Hello. I’m new to this group.
I have done ls swaps before but only stock swaps. So with saying that I’m still trying to learn all the ways to build a reliable ls engine that can hold power.
I am currently wanting to use a complete stock 4.8 motor and turbo it. What cam and what turbo could I use on it to get the most hp for cheap? or what all do I need to be able to get the most out out it?
I seen on here that “Stock48” has a great cam for this application. An may have some good advice for what I’m wanting. But I’m not sure how to get in touch and talk to anyone on here. If anyone else has good advice or knows how I can get the most out of my stock 4.8 for cheap please let me know. Anything helps! Thanks

 

I think the common response will be a stage 2 cam from a number of different makers. I used a Summit one, they are all very close.

If you want to just turbo a stock 4.8l, then I would recommend just leaving it literally stock except for the valve springs, exhaust manifolds, injectors and fuel pump. Put PAC 1218's in there, a Holley/Hooker turbo manifold, 78/75 turbo, decapped injectors or Deka 80's and stuff a wal 400 pump in the tank. 400-500hp easy peasy. Thats the most HP for the cheapest, add in a $600 meth injection kit if you want to turn the boost up. Toss a cam in there and some new head gaskets, maybe some head bolts and chromoly push rods($700-$800 total) and all of a sudden we aint doing things cheap anymore.

Stock engine with Pac springs, deka 80's and a 400 pump in the tank is a really good and really simple place to start. Takes nothing after you get all that together and running to add a camshaft in later if you still want more. PLus, you'll want to save some of your budget for the new transmission you'll need as well. No one ever mentions the transmission to new guys.

 

I wouldn't bother with a 7875 for only 4-500hp. Something smaller will be way more fun on the street.

 

Thank you for the feed back.
I plan on using a built 350th trans. I also plan on using the stock manifolds. Just turning them around and fabing up my own crossover and turbo location. I want to go as cheap as possible!
what pcm should I go with?
what kind of wastegate should I look into?
Thank you!

 

A stock PCM is fine for most builds. Look for a 44mm wastegate as a good compromise.

 

I agree but man the price of those billet 7875s vs a decent smaller turbo is hard to swallow lol.

Billet 7875 for $260 or a cast 6673 for $100 more.

 

Yeah Im just thinking for a 4.8 with low power goals why not have your cake and eat it too. Heck a 60-1 would do it.

 

When you look at the cost of a blower.. or turbos ten years ago.. or even a well setup nitrous setup... cost of a turbo is nothing.

If a person has reasonable goals then size the turbo accordingly it. It’ll be way more fun to drive. And if goals change in a couple years then swapping turbos isn’t that big of a deal.

I mean I just spent almost a grand on front shocks. A $2-500 turbo is really nothing

 

I just realized I've gotten to the point where $100 extra for a turbo seems like a lot LOL.
I spent $150 on fuel fittings earlier just for a new rail/regulator setup and panicked.

 

I know this is a 6 month old thread, but what are some good turbo options for smaller builds? Sort of like if the 4.8 came turbo from the factory and had a Summit truck cam what are some examples of what it might have had? Something like a VSR 67/66 Billet T4?

What would give the best curve with a 550 wheel goal?

 

That 67/66 would be a good choice if you arent scared to spend the money. Should spool really well on a 4.8

 

If it came turbo from the factory in a truck, it would have something like a GT35 in it in T4 with a .82 A/R.

 

People want 500hp for about 15 mins, then the realize they turn the ole boost **** up and they can have 600, 700, etc... never ends!


The $260 billet 7875 is a heck of a deal... I grabbed one just because of the price, even if I only use it for mockup. Compared to the VSR turbo, really not much difference at all unless you opt for the larger VSR turbine.

 

this should be written everywhere lol. I haven’t driven at 500hp car before. Put my twins on the 5.3 and had 450 on a basemap with 0 tune. Wasn’t quite sure how I felt about the power cause no tune. Finally I got it tuned and made 580. This is literally exactly where I wanted to be when first put the car together. I have the gen3 motor so I felt like this was safe ish spot... until I turned the boost up 2 psi, you can’t go back once you’ve felt the car wake up that much more. Got the air fuels in spec and the extra 2 psi and now I’m at 700, complaining that my shifts are way to long and cutting away from my power. Soon to be automatic.

 

To be fair, not everyone has the drivetrain to handle the extra power, or the driving ability to add another couple hundred HP at first. The nice thing about it is you can always turn the boost up, or spend a couple hundred bucks and get a bigger turbo later on.

 

So does anyone have any actual experience with the 260 dollar 78/75 yet? Hard to beat for the price if it makes 5-600 easily.

 

My buddy bought his car with an on3 turbo that size. I remember looking it up to replace it and was alittle over $200. Supposedly was on the car at 500hp for over 3 years before smoking.

 

If budgets the main concern, the GT45 is pretty hard to beat as a single around 500-600, and dirt cheap. I picked up a set for $120 each shipped. They look to be $160 now. Bit clunky and heavy, but they seem to be reliable and spool more quickly than the 78/75... Bud did a direct swap on his manual 5.3 w/ no other changes. Was pretty disappointed how much slower the 78/75 spooled. Its a twin scroll as well. So you can run a divided setup with 2" pipe to the turbo. Bet it would light off pretty quickly!

 

That seems odd to me. You are like the third person Ive heard say the have had or know someone who has had issues with the 78/75 spooling slow. I have tuned several cars, trucks, jeeps with different 78/75s everything from the vs racing cast to the first gen billet 11 blade vs racing to the the gen 2 vs and on3 version as well. I have never had one spool slowly. The gen 2 with the 1.24 housing is definitely laggier than the others but none were lazy. I wonder if there is a bad batch of them with clearance issues.
Cause everyone I have been around spooled as soon as you hit it.

 

Not slow... but not as fast as A GT45. On a like (possibly poor) tune anyway. A TON of the spool time is in the tune. I agree, the 78/75 is a great unit esp. now that you can get them for $270. I plan on 2 of them for my next setup.