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-   -   Bias ply tire pressures (https://www.yenko.net/forum/showthread.php?t=106472)

Alss 09-01-2009 04:34 PM

Bias ply tire pressures
 
I have asked this before..and really tried the search function but to no avail..where should I set my Goodyears for the strip??..If I remember it was near 40 psi??..last item to do before loading the car in the trailer..thanks

Albert

Chevy454 09-01-2009 05:29 PM

Re: Bias ply tire pressures
 
The rule of thumb used to be pump them up and then lay a short black mark and check it...you want it to be the same shade across the entire pattern (not black on the edges/light in the middle, or vice versa). For our car, depending on the age of the tires, it was anywhere from 42-46 psi.

Now, some guys (especially the FAST cars) are going the extreme opposite direction...I've heard as low as 12 psi in some cars, and have seen them wrinkle the sidewall while yanking the wheels...and "yes" I'm still talking about an F70 Polyglass! But, some guys run in the middle and do quite well, also. Seems to be different for every car...

I will finish with this bit of worthless knowledge...our Camaro went a 1.8x short time @ ~20 psi on it's 11.7x passes, but has also done it at our normal 42 psi setting...you gotta remember, it's a 6" bias tire, and just when you think you have it figured out you launch and it's Cheech & Chong all over again (Up in Smoke!)... https://www.yenko.net/ubbthreads/imag...lins/smile.gif

Your best bet is to hope there are some big tire'd cars running during the same program...us street tire'd cars eat the rubber off the track and make the track really really difficult at times.

VintageMusclecar 09-01-2009 05:37 PM

Re: Bias ply tire pressures
 
Rob;

How "wiggly" do the Polyglas tires get on the big end when the pressure is down like that? I know how larger bias ply's (i.e. DOT legal street slicks) feel through the traps, just wondering if the skinny tires are any worse.

Chevy454 09-01-2009 05:49 PM

Re: Bias ply tire pressures
 
Not nearly as bad I reckon, because you're talking a lot smaller tire and a lot stiffer sidewall. We've got a hole in the wall track over by Springfield, rough as a cob...I've ran a big 33x12 tire'd car there as well as our Camaro and while the ride is "interesting" at times on the big end in the Camaro, it was nothing like on the big tires...

SmallHurst 09-22-2009 12:02 AM

Re: Bias ply tire pressures
 
This past weekend, I thought I would try something a little different on tire pressures. I typically would air mine up to 38#'s in the rear. Today, I left the rears at 26#'s (the tire pressure recommended on the door sticker) and ran them hard. I managed a 1.94 60' in my 4200#'s coming off the 'suspect lane' at Stanton. I also did not have the trouble blowing the tires off on the 1-2 shift that may people had. Some food for thought.

Chevy454 09-22-2009 12:24 AM

Re: Bias ply tire pressures
 
[ QUOTE ]
This past weekend, I thought I would try something a little different on tire pressures. I typically would air mine up to 38#'s in the rear. Today, I left the rears at 26#'s (the tire pressure recommended on the door sticker) and ran them hard. I managed a 1.94 60' in my 4200#'s coming off the 'suspect lane' at Stanton. I also did not have the trouble blowing the tires off on the 1-2 shift that may people had. Some food for thought.

[/ QUOTE ]
Ha...I tried low pressure, high pressure, and everything in between, and 2nd gear was like a drifting contest...hazing the tires and hanging the rear out at 80+ is a bit unnerving. I was really pleased with my 60 times, as I hit a 1.8x and besides a single 2.0x every other pass was in the 1.9x range. But it was so slick downtrack I never could put together a real good pass... https://www.yenko.net/ubbthreads/imag...ins/tongue.gif

23 psi is where my tires were most of the weekend... https://www.yenko.net/ubbthreads/imag...ns/scholar.gif

ra6t7gto 09-30-2009 08:05 PM

Re: Bias ply tire pressures
 
i run my 67 gto at stock drags with f - 70 redlines,i tried a few different psi stock @ 32 psi it seemed ok, went to 45 in the rears and car had no traction broke loose going into 2nd gear,went to 40 psi and got a little more traction, last time out at e town i had rears at 30 psi and it seemed to get more traction, just my 2 cents

Donny Brass 10-09-2009 07:34 AM

Re: Bias ply tire pressures
 
Where ever you have the pressure, somewhere they will work.......

http://i37.tinypic.com/2d9tcer.jpg

JLerum 10-09-2009 04:42 PM

Re: Bias ply tire pressures
 
Donny,

Striking hard with the lone small block in the 60 foot DATA. Nice job!!!!!

Jim


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