onfire

iTrader: (17)

I just leave mine in 3rd until I get to the timeslip booth....less stuff to worry about.....

RICE ETR

iTrader: (3)

Thanks for the replies.
I read the link but still don't understand the difference between 1-2-3 in the box or WOT....still accelerating and shocking the tranny...I would think much harder during a pass because it's full load and full throttle where the burnout box is partial load/high rpms and part throttle.
So i read somewhere else that it's bad to be constantly downshifting the tranny...like on the street...so maybe this is the wrong tranny for me?

kp

iTrader: (34)

Its kind of like why it isnt it OK to just keep sitting there and free reving your engine to 7000rpm but its ok to shift it there - sorta Lot of times people are off the throttle before pulling 2nd in the water and thats what causes the problem when the tires drive the trans when you hit 2nd. Also the rate its accelerating on the 1-2 shift in the water, you can go from idle to 7000rpm in 1/3 of a second in the water and then pop 2nd..

Its OK to downshift, just dont do it to slow the car down - because it wont slow the car down and its hard on the trans IF you dont have the front band. As long as you downshift at reasonable speeds or give it throttle it will be OK. Or just get a manual valve body trans that keeps the front band and you dont have to worry about downshifts hurting anything..

6techniques

iTrader: (7)

Jeez, Im starting to feel spoiled with my M6!

engineermike

I'm sure an improperly shifted TH350 or 400 is still more reliable than an M6/clutch.

Mike

6techniques

iTrader: (7)

Well, I made that statement in relation to what people do when they get off the gas in an A3...I think most M6 drivers usually pop it into neutral and call it a day. Compared to what some A3 drivers do for "durability's sake", I would say a M6 driver should feel a little spoiled. But Im going auto in the future so Ill be joining the '2nd gear burnout club' soon!

kp

iTrader: (34)

Not really as bad as it sounds and its pretty simple what you need to do. Its not a stock trans though, a stock TH400 you can do whatever you want. Its a modified race trans made for limited consumption, same thing as if you pro shifted that t-56 and took 5th and 6th out. Try to downshift one of those

Its not hard to just leave it high gear and let off the gas (or put in 2nd with a VB like mine), not like it has so much engine braking that its going to put you through the windshield when you let off. Matter of fact you dont even notice it going 150mph and trying to stop on a short track. Once the engine rpm drops lower then the stall speed the engine braking is pretty much gone in high gear..

OutlawZ

iTrader: (4)

yeah all the stuff that kp said is exactly the stuff that ATI told me when i bought my TH400 with RMVB and internal trans brake... their documentation tells you to start the burnout in 2nd, shift to high until you're satisfied with the tiresmoke and then "POWER" out of the box... don't just do this let off the gas and let the tires "******" the pavement.... bad for the internals.... it didn't have any specific info about finishing up at the end of the 1/4 though... i have downshifted to 2nd but for some reason my tranny didn't do anything if I was going too fast.... then i talked to joe overton and started leaving it in 3rd until i got to the return road.....

On a side note can any of this stuff hurt your thrust bearing inside your motor???? cause my TH400/converter combo shelled my thrust bearing after about 3000 miles..... low 10 second car and probably had like 20 passes on the car before i figured out the thrust was shot..... basically complete rebuild required... i've talked to several people at continental converters and john kilgore and he said that continental has a setup where they drill holes inside the converter so fluid can pass between the seperate stages of the coverter and it reduces the pressure in the converter and it's tendency to try and walk down the input shaft (hence pushing on your flexplate/thrust bearing/crank)..... continental says that solved problems of people with repeat thrust bearing failures.... just something to think about... thrust bearings are generally one of those things that can be going bad and you might have NO idea cause there's no external signs until the motor blows up and then it's blamed on sumthing else anyways.... i'm having this done to my converter at continental.....

kp

iTrader: (34)

Most likely your converter didnt have enough 'pull out' or was ballooning and tearing the thrust bearing up. Or the thrust bearing clearance wasnt right to begin with, its pretty to easy to check - just pry the crank back and forth and if you can see it move time to pull the motor

I have owned and built a lot of SBC and BBC cars and never ever had any thrust bearing issues unless something was pretty wrong. But when you start getting into low 10 and 9 second cars rebuilds get a little more frequent and if something is wrong it will usually get get caught. Normal street driving shouldnt be hard on the thrust bearing at all if everything is right.

I mostly leave it in third after a pass since I'm too worried about stopping the car and have two hands on the wheel then fooling with the shifter, I wont put it 1st or 2nd until I make the turn on the return road..

OutlawZ

iTrader: (4)

well i've got an anti-balloon plate on my converter (ATI converter)..... how will you know if the converter ballooned after pulling it out of the car...

and when you say "pull out" are you talking about the measurement between the end of the bellhousing to the mounting tabs of the converter? basically the slop distance between the two????? I could have sworn i measured and it was within the specs ATI sent me.....

DMH Fabrication

iTrader: (126)

Why does rossler's trans brake say it has a built in easy stage? Is it any different then a normal trans brake?

kp

iTrader: (34)

I doubt you ballooned the converter if its an ATI unless you sat there for an hour on the brake WOT

Pull out is the how far you can pull the converter from all the way back until it hits the flex plate like you said. 3/16 should be minimum on a trans brake car. But there are a lot of things that can case thruse bearings to get chewed up, letting off the car shouldnt be one of them unless its running out of oil when you brake hard..

engineermike

kp, since you know so much about auto's, answer me this. . . I can't build boost on my foot brake and I don't want a trans-brake because I like my full-auto for cruising.

Would it kill the transmission if I were to put it in neutral, floor it with a 3000 rpm 2 step (to build boost), then drop it in gear. Then, as soon as the clutches engage, release the 2 step? At first glance, it seems like it would break something bad, but on the other hand, it doesn't seem to be any more abusive than a trans-brake or even a full-throttle upshift.

Mike

2001-WS6

Boom potential is way too high with this plan.

Are you running the two step now? What's the current stall on the converter and what are you running for brakes?

Rick

98 Z28

I know it a little off the subject but does any one know who makes a valve body that keeps the front band? any of them have a trans brake too?

kp

iTrader: (34)

I dont know if I would want to try it, TH350s arent exactly the strongest transmission in the world, lack of a decent center support is their downfall.

May work a few times but thats some pretty critical timing to get all that right. Do like I used to do in my GN buick 20 years ago, put drum brakes on the rear, cut the drums out of round and use a line lock on the rear wheels

kp

iTrader: (34)

I think rossler has a manual forward patern valve body that keeps the front band with a brake. Have to call around.

Zombie

iTrader: (2)

If the having the front band allows downshifts from 3-2 and keeps engine braking in 2nd gear then Rossler does it, my trans is setup that way. If I go 3-2 I get have engine braking, it does not freewheel.

I believe John Kilgore can also hook you up with a setup that keeps the front band.

engineermike

I do have a 2-step now, but can't build any boost on it because I can only foot-stall it to about 2000 rpm. If I set the 2-step any higher than 2000, it over powers the brakes. At only 2000 rpm, it won't build boost. The converter is a Vigilante 10.5" turbo converter that flashes to about 4400 rpm at full boost. Brakes are stock LT1.

Mike

onfire

iTrader: (17)

I used to launch the exact same way...sixty's sucked...generally 1.65 to 1.68.....

A TB is your friend...dropped my sixtys down to 1.35 to 1.38 with the wheels up....It also stopped a bad problem I had with boost hitting 40ft out and blowing the tires off just after I launched....now it loads the suspension like it should.