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I have a set of hoosier 31x16.50 x15 on a 1936 plymouth pro street
I have a bad vibiration starting at 70 to 80 miles hr.
what should a good air pressure be? I am thinking that 25 was to high
as it was the max. DOES ANYONE RUN THESE AND KNOW WHAT WORKS BEST.
it sounds like you have another problem other than tire balance,or pressure.
normaly a tire problem presents it's self at 55/60 mph range.
it sounds more like drive line related, how about your pinion inclanation or u/joints in phase. or u/joints period.
hope this helps
Put the car on jackstands and remove the rear tires/wheels. Run the motor up to 70-80 mph in gear and see if you have the same vibration. If yes, then it's the drive shaft.
I have 29x14.5x15 Hoosier cheater slicks that I run at 11-12 psi at the strip on a 68 Firebird. Of course, correct tire pressure depends on many things including vehicle weight distribution, application, etc.
As for the shaking problem, I would bet on wheel balance being most likely followed by drive line. I had a similar shaking with a previous set of tires that set in > 70 mph but was smooth as silk to 100+ after rebalancing the rear wheels.
Two cents,
Chris
THANKS ! my problem seems to go away or get better above 80
I ran my hoosiers at 26 lbs,remember that they are radials and need the pressure.-- They hook good dont they?
mebeached: getting better above 80 I guess is less likely the tire balance. I once had an old Datsun that behaved like that from a bent frame.... at the time, the economics of replacing the tires periodically was more feasible than straightening it out :))
bigdude: Those hoosiers hook mad... I love 'em! Mine are bias ply and I am running tubes and rim screws (only on the strip), hence my lower pressure. I've found optimum 60' at 11.5psi with my setup. I have mickey sportsman pro's for the street, also with tubes.
i ran my hoosier quicktimes with 12 lbs in them last weekend for the 1st time think still too much looking at my tire pattern but they never squeaked a bit and were not mushy at all. . will try 11 lbs next time and see what they do
Thanks i will give a lower range a shot ! thanks for the reply!
I've ran the Hoosier's as low as 8 pounds (with tubes and screws) for some of the heavier Saturday night action..... They are a bit squirrely at that pressure when you lift on the big end....