How bad is it to do a blast in OD?

[Rafs-T-Type]

Not that Ive ever done that , but how bad is it from the transmission and/or engine?

 

[notacarlo]

Pedal a mountain bike uphill in the highest gear and get back to me.

 

[Rafs-T-Type]

I understand that part of it, but I was looking more for the end result.

I actually just got done reading a thread you started about doing the same thing, but never seemed to get a direct answer either.

 

[notacarlo]

I'm never direct.

OD is weak. The carrier can split/come apart from the massive torque these engines produce. OD is intended for mileage/cruising, the first three gears are battle mode.

If you are in OD and you hammer it, she will just drop down a gear or two and that's fine. When hauling the mail approaching top speed and the tranny decides to go to OD is where the most load between the engine and tranny occur. The engine will develop massive heat (EGT) trying to push the car and the weak OD wants to leave the transmission casing, but can't.

Not sure I ever started a thread asking this, but on numerous occasions have told/advised to not do it. I could be wrong...I've been here for a while.

 

[overkillphil]

Been doing it for over 20 years on occasion in our various 200-4R equipped Buicks and older musclecars and never had a single problem. Had a few tight runs with other cars and the sweet autoshift to OD in our 200-4R's saved the day.

Did some high speed late night runs to the Jersey Shore on Rt-72 (very stupid in retrospect) with foot planted most of the time, again without incident or breakage.

 

[pacecarta]

i ran 26" mt drs on gtas and used od every run (I needed OD) shifting at about 117-121 at 5850 with an old art car 9" ,too many passes to count but over 500 running 10.5s high 120s, even made a few runs that accidentally over shifted third and ran od as early as 400 ft ..still went mid 10
oh and using a stageright tbrake every run despite being told how bad it was to my tranny back then with 60's in the 1.5 norm and as low as 1.40

on a totally stock trans or marginal tune its best to not push your luck.. at your power level i would assume a stout 200 4r is inplace , either way with the ptc efficeincy and taller tires and your valvetrain/cam you shouldnt need OD

 

[GNeric]

I built one way back (93ish) for a friend who was racing his El Camino in the Big Bend race down in TX and he ran the 140mph class quite a few times and he had sent me a few "in car" videos and he said the trans had performed flawlessly every time. Only thing he did was run Amzoil and changed it after every race.

 

[williambavila]

i wish i would have read this a year ago.. i have been taking off in 4th and now i am finding out it wasnt so good..

 

[bison]

A blast in OD? Id be shifting into OD at 145+mph. I dont think that would be safe. I highly doubt it wudl hurt the trans either. Id be more concerned about losing control on the highway.

 

[overkillphil]

i wish i would have read this a year ago.. i have been taking off in 4th and now i am finding out it wasnt so good..

Can you be more specific? It almost sounds like you may be confusing the thread with gearshifter position? Otherwise, how is it even possible to start out in 4th gear with a 200-4R??

 

[Way2QWK]

My car pulls like crazy after the shift to OD. Its too addicting to stop

 

[williambavila]

Can you be more specific? It almost sounds like you may be confusing the thread with gearshifter position? Otherwise, how is it even possible to start out in 4th gear with a 200-4R??

i assumed you all were talking about launching from the line in D?? am i mistaken?I tend to throw the car in D and go.

 

[Way2QWK]

I thought the question was WOT letting trans upshift to OD.

 

[williambavila]

I thought the question was WOT letting trans upshift to OD.

maybe i am confused is it good or is it not good to do a pass in drive or shall it be in 3rd i am talking about a 1/4 mile pass. i ran mine in 4(D)

 

[Rafs-T-Type]

A blast in OD? Id be shifting into OD at 145+mph. I dont think that would be safe. I highly doubt it wudl hurt the trans either. Id be more concerned about losing control on the highway.

145 That's insane....what would a normal car get to in third....(I assume you are reving higher than most giving you more MPH in D)

Can you be more specific? It almost sounds like you may be confusing the thread with gearshifter position? Otherwise, how is it even possible to start out in 4th gear with a 200-4R??

Obviously the car isn't leaving in 4th....It's just leaving and/or getting on it on the highway while the cars gear selector is in OD....Just trying to get to the bottom of how long it takes something like that to start messing up.

My car pulls like crazy after the shift to OD. Its too addicting to stop

So many addictions with these cars....boost, alky, timing :biggrin:

maybe i am confused is it good or is it not good to do a pass in drive or shall it be in 3rd i am talking about a 1/4 mile pass. i ran mine in 4(D)

I was under the impression that 4th is OD and 3rd is D....Anyway it seems like everyone agrees with that you should be in D for a run unless you run out of MPH because of RPM

 

[we4Mateo]

I run my car to 140mph+ a few times every year just to make sure everything is working ok. I'm addicted to the 4th gear pull too I need OD to do that. I run Amsoil but my stock tranny lasted 60k miles + with at least 50 low 12sec passes (all in 3rd though) with this use and I'll get back to you on how many miles the new tranny gets with the same abuse. I'm shooting for 100k more miles before the next rebuild.

 

[Roadrage david]

Are you guys for real!!!. ofcours you can blast in OD hell im doing it with a Bowtie overdrive level 3!!!.
right now we are building a new 475ci 730 hp 600lbs feet of torque 7000 rpm engine. with a revolutionair variable rocker system(V-Tec) specialy disighned for Pontiac. and im going to use one of the trans builders here that can work with us on our project. looking for a 1000 hp tr2004r trans that can handle the up and douwn shifts. top speeds will be wel over 200mph .
chek the 170 mph drive by clips and some other nice stuf you can see me shift in 3e clip at 138mph into od, i most of the time manaul shift it like a wel manual transmission........

YouTube - pontiac drive by
YouTube - pontiac firebird drive-by
YouTube - ROADRAGE FIREBIRD 68 PRT 2
somewhere in the se clip you see me shifting at 138mph into OD
have gone as fast as 190mph beating a Aston Martin Vantage.
below some road racing video,s im the green firebird
YouTube - PTGMC op zandvoort april 2010
YouTube - PTGMC op zandvoort april 2010 take1
YouTube - PTGMC op zandvoort april 2010 take2
YouTube - Dave 68 Firebird Pro Touring American Sunday 2010
YouTube - Dave 68 Firebird Pro Touring American Sunday 2010

 

["Turbo-T"]

Maybe some of you mean that you shouldn't be hard and heavy on the pedal in OD?

FWIW plenty of times I'd taken my car down a back country road and topped out at 130 mph in OD. I'd start off at a dead stop in OD and floor it, let the boosr come on, and just let the auto shift normally thru the gears.

I could have gone faster than 130 but decided not to push it. And while going this fast I was just letting out of the boost. I suppose this isn't good on the trans?

Hey it's not like I was also doing wheel stands/hole-shots on slicks at the track.

So unless what you really mean is do a WOT blast from 1-3 but by the time you hit 4th let off...???

 

[bison]

145 That's insane....what would a normal car get to in third....(I assume you are reving higher than most giving you more MPH in D)

143-145mph 6300+. It takes power to pull that far into 3rd. A lightly modded engine with stock cam and heads, small turbo with good springs with stock gearing might get to 5300 in a full weight car @110-115.

 

[bison]

I was under the impression that 4th is OD and 3rd is D....Anyway it seems like everyone agrees with that you should be in D for a run unless you run out of MPH because of RPM

You are correct. Your converter and gearing should get across the line in 3rd. If not id look into the converter first. Its the problem 99% of the time on these cars when they start making power. Pulling gear vial taller tires or reduced ring and pinion ratio further aggravates a converter slip issue.``