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Rail Pressure?

tylerrustLB7

tylerrustLB7

"Addiction"
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Location
Stephenville Tx
Ok, guys getting trans & Air-Dog 150 next week and I will be running the 300hp to 350hp PPE tunes do yall think I need to put rail pressure gauge in the truck?:eek:ut:
 
nope, but when you get your trans done, after it is done, you will want to tech 2 it to clear the trans taps out and put the TCM into fast learn.

When you do that, you can check everything all at once. You can raise the pump pressure all the way up and check your injectors, and you can also check your balance rates too.

But with the Airdog, you should be good. It pushes alot of fuel.
 
Philbilly2 said:
nope, but when you get your trans done, after it is done, you will want to tech 2 it to clear the trans taps out and put the TCM into fast learn.

When you do that, you can check everything all at once. You can raise the pump pressure all the way up and check your injectors, and you can also check your balance rates too.

But with the Airdog, you should be good. It pushes alot of fuel.
Click to expand...

Ok, so do I need to clear the trans taps even if it is a totaly diffrent trans? Its a core thing I am doing, not building the trans that is in the truck now.If I still have to clear the taps on the trans how do I get my hands on a tech2?
Thanks alot Phil you have been alot of help!!! Ok so no rail pressure gauge got ya!
 
Well, what happens is that there is a TCM under your hood (under a shroud next to your drivers side battery. It more or less is what stores all of your transmission information and makes the ajustments that are needed to make the transmission shift like only an Allision can.

When I built my Allision, I didn't get a chance to Tech 2 it for about 10 days after I finished my trans due to that my buddy at the Chevy dealer couldn't borrow it and I couldn't get there after work. All you do with the Tech 2 is clear the TCM taps out. Then you put the TCM into a fast learning mode and it will shift like it is gunna blow for around 5-10 shift patterns then it all smooths out and it drives great.

You might be able to get away with switching the transmissions and not Tech 2 the TCM. The only thing is that it will shift very violently for about 40-50 shift patterns as it learns the new transmission corks.

Tech 2's are about $1000, so most have to find somone who has one. I would start with anyone you know that either A: Builds Allisions, B: Has a Dyno, or C: if you know someone who works for a GM dealer, dealerships have them.
 
Philbilly2 said:
Well, what happens is that there is a TCM under your hood (under a shroud next to your drivers side battery. It more or less is what stores all of your transmission information and makes the ajustments that are needed to make the transmission shift like only an Allision can.

When I built my Allision, I didn't get a chance to Tech 2 it for about 10 days after I finished my trans due to that my buddy at the Chevy dealer couldn't borrow it and I couldn't get there after work. All you do with the Tech 2 is clear the TCM taps out. Then you put the TCM into a fast learning mode and it will shift like it is gunna blow for around 5-10 shift patterns then it all smooths out and it drives great.

You might be able to get away with switching the transmissions and not Tech 2 the TCM. The only thing is that it will shift very violently for about 40-50 shift patterns as it learns the new transmission corks.

Tech 2's are about $1000, so most have to find somone who has one. I would start with anyone you know that either A: Builds Allisions, B: Has a Dyno, or C: if you know someone who works for a GM dealer, dealerships have them.
Click to expand...

I think I know somone with one, Snap-On has there version of one i think because that is what my buddy has. So you said somthing about bumping the line pressure up? I know somthing like when an allison shifts into 4th 0r 5th cant remember it drops like 50psi of line pressure right? So when you Tech 2 it it will have that option to up line pressure? thanks
 
line pressure on the fuel rail is what I was saying to bump up.it will make your truck run really funny. but it makes sure that the CP3 pump is good. You can do that the Tech 2. I was just telling you the things I would recommend that you check while you have access to a Tech 2.

But yes you are spot on with the Allision dropping Line pressure on the 4-5. The line pressure on the allision is changed my putting a shim in the pump inside the transmission. I used 2 nickels ($0.10) to shim my pump to boost the line pressure in the pump.
 
Ok Phil got ya, thought you were saying about trans line pressure.I will get it all checked out!
Costello Racing trans out of Oak Grove Lousiana he knows about allision's he has built many of them including his own.
 
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