Faster???

If...... you have a given amount of hp. Using a 2 speed tranny, with 4:30's, and
34.5 x 17 x 16. Saying the weather stays the same and the car goes mid sixes.

If a 3 speed is installed and the rear end gears are lowered, using the same tire size, would there be any difference in et. or speed?

Thanx'........

 

faster

Alot of variables. Chassis? Wheel speed is going to change for sure.

 

More gears is always faster. Why do you think there is a limit in a blown promod . A 500 in pro stock has 5 speeds. Just think how much it would slow down being a 3 speed. Gears are a torque multiplier the more the faster. If a nos car had 3 gears it would slow down considerably.

 

Number of Gears

I am not disagreeing with anyone here but I know of a couple of alcohol altereds that are switching from a 3 speed to a 2 speed. They are running Bruno/Lenco on a 1/8 mile track at 3.80's or so. One racer I talked to even said he is changing the rear gear from a 4:30 back to a 3:90. Is it because a convertor changes the torque multification or is it because they are only running a 1/8 mile?
It seems to me that even a 3 speed/ convertor set-up only using 2 gears in the 1/8 would produce the same speed as a 2 speed. Maybe I missed something.
I run an alcohol dragster 526 hemi, 4.375 x 4.375 w/AJ2 fuel heads, 13:1 Comp, 14-71 roots w/40psi boost, 3 speed Lenco 1.98 low with a 3 disk Crower clutch with a 4:30 rear gear. I have a quickest ET of 4.205 in the 1/8. I am trying to figure out what I am doing wrong.
Any suggestions as to what would help me pick up the numbers?

 

What kind of mph? How much are you wearing off of the clutch? Either your tuneup is off or you don't have enough weight to lock the clutch up. As far as a two speed/ three speed goes, the more power you have the less gears you actually need. Take the top fuel cars for example, they used to run two speeds, now they are direct drive. If you were to run a two speed and the a 3 speed with the same low gear, you are going to get less rpm drop on the shift, thus hanging the engine in the sweet spot of the rpm band for a longer period of time.

 

-If we only ran 1/8th mi. I'd have a 2spd. in my TAD. The weight is a big reason but the other is regardless of what gearing you have the car will barely or won't at all reach 3rd gear before the 1/8th. If you're shifting right before the 1/8th your car isn't optimally setup and can be improved exponentially. The 3.90 gear changes trap RPM, but you can accomplish the same final drive ratio with a few changes in the trans.

-It depends if the 2nd gearset is removed or is still being used, if it's still being used you aren't in 1:1 and like I said before you can improve the setup. If you have a 1.28/1.32 and a 4:30 rear you have a 6.9875 final drive ratio; now divide that by whatever gearset you shift first (lets say 1.32) and you're at 5.294 and going through the traps as such. If you wanted to be in 1:1 just put a 1.62 and a gear eliminator, now you're the same down low and in 1:1 (4:30) going through the traps.

-I'd recommend putting a converter in the car. The fuel heads aren't helping you much, a Fathead for your combo would help you tremendously. Is the PSI a high helix or std. rotor? We ran a 451" brad with an 8-71 and would run low 3.80's in the 1/8th and had run 5.9x's in the 1/4mi.

Brandon Booher
NHRA TAD #34
Torque MGMT. - Owner
217-840-1500
underby6@gmail.com

 

Something to think about. A 2:1 torque multiplier is like a 50% gearset, the rest of the gears x 1.5. A typical torque converter is a 2.5:1 torque multiplier just above stall speed the multiplation deminishes as the tubine reaches the speed of the pump ( cover ) and the stator starts to turn the direction of the pump and turbine, instead of trying to turn backwards against the sprag while its multiplying torque. 2.5:1 is like a 60% gear reduction, so 1.60 x a 1.76 powerglide is the same as 2.81:1

 

Performance Issues

Just got back in town last night. My blower is a hi-helix Littlefield roots. There is a lot of excellent advice given in the last few posts. Since my motor does not over-rev during the launch, I am thinking that I have enough clutch in it. I am wearing about .003 off the clutch, sometimes less. If it slips more the rpm goes too high. The clutch goes 1 to 1right before the shift, making me think I have enough weight on it. Locking it up sooner seems to tug the motor too much. It winds out 2nd gear right about the 1/8 mile mark so I think I am ok on the 1-2 gearing. I just don't seem to be getting enough wheel speed at launch to do better than a 1.02 60'.
It may just be that my tune-up of off at launch. I would think it would light the tires and go up in smoke at launch but it doesn't. Maybe the tune-up is off and I am either too rich (even though I am bypassing fuel during stage and launch) or it is on the "backside of lean" as I have heard on here before. I guess either conditioin would account for a slow 60' and a slow ET. 1100 Enderle w/bypass loop w/.105 pill taking about 1 gpm at 40#, stage lean at 40# max stage pressure, port check 30#, egt still nosedives at the hit and comes back up about .75 into the run.
I do realize a convertor would be an advantage and also realize that fat heads would help but the budget is a limiting factor here. Donations are gladly accepted.
Thanks for all your help and advice.

 

Didn't mean to hijack this thread

Sorry Guys,
I just realized that I had basically hijacked another racers thread. I did not intend to do so. I appologize.
Barry

 

Barry....
over 20 years ago there were alot of cars running your combo (with less cubes) WITHOUT FAT HEADS running in the 3's. you should be able to easily make enough power to do what you want to do.

 

I agree

I agree completely. Now figuring out what I am doing wrong is the next thing to figure out.
Thank you for your support.

 

Faster

How much pack clearance do you have in your Crowerglide?

 

Pack Clearance

Actually, I am running a 3 disk pedal clutch.
Thanks