How much air should I put in ET streets with tubes? Car is a Z with stock suspension except LCAs and brackets, street twin/9" with 4.11gears. T56 of course.

What rpm should I launch it at? T56 will take this right?

 

i ran about 10.5-11psi in mine.

launch depends on your power, track conditions etc. When I was making ~500rwhp, I was launching WOT off my 7K RPM limiter with the conditions were right. T56 took it... but mine is special :-D

 

so i take it your t56 wasnt stock? I dont have near 500 rwhp, think a stocker will be fine?

 

Mine launches best with 12.5-13psi, but does get a little squirrely over 120mph with that low pressure.

Rich

 

I have always ran about 12 heated. That means start off at about 11, and go run them once. Come back and readjust them while they are still warm to 12 and go all day from there.

 

so maybe about 13? Whats the absolute max pressure I should try? I think I should start at the upper end of the spectrum, and then work down.

T56s holding up to this?

 

the trick to getting rid of what top end squirlliness is to make sure they are on a nice wide rim. I ran a 10.5" ET drag on a 15x10, and it was WAY better than a similar tire on a 8" rim

 

They are on 16x8 rims. Max mph is going to be around 127 or so.

 

Ya my t56 is still good, has TONS of low low 1.7/high 1.6s on it. Thing is the clutch isnt a street twin, so it slips before the tranny would break.

I ran the 11.5 in ET streets on a 8 inch rim, its scary top end until you get used to it. Just have to know that the tire is firmly on the pavement, and the car is whats swaying on the tire.

 

My personal theory, which anyone is free to criticize; is that you run the highest pressure that you can get away with and still hook, because higher pressure means better stability and less rolling resistance.

I also think that it's best to start at a higher pressure and work your way down, until you eliminate ALMOST all the spin. Another theory of mine is that a half-turn or so is good because it softens the driveline shock.

My theories apply to doorslammers, since that's all I've ever driven.

 

As far as the T56 is concerned, there will always be a weakpoint in the drivetrain. If your rear end is strong, the clutch is unforgiving such as the street twin and the driveshaft is solid; the stress will be on the transmission. Usually the most important factor is the clutch. That is the part that shocks the gears even if the other components are weak or the car isn't hooking.

With that said, the T56 is strong, but you are putting greater amounts of stress on it.

 

I agree with this.

 

With enough pressure, I can still get a good launch, yet have a little wheelspin to help preserve the drivetrain?