Tire pressure with tubes?

Posted By: tboomer

Tire pressure with tubes? - 08/24/11 12:26 PM

We may go racing this weekend at Tri-State here in Iowa. I have not been out since I had tubes put in both rear slicks. The tires are M.T. 31x15x10.5ws..I was running 9 to 9.5 pounds without tubes. I assume that I should stay the same? Thanks!! Ted

Posted By: MR_P_BODY

Re: Tire pressure with tubes? - 08/24/11 12:33 PM

Quote:

We may go racing this weekend at Tri-State here in Iowa. I have not been out since I had tubes put in both rear slicks. The tires are M.T. 31x15x10.5ws..I was running 9 to 9.5 pounds without tubes. I assume that I should stay the same? Thanks!! Ted

Ted I would start out at the same pressure but with
the tubes they will stiffen up the side walls... you'll
need to play with the air to get your best launch...
have fun... go fast

Posted By: tboomer

Re: Tire pressure with tubes? - 08/24/11 12:39 PM

Thanks,Mike! I will try 9# to start..I will also leave the 3400 chip in for the brake. It is supposed to be a nice day Saturday. Sure would be nice to go a couple of rounds to get my confidence back!

Posted By: MR_P_BODY

Re: Tire pressure with tubes? - 08/24/11 12:49 PM

Quote:

Thanks,Mike! I will try 9# to start..I will also leave the 3400 chip in for the brake. It is supposed to be a nice day Saturday. Sure would be nice to go a couple of rounds to get my confidence back!

Ted I found that on my car the lower the launch RPM was
the higher I needed the tire pressure... high RPM =
lower tire pressure... if I launch at low RPM with the
tires at 7.0# it would cup the tires big time

Posted By: tboomer

Re: Tire pressure with tubes? - 08/24/11 01:02 PM

I don't think there will be time to play with it..Two time trials...I think than right to eliminations...

Posted By: moparacer

Re: Tire pressure with tubes? - 08/24/11 01:24 PM

People still run tubes?

I think I seen a actual tube that they used to install in tires at the Smithsonian once....

Posted By: tboomer

Re: Tire pressure with tubes? - 08/24/11 01:29 PM

I punctured one slick a while back...The hole was too close to the sidewall for a patch..

Posted By: MR_P_BODY

Re: Tire pressure with tubes? - 08/24/11 01:38 PM

Quote:

People still run tubes?

I think I seen a actual tube that they used to install in tires at the Smithsonian once....

Makes my slicks last longer

Posted By: Dabee

Re: Tire pressure with tubes? - 08/24/11 02:43 PM

Quote:

People still run tubes?

I think I seen a actual tube that they used to install in tires at the Smithsonian once....

Yep, some of us still do.

Posted By: 440Jim

Re: Tire pressure with tubes? - 08/24/11 03:56 PM

Quote:

People still run tubes?

I think I seen a actual tube that they used to install in tires at the Smithsonian once....

That is funny.
But putting tubes in my slicks was the best thing I ever did for my application.

I was killing the side wall on my slicks around the 100 pass mark. Then I added inner tubes, changed from 12" wide rims to 14", and this allowed increasing tire pressure to 11 psi. Now I get over 200 passes (225 on the last set) on the slicks.

Posted By: Dave64

Re: Tire pressure with tubes? - 08/24/11 04:05 PM

Tubes are your friends.

Posted By: bumps440

Re: Tire pressure with tubes? - 08/24/11 08:37 PM

I use tubes also. Find better consistancy and stability .

Posted By: deaks

Re: Tire pressure with tubes? - 08/24/11 09:46 PM

I dont like to hijack but your car is very quick for an iron head 440, would you be willing to divulge the spec. You can pm me if you wish.
Oh Ted, i run tubes as well.
Mick

Posted By: 69CHARGERMD

Re: Tire pressure with tubes? - 08/24/11 09:52 PM

wow,,you guys run low tire pressures compared to what i am used to.
I was running 14lb,,,,but dropped to 12 recently,,,maybe I need to experiment a bit more,,eg 11 like 440jim.

never considered running less than 10,,does the car "wave" around at the high end of the track ?

I run tubes in mine,,,fyi,

Posted By: bumps440

Re: Tire pressure with tubes? - 08/24/11 11:17 PM

you are on the right track
run the most pressure that will still hook the car.
when you dropped the pressure what happned?

I run about 11.5 in mine.

Posted By: Crizila

Re: Tire pressure with tubes? - 08/25/11 12:20 AM

Quote:

run the most pressure that will still hook the car.

10-4 on that one. Improves consistancy and makes the car handle better. Inner tubes for you slicks - don't leave home withoutem!

Posted By: rowin4

Re: Tire pressure with tubes? - 08/25/11 12:32 AM

Some people would rather put air in between rounds, in the staging lanes and stop three times on the way home, I run new slicks till the side walls start to leak, then in goes the tubes.

Posted By: Crizila

Re: Tire pressure with tubes? - 08/25/11 12:42 AM

Es-no-my-shab-mon! That's what wives are for.

Posted By: Chris2581

Re: Tire pressure with tubes? - 08/25/11 02:09 AM

12.2x31.25 Phoenix with tubes...9.5-10lbs.

Posted By: 440Jim

Re: Tire pressure with tubes? - 08/25/11 03:04 AM

Quote:

wow,,you guys run low tire pressures compared to what i am used to.
I was running 14lb,,,,but dropped to 12 recently,,,maybe I need to experiment a bit more,,eg 11 like 440jim.

never considered running less than 10,,does the car "wave" around at the high end of the track ?

I run tubes in mine,,,fyi,

There are lots of factors for tire pressure. For example:
Car weight (heavier = higher pressure)
Tire size (smaller = higher pressure)
Launch torque(higher = higher pressure)
Chassis setup, rim width/tire width, weight distribution, weight transfer, instant center... (depends)

etc.

Posted By: Barnstorm

Re: Tire pressure with tubes? - 08/25/11 03:15 AM

14x32 Phoenix here..10 1/2lbs works best usually. Car wads the tire up on launch and gets wiggly after the 1/8 at 9-9 1/2lbs. 3420 weight.

Attached picture 6793768-998852905_4DmMz-O[640x480].jpg

Attached picture 6793768-998852905_4DmMz-O[640x480].jpg

Posted By: tboomer

Re: Tire pressure with tubes? - 08/25/11 01:52 PM

Thanks for the info,guys!

Billy...Great shot of your 64!!