so posting this as a curiosity thing more then anything cause ive googled the hell out of turbo 5.3s and havnt found hardly anyone running around 16psi on 93, every things basically e85, or havnt found anyone with 243 heads on a turbo 5.3

ive been searching it to see how reliable it may be or what type of power i might be at, i find 100% stock 5.3 long blocks with most running e85 and not 93

not posting this as a bragging thing as im sure im not the only one but that being said am i the only one running boost numbers in the teens on 93 octane still, or have done head/cam swaps to a 5.3 but anyone have any insight on if this is one more drive from lettin loose or if it
s just not a common thing since E85 is better in every aspect lol

btw engines stock 5.3, epp blower cam, 243 heads and arp head studs on 10 degrees timing and 16psi, no meth or anything

 

Most guys are running E85 bc as you know, it cools things down internally and then they can get away with even more boost. Im doing something similar to yours but a 5.7 iron block, 317 heads, cam, forged bottom end NO meth, pump 93 gas and 15-18lbs of boost. Hoping to be around 800rwhp.

 

yeah only thing holding me back from going e85 is funds for the fuel system atm, and i have no clue my rwhp atm, i figure im at 9:1 cr, and im guessing 600rwhp ish

 

My 2000 LS1 with only a cam swap im sure is weaker than the 5.3 truck engines and its holding up to 21psi with a s475 on 93 pump gas. I have methanol though. 16psi shouldn't be an issue on pump gas 5.3.

 

o wow, thats awesome! makes me feel safer about my setup lol

 

How long have you been running that boost level? Also how much meth are you spraying? I'm scared to go above my current 7 PSI lol, but people like you make me want to crank it up a bit!

 

Denman runs 16+ psi on most of his builds on pump. Probably the majority of the people here are on pump gas.

L33s came with 799 or 243 heads, as do almost all of the 4th generation 5.3 engines. You are not alone.

At your compression, you should be just fine up to 16 psi on 93. Add meth and you can probably squeeze out 20 psi.

 

Just food for thought about what youre missing. A previous car of mine made 590rwhp tuned on 91 octane (347", 70mm, t56). Then we reattached the boost reference on the methanol kit and the car made 616rwhp. The car wasn't even tuned for methanol, but added 2 degrees of timing due to the placement of the nozzle before the IAT sensor.

Every lb of boost you increase with an efficient combination will net you 17-20rwhp. Add more timing in there at 13ish rwhp per degree and you've picked up a substantial amount of power, along with making things safer and stock motors last longer.

If E is available near you, save your pennies for some injectors and E safe fuel pumps to go in the tank. It's a no brainer with a turbo car if it's readily available in your area.

 

Every setup is going to produce different gains per psi/degree. There is no general number.

 

Point was there's lots to be had with a fuel change.

 

L33 is also near 10:1 CR
You are doing it just fine because of only 10 deg of timing.
Ron

 

no i deff plan E85 sometime in the future but not right now lol, and mines an 2003 5.3L (LM7?) with dished pistons not the flat tops, that i put 243s on to get the 9:1 CR, plus ls9 gaskets which idk if they add or take away from CR but, and yeah meth is probably some where in my future also

 

I have a friend with a 5.3 T/A. Just a LM7, 243 heads with comp springs, ls6 cam, ls6 intake, 60lb injectors, procomp head studs, ls1 mls gaskets, 2 bar map, and a On3 turbo kit. We maxed out the 2 bar map with the On3 70mm on 91 pump, no meth. I think that was around 218 kpa? I can't remember exactly. Now the car has a On3 76mm at around 165 kpa (81 kpa is atmospheric here) on 17-18 degrees of timing.