you guys running at the track? I have Nitto 555R drag radials and I cant get them to stick right now with 30 psi in them and I plan on going to the track on Sunday if all is running right.

Would 15 psi be too low? Just throwing a number out there I guess, and Ive never noticed a thread about it here, so if anyone has any ideas, I would appreciate it.

Thanks,
Brandon

 

[tissimo]

i'd try 20 first.. dont go too low though.. I wouldn't go under 15 at the max.. personally I wont run under 18

 

[2543arvin]

i'd try 20 first.. dont go too low though.. I wouldn't go under 15 at the max.. personally I wont run under 18

Ill try 20, and see how that goes......what happens when you go too low though? Not trying to push the boundaries, just curious...

 

[MKIIINA]

best bet is going to be to experiment. the track temp will vary and depending on the prep that was used. one day you may have to use a lower/higher pressure.

keep a log and see what works best for the conditions present

 

[2543arvin]

best bet is going to be to experiment. the track temp will vary and depending on the prep that was used. one day you may have to use a lower/higher pressure.

keep a log and see what works best for the conditions present

Thanks guys for the quick responses. I will experiment a little and then post what pressure I went with if all goes well.

 

[dbsupra90]

best bet is going to be to experiment. the track temp will vary and depending on the prep that was used. one day you may have to use a lower/higher pressure.

keep a log and see what works best for the conditions present

yep!

i generally try to stay over 17psi on radials. you might take shoe polish on the rim and tire to mark it. that way you'll know if the tire is slipping on the wheel during launch.

i would also air up the front tires some too. it will make a more narrow contact patch and less rolling resistance. i usually take mine up to ~42psi, but this will depend on the tire. you might want to air it up and drive it around on the street some before going to the track. it will behave a little differently. not unsafe in anyway, just handles a little different with steering input.

good luck at the track!

 

[Jostar]

Nittos Drag radial love heat, So heat them real freaking good & play with tire pressure & RPM launches, I cut a bad 60' on street tires, I know that drag radials with good heat will do better but might wheel hop, I personally will stay away from drag radials & go with slicks.

 

[upgradedsupra]

Moved to proper section.

Get some sticky tires (MT/ET Streets) and be done with traction issues (depending on your power of course :sarcasm

Duane

 

[NegativeGeForce]

You shouldn't air down street tires down at ALL.

Lots of people have said too little air is bad, but never why. So thats why I thought I would give a little explanation.

STREET TIRES

You will have worse traction on a street tire if you go below 30psi on an mk3 supra. The sidewalls on street tires are a lot stiffer then a tire designed for drag racing and airing them down will cause the middle of the tire to bend up like an upside down V, thus reducing the weight the middle of the tire can support which is the gripiest part of the tire.

Do yourself a favor and if your going to the strip with street tires, leave them at 35psi and do a burnout to clean off the tires, thats about the best you can do to prepare them.

BUBBLE GUM

Otherwise get a real set of bubble gum, their sidewalls aren't as stiff, so airing them down will help rather then harm. This doesn't mean they are an exception. You still need enough pressure to keep the tire from folding in.

To answer your question, the mk3 supra is a fat ass. Drag cars (top fuel) are light so they can run on 8psi, but an mk3 supra you need around 20psi (mk3 is 1500lb heavier then a top fuel car) to keep the tire from folding. Each car and tire is different, so the sweet spot for the tire can vary quite a lot. Heavier cars need more air to support the weight of the car from crushing the tire basically.

 

[MassSupra89]

Stay at your 30, practice by taking 1 or 2 psi out each run.

Then once you get to a comfortable psi play with launch rpm's and clutch release... this will proabbly require you to make small changes to tire pressure again.

 

[fstlane88]

You shouldn't air down street tires down at ALL.

Lots of people have said too little air is bad, but never why. So thats why I thought I would give a little explanation.

STREET TIRES

You will have worse traction on a street tire if you go below 30psi on an mk3 supra. The sidewalls on street tires are a lot stiffer then a tire designed for drag racing and airing them down will cause the middle of the tire to bend up like an upside down V, thus reducing the weight the middle of the tire can support which is the gripiest part of the tire.

Do yourself a favor and if your going to the strip with street tires, leave them at 35psi and do a burnout to clean off the tires, thats about the best you can do to prepare them.

BUBBLE GUM

Otherwise get a real set of bubble gum, their sidewalls aren't as stiff, so airing them down will help rather then harm. This doesn't mean they are an exception. You still need enough pressure to keep the tire from folding in.

To answer your question, the mk3 supra is a fat ass. Drag cars (top fuel) are light so they can run on 8psi, but an mk3 supra you need around 20psi (mk3 is 1500lb heavier then a top fuel car) to keep the tire from folding. Each car and tire is different, so the sweet spot for the tire can vary quite a lot. Heavier cars need more air to support the weight of the car from crushing the tire basically.

The OP is running DRAG radials, which have softer sidewalls than STREET tires, the sidewalls on even the Nittos will wrinkle when you launch, when aired down, giving you more contact patch that is grabbing the track so you can hook. I agree with most, you don't want to air down DR's very low, but you defintely do NOT want to air them up.

 

[Buddafucco]

About 18psi is where I'd start and drop or raise from there if neccessary.
For reference MT recomends 12-16psi at the track for their street radials.

 

[F&H Performance]

With mt drag radials 275-40-17 on tt wheels I started at 18 and got all the way down to 11 and cut 1.61's with them and feel they are very capable of a 1.5. With rx-7 wheels and 255-50-16 drag radials (mt), I ran about 14psi. And cut a 1.68 but could've gotten a lil better.

 

[mrsuprafreak]

With mt drag radials 275-40-17 on tt wheels I started at 18 and got all the way down to 11 and cut 1.61's with them and feel they are very capable of a 1.5. With rx-7 wheels and 255-50-16 drag radials (mt), I ran about 14psi. And cut a 1.68 but could've gotten a lil better.

I'm Buying the 255-50-16 drag radials (mt) as soon as my car is up again.

I did a 1.90 on 275/40-17 street tires stock air pressure.
It was my first time out. And that wasn't coming out the hole hard afraid of braking.

 

[F&H Performance]

Having both sizes I would have to reccomend the 275-40-17's they hook much better.