85 lwb turbo 5.3 build

[85burb]

Ok this is a new one for me. I did a 6.0 in my burb but it was carbed then aftermarket efi. This one will be factory efi with turbo. Never had or built a turbo motor before. So i will be needing some help. I plan to get a 5.3 and change the ring gap and maybe a cam and head studs. But no heads or crank/rods. Would like 500 hp to the ground. I have looked on the ls1tech site and the lowest on there i can find with a 5.3 and turbo is 550. Should not be too hard to get that power mostly stock. We went around and around about what to do with this truck and it has been for sale for a while with no real takers. So i finally talked wife into keeping it. YAY. Now the fun starts. It will be a slow build as i dont even have the motor yet. I have my eye on just chevy trucks.com they have a ebay store that sells stand alone motors. All pullouts and come with a current performance harness and ecm. I have seen 5.3 with stand alone for under 1000 bucks. Has anyone used them or that harness? Not sure what size turbo yet. I have tons of resurch to do on that. Should be a fun swap. So here are some pics of the truck. Any advice will be appreciated.

[High ho silverado]

Keep an eye out on craigslist, I'm constently seeing turbo/supercharger kits on there used or jus used for mock up at a pretty good price, atleast in my area. If u talk to these guys they can tell u what u need to use to make these setups work. As far as motors there is a place out of Texas that u can submit offers too and they usually take them, I offered 550 on a 75,000 mile 5.3 and they said ok, I had to back out tho because a 6.0 fell in my lap and I decided to go that route instead. Shipping was 250 flat rate and they would work with me on the warrenty. If I can find the eBay site again ill let u know what it is if ur interested. Looks like a cool build and will be following.
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[Wasted Income]

For a goal as low as 500 rwhp, I wouldn't bother dicking with the ring gap. Lots of guys making way more than that on bone stock bottom ends.

[85burb]

That is just a starting goal. I figure when I have to motor out will be the best time to do it. I don't really know what to expect for power yet.
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[85burb]

Well i put in some emails to different turbo companys. Already got a email back from one asking about the motor specs. So hope i can figure that part out. What kinda fueling mods will be needed? Bigger injectors? Fuel pressure regulators? I plan on ls1/6 type manifold with aftermarket rails and -6 or -8 fuel line. But not sure on sizes cause this is my first efi build with factory stuff.

[Wasted Income]

My last setup was a Borg Warner S475, stock truck rails with regulator, stock truck intake, stock truck TB, Siemens 60 lb/hr injectors, Bosch 044 fuel pump, -6 feed line. Pushed my 4300 lb LWB into the 11s with a 5.3L and 4L80E.

[High ho silverado]

As far as intake the truck intakes make the better torque and hp for the bang, I've seen and read a ton on the stock intakes and dyno testing and they did the best till I get into the ls3 and ls6 but they are head specific and then the lsx intakes are another story too. Like wasted incomes set up is all ud need as long as u have a good tuner for it, the tune is the hard part. There are tons of diff turbos on the market and a sh*t load on the used market, I've seen lots of whole ls1 setups using stock truck manis and the do all the hard part of welding and making the tubes and everything on craigslist for under 400 some even with injectors and most of the stuff u need.

I'm sure ther is tons of help on here and I can't wait to see how it goes, I've been thinkin hard on doing one too and am hoping ur build makes my mind up for me.
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[Wasted Income]

Yeah the tune took a lot of work to get right. I did it all myself with EFI Live, on the street. I was real conservative with the fueling and timing, so there was a bunch left on the table.

I'm redoing my setup again now with an Edelbrock Pro-Flo intake, Aeromotive rails/regulator, Fuelab pump, -10 feed from a sumped tank, megasquirt ms3x engine management, a different turbo, and revised hotside plumbing.

Hoping for a little better than high 11s with the new setup.

[85burb]

So all i need is bigger injecters? That would save tons of money. I will be most likely putting a tank in the bed. And using a external pump cause i cant find any internal pumps and would like to move my factory fuel tank to the trash can. I think it has crap in it. I am not sure who will be doing the tune. I dont know anyone for that. I know a shop with a dyno but not sure if he tunes. I think he may. Hope so anyways.

A nother question is would it be best to buy a motor that comes with a modifyed harness. or make one. I know where to get a 5.3 with current performance harness for 1100. But i am new to both turbo and factory efi so i dont know if speed density tune will be needed or not. I would like to keep it cause some people say it drives better with a maf. Any ideas?

[Wasted Income]

Screw the MAF. You don't need it for perfect drivability with a good tune. EFI Live open loop speed density on a COS5 2/3 bar operating system is what I've used for many swaps with good success.
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[68GMCCustom]

IIRC most guys that run boost are running in speed density instead of using a MAF?

[85burb]

I know the guys running big boost like over 1000hp dont. Sounds cheaper to me. Not sure about the operating system or what not. Open loop though it kinda weard. Dont cars run better in closed loop cause they use all the motors sensors to figure the fuel and spark tables? I would asume anyone that can tune the motor can turn that on and off? What about mail order tunes? Are they worth the money?

[clinebarger]

85burb, Is that the truck with the TH375?? Good trans for a boosted truck.

[85burb]

Originally Posted by clinebarger

85burb, Is that the truck with the TH375?? Good trans for a boosted truck.

Yes it is. I need to have it built. Would a 400 be better or just have the 375 built?

[clinebarger]

Originally Posted by 85burb

Yes it is. I need to have it built. Would a 400 be better or just have the 375 built?

Build the TH375, The only "weaker" part is the output shaft, Breaking it would still be a badge of honor

[85burb]

Well comp turbo was the first to email me back. They recommended a ct43-6767 with a .91 Ar. So I called them and talked with Justin. I asked why the web site says that turbo is 975 hp rated. He says that is with the turbo maxed out. He says he recommends that one cause it will not be maxed out there for my temps will be a lot lower. He said I will only need about 7-8 psi to make 550-600 at wheels. The turbo is way more then I was thinking on spending but it will have power left in it if I was to add more boost. He also said it has a one year warrienty and can be sent back and have a 80 size wheel put on it. It will come with a billet compressor wheel and ball bearings. Still waiting on a few more places to email me back. So still not sure on the turbo
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[clinebarger]

Originally Posted by 85burb

I know the guys running big boost like over 1000hp dont. Sounds cheaper to me. Not sure about the operating system or what not. Open loop though it kinda weard. Dont cars run better in closed loop cause they use all the motors sensors to figure the fuel and spark tables? I would asume anyone that can tune the motor can turn that on and off? What about mail order tunes? Are they worth the money?

Part throttle Closed loop Speed density tuning is still optional.
At WOT they enter open loop anyway.

[68GMCCustom]

I've been a eaton/magnuson fan.....but I have to admit...Procharger has a great new boost solution.

videos/power-adders/procharger-introduces-revolutionary-programmable-ratio-supercharger/

[85burb]

Wow that is very cool. I am sure those are crazy expensive. Prices for some of the non-fancy ones are like way over 5k. I am sure that programable one is crazy high. That technology never worked real good in a transmission so maybe it will be ok on a supercharger with out the hole cars weight on it.

[Wasted Income]

Originally Posted by 85burb

I am sure those are crazy expensive.

LOL, but a ball bearing, billet wheel turbo isn't? You need to consider the WHOLE cost to make the comparison...the turbo, oil feed and drain lines and fittings, wastegate, flanges, v-bands, mandrel bends, welding, coating of the hotside.
Intercooler, mounting, silicone hoses, aluminum charge pipe tubing, etc.

The cost might be closer than you think when you add it all up, espeically if you farm out some/all of the fabrication.

[85burb]

I never said the turbo was a lot cheaper. It is more affordable for me. A few hundred here and there is a lot easier then a 5k all at once for my budget.

So after finding out i will prob need speed density tune would it make sense to buy a motor that already has a modifyed harness and programed ecm that uses a maf or to just get a motor with a stock ecm and harness?

[Wasted Income]

I would go with the stock harness and ecm, since it will need to be reflashed specific to your setup anyway.

[85burb]

Ok that is kinda what I was thing but had to ask.

May have trucks 350 sold this weekend!
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[69trk]

I'm doing the holley dominator efi complete kit... It's around 2500 but is self learns which would save some money from having it tuned all the time...

[85burb]

I am pretty sure my motor will be gone buy Sunday. I have 3 people interested. Who ever shells out the money first gets it. And I have a motor I want. It's a 04 5.3 so it should have the better ls2 rods in it I have read.
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