Question on rear gear selection

Ok, I know a lot of people have asked before. I've read a few old posts.
I'm sorry if I'm beating a dead horse. Asking for help or recommendations on
gears for the rear-end. And maybe converter. If someone on here has seen a
setup close to this before.
Or is this setup not feasible? First gear is pretty low.
Thank you in advance for everyone's time.

I have a 14-71 supercharged HEMI on alcohol.
RPM range is 7400-7600 ( guessing but should be close )
car weighs 1950-2050lbs on the line.

34.5x17x16 slicks
Might be able to get 36x17x16 slicks

Rossler T400 3-speed
2.10, 1.41, 1 to 1

No convert yet

Quarte mile racing only.

I already have all the pieces I listed. So a bit harder to run out and just buy
other pieces. Money is flying away in all directions. Especially a new build. Hahaha!

 

Converter...Id tell you to get a hold of Marty at Neil Chance converters. He'll build you what you need with quick turn around (ordered mine on a Tuesday and it shipped on Thursday) built to suit my application,

 

some in the region of 3.9 to 4.3 should work

 

Mark Mickie all the way. His knowledge of turbo 400 is second to none. My guess will be a 4:30 gear to keep the car moving in 2nd gear with the rpm staying low. Don't want the engine loaded down that hard in the 1/4. Will do ugly things.

 

I would suggest a 4.30 gear

 

Hi Jay!
Thank you. I've always enjoyed reading your posts.
So you think first gear wouldn't be too low? I haven't heard (read) of anyone on here with this caliber of car with a first gear this low.
Maybe for 1/8 mile racing. ( I'm not disagreeing ) Just asking.

Oh and I'm not out to rotate the earth and set new records. I'm saving that for the guys that have the funds for that. I'm after getting down the track consistently respectful. I'm not trying to sound like an a$$. Just letting you know it's not an all out car. I will be in a nostalgia class.

I've read on past posts that a few of the, Wise big power guys, like to use the to 7 ratio. first gear multiplied by the rear gear. If I remember right, above 7.5 to 8 you will most likely have bad tire shake and it's hard to get rid of it. Below 6 and it will be too soft and a lot of load on the motor. With a BAD 60'.

Once the rear gear is picked I can talk to someone about a converter.

Also trying to avoid having the growing pains of buying and trying many different converters. Heard lots of horrible stories.

The reason for going converter is VERY limited help. No choice

With my Rossler I do have the second gear leave option if the track is real crap. And didn't want to use it unless I absolutely had to.
And yes with what you said earlier- I am worried about loading the motor down that hard too.

So I'm up for listening to your and anyone else's recommendations.
I do appreciate it!

 

I run a 2.01 First in my 3 speed Lenco. we have gone 6.14 at 235 so far . 2650 door car

 

Are you running a 4.30 rear gear too? And are you using a Bruno as well? I'm asking because of the converter being a torque multiplier.
Thank you

 

Yes , our rear gear is a 4.30 and we do run a Bruno Drive with a 3 speed Lenco. We did actually initially start with a 3.90 rear gear

 

Do you run any type of a timing controller?

We can't use a launch controller.
Timing controllers are debatable still.

 

Your gonna want the ratio to keep the car moving in 2nd gear. My fear with a 3.90 gear would be you'd have to run the rpm way out in 2nd to keep the drop at the gear change from hurting the engine in 1/4.

 

Yes we do , I am sure you will have to manipulate the timing curve. we are using a Powergrid

 

One of the reasons we changed from a 3.9

 

We can't use ant type of a launch/throttle control. Timing controller is debatable.

I've been concerned about running too tall of a gear for that reason as well.

 

We can't use ant type of a launch/throttle control. Timing controller is debatable.

 

So your not allowed to use a two step or an air throttle? What’s debatable with a timing controller? What’s the rules state about converter dumps? I would talk to your converter person of choice before you lock in a rear gear. They might be able to steer you in the correct direction on both, especially since your kind of in a weird place, low rpm Hemi deal.

 

Yes sir. We don't have to spin them hard. It is an index class.
Both leave on green. First one to the finish line wins. As long as
we go 6.70 or slower. No air throttle or 2-step. Most everyone uses a Lenco and clutch. Trying to keep it as close to nostalgia as possible with out getting too carried away. Been talk about not allowing automatics. But that would limit more entries. Really no rules on trans. Except has to be manually shifted or button shifted.
Nothing mentioned about a converter dump.
( I know absolutely nothing about a converter dump)

I follow the group really close. If I'm not mistaken, I've heard about some guys being able to use a grid at some tracks but not others.

 

Would you be allowed a trans brake? Again, I would consult a converter company of your choice and see what they recommend not only converter but the rear gear as well. Less gear, 3.90 would be a lot more calm than say a 4.30. Sounds to me that something with minimal gears and a loose converter would be ideal. You could take off in second with more rear gear ratio.

Back in the hay day guys used to have a cable hooked to the mag, the leanouts were manually operated and when the top fuelers started using lock up clutches, the driver had a button for that as well. You can get pretty creative with ways to manage power. Spud Miller still makes an air retard deal that actually rolls the mag to advance/retard timing.

 

Yes I can use a trans brake. Just can't be on the two step or air launcher.
With a 4.30 gear and 34.5x17x16 slicks ( if my math is correct )
and went to a 36x17x16 that puts my rear ratio at 4.12ish.
Been looking into the converter dump. That might be a way to go.
with either tire combo.
But that's also why I'm asking you guys on here that have WAY more experience with these animals than I do

 

Do you like your grid setup? I am going to run the MSD coil near plug deal. MSD 600 pro I believe. I think I have to run a Grid with it. Do data loggers get along with it alright? I've ask a couple people and never got an answer back. So I just been focused on the transmission and rear gear situation.