I dropped a junkyard LM7 and a TDP stage 2 t56 in my Colorado last fall, and now I'm looking into a turbo for it.

My buddy has a Turbonetics Tc78 that I'd like to pick up, so I started digging around, reading build threads and so on.

So, here's what I was thinking, and where I'd like advice.

LS6 springs/cam
LS9 headgaskets
truck manifolds
pushrods
arp head studs

Fuel is also where I'm not sure. I was thinking 42lb injectors and swapping out my stuck Colorado fuel pump for a walbro 255.

Find an ls6 intake or keep stock truck intake?
Right now I'm on a speed density tune, no maf. Should I go maf?

Looking to push 10psi or so, nothing too crazy, at least to start off with.

Thanks

PS
Here's turd truck in all it's glory. I rescued it after 8 years as a work truck.


Here's what I have to play with. It's dirty, I haven't washed it and didn't wash it before the motor went in but that's what the plan is for this winter.

 

The whole concept is ridiculous. Don't you know? You can't make a LM7 fast...











































Little truck should surprise a few people, if you can get traction! Should be pretty damn fun.

 

Right now it's wheel hop that's killing me, but cal tracs will be on here soon. Messing around at the track I pulled a 14.0 at 102 with 2.3 60ft. Doesn't help my tires aren't mean for launching. lol

 

To answer your questions a little better.

If you get a smokin deal on the 42#'ers, go with them. Otherwise jump stright to 60's.

The Walbro 255 may get it done, but I'd go straight for the A340/Hotwire setup. Eventually you're gonna want to turn up the boost, so do the fuel system once and be done with it.

Keep the truck intake, unless you really would rather have the looks of the LS6. It's a bit of work to make it fit with the truck accessories, and the performance increase much. Not worth the time or money IMHO.

The rest of it seems okay. The LS6 cams seem to be overpriced these days, but if you find a steal on one, they do work. You could gain even more with a custom cam, but who's to say how much?

Can't go wrong with ARP head studs. I've never used ARP head bolts on a FI build, and I probably never will.

As for the tune, I'd stay SD. It doesn't take much to max out a MAF on the Gen III pcm.

 

go with the 60's like above said to do, and dual 255 intake pumps with a hobbs switch and be done.


Anybody wanna recommend a isky turbo cam or the speed inc one. i have no prior experience with either but have read about them im using a speed inc one on my current build.

 

The triple 12 is a proven cam that works.. 212/ .561 / 112.
TU1 Cam 225/.581 113
Either one would work and wouldnt make a whole bunch of difference in a light truck.

 

got to agree about the injectors i wouldnt go any smaller than 60's

 

You definitely dont need to pull the heads right now IMO. I think you will have your work cut out for you making it hook at 450-500, and the stock gaskets and bolts are plenty sufficient at that power level. 42's would be ok at that power level too if you keep the stock cam, but if not you need to step up to the 60's. Wouldn't even consider the ls6 intake, but the TBSS/NNBS 90mm intake would be an upgrade. Personally, I would leave the stock long block alone and get it running with the turbo first, work out traction issues you will have, then roll with a cam and TBSS intake and maybe turn the boost up a lb or two. The stock motor would put you at 450-500 at around 10lbs, and the cam/intake would have you up close to 550.

 

Yea i agree.. just put a set of valve springs in there and leave it stock. Your gonna have fun keep traction as it is.
6# boost is roughly adding 125rwhp so that gives you an idea of what your gettin into ha
When you get it to hook up and go, then slowly turn the boost up till you get to 10#.. if its still rocking then throw a cam in it and go have fun.

 

60# injectors should do it. I would go with a heavier valve spring than the LS6 ones. Remember that the boost will be trying to push the intake valves open, so you need a heavier spring. At 10psi that's roughly 30 lbs of pressure trying to push the valve open.