As I'm sure you know, a number is simply a measuring device. Whether the motor makes 2hp or 500hp, it still boils down to what you're using the truck for in the first place. Are you aiming for a certain ET? Do you have a vehicle in mind that you're trying to gun down? Bottom line, build it to do something and have a realistic goal in mind.

With that said, I think your original intended goal of 350hp is within reach..you bet. If you think about what the stock LS1 put out right around 325hp and 340lb-ft of torque, you'll be there plus some. The LS1 began it's life with 10.1:1 compression, a gentle camshaft, mediocre heads and a mediocre intake manifold. The LS1's tight living quarters also meant more tightly packed exhaust manifolds, small-ish exhaust and a tune designed to pass all California emissions tests with flying colors all while trying to be as fuel efficient as possible. Your 5.7L on the other hand has much better flowing 317 heads, and despite the 0.58 point loss in compression, the heads will make up for that. Your camshaft selection will hands down end up making more torque and midrange power over the stock LS1's cam while complimenting the truck intake manifold's breathing capabilities of idle-6500+/-. I'd hope with this motor build and turbo that a spot-on tune is in order, and that your exhaust system will be more thought out now that a turbo is in the picture.

I think 350hp is easily obtainable. Just a cam swap and a good tune will do that, and you're bolting on better flowing heads, a good intake and exhaust. 375hp out of the 5.7L is a good estimate, I think. I figure my 5.7L is right around that range as well, with very similar parts, most listed in sig. As for the power potential under boost, that's a horse of another color. Many many factors go into calculating rough power output. I'd need to know more about your forced induction system to even take a stab at calculating the potential.

 

At 7.5 psi, I'm right at 500 to the ground, which is right at your goal for crank power with boost. I'm using a gt2-3 cam which is very similar to a zo6 cam. I'm running 8 degrees of timing and 11.2-11.4 a/f. Drive the truck 30k per year for work. If you decide to go n/a a different cam and you will hit your hp goal.

 

Well a mid-low 12 truck would be nice but it has to be usable to drive the thing to pick up dirt, mulch, trips to the dump, hauling the lawn mower or motorcycle. Its not going to be daily driven but I want it to run well enough and long enough so I never have to re-do this again, ever if possible.

I will probably take it to the track a couple time just to see what it does but I will not be tweaking this thing week after week to get very last thing out of it. I know power is addicting but you have to have the funds to support the mad rage to get you into the 10s or whatever the individual wants.

I want a fast, powerfull, reliable, streetable, liveable set up that will be easy to maintain and good enough for the occasinal long trip north to the woods.
I know its possible and I am willing to sacrifice all out speed for better low end power and better street manners. I know the Radix would be best for low end but the turbo along with a decent HP number NA with 9.5ish compression is more my style. The whine of the blower is not something I want to hear as I'm crusing on the freeway. Dont get me wrong, they are great units just not my thing.

I like my STS set up, but now that I have seen other set ups converted to front mounts and have ordered the hot pipes from Kyle that is my goal.
Front top mount, no return pump, forged pistons/rods and all the asociated hardware to make it last and bullet proof if possible.
Like it came this way from the factory!!

I already have an intercooler with 3" in/out I bought from TurboBeserker a while back and will probably add meth for towing situations and track use just to be safer. I may have to upgrade injectors again since I have the 44lbers now, maybe not.


I'm a dreamer, I know it.

 

Your pipes should be ready to go first of the week, PM your address again. Your gona love it. You will have pretty much the same set up as me, only in a lighter truck. My truck is everything you just described, and I'll tell you what, in just low boost, 7-8 lbs, this thing is a beast on the street, but yet cruises effortlessly down the high way. Your going to LOVE it!

 

It sounds like an awesome build coming along. You are dead on with wanting a torquey son of a b!tch for a motor and then have the boost later on for "play time". For the past few weeks I've been reading reviews and posts on the GT2-3 camshaft for turbocharged applications and I think that is your best bet if you were looking to use something other than a stock LS6 cam. The cam has been proven time and time again to make 30hp or more in a stock LS1, with torque gains proving minimal. What that tells me is that the camshaft is very efficient, and will pull long and hard from idle to red line. It favors boost, as you can see be the aggressive split on the exhaust side. It's a 207/220, .571/.578 on a 118.5 lsa. Guys are installing that cam into their LS1's still using the LS6 "yellow" springs with success. With lift numbers such as these, it may be a wise expense to have your 317's reworked to the extent of a "stage 1" job to keep flowing at the lift height your cam will pulling to.

Just playing around with desktop dyno a little, using the GT2-3 camshaft and stock flowing 317 heads, 9.5 compression and the truck intake, I come up with 367hp @ 5100rpm and 409lb-ft of torque @ 4000 rpm provided your exhaust is well thought out. That's rather impressive, IMO, but not too far out of reach. If I had to make a guess at rwhp I'd say you're heading into a build for 310rwhp and 340rwtq which is a low low 14 second truck, maybe even dipping into the high 13's. With the boost cranked up to 8psi, your goal of 12's is within grasp I think. You have a great build coming, good job.

 

Great responses Inchup and KB, lots of details, this I like.
Well my down pipe will be a 3.5" from Kyle, that will most likey be dumping into a 4" duramax Cat Back system if that system will work on a SCSB 4x4 that is.
I will have some type of muffler or resonator on there to to keep it stealthy. I dont need the cops harrasing me just because I'm a little loud.
Since I live in a non emmisions test area I'll be catless as well.
This is going to take a while to amass all the parts but I already have a donar 5.3l and the 317 heads so the big stuff is done. The bank account will be taking some hits shortly.
Oh ya, any suggestions on where to purchase parts and possibly help support our sponsore too? I want to buy from reputable places that get back to you when you have issues since my work schedule is wacked.

Thanks again guys.

 

For starters, here's the camshaft. Lingenfelter has a great name, need I say more.

http://www.lingenfelter.com/store/l210085297.html

Looking down one link, however, you see the springs and camshaft kit all rolled into one purchase. I am pretty sure the springs for sale are the LS6 springs. Considering the aggressiveness of the lobes, I would opt for the hardened push rods which you can buy right under both of those links as "add ons".

http://www.lingenfelter.com/store/l210125297.html

As for the actual rotating assembly, I do not believe forged pistons or rods are necessary. 8lbs of boost on these motors is child's play and I think you'll be wasting your money at least buying forged rods. Consider forged parts to be what you'll need if you plan to rev the motor out way past stock. T6 hypereutectic alloy pistons have similar strength properties as forged alloy pistons, however the T6 alloy pistons have the advantage in the ring land area where great strength is most important. Hypereutectic alloy pistons are cast aluminum alloy with a high percentage of silicon. Their most useful characteristics are lower thermal expansion and reduced heat transfer. Of course with forged pistons you get the added security of being able to rev the hell out of the motor but I don't think you need to rush to the forged piston store just because a turbo enters the scene. The decision of cast aluminum vs forged should actually be made based on three things: Percent increase in the rpm limit, boost pressure and finally how effective the intercooler is. Keep in mind that inertial loads in pistons skyrocket with the increasing revs, more boost makes more heat, and good intercoolers take out heat. It's all a judgment call. Unless circumstances are highly unusual, street cars with stock redlines will prove more successful with cast pistons. Forgings should be reserved for the high revvers, while T6 hypereutectic alloys can cover almost all requirements. That's why the LS1 block is made of 356-T6 aluminum, because that particular alloy covers everything very well.

These are the pistons I put into my 5.7L, however they are just cast OE replacements from Speed Pro.
http://shop.enginekits.com/osb/itemdetails.cfm?ID=1301

I have never looked into where you can find T6 alloy pistons for the 99mm bore. They seem to be everywhere though for the 4" bore of the LS2/LQ4 or LQ9. Hunt around a bit. I believe the T6 alloy pistons at least merit some investigation before purchasing a set, although for your build I'd bet money that the stock OE replacement pistons I put into my 5.7L would be plenty strong for occasional 8psi blasts. Be sure of your tune and intercooler efficiency, those are my main suggestions.

 

Main reason for wanting forged internals is the uncontrollable urge to kick the boost up to say 10-12 psi for a track day, or if I need to smoke my neighbor with his Vette again.
The forged internals would give me peace of mind and give me some leeway when tuning in case I do get some knock. My current 5.3l is hurt and has been for a long time. It blows so much oil/condensation gunk out the valvecover outlets its crazy! I dont want another engine with a busted ring land or worse.
I can afford the forged parts once, but not two to three times, LOL.
When the day arrives that my new engine goes in and the old out I cannot wait to seed what' sreall wrong with my original engine.

 

I'm slow...must be the lack of coffee. I just noticed you're in Wisconsin. Once this thing is done I'll be itching to see what it's capable of. I think a road trip to WI is in order, since I'm just over in MN.

 

Sounds like a great idea! You may be waiting a while though, I'm never in a rush to do things since I'm broke from the first $6000.00+dollars I've blown on this thing! I do have some cash saved up for this build.

This will be a winter project more or less, as soon as I get the parts together and talk to at least a couple engine builders here who can bore the block and do some assembly for me I will be swapping engines when everything is in place.
Nelson should be able to get me a base tune to get it running since he has done about 8 tunes for my set up as it has evolved to this point. After that I'm hoping to have HP Tuners, EFLive or what ever is best at the point I take the plunge and buy. I want to be able to tune this myself, pretty good with computers and trouble shooting so I am confident I can do it.
Oh ya, my wife STILL doesn't know my truck is Turbocharged!