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Discussion Starter #1
I have a 2004 Duramax with the 5 speed Alison. I was wondering if anyone knew that a 3 inch downpipe was the biggest you could fit between the firewall and the back of the motor? I seem to have too small of a down pipe and was wondering if I could upgrade.

No matter what the conditions are if I'm on 5 on my chip and put the skinny pedal to the wood:fart the EGT's will jump up to 1418 between 3rd and 4th (that seems to be when it lugs the most).
 

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You can get a kit for it, but unless you are going with a bigger turbo, it won't make that much difference. Do you have the LB7 or LLY in your truck? If you have the LB7 you can get a PPE boost increase valve and your EGTs will go lower. Also, what exhaust do you have on your truck? A 4" exhaust will work wonders along with a cat delete if you have one. As far as EGTs, you will see those numbers with any programmer. The only way to not see that high is to get a bigger turbo, but you will still see numbers into 1400. I have seen 1500 on mine no problem. As long as you don't hold it for more than a couple of seconds, you will be ok. I have read on other forums that guys peg out 2000 degree pyros in the 1/4 mile. Do a little test, download your program and return it back to stock. I will bet you will see over 1300 in your current set-up.
 

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I do have the LB7 so I will be getting that boost valve. I already have 4 inch exhaust all the way back with no cat, and I'm not quite ready for a bigger turbo.

My pyro sensor is in the manifold, where is yours? I was wondering if it could be reading a couple hundred degrees hotter because of this. Edge recommends that you put it there, but that is the hottest point of the engine. So I was wondering if I could bump the alert a couple hundred degrees more.

I have the Juice so it's backing down 100% everytime I put the chip on 5 and step on it.
 

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Well, part of what yours is backing down for is the tranny too. I would not run edge on 5 unless you have some upgrades to your tranny. My EGT probe is in the exhaust manifold pre turbo. I have the TST powermax and it defaults to 1300* F for EGT. With that PPE boost increaser, your EGTs should come down some. To be safe, I would not bump your EGT alarm too much above 1450. You could do 1500, but I would watch it so that it wouldn't stay there for an extended period (like 30 secs). I have a boost increase valve that came with my TST and it tops out at about 30 psi, but I still see the EGTs well beyond 1300....I have seen about 1450 even with the alarm. I looked down and it was flashing, but it didn't back down because I barely had the TST turned on (I also run the predator on 65).
 
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