ok a3 guys what do you do at the end of the track????

OutlawZ · 05-27-2008, 05:06 PM

Alright i'm about tired of hearing what i SHOULD do to avoid damage to my tranny when going thru the traps..... I have heard so many things and wanted to find out what you guys do after going thru the finish line...

Tranny is a RMVB TH400 from ATI, ATI 4200 stall converter.... Some people told me to put the tranny in neutral immediately after going thru the finish line (which will require going from 3 to 2 to 1 and then N and will take awhile when I SHOULD be concentrating on slowing down....

Others have told me to leave it in 3rd, slow down and when I get the car back on the return road shift it down to 1st or 2nd depending on speed and go on about my merry way....

So what gives and why????? Something about slamming the converter or boiling fluid or overpressurizing it.... there's gotta be a right way and a wrong way and a reason and i'm looking for it...

frcefed98 · 05-27-2008, 05:14 PM

My builder told me to brake/coast down in third and drop it into 2nd when on the return road and rpm's dropped to under 3000rpm.

So thats what i'll do whenever I get the damn bird to the track again.

pddye · 05-27-2008, 05:20 PM

I've also wondered this. I was just going to go with the downshift at lower speeds on my new th400 but i've never been told any different. Also i've read on a few forums the correct way to do the burnout but how is everyone doing this also? Sorry for the hijack to the original poster. That is the problem with buying used parts off of guys that don't give you a lot of info on the tranny and how to use it correctly.

DanZ28 · 05-27-2008, 05:24 PM

I leave it in third myself. I pulled this directly from Rosslers site:

3 speed and overdrive transmissions: Caution never shift into neutral position at high speeds. This will cause internal components of the transmission to rotate 2 and ½ times faster than your finish line RPM. (Example, If your car’s finish line RPM is 7,500 RPM’S and the Transmission is shifted to neutral then the internal components will spin at 15,000 RPM’s THIS IS VERY DANGEROUS! The parts are spinning so fast, they can explode, turning your transmission into a shrapnel type bomb possibly causing bodily injury and death.

On full competition transmissions with manual valve bodies or transmission brake down shifting to second will cause the same reaction. This also is very dangerous and not recommended.

red83 · 05-27-2008, 05:28 PM

another note on the turbo 400. my builder told me not to finish a burnout in 2nd gear and let the tires grab.

OutlawZ · 05-27-2008, 05:47 PM

ATI fully describes the burnout as:

start tires rotating after rolling them thru the water and pulling a few feet forward of the box...

start burnout in 1st, shift to 2nd then after a few seconds shift to 3rd and drop the hammer. It then says "POWER out of the box for a few feet before letting off, do not allow the tires to snatch traction by just letting off the gas... You should continue to do a burnout after releasing the line lock or the brakes.... then close the throttle slowly instead of just releasing it abrubtly....

nothing about what to do at the end of the track..

But I just talked to my tranny builder and he concurs DO NOT shift to neutral and just leave it in 3rd till you get onto the return road....

Camaro396 · 05-27-2008, 05:58 PM

I have always been told to leave it in 3rd until your on return road.

RAGENZ28 · 05-27-2008, 06:05 PM

Burn outs, start in second gear and shift to third gear asap, then roll out of the burn out in 3rd.

After you get out of it on the top end, I leave it in 3rd and then once on the return road, I down shift to 2nd, then 1st gear and cruise to get my time slip. I was told never to down shift under power.

As far as what ATI says about not letting the tires grab, they will do that as soon as the tire speed slows down so that is unavoidable so you should be in 3rd gear when burning out.

dlove · 05-27-2008, 06:09 PM

NEVER downshift a RMVB 400 without first giving it very slight throttle, just enough to make sure the car is not slowing down. Otherwise when you let off in 2nd the car turns the drum the opposite direction and the second you hit the gas it has to spin back the other way. Never slow down in second eaither.

DanZ28 · 05-27-2008, 08:01 PM

Mine doesn't actually "brake" in any gear, let off the gas is like neautral.

red83 · 05-27-2008, 08:06 PM

Quote:

Originally Posted by DanZ28

Mine doesn't actually "brake" in any gear, let off the gas is like neautral.

i think 99.999% rmvb's are like that... i think you can get them built with the engine braking feature.........i think

Smoke346 · 05-27-2008, 08:30 PM

In my 69 camaro I had (468BBC w/ RMVB 400), I would clean the slicks for a split sec, shift to 2nd, mash it , shift to 3rd and roll out while slowly letting off the throttle. As for the big end I would leave her in third, slow down and when around 20 mph or so, start downshifting until I was in 1st. Never had any issues doing it this way, probably ran the car that way 40 or 50 times.

TwoFast4Lv · 05-27-2008, 09:18 PM

DO NOT shift to nuetral at speed, NEVER! Some brake setups WILL explode the transmission if you do! IF you do it can over drive the third gear drum until it exploded like a grenade.

Burn outs start in 2nd and go to third rolling out and lifting before you hook. If you hook you slamm the sprag inside the converter

MADMAN · 05-27-2008, 10:01 PM

HMMMMMMMM maybe we need to buy a good valve body????? All the 400s I have built donot allow down shifting. The standard procedure I teach my drivers is to cross the traps and throw the chutes. Then let off the gas and put the car in nuetral. At that time shut the engine down so I can read a plug. I have 1000s of passes on cars with over 100hp engines and have yet hurt a trans. Also all my burnout start in 1st and then second then third and you roll out.

Sorry Ellis but we need to talk !!!!!!!!!!

red83 · 05-27-2008, 10:06 PM

Quote:

Originally Posted by MADMAN

HMMMMMMMM maybe we need to buy a good valve body????? All the 400s I have built donot allow down shifting. The standard procedure I teach my drivers is to cross the traps and throw the chutes. Then let off the gas and put the car in nuetral. At that time shut the engine down so I can read a plug. I have 1000s of passes on cars with over 1000hp engines and have yet hurt a trans. Also all my burnout start in 1st and then second then third and you roll out.

Sorry Ellis but we need to talk !!!!!!!!!!

fixed the hp number for ya

TJ · 05-27-2008, 10:41 PM

ive made hundreds of passes and always shift to neutral. i dont understand how the tranny can spin twice the speed?
i dont mind learing something new.
i dont do it to save a tranny, i do it to save my motor. dont want the rods at high rpm unless they need to be.

downshifting a manual valve body is a no no unless you are under throttle.

OutlawZ · 05-27-2008, 11:57 PM

my valve body doesn't let the tranny downshift that's for sure. cuz i had it on the dyno and shifted to neutral and it was fine... never downshifted....

i'm just wondering does it hurt the tranny to keep it in 3rd and just start getting on the brakes... (hard)....

Dave J · 05-28-2008, 12:07 AM

Quote:

Originally Posted by frcefed98

My builder told me to brake/coast down in third and drop it into 2nd when on the return road and rpm's dropped to under 3000rpm.

So thats what i'll do whenever I get the damn bird to the track again.

thats what I do

Dave J · 05-28-2008, 12:12 AM

Quote:

Originally Posted by MADMAN

HMMMMMMMM maybe we need to buy a good valve body????? All the 400s I have built donot allow down shifting. The standard procedure I teach my drivers is to cross the traps and throw the chutes. Then let off the gas and put the car in nuetral. At that time shut the engine down so I can read a plug. I have 1000s of passes on cars with over 100hp engines and have yet hurt a trans. Also all my burnout start in 1st and then second then third and you roll out.

Sorry Ellis but we need to talk !!!!!!!!!!

on a rmvb how do you shift to neutral with out going to 2nd and 1st before that?

patriotformula · 05-28-2008, 12:12 AM

Maybe things have changed... But I have seen tons of guys shift into neutral after going through the traps with no problem... But I have also seen 2 guys shift into neutral with a rmvb 400 to see it catch a lower gear and actually flip the car... Its up to you, but if your not reading plugs (even if you are) you need to realize you're shifting down through gears and cant trust it to not accidentally catch one...