Trans. adapt data

[Fuzzman]

Hey guys, I need some help/advice.

Finished 411 swap on my 1997 GMC, 5.7L with hotcam. My local tuner guy came and did the base tune and after that tried to do the final tune to squeeze out the HP and torque on this girl........
But we couldn't. For some reason my truck is stuck in second gear. Limp mode?? I had the mechanic at the shop I work at scan my truck and he found that the transmission adapt data is blank.
Anybody know what the heck I'm looking at here? Obviously, I'm guessing a wiring issue from the swap. I'm just not sure where to start.

Any help??

Thanks guys,

[Doc]

What transmission are you running?

[Fuzzman]

Sorry. 4L80E.

[Doc]

Can you post the tune file. Could be a 4L60 segment while you are attempting to run a 4L80.

[Supercharged111]

Do you have power to the transmission? Lack of trons will also cause 2nd gear only.

[Fuzzman]

Well guys, turns out that my tuner guy flashed the computer for a 4L60E instead of the 80 like my old girl has in it. Now she shifts like a champ.
One question, though: He mentioned doing an EGR delete on my truck. Any thoughts on this?

[Doc]

Cool beans on getting the segment swap. EGR. depends on what how your local emissions are enforced? Do you have annual inspections? If not, delete it in the tune and physically remove the EGR. Weld the port shut.

[Fuzzman]

Thanks Doc, feels good to have the old girl running again!
Emissions isn't that crazy up here in sunny Alberta, so deleting wouldn't be an issue that way. Not knowing what the plus and minus is on deleting is my question. What's my benefit and what might be an issue if I delete?
I've done some reading but I'm getting huge mixed signals.

[Doc]

EGR, Mheh, ask yourself this, when was the last year GM fitted an EGR on a vehicle? They all eventually get stuck open or closed. I am not an engineer but, I think it is pretty worthless and has no effect on power or fuel efficiency. I think GM did it at the time just to satisfy the Gubment.

[Fuzzman]

Thanks Doc, I'll talk to my tuner guy about the delete. I found a delete kit on ebay. That should do the trick.

[joecar]

The EGR was used for lowering combustion chamber temperatures by diluting the intake air with spent combustion gases (for the purpose of avoiding creating NOx combustion by-product)... this also has the side-effect of dirtying up your intake manifold... yech.

GM has long since figured out how to lower CC temps (and NOx) by other means (timing and fuell).

If your annual vehicle emissions inspection does not force you to have it, then delete is as Doc said.

[Supercharged111]

I figured their abandoning had a lot to do with the way cam profiles are now vs where they were with my old ass trucks. That and much faster, more responsive processors and more adaptable OSs. My truck came with similar cam duration to the LM7 (which I believe still had EGR), but sat on a 111 LSA and used a 106 ICL. That builds a lot more cylinder pressure than the ~115 LSA of the LM7 and what may have been an ICL later than 115. Add variable cam timing to the mix and you really can alleviate the need for an EGR valve. I've never seen a difference in fuel economy by removing them on 3 of my trucks, but it keeps the intake manifolds and throttle bodies sooooo much cleaner. Like Joe said, its real reason for using them was to lower cylinder pressure, but supposedly on lighter cars it also had the side effect of helping fuel economy. Make sure you wipe it out in the tune too. I'm inclined to believing that the LS based PCMs were smart enough not to advance the timing with a physically defeated EGR valve, but some earlier OBDI engines were not so smart. My friend lost a 2.2L Toyota Celica engine and we believe the cause was the EGR that was physically disabled with the tune left alone. It doesn't help that the fuel is reduced too. This is necessary with a properly functioning EGR valve as, theoretically, the air injected by the EGR has no fuel or oxygen leftover for combustion so your engine acts like a smaller displacement engine.