LS Turbo'd Guys... Suggestions needed!!!

[67see10]

I currently have a 6.0 LQ4 at the machine shop that I have no money into it. I got the motor running with low oil pressure because the cam bearing walked.

I was going to do a simple rebuild and although I have no experience with turbos, I can't shake the idea of building a twin-turbo build. I guess I just want to do something different.

I plan on building the motor first and then decide which truck I want to put it in. I currently have an 86 GMC C3500 RCLB and a 86 RCSB C10 with no motor or transmission, and a factory 86 2WD Jimmy that runs with a 305/700r4.

I jumped headfirst into the turbo idea and purchased the ARP Main Studs, Connector Rod Bolts.

My first question is, is it even particular to have a twin-turbo'd truck as a daily driver? If so, what would you recommend?

[Ziegelsteinfaust]

Turbos are street friendly till you hit the gas. Beyond I only understand things of them.

I DD a 350 with a old school near Duntov 30 30 can for 2 years in a C10.

Follow the basics like opening the ring gaps, and timing. Watch the rpm as it typically is worse for the engine then hp.

[bnorth]

Your power goals should determine the build on the motor. Factory gen III internals are generally considered good to ~750whp and gen IV to 1000+whp at which point the pistons are the weak link but rods are good for a bit more. Sorry to say but you're pretty much wasting your money on ARP main studs and rod bolts, neither is a weak link for streetable horsepower goals. If I were in your position I would pickup good used gen IV rods and new Gen IV pistons and install new cam, rod and main bearings as well as new rings with opened up ring gap and stage 2ish turbo cam. Do some reading over on sloppy mechanics to get yourself started.

[67see10]

Originally Posted by bnorth

Your power goals should determine the build on the motor. Factory gen III internals are generally considered good to ~750whp and gen IV to 1000+whp at which point the pistons are the weak link but rods are good for a bit more. Sorry to say but you're pretty much wasting your money on ARP main studs and rod bolts, neither is a weak link for streetable horsepower goals. If I were in your position I would pickup good used gen IV rods and new Gen IV pistons and install new cam, rod and main bearings as well as new rings with opened up ring gap and stage 2ish turbo cam. Do some reading over on sloppy mechanics to get yourself started.

I read somewhere, that putting Gen IV internals in a Gen 3 will cause some balancing issues. Is that not the case?

[biketopia]

Originally Posted by 67see10

I read somewhere, that putting Gen IV internals in a Gen 3 will cause some balancing issues. Is that not the case?

You'll need to balance the rotating assembly. Like stated, unless you're going for BIG numbers power and RPM wise, the arp stuff in the bottom end is just over kill. Keep the stock crank, get some gen 4 rods and pistons, open up the ring gap, new bearings and get to getting. Some 799/243 heads are a great choice, a stock ls6 or stock truck intake will make 5-600+ on boost. Good springs, and lifters, and you're set. ARP head bolts, no need for studs.

[ChevyCO]

I have a lifted k20 on 35s with a gen3 5.3 turbo. I run about 11 psi with a stage 2 cam and valve springs. It’s not exactly my daily drive but I do drive it quite a bit because it is a blast to drive. I also tow toys with it, nothing crazy but it’s nice to have the turbo. If you tune it will you will be fine for a while. However, I will tell you that you will not be able to keep your foot out of the gas once you turbo it. If you are going to drive this thing every day, I would just throw some forged pistons and rods in it for insurance. Just remember, nothing will compensate for a bad tune.

[tinydb84]

Pictures because everyone likes pics:


Not my daily but I have been dailying it for the past few weeks while I fix the wife's 4runner. If I didnt have the 4 inch fender exit I would have no issue with it being my daily.

I have a bone stock 5.3. Trailbazer SS intake and exhaust manifolds (because I got it all cheap). Running a gt45 and ebay intercooler/coldside/BOV because I got it all for free from someone I helped with his bag job. It has plenty of power and I haven't even turned it up.

The main studs and rod bolts were probably unnecessary. I personally would have went with head bolts (or studs) before the rods and mains but since you already have it at the machine shop add the head studs now.

All the discussion of the gen 3 or 4 is fine. I dont know how many people really need more than what a gen 3 can do but if its in your budget then it makes sense to overbuild it the first time. Let your builder know you are boosting it so they can gap the rings appropriately.

Twins are cool but remember you are effectively doubling the price and more importantly the number of things that can go wrong as well as packaging it all.

Keep us updated. Sounds like it will be a lot of fun.

[Ghost's68]

I have a SBE LS3 with head work, custom speced cam, running E-85/flex, Holley Ter
X MAX, 4l80e, 1500cc injectors, and a VS Gen 3 78/75. I absolutely love this thing, boost kicks your teeth in and comes in early in the RPM’s. I have zero doubt when I get in. Everything works well and is just a blast to drive. I could only imagine a twin set up. If it wasn’t for the cost, I would have done a twin. I will eventually go twins down the road, but for now I’ll enjoy my single.

Also there’s a bunch of people who drop Gen 4 parts into the Gen 3 block with no issues. Check out sloppy mechanics page on FB.they do that stuff regularly with great results

[indymachinist]

I honestly think packaging small twins would be easier than a bigger single. I agree the cost to get started would be more.

[ChevyCO]

Single turbo with 3.5 down pipe, and functional ac.