full foot notch

05 Colorado getting 2006 LQ4 6.0 , 4L80E, 205/75 15" tires for right now , 3.73 gear ratio , curb weight without driver should be roughly 3300/3400 (3112 with stock 4 cylinder , and the v8 is roughly 250lbs more.

Engine will have LJMS Stage 2 Cam, Melling 10296 oil pump , johnson 2110 lifters, Brian tooley racing 660 lift dual valve springs , LS2 cam gear and sprocket and IWIS corvette C5R chain. Arp main stud kit and head stud kit , arp stud kits top to bottom, LSA/LS9 7 layer head gaskets, and probably a on3 7875 turbo. I'm going very close to what sloppy mechanics / denmah / Matt is running on his Colorado. The hp range I would estimate at 500-800 depending on how deep my pocket and willingness to grenade the motor goes lol.

It's going to be a street truck for fun use but something still be able to drive in traffic if I want to. LJMS says the rpm range for this cam is 3k-6k , so by the math I'm seeing the stall should be around 3500 ? The math being 500rpm over start of rpm range. This being my first turbo build , will that stall speed be too high for street use ? I'm just trying to make sure I'm getting the correct rpm stall so it's a buy once cry once scenario but that I'm not having to rev high all the time to get the truck to move under its own power.

Circle-D_Brian

Sounds like a fun build. I think you're pretty close on the stall speed. In our experience, you will want to look at a converter core in the 258mm diameter or equivalent for a nice mix of spool, top end efficiency, and street drivability. Are you going to be launching the truck off the footbrake or the trans brake?

-Brian

FTICONVERTERS

iTrader: (3)

I would personally put the converter is the 3600 range as you will need the converter loose enough to allow it to spool but tight enough to hold it once it is spooled. The beauty of the turbo build is that when Daily driving the car will drive great as the converter will be tight when not spooled. If you are only going to make 500-800 then a 9.5' converter will do the job great. A 258 will also work. The performance of the 9.5 will be better, while the drive ability of the 258 better. It is a trade off.

Greg

full foot notch

It will be footbrake'd as it may not see the track once or twice in its life

FTICONVERTERS

iTrader: (3)

Even more the reason to use a 9.5" being you are footbraking

Greg

Circle-D_Brian

If you do it right, you can achieve a good spooling, efficient, drivable, 258mm core and have room to grow your setup in the future. I would hate to limit you with the 245mm core when you may decide to go built motor, bigger turbo etc. We all know how these builds snowball. Just my .02 however. I would be happy to help sort out the details via pm or over the phone if you're interested.

-Brian

full foot notch

It's only roughly 3/4" difference between the 9.5 and 10.25 but since I'm new to this what are the different characteristics of each. I'll get XYZ with the 9.5 but the 10.25 varies in that it will handle ABC

FTICONVERTERS

iTrader: (3)

You would want to contact each converter builder and discuss your needs and wants. Listen to what they have to say. You will learn a lot. Dont get stuck on a few sentences on this forum board.You can also send a PM!!

Greg