Overdrive question

[StormShadow]

I noticed the other day while I was at Hallsville that my truck was shifting into overdrive right before I crossed the finish line. Should I be running in D instead of OD? I'm not sure if it makes any difference at all. I did run in D one time to see if I was losing any trap speed with the shift but I spun out of the hole and ran a 12.4. I didn't make any more passes after that to compare to so I don't know the effect, but I wanted to ask everyone's opinion.

[03LightningRocks]

I noticed the other day while I was at Hallsville that my truck was shifting into overdrive right before I crossed the finish line. Should I be running in D instead of OD? I'm not sure if it makes any difference at all. I did run in D one time to see if I was losing any trap speed with the shift but I spun out of the hole and ran a 12.4. I didn't make any more passes after that to compare to so I don't know the effect, but I wanted to ask everyone's opinion.


You be making BIG POWER now:eek: ...time to do it like the BIG BOYEEZ:cool: . Turn Dat OHDEE da fock off:D

[L8 APEX]

With 3:73's the truck will redline in3rd about 120mph. At that point you will need OD. Rob hit OD on his low 11 @120+ runs.

[03LightningRocks]

With 3:73's the truck will redline in3rd about 120mph. At that point you will need OD. Rob hit OD on his low 11 @120+ runs.


What is red line????? LOL.......I thought that red stuff meant I was just getting going real good....:rll: .


:evil

[03LightningRocks]

By the way T....your opinion today just cost me about 4 grand......:rolleyes: . I called and went with the Lariat Crew cab.....yes...with the leather heated seats. So if you make a race or two with me this year, your ass will stay warm....:rll:

[sonicbluetommy]

I dont like where this conversation is going!!!! Rocks is gonna warm up Terry's ass? :rll :rll: :rll:

[03LightningRocks]

I dont like where this conversation is going!!!! Rocks is gonna warm up Terry's ass? :rll :rll: :rll:


LOL..........Let me help you understand...you may not have read the whole post...."the leather heated seats."

[sonicbluetommy]

j/k, we all know how Terry likes to be comfortable on them long rides. I am sure he will appreciate your thinking of him.

My only question is can you handle his taste in music?

[03LightningRocks]

j/k, we all know how Terry likes to be comfortable on them long rides. I am sure he will appreciate your thinking of him.

My only question is can you handle his taste in music?


I usually subscribe to the belief.....My Truck...My Radio....My Music...;) . I have heard he really digs the back street boys.....but he will just have to suffer without for a few hours...:rolleyes:

[02BOLT]

Back on topic....Adam, with the stock bottom end, I left the O/D on, because I didn't want to over rev the motor, and scatter the bottom end all over the top end of the track.

When I had the "built" shortblock in the truck, I turned it off, and she was SCREAMING on the big end. It's up to you. I don't know whether it really helps or not(to turn the O/D off). It seems logical enough and the "big boys" seem to think it does.

I'd probably play it safe if I were you. No sense in hurting a perfectly good running motor for a few hundredths in the 1/4, IMHO.

Later...

[L8 APEX]

I just looked at your tune Adam. It is programmed to shift into OD at 120.5 mph. If you hold OD off it will stay in third to 8000 rpm. I always say leave OD on the computer will do the rest. Nobody will see OD until they exceed 120mph or they have a special tune shifting it earlier.

[L8 APEX]

By the way T....your opinion today just cost me about 4 grand......:rolleyes: . I called and went with the Lariat Crew cab.....yes...with the leather heated seats. So if you make a race or two with me this year, your ass will stay warm....:rll:
Now if it was only FX4 you would be golden. I like this one 03, last 7.3L made, 36K miles only $32K.
http://images.getauto.com/vehicles/1FTN/1FTNW21F33EA75141-1.jpg
http://images.getauto.com/vehicles/1FTN/1FTNW21F33EA75141-4.jpg

[Mark #2]

Back on topic....Adam, with the stock bottom end, I left the O/D on, because I didn't want to over rev the motor, and scatter the bottom end all over the top end of the track.

When I had the "built" shortblock in the truck, I turned it off, and she was SCREAMING on the big end. It's up to you. I don't know whether it really helps or not(to turn the O/D off). It seems logical enough and the "big boys" seem to think it does.

I'd probably play it safe if I were you. No sense in hurting a perfectly good running motor for a few hundredths in the 1/4, IMHO.

Later...

Okay, all my 11.6 to 11.8 runs have been made with the OD off.
I have 3.55 gears, but I do run the 26" tires, so effectively I have 3.80 gears.
I don't think that one run with it off with scatter the engine, but no warrentee implied either.:)

[03LightningRocks]

All that being said..................and every single one of the suggestions are correct. The real issue...or question....would be, why did Adam's truck move into over drive at 114 MPH???? If it is "programed to hold off until 120....something is amiss.


Rocks:beer:

[L8 APEX]

Okay, all my 11.6 to 11.8 runs have been made with the OD off.
I have 3.55 gears, but I do run the 26" tires, so effectively I have 3.80 gears.
I don't think that one run with it off with scatter the engine, but no warrentee implied either.:)
We are not saying OD off automatically scatters an engine. Only that locking out OD allows you to run the engine to 8000 rpm without shifting. So where it would normally shift 3-4 at about 115 and 5400 rpm. With OD locked out you could pull it over 5400 which gets increasingly dangerous. RPM kills.

[03LightningRocks]

All that being said..................and every single one of the suggestions are correct. The real issue...or question....would be, why did Adam's truck move into over drive at 114 MPH???? If it is "programed to hold off until 120....something is amiss.


Rocks:beer:


11.3x with OD off............now answer the real question Terry...:D .

[L8 APEX]

11.3x with OD off............now answer the real question Terry...:D . I say it didn't hit OD. Adam is mistaken. You old codger:D

[03LightningRocks]

I say it didn't hit OD. Adam is mistaken. You old codger:D


You see that Adam. Terry just called you a lier :eek: . You gonna let him get away with that????

:evil

[wesman]

rofl...I'm still convinced rocks is a 10 year old trapped in a old mans body... if the above statement didn't convince you, this pic should help illustrate my point

http://www.svtgalleries.net/gallery/data/6061/1P1000104-med.jpg

[StormShadow]

I say it didn't hit OD. Adam is mistaken. You old codger:D

I will double check where I'm shifting the next time I run. I do know that it shifted at the end of the track (and I don't normally keep it floored very long after I cross the finish line) but will give you the benefit of the doubt. Maybe next time someone can set up at the end of the track and help me figure out where exactly it is shifting.

[02BOLT]

Okay, all my 11.6 to 11.8 runs have been made with the OD off.
I have 3.55 gears, but I do run the 26" tires, so effectively I have 3.80 gears.
I don't think that one run with it off with scatter the engine, but no warrentee implied either.:)

O.K. Allow me to clarify my opinion. Last December('03) at the TALON Fall Classic, I ran back to back to back to back 11.60's at 117+ mph on the stock bottom end, with the O/D ON, and it shifted into O/D on EVERY pass between the 1000' mark and finish line.

When I went back last February with the built bottom end, I turned the O/D OFF on each pass(because I was no longer worried about scattering the bottom end), and that sucker was pulling about 5700 rpm going through the traps. Now, granted I was running a 4# lower, and 3" upper making upwards of 18-20psi at the top end of the track(weather was in the 40*'s that day), and the truck was trapping 120mph.

All I'm saying(and this mainly refers to Hallsville, due to its "optomistic trajectory"), is that IMHO, any minimum gain you may or may not see by locking out O/D is not worth the CHANCE of lunching your stock motor over, especially if you're there on a really COOL day. You may get away with it, and you may not.

[L8 APEX]

Yeah, I wouldn't turn 5800 rpm in top gear on a stock bottom end. I stay conservative at 5400 under those conditions. Don't confuse converter clutch lockup with shifting into 4th. A lot of folks get the two confused with auto trannys.

[03LightningRocks]

OOPs.........hit post by mistake