LS Engine Conversion Info

[Ataki]

Nice job on moving away from the 4.8! If you're doing the LS swap do it right!

Nothing wrong with the 4.8, they can handle alot of abuse!

http://www.hotrod.com/techarticles/hrdp_1109_stock_gm_ls_engine_big_bang_theory/

 

[Joshua8336]

yes, but you can't run a fast 102 intake and throttle body on them, and FAST discontinued the 90 and 92 intakes like a dumb ass. you can run a fast 102 on a ls1, but you'd have a power lag.

 

[Joshua8336]

4wheeloffroad did a good write up in swapping a 6.0 into a k5 blazer, using fbody manifolds and retained use of the truck accessory drive. check it out http://www.4wheeloffroad.com/brandpages/chevy/131_0406_6_0_liter_gm_engine_swap/viewall.html

 

[devious]

any thoughts on a 5.3L with twin compressors..?

 

[Joshua8336]

as in turbo's? buddy of mine had a 5.3, weiand intake, ls6 cam and heads and a single turbo, and made 460 HP, and 431 torque.

 

[HotRodPC]

as in turbo's? buddy of mine had a 5.3, weiand intake, ls6 cam and heads and a single turbo, and made 460 HP, and 431 torque.

I'm thinking 2 AC compressors. It's hot everywhere in the country !!!

 

[devious]

ha! well 2 ac compressors would be a sweet idea, dark paint = sauna... i'm going to start a resto mod on mine within a year or two and i would like to decide on an engine so that if i see what i want come up randomly i can grab it. anyway i've been leaning towards an LS engine of larger displacement but the 5.3 just really seems more interesting. i figured i would toss around the idea and see what everyone thought about a twin turbo 5.3L in an '87...

 

[wildcatjason]

ha! well 2 ac compressors would be a sweet idea, dark paint = sauna... i'm going to start a resto mod on mine within a year or two and i would like to decide on an engine so that if i see what i want come up randomly i can grab it. anyway i've been leaning towards an LS engine of larger displacement but the 5.3 just really seems more interesting. i figured i would toss around the idea and see what everyone thought about a twin turbo 5.3L in an '87...

An hy35 from a cummins would be good for about 35 psi. You could get a good used one off eBay for a couple hundred. A rebuild kit is about 50 bucks if you find one that needs it and the instructions are online. Just mark your pinwheel so you dont have to have it balanced. They spin fast and one off each bank would be crazy. I'd pick up a good used air to air intercooler too. It takes a 3 in exhaust. It could be mounted anywhere. Love seeing them sticking from the hoods. I have part of an h1c lying around but I sold the exhaust housing. I thought about using it for a sbc, but probably never will.

 

[foamypirate]

I was going to put a 6.0L in my truck, but I've been dialing back my plans a bit, so I figured I'd put in a 5.3L. My backup plan, once I got bored down the road, was to turbo it. I figure it should haul some ass, even on low boost.

 

[wildcatjason]

My questions if you were to stick a turbo off a cummins or any diesel for that fact. I picked a diesel engine because it's inexpensive to pick them up used and I know them. Does anyone know what would need to be done to the puter for fuel mapping. Are they pretty easy to add fuel. How would you get it to match the map of the turbo? I know a lot of ricers stick these on Hondas and get them to work. I'm curious about a real engine.

 

[foamypirate]

My questions if you were to stick a turbo off a cummins or any diesel for that fact. I picked a diesel engine because it's inexpensive to pick them up used and I know them. Does anyone know what would need to be done to the puter for fuel mapping. Are they pretty easy to add fuel. How would you get it to match the map of the turbo? I know a lot of ricers stick these on Hondas and get them to work. I'm curious about a real engine.

Pretty much just need bigger injectors and to tune the computer. As long as you don't max your injectors, you can play with fuel and timing all you want to dial it in just right. Pretty much like tuning an NA motor, but you do need to dial back the timing with boost. You do need a good tune though, or you'll smoke the ring lands on the pistons with detonation in a hurry.

 

[wildcatjason]

Pretty much just need bigger injectors and to tune the computer. As long as you don't max your injectors, you can play with fuel and timing all you want to dial it in just right. Pretty much like tuning an NA motor, but you do need to dial back the timing with boost. You do need a good tune though, or you'll smoke the ring lands on the pistons with detonation in a hurry.

What programs have you used to do this. I mean all turbos have a different map curve. Are there programs that allow you to change the fueling per air flow or is it just guessing? Cummins turbo maps are not easy to come by anyway. I was just wondering how it worked or if anyone had a good website for a laptop computer programmer.

 

[wildcatjason]

Would you retard the timing past zero?

 

[foamypirate]

What programs have you used to do this. I mean all turbos have a different map curve. Are there programs that allow you to change the fueling per air flow or is it just guessing? Cummins turbo maps are not easy to come by anyway. I was just wondering how it worked or if anyone had a good website for a laptop computer programmer.

I can't speak for GM tuning software, but on the Hondas I worked with, you basically had an x/y graph based on MAP pressure (vacuum or boost), and RPMs where you could modify fueling and timing values. If I recall correctly, we usually retarded timing about 0.5* per pound of boost, but it has been a while so that may be incorrect. I'm not sure how you would tune a MAF based system, I have no experience with them. We used a wideband oxygen sensor to get the A/F ratio, and just watched the computer logs for any knock. You don't really need to know the specific compressor map to tune, just the knowledge of how to tune.

 

[wildcatjason]

Thanks what program did you use for Hondas?