some help with tranny tuning

[dracing70]

Well here is my question i have not really tried to mess with the tranny at all and dont intend too. However i need to know if i can use efi to start out in a certain gear that i desire, such as third instead of running through first then second. Or is this not a option and i have to go with a copilot. If it is where do i start????

 

[frowningrdaddysLBZ]

IIRC EFI can set/change shift points,but I have no idea about selecting a specific gear to start out with......

 

[othrgrl]

Do a search - there are plenty of threads that discuss deleting 1st gear.

To answer your question briefly yes EFI Live can do it.

 

[The Neens]

I don't think I'd start out in 3rd...IIRC, the ratio is 1.41

 

[dracing70]

alot of guys are doin it via a copilot then shootin fourth i need to look into this

 

[dracing70]

well what do you think of starting in third in four low think it will do it or still no?

 

[MMLMM]

well what do you think of starting in third in four low think it will do it or still no?

Just skip first gear if you want to ditch a gear, otherwise adjust shift points as needed. Dont make it too complicated. You will find better results at the track playing with the ECM rather than all your work in the TCM.

 

[othrgrl]

Now I assume you are talking about sled pulling. Why would you want to put the converter through that much abuse. Leaving in 2nd seems to be plenty for the 700++ hp Duramax's around here.

 

[dracing70]

well i know a couple that start third i usually start at one but somethin is noy workin will try second first and start there

 

[MMLMM]

Are you talking about how people put it in 4lo and Manual mode 3 and go....?

Thats not starting in 3rd, it starts in 1 and moves up to 3rd.

I do this when I pull....

 

[dracing70]

no i know that there are a few big horspower guys who claim to start in third then shift to fourth in four low i believe with help from a co pilot

 

[juddski88]

i think MMLMM is right, you are just misunderstanding what they are telling you. they start with the Gear Selector in 3, then if they get enough rpm, they bump it to D with OD off.
I have also misunderstood stuff, it happens.

 

[JoshH]

If someone is telling you they are starting in 3rd with a Co-Pilot, they are lying to you or are confused themself. A Co-Pilot will do nothing for gear selection.

 

[othrgrl]

no i know that there are a few big horspower guys who claim to start in third then shift to fourth in four low i believe with help from a co pilot

What do you call big horsepower for sled pulling. I think 700+ is when you start to get into big horsepower. I agree with Juddski that you are probably misunderstanding what they are trying to tell you:

They start off in 3rd (with the gear selector in 3rd), then if the RPM get high enough they shift to 4th (move the gear selector to 4th).

The truck is actually leaving in 1st, shifting to 2nd, then 3rd, then if the RPM gets high enough they are moving the shifter to allow the truck to grab 4th.

We have and pull with some big horsepower trucks and I have never heard of ANYONE tuning to leave the line in 3rd - and as Josh said the copilot has no control over that to begin with. You can tune for it in EFI Live but you wouldn't want to - it would be eating up the converter and wouldn't help to begin with.

 

[05smoker]

If he is pulling in NE Ohio and Pa, he IS pulling with some guys starting in third and 4th. I know of at least one that has been tinkering with both. The Co-pilot is being used in order to lock the converter manually (tap blue wire to a switch I believe) so they can get out of the hole easier.

And if it's the trucks I'm thinking, yes they are big HP trucks and need to be to pull it off.

I'd do a second gear start and go from there.

 

[dracing70]

yes we are probably thinkin of the same guys i know a bit to know that when the selector is in third it still starts in first . but these guys are claimin to start in third gear i dont know how but they are and when i say big hp i mean definately 700 plus

 

[othrgrl]

yes we are probably thinkin of the same guys i know a bit to know that when the selector is in third it still starts in first . but these guys are claimin to start in third gear i dont know how but they are and when i say big hp i mean definately 700 plus

They are more than likely doing it through a custom TCM tune via EFI Live. It's still not something you need to be worried about at this point.

 

[dracing70]

so do you think it is possible at 550 rear wheel hp to start in second??

 

[05smoker]

so do you think it is possible at 550 rear wheel hp to start in second??

Don't know why not. My brother did it with a stock LMM last year.

 

[othrgrl]

Second, yes both at the track and sled pulling. 3rd - you could try but I doubt it would work out well, dependind on the track most <600hp trucks don't hit 4th pulling.