5.7 Vortec Upgrade Options

[Supercharged111]

Awe hell. All this fighting. Y'all should have told me your at 8600ft. **** you need 5# just to compensate for elevation.
Hell yeah man boost away.


Are all you guys at high altitude?



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I'm at 6200', but took the boosted big block dually back home to MI dragging my enclosed car hauler, loaded it, and dragged it back to CO. As previously stated, proper fueling and timing is key. The computer does the rest. It sees the additional airflow, it see the boost, and it adds fuel and pulls timing accordingly. It also sees the elevated IATs and pulls timing there too. People boost stuff all the time on daily drivers at lower elevation, nothing dangerous or unusual about it.

 

[RDF1]

My motor couldn't take boost. I had to roll the timing back to run 89octane.

Really, At sea level nobody boosts anything. At least not around here. Just #6 down here is 11# on OPs motor.

Plus I've seen the Dyno numbers on 6# of boost. I can do better with a cam and heads.

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I'm nobody then haha.
250' above sea level here

That's why I like turbos. More boost/power is a flip of a switch away. Tow on 8psi, play on 16psi.


My first dyno session I had ~500ftlb TQ at 3000 rpms in 2nd gear with TC locked.
Small turbo cam, small turbo.

Went with larger turbo (S475 I have now) and no regrets. Towed like a diesel, still got 22+mpg empty and bottom end is still together with about 380,000 miles on it. It smokes now but still going strong.

My buddy sold his 5.7 before we could put a LS PCM on it and turbo it. I'd loved to give that a try since them engines had more low end grunt.



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[Trenton]

I'm nobody then haha.
250' above sea level here

That's why I like turbos. More boost/power is a flip of a switch away. Tow on 8psi, play on 16psi.


My first dyno session I had ~500ftlb TQ at 3000 rpms in 2nd gear with TC locked.
Small turbo cam, small turbo.

Went with larger turbo (S475 I have now) and no regrets.

If I had fabrication access and a bunch of money, id honestly 383 ci stroke the block, install a marine intake, and put twin Borgwarner s366 turbos! But with that much money id rather diesel chassis swap it. I love the GMT400 body styles but there's almost nothing like the power, handling, ride, and efficiency of a Duramax.

 

[Supercharged111]

Or instead of the stroker, just crank up the boost higher.

 

[Trenton]

Or instead of the stroker, just crank up the boost higher.

Well if I put the boost higher and have that much power i probably NEED upgraded internals. While I'm replacing it might as well make the displacement bigger. So both

 

[Supercharged111]

FYI Lextech pushed 500whp through an internally stock 305 Vortec. Not sure how much you're looking for, but the bottom ends are pretty stout. Not LS stout, those will take a little over 600whp in stock form and still be reliable.

 

[Trenton]

FYI Lextech pushed 500whp through an internally stock 305 Vortec. Not sure how much you're looking for, but the bottom ends are pretty stout. Not LS stout, those will take a little over 600whp in stock form and still be reliable.

Interesting hm. I assume twin S366 turbos and 48 lb fuel Injectors would push more than 600 horsepower, though lol. Also, my 258k towing/back road miles on this truck is probably rough on the engine, so I'd like to rebuild it with upgraded internals anyway since it consumes oil.

 

[Supercharged111]

Well like I said, I put the blower on around 240k but it only musters 4psi where I'm at. I imagine it'd be 6-7 at lower elevations.

 

[L31MaxExpress]

Well like I said, I put the blower on around 240k but it only musters 4psi where I'm at. I imagine it'd be 6-7 at lower elevations.

I ran a stock 8.7:1 350 TBI with 0.016 compressed head gaskets nearer to 0.040" quench and 8.9:1 compression with the stock TBI cam and a Weiand 177 on it at 10 psi for almost a year. Went through 2 well built 700r4s and two well built 4L60Es. Was only making about 400 hp but had nearly 500 ft/lbs practically off-idle and it idled and drove like a stock engine. Cruising down the highway the MPG was better than stock. It would build boost rather than unlock the torque converter or downshift and rev to pull the G20 van uphill with 3.08s. At 80 mph turning about 1,850 it would build 5 psi. Naturally aspirated the 350 TBI was probably 320 ft/lbs at that RPM but with the blower it was well over 450. It was a recipe for burning 3-4 clutch packs up regardless of the material used. The 700r4/4L60E pump does not build enough line pressure at that low of a RPM. The 350 TBI heads liked about 22° of timing advance at 10 psi. It never detonated on 93 octane with the 160°F thermostat, big block radiator and clutch fan. I was fueling it with stock 350 TBI injectors running at 50 psi at 10 psi boost using a Vortech supercharger FMU.

 

[L31MaxExpress]

Well like I said, I put the blower on around 240k but it only musters 4psi where I'm at. I imagine it'd be 6-7 at lower elevations.

Also sounds like it is time to pulley up that little 1.6L. Slip a F/Y car LT1 cam into it and run 10 psi on 93.