Where are the cam sensors on these trucks? Maybe when the supercharger went on the sensor may have been damaged, I only saw misfire codes after a cam install on my LS1. I also broke the oil sending unit due to it being behind the manifold where I could not see it. Could happen to anyone.

 

Sound advice, dhpro....

First step in troubleshooting is to go back to a known good condition.

 

I run TOG mid lengths (almost long tubes) and i don't have any problems putting 540 ft/lbs to the ground.

 

You need to look at your current misfires and misfire history for each cylinder. I bet you'll see one cylinder thats causing your misfire problem. Replace that plug or plug wire and see if it cures your issue. (I bet it does) If you don't already have a set of colder spark plugs (NGK TR6), then this is a good time to install some.

I'm running long tubes with a radix and have no issue with tuning. BUT, in the past, I hit a plug with the header during the install and started getting a 300 code and flashing SES light. I replaced the plug and bingo, back in business. I've also broken two plug wires when pulling them off the plug during a plug change.

 

We've already done all that guys (except the reinstall of stock exhaust). Thats why I'm at the "pissed off" stage with Mag! they basically said theer was nothing more they cud do, and keep insisting their tune is not the prob! Its definately a tune issue, or why else doesn't the Nelson tune spin up the same code?! Mag needs to send a fresh tune and we can trouble shoot that as thats the only thing we haven't done yet!!! U need to speak to ur guys I EM'd u and confirm whats been tried. R/

 

All wires & plugs have been changed and rechecked since. I'll recheck plugs again to be certain, but if it was any of these mech issues, then I'd get the same misfire code with my Nelson tune installed as well. The code only happens with the Mag tune installed on the OEM PCM. R/

 

as I said keep it simple...you said mag would take back the unit right?...then send back the unit you have and get a new uniiiii...wait a minute...so what was your problem with Allen's tune then if you have no codes on his? Oh yeh, nothing down low. But to get something down low you have to settle for the 0300 code on the mag tune. Hmmm. What was Allen's take? And Allen certainly should be able to fix the "down low".

 

Neither one had the down low power, but its been mid 90's and very humid, so that cud be the prob there. No code on Allen's, only with Mag's. R/

 

Just so we're on the same page, this is my first Blown Chev. I opted for the Radix instead of centrifugal as all the info I found told me the Roots style had power off the line. I drove a centrifugal S/C Avv and it squeaked tires off the line. Mine's like a hunk of lead at the line, and finds its own once I shift into second - no matter what tune I use...R/

 

Yeh but I am not sure about heat effecting down low power...maybe your second drag run, or you middle or certainly up high pull...those IAT's will go quick...but ( I know you are frustrated with them) that radix cools itself (err IAT's) fairly well. You should certainly feel you have more power down low versus stock. You do weigh 6500 lbs right...whats an avalanche weigh these days? Neither here nor there I guess...I would just take the angle with Mag that for over $6K you have a slower vehicle down low than stock. BUT first getting it back to what Mag will work with...I can't see them not supporting the header choice either, they suggested the dyantechs to me on the phone before I made my order. But, you migh have to go back stock just for arguing room. ugh.