But let me stress that all valve bodies are different, some manual valve bodies retain the front band also. Best to ask the person/company building the trans or the company who built the valve body about shutdown at the track before you move that shifter out of 3rd at 140mph..

 

I just realized that too...search the auto forum and its 98% 4l60/80 stuff, not a whole lot of deep info on 3/2 speeds like this thread.

KP, you need to hang out in there more often!

 

Really good info from KP, Thanks for the help.

 

hey kp, you go to the big bucks races? i should be down there with my LeMans this year.

 

Depends on which races, but I have to put it back together before I go anywhere

 

Thanks for all the info KP! I didn't realize alot of these things about the th400s. I just know when i got mine from Rossler he had mentoned that it def. needed to be 2-3 shifted during the burnout.

 

well i have a rmvb and a transbreak i will be starting my burn outs in 2nd and ending and 3rd i have never downshifted because its neutral, though all this reading, with what i have gatherd it is bad to down shift into 2nd for neutralization , how ever what does it mean when a tranny makes a whistling noise in certain RPMS?

 

It will make more noise then a stock trans, line pressure is jacked up and the pump will be noisier. Converters cam get noisy also, as long as its not super loud I wouldnt worry about it. If it shifts OK and the fliud level is correct I wouldnt be too concerned.

Its not bad to downshift some valvebodies to 2nd after a pass (nuetral), if thats how its made. Ask the guy who built it if its ok

 

I need to call TCI and see how my Competition TH400 is setup. I really dont want to roast the tranny to soon.

 

I do 1-2-3 in the burnout box, but i'm only in 2nd gear for about 1-2 seconds because at that point it gets to where it's completely unloaded and I grab 3rd then roll out of the box. Do you think there is any issue with me doing this? I have to use first to get them spinning because of the 2.75 gear. Total burnout time once the tires start spinning is about 6-8 seconds, just enough to get some smoke (light burnouts).

I never worry about putting it in neutral after a pass. I'm only trapping 130mph right now and 6000 rpms is like 165 mph.

BTW, when using rosslsers trans brake it will ONLY engage reverse in 1st and neutral. You can hit the button in any other gear and it doesn't do anything.

 

the 1-2 shift in the burnout is what hurts the sprag, I got about 150 passes doing it. Main reason I was using first was because a lot of tracks here have no one to put you in the water and you have to back in. So when you are strapped in a car tight its like a monky ******* a football trying to get the car in the water - in 1st even if you miss the water you can get them going pretty easy I would get it into 2nd as soon as the tires start spinning as low of rpm as possible if you have to start in 1st.

Park neutral and 1st are the only time the trans brake does anything on mine, but I wouldnt advise pressing the button in high gear to find out.. Have to be real carefull about pushing that button in first gear as well. I had a BBC TH400 car and I made the big mistake of grounding the trans brake relay with the wires going to the button, made it easier to do the 2-step/delay box/trans brake wiring. I left the line and one of the wires shorted and hit the trans brake about 25' out and ripped the trans right off the back the engine, also twisted the crankshaft and put the driveshft through a rear slick - so make sure if that wiring to that button shorts out it blows a fuse and its where you have no chance of pushing it. Sometimes you have to learn the hard way

 

That's a good one! Thanks for all the good info.

 

Thanks for the advice KP, I'll try to get into 3rd quicker. I'm not strapped into my car so I just open up the door to look back and put myself into the water if the track guy is sleeping. I don't drive through because I run stock front wheels and we have enough FWD cars screwing up the track dragging water everywhere as it is.

I'm amazed at the damage that happened to your car from the TB short. That's just amazing and scary. Goes to show how strong a th400 is I guess.

 

Think of sticking a baseball bat in a 1000hp bicycle's spokes at 40mph, thats exactly what happens if you hit the brake in first gear WOT. Only thing that really survived was the converter, I have known guys that pushed the button by accident for a second and screwed up the trans but turning the brake on and leaving it on isnt a good idea. Needless to say nothing on a race car gets wired for a ground side activation by me since

 

First off, thanks for all the great info KP and others!! And sorry for hijacking the thread even further but i am working on a M6 to Th400 swap and this post has me worried.
I'm going with a RMVB 400, tall rear gear and a tight stall (similar to Zombie's set-up)....but with no engine braking.....so someone explain to me how going 1-2-3 in the burnout box is any different than 1-2-3 down the quarter mile?
My car is 80% street, 20% drag so now i am thinking this going to be a pain to drive around town.
So after a WOT pass, leave it in 3rd until car slows down enough (50mph-ish?) before shifting back to 2nd then do i have to come to a complete stop before going into 1st or just match the rpm's? When i downshift, can i just bump the stick or do i have to apply light throttle to match things better?

Sorry to ask redundant questions but i just want to be sure ...thanks in advance. And i will ask the builder about the specifics of the TB...hitting that button any other time then when i am stopped (and have reverse applied) is a rather frightening thought.

 

Read the link in post #38, you really have to understand what that sprag does and its explained very well. Have to remember how fast it accelerates in the water and pulling 2nd shocks it hard, if the valve body timing isnt perfect the faster it accerates the more amplified the shock to that sprag can be.

If you want to do caveman 1-2-3 burnouts pony up for the aluminum direct drum Also buy a TH400 book and do a couple of your own freshen ups (very easy for the most part, just messy) and after you take one apart you can see exactly what you are doing wrong

 

I have T400, and now do 2-3 gear burnout, I did break the sprag last year.

At the end of a pass, I stay in 3rd gear, until I turn onto the return road at which point I put it in 2nd.

 

good thread. when you let off at the end of the track and leave it in 3rd do you have engine braking?

 

Yes, until it gets to around the converter stall speed anyhow.

 

So you're saying if for example you have a 4000 stall converter you would let it coast in third until around 4000 and then you can kick it into 2nd?? Just a lot more details about a RMVB Th400 than I thought and I don't want to F it up because of user error... =)