Well, guys I have a question.

What kind of tire pressure do you boys run in your drag radials?

I have been running 18 or 20 cold tire pressure in my Hoosier drag radials. Should you go any lower than this? Or, a better question would be is it SAFE to go any lower?

 

Like every other tire including the big slicks I use. You put as much as possible until your 60' times get worse. Start low and work up 1/2 pound at a time. With the drag radials, start at around 16 psi. No radial tire likes low air pressure. The sidewalls don't flex like a true slick. With low pressure, the sidewalls will not curl under and the center of the tire will lift off the pavement. Radials are designed to run higher pressures than what slicks use. It's not uncommon to have 25+ psi in a drag radial.

 

^ pretty much. The more you can run and still maintain traction, the quicker the car will react, and the more stability you will have.

Tire and wheel size make for many variables as to what is "safe", then of course all the other varibales of the car feed into what will be "best".

 

The sweet spot for my M/T drag radials is 17lbs.

 

hey alky thanks for the tire lesson. Always wonder about drag radials since all I have ever ran was slicks. Main reason for asking if going lower was safe is that I know if you run a slick to low, you'll be shakin yo a$$ at the top end. Which is no fun.

So I wouldn't put any less than the recomended 18psi min. Just didn't have the ***** to wreck my car if you know what I'm saying.

 

Do you have any traction problems using the radials?

When I ran slicks I didn't but when I switched to the radials the traction is only there on a well prepped track. I have adjusted my shocks and tried different length burn outs. None of which did much of anything. Ideas???????

I have installed spohn LCARB over the weekend to replace my lakewood lift bars.
Gonna start them in the middle hole. hope they work the way everone says they do.

 

The advantage of radials is that they run higher tire pressures than slicks. Higher tire pressures equals less rolling resistance. Many Stock/SuperStock racers are switching to radials just for this purpose.

For me, the increased cost of radial slicks isn't worth it.

My last race weekend, I bumped my pressure up to 8 psi and still hooked up good. Next race, I'll try 8.5 PSI. Video from my last race with 7.5 PSI showed the rim being driven down to the ground which told me I needed a bit more air pressure. I'm also running 32 x 15 slicks on 15 x 15 rims. Heavy cars also need more air pressure than lightweight cars.

 

No not at all my 60' actually got better when I switched from bias ply Hoosier Quick Time DOT tires to the M/T radials. I was very impressed with the tires, they are more stable at high speed and I got a better 60' with them.

 

I had issues on my car. With my BFG's, I could pull low 1.6 60' times...if the track was okay. With the Hoosier QTP's, I am more consistant, but not faster. My Hoosiers seem to like 14-15psi. My BFG's I usually kept around 20-22psi. My MPH was definitely faster with the BFG's...but not my ET.

 

FWIW....14.5 psi in my Hoosier Quick Time Pro's. Bias ply, Not radials, though.

 

15 and working my way down

 

Many of the radial class guys I know run in the 14-16psi range.

I run 10.5-11psi in my slicks.

 

went to the shop last night and did a couple of hole shots with 20 psi and then put them up to 22psi. Both pressure changed when tire is cold. Found out that more pressure narrows the contact patch on the pavement. So with Hoosier drag radials I would say that 20 would be about max.

Going back out Thurs. to load car for norwalk's "Night under fire". Maybe I will lower pressure and check the contact pack before I put it on the trailer.

 

^ again, wheel size plays a roll as well. 20psi may be about max for your combo, but not neccessarily someone else's.

 

Totally agree. Meant to edit my post earlier.

Was going to add that 20psi is about it for my power level and car weight.
That just in my opinion. By the way I am running P255/50R16 hoosier's.

 

my current combo worked well at 20psi with a 275/60/15 mt on a 15x10 wheel. however that was with a glide and the best 60' i could muster was a 1.66. the th400 may light them up. this is with a combo that will run 122mph @ 3330lbs in the heat here in GA.

 

been a 1.31 so far on my 275/60/15 goodyear radials. 14-16psi.