I've been thinking about switching to an automatic trans, reverse value body T400 with a good stall. I like to drag race, but trying to get a great time out of a Big block M21 car can be challenging.
I have 430RWH and 466RWT and have run a best of 7.52@93.55 in the 1/8 with a 1.719 60ft. I figure that run was good for a 11.7 in the 1/4 at 118-120. I'm thinking that with an Automatic I could bring my 60ft's down in the 1.50 range and my 1/8 times down to low 7's. What do you guys think? Keep banging gears or switch to a slush box? :confused:

 

When I go to the track all the "quick" cars (11 seconds and faster) are ALL running autos. They are either Th400's or power glides. Manuals are 10 times more fun to drive but in drag racing, an auto w/ a high stall and gears are King.


[Modified by Corey 68, 7:04 AM 10/16/2002]

 

Go for the TH400 or whatever will fit.

 

I switched from a automatic to a manual and my car slowed down. The fun factor went way up but launching with the manual is so much harder and banging gears gets tricky.
The 400 with a high stall convertor is hard to beat. If racing is all you want go with the automatic.

 

I will personally never have an auto in any of my "sportscars" I really have a lot of fun banging gears. For you, it depends on how much you want to race, and how much you want to drive on the streets. There is no doubt for drag racing applications auto's are more durable, faster and consistant, but not as much fun. There is also the streetablilty issue, high stalls and low gears are not real streetable.

You could always go with the G-force like 542C2, and have the best of both worlds. Prepare for you wallet to lighten significantly.

 

Not that anyone cares, but, I hate automatics... for the street anyway. They are always downshifting when you don't want them to. :seeya

 

C'mon....didn't we just go through this with Steve (542C2)???

REAL cars have 3 pedals!!! No doubt about it!

Now, are autos EASIER to drive? Sure!

Are they more consistent? Maybe. They are for most folks but there are many excellent drivers who can lay down fantastic consistency with a stick.

Are they faster? Only if the car is not setup right for it. The stick's advantage is the ability to come out at high rpm and shock the tires. If you have enough tire/chassis to hold it, the stick will win. If you don't, they can still be faster IF you are good at "working" the clutch and gas pedal.

Are Autos easier on parts? Usually.....but doesn't that tell you something about the amount of power being transmitted? The converter actually multipies TQ initially out of the hole, but that advantage is used up very quickly in the amount of time it takes to get to stall speed. Once you are above stall speed, ( a very small portion of a second!) the advantage is gone and you are transmitting only a portion of the available power not to mention the power used to run the pump etc.

My thoughts are to develop the chassis to utilize the power available and use the natural efficiency of the stick.

Plus, IF you actually hit all the gears there is not much out there that is more fun! You KNOW that YOU made a good run. Otherwise you could run them all remote control from the tower!


Don't get me wrong. I used to switch my '68 Camaro back and forth regularly between a stick and a T-400. Just kind of depended on the moodat the time. It was just as fast or faster with the stick and a LOT more fun. I gave the keys to a buddy of mine once at the track. He went up and made the fastest pass of his life (seems like a high 10 something) and promptly gave me back the keys telling me how boring it was as compared to his 13 second 4 speed Roadrunner!

C'mon...hang in there with us and let's bang some gears! You could even use an adjustable clutch to soften the initial hit and use a slickshifted trans. I've had them, they are unreal to drive! Nothing better!


JIM

 

AUTO all the way :D

 

my drag racing experience comes from the late 80's so this might be a lil outdated, but i have always liked the 2 speed powerglides or a clutchless lenco (1 lever per gear just pull), you will never get off the line fast enough with a clutch as you can with a tranny brake

 

Thanks for the responses!
I can always put the 4 speed back in the car.
I ran my car tonight at my local crappy 1/8 track with a friend and his 460BB (470RWH) 66 chevelle. He just switched from a 4 speed to a turbo 400, reverse valve body
5000 stall. He ran in the mid to high 7.40's @ 91/92 MPH all night with 1.6 60 fts. His best 1/8 before was 7.68 to 7.7 with a 4 speed at a better track.
My best run was a 7.41@ 96mph with a 1.70 60ft with a 125 shot.
My clutch was hurting after a couple of runs. (nitrous and clutchs don't go together)
I guess I'm tired of granny shifting when Im using nitrous. With a auto I could stay in the nitrous the entire run.
:)

 

Banging gears on the street is fun but an auto tranny will make your times very consistant at the track. Food for thought :cheers:

 

An automatic uses more HP than a stick so it will always be slower on a correctly setup car. The only advantage is consistancy for braket racing.

It can cost $3000 to get a real TH400 racing tranny/T.C./trans brake and reverse shifting pattern. That money would make a good down payment on a racing manual tranny

 

I was just thinking of swapping my stick for an auto. The other night I was stuck in traffic for over 2 hours. That big McLeod gets kind of heavy after a while. I have a good TH400 out of my truck that I could use. How tough would the swap be considering that the manual cars have the fixed crossmember? Also, I don't want to alter the car to the point that I can't reinstall the Muncie at a later date.

 

Tracy - They make these things called hydraulic clutches!:) My drag racing buddy used to own a clutch type TH400. It was a hot item before they came up with Torque C that could withstand high hp

 

Autos can take way much more power than Manuals. :yesnod:

 

I realy like my th400/Gear Vendors combo. Take a look on my web site.

 

71 Coupe,

I have a removable crossmember.

gKull,

My friend just did the swap. $875.00 T400 RMVB rated to 1000HP, $900.00 ATI custom
8 inch converter, Cheeta SCS shifter, trans cooler. He told me he had $2400 in the swap.
I'm not going to spend that much, maybe $1500. I might use a built T350,and a 10'' converter.
I like to drag race to much and a stick car dosen't get the benefit of torque multiplication that a stall converter gives when your car launches.
My buddy ran his car Sunday at a different track and got a 7.32 1/8 mile
and a 11.50 1/4 at 117mph with a 1.65 60ft. His car is a 66 Chevelle 3850lb race weight. The best he could do with a 4 speed was a 7.68 1/8 and a 11.87 1/4 @ 120mph. He lost some mph in the 1/4 with the automatic but not much. If he can get the car to 60ft in the 1.50 range it will run low 11's. I'm impressed with his results.
My corvette is 3475lb race weight. I hope with a good automatic and a 3500-4000 stall converter I'll see some low 11's on motor and 10's on nitrous.
:)

 

One other thing to consider. If you go with a manual valve body: the only manual valve body with engine braking is a forward pattern. If you get a reverse pattern it will not give you engine braking. If you just drag race then that's fine to not have engine braking. But driving around on the street or autocrossing sure is much nicer having engine braking. I had a manual valve body 700r4 reverse pattern that had no engine braking and it was awful for autocrossing and road racing.

 

You mentioned using a built 350. The 400 soaks up about 35 more horse then the 350 so it might be a good idea.

 

I almost went to the dark side(automatics) but thanks to people like Jim(427Hotrod) and Mark(ML67) I stuck with a manual and I am thoroughly happy that I did.

If you guys want the ultimate in a manual trans, the G-Force clutch assisted 5-speed is the way to go. It will handle at least 1200hp and can be driven on the street. I can't wait to try it at the strip.

Steve