94 5.7 More power on a really small budget

[Drick37]

My son bought a 94 c1500 5.7. It's a one owner farm truck. He wants to keep it for a daily driver, but he wants better power out it. I've been researching and it seems like some vortec heads, Edelbrock intake would give him some decent gains. Anyone do something different? Can't afford a swap. Just some minor upgrades.

Thanks

 

[Erik the Awful]

I take it he's still a teenager? My oldest's shenanigans led to my "No V8s for teens" rule. Personally, I'd be looking at the nearly-free mods that take work instead of money so that he's less inclined to break it.

Vortec heads take some work and money to adapt to a TBI block. Finding a good, uncracked set at Pull-A-Part takes a bit of luck and careful inspection. Why not have him port the TBI heads? If you do go the Vortec route, the Summit intake is significantly cheaper than the Edelbrock.

What fuel management system are you going to use, the stock TBI? Carb swap? Homebrew TBI mods? Holley Sniper? The factory TBI isn't good for too much more than stock - but @PlayingWithTBI can give you tips on making it work with more power. Plan on spending a couple Benjis on TBI tools.

The most bang for your buck comes with exhaust. If you have a welder, some cheap headers, cheap mufflers, cheap cats, and raw tubing is a great exercise in working for more power with little cash outlay. I have about $500 in my full exhaust. If you don't have a welder, the $100 no-name flux core welders don't absolutely suck at welding exhaust, but I'll stick with my Miller 211, thank you.

If he's looking to pick up dates, remind him that girls prefer a clean and comfy cab to a loud exhaust.

 

[PlayingWithTBI]

The most bang for your buck comes with exhaust. If you have a welder, some cheap headers, cheap mufflers, cheap cats, and raw tubing is a great exercise in working for more power with little cash outlay. I have about $500 in my full exhaust. If you don't have a welder, the $100 no-name flux core welders don't absolutely suck at welding exhaust, but I'll stick with my Miller 211, thank you.

I'll join in, I agree with the exhaust as your biggest bang for your buck. Whether it's a dual exhaust or a free flowing Y pipe and 3" single. High flowing cat(s) and muffler(s) help tremendously, you just have to decide how quiet you want it. The more free they flow, the more gain you will get. If you go with dual exhaust, it's better to include an "H" or "X" pipe.

Then start thinking about the intake. The stock 42mm Throttle Body is fine for the anemic swirl port heads and peanut cam in these engines. Fuel pressure is also critical on these to achieve proper AFR. The decision what to do, going forward, is dependent on your budget.

Porting your heads is an option, there are others. These heads will bolt right up to your TBI block and intake manifold, they flow a little better than Vortecs but, not too cheap, ha ha
https://www.summitracing.com/parts/sum-162108

Tuning is always helpful, GM left quite a bit on the table but, with these early EPROMs you'll need to spend some money on modifying the PCM to accept an emulator of flash chip. You can always get someone to "burn" a chip for you but, buyer beware, some "mail order" guys aren't that good. It's always best to data log and tune. As @Erik the Awful asked, maybe a Holley Sniper or FiTech EFI on a 4-BBL manifold?

 

[Drick37]

I take it he's still a teenager? My oldest's shenanigans led to my "No V8s for teens" rule. Personally, I'd be looking at the nearly-free mods that take work instead of money so that he's less inclined to break it.

Vortec heads take some work and money to adapt to a TBI block. Finding a good, uncracked set at Pull-A-Part takes a bit of luck and careful inspection. Why not have him port the TBI heads? If you do go the Vortec route, the Summit intake is significantly cheaper than the Edelbrock.

What fuel management system are you going to use, the stock TBI? Carb swap? Homebrew TBI mods? Holley Sniper? The factory TBI isn't good for too much more than stock - but @PlayingWithTBI can give you tips on making it work with more power. Plan on spending a couple Benjis on TBI tools.

The most bang for your buck comes with exhaust. If you have a welder, some cheap headers, cheap mufflers, cheap cats, and raw tubing is a great exercise in working for more power with little cash outlay. I have about $500 in my full exhaust. If you don't have a welder, the $100 no-name flux core welders don't absolutely suck at welding exhaust, but I'll stick with my Miller 211, thank you.

If he's looking to pick up dates, remind him that girls prefer a clean and comfy cab to a loud exhaust.

Yeah, he's a teen. He was going to go stick with the TBI. Maybe go with a 454 TBI set up with a vortec fuel pump.

 

[PlayingWithTBI]

He was going to go stick with the TBI. Maybe go with a 454 TBI set up with a vortec fuel pump.

On a 5.7L? Without a lot of go fast parts, you won't get it to idle, let alone perform well. It'll be running way too rich all the time. the 50mm TB is OK but the 71 - 80 LB/Hr injectors (depending on which ones you go with) are too much for a stock SBC. The AC Delco EP381 fuel pump is the way to go, it'll give you 155+ L/Hr where the TBI pump is only ~75L/Hr. I was running flow matched 7.4L injectors at 15 PSI on mine and couldn't get it to idle well with the EBL Flash-II ECM. When I put it in VE Learn, it shut off the injectors completely to try and get close to 14.7 AFR. Now I'm at 20 PSI with 5.7L 61 LB/Hr injectors and keeping my duty cycle around 90% @ ~5300 RPM WOT. At 18 PSI I was ~106%, meaning they were open all the time

If you're gonna play with stuff like this I strongly suggest you get a WBO2 sensor too. Again, how many $$$$ do you wanna spend? Once you get happy with your engine, save some more $$$$ for a new transmission, ask me how I know,

 

[Drick37]

On a 5.7L? Without a lot of go fast parts, you won't get it to idle, let alone perform well. It'll be running way too rich all the time. the 50mm TB is OK but the 71 - 80 LB/Hr injectors (depending on which ones you go with) are too much for a stock SBC. The AC Delco EP381 fuel pump is the way to go, it'll give you 155+ L/Hr where the TBI pump is only ~75L/Hr. I was running flow matched 7.4L injectors at 15 PSI on mine and couldn't get it to idle well with the EBL Flash-II ECM. When I put it in VE Learn, it shut off the injectors completely to try and get close to 14.7 AFR. Now I'm at 20 PSI with 5.7L 61 LB/Hr injectors and keeping my duty cycle around 90% @ ~5300 RPM WOT. At 18 PSI I was ~106%, meaning they were open all the time

If you're gonna play with stuff like this I strongly suggest you get a WBO2 sensor too. Again, how many $$$$ do you wanna spend? Once you get happy with your engine, save some more $$$$ for a new transmission, ask me how I know,

Thanks for the warning. With so many options, I think after we sit down. He would be happy with some headers and a 50 series muffler.