[tc]

I ran a 4 speed for many years. Best 60 ft was 1.62 and that was only running a low 12 second 1/4 mile. The Muncie did not last long with traction. I put a Moper manual trans in. I used a RAM diaphragm pressure plate and a Hays organic disc.

I use the same tires as you have. I run 22 psi cold, 20 psi hot-after the first run. I think 16 psi is too low and that may be some of your traction problems. For the burnout, you need to get the tires wet, driving through the water. Once out if the water, you need to get them hot by having enough tire speed. Try 2nd gear and up to 5000 rpm quickly. Looking in side mirror, 2 seconds of smoke is all that is needed and the smoke should start quickly. Drive out of the burnout taking 2 seconds to let off on the gas pedal. Now you will probably need to launch at up to 3000 rpm to keep the engine from bogging. But your Muncie will not like that!

I tried "drag shocks", to keep the rear passenger side from driving up into the fender well, to help traction. That bent the upper shock mount. Now I use station wagon springs and air bags. The driver side is 6 psi and the passenger side is 24 psi.

Racing with the 4 speed, I would speed shift and sometimes miss a gear, I'd want to shift fast and my foot/arm was not always right. Hard to win when you miss a gear. I did not want to put an automatic trans in because it was a lot of fun driving on the street with that 4 speed. But now I can still shift when I want to and don't have to coordinate with my left foot anymore.

[Chris-Austria]

I did some calculation and believe that shifting near to 6000rpm gives the best wheel torque (not engine torque.. but less engine torque multiplied with 1.64 can be better than more engine torque multiplied with only 1.28.
I'll try shifting a little bit earlier and see if that helps.

So my plan for the next race:

1. shift point at 5700rpm instead of 6000rpm
2. don't go through the wet box if possible and do a short dry burnout
3. launch at 1500-2000rpm to help traction (not too much because I don't want to break the gearbox)
4. install air bags in the springs and put some pressure into the passenger side
5. more tire pressure in the MT Street SS (I thought I may need less.. like 14-15psi.. why do I need more?)
6. do some training

What I'm not sure:

1. install drag shocks front and rear
2 install traction bars
3. install a larger cam for some additional power

By the way.. I use a Centerforce clutch setup... I think it's pretty strong.
60ft in 1.62 sec is pretty good... maybe it's too much for my drivetrain. But a litte bit lower than 2 sec. should work I guess and it should be possible with my car.
Should I add some weight in the rear right? Like don't remove my spare tire? I removed everything for the last race.

[Steve C.]

From Mickey Thompson / AIR PRESSURE GUIDELINES

https://www.mickeythompsontires.com/...ure-guidelines



.

[Chris-Austria]

thank you!
so 14 to 18 should be used.. should I go to 18 instead of 14?

[Dragncar]

Originally Posted by tc

I ran a 4 speed for many years. Best 60 ft was 1.62 and that was only running a low 12 second 1/4 mile. The Muncie did not last long with traction. I put a Moper manual trans in. I used a RAM diaphragm pressure plate and a Hays organic disc.

I use the same tires as you have. I run 22 psi cold, 20 psi hot-after the first run. I think 16 psi is too low and that may be some of your traction problems. For the burnout, you need to get the tires wet, driving through the water. Once out if the water, you need to get them hot by having enough tire speed. Try 2nd gear and up to 5000 rpm quickly. Looking in side mirror, 2 seconds of smoke is all that is needed and the smoke should start quickly. Drive out of the burnout taking 2 seconds to let off on the gas pedal. Now you will probably need to launch at up to 3000 rpm to keep the engine from bogging. But your Muncie will not like that!

I tried "drag shocks", to keep the rear passenger side from driving up into the fender well, to help traction. That bent the upper shock mount. Now I use station wagon springs and air bags. The driver side is 6 psi and the passenger side is 24 psi.

Racing with the 4 speed, I would speed shift and sometimes miss a gear, I'd want to shift fast and my foot/arm was not always right. Hard to win when you miss a gear. I did not want to put an automatic trans in because it was a lot of fun driving on the street with that 4 speed. But now I can still shift when I want to and don't have to coordinate with my left foot anymore.

Which Mopar tranny did you use ? I ran a Ford Top Loader for years after hurting Muncies. Still have all the stuff.

[tc]

Originally Posted by Chris-Austria

thank you!
so 14 to 18 should be used.. should I go to 18 instead of 14?

From magazine articles to forum posts and talking to people who race with the ET Streets, 14 psi will give slower 60 ft times than 18 psi. 18-22 psi seems to be what most people use and those that have traction issues at 18 find that setting the tires at 20-22 psi helps to solve that problem.

I have tried the dry burnout, and the tires always spun on the launch. In fact, for me, the good runs ( 1.63-1.68 60 ft ) are when they spray plenty of water for the tires to roll through. I set the tires at 20 cold, they are 22 psi after a run ( had that backwards in my previous post )

Originally Posted by Dragncar

Which Mopar tranny did you use ? I ran a Ford Top Loader for years after hurting Muncies. Still have all the stuff.

The A833. On the alum case version I would put in a steel bushings for the cluster gear. They had 3.09 first gear and overdrive for 4th. Great on the street, but the smaller/weaker mainshaft does break. When I take the GM T-400 auto trans out I will replace it with a A833 cast iron case ( larger mainshaft diameter ), 3.09 first gear 1:1 ratio 4th gear. I too still have a few tyranny's left as well as a bunch of parts.