Hey guys, been a few years and im ready to build another turbo truck. I have experience with the 4.3L's in my old 2002 blazer but I am looking at a newer 05+ Trailblazer with the 4.2L I6 engine that is supposed to be pretty damn strong minus the ring lands.

I have been looking into how strong the motor is and fuel/tuning options and can't find much. I am looking for just a 350/400whp truck thats just reliable and not to bad on gas.

I was wondering if anyone had some information on how sturdy the pistons/bottom end is (from what I have read the crank is strong and the rods are pretty unbreakable), can the stock bottom end hold 400whp reliably?

As far as tuning do you know of any options? I know that EfiLive only has software for the 08-09 4.2L


Any insight would be appreciated!

 

 

You can build it to make the power you want, but what is your motivation? If you are attracted to the 4.2 for fuel efficiency, you might as well just start looking for 5.3 and 6.0 Trailblazers right now, because the difference is negligible stock and you'll have a much easier time reaching your goals with the V8s. If this is more because you want to build something different, throw some forced induction at it and have fun.

 

Isn't that the car Parish and his buddy's caught cheating at drag week a few years ago?

 

I have an 04 Colorado with the 3.5 which is the same engine minus a cylinder, same pistons, rods, valves etc. I'm running a Garrett GT 3582 R at 12 psi putting down 314hp and 328tq to wheels with no issues. I'm also on a colorado forum where there are at least 5 or 6 of us doing this with no big issues. One guy is over 20 psi on stock motor and claims no issues. HP Tuner covers all TBs.

 

Pretty sure, they were stopping out away from everyone and loading it up if I recall.

 

The atlas lineup is stout. With a 76mm I got my crew cab to trap 114 (91 in 1/8) the first time out with a pretty pathetic run with the 5 cylinder version. That was around 14lbs. Pulls like a freight train!

 

Also if possible. Go e85.

Might have to go to 160s depending on your goals. My 80s were maxed out at 80psi base

 

How much does the Trailblazer weigh?

 

Mine is 4wd and weighs 4600 lbs.