How much boost can I run on a 5.3l on pump gas?
Dec 10, 2012 | 10:59 PM
#15
Launching!
Joined: Sep 2005
Posts: 271
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If I'm thinking about the same magazine article they found out later that it was actually a 4.8l engine and I believe it was 450hp NA at the crank. Which is still an impressive number but they did put in a big *** cam and spin the motor pretty high.
As for the boost level, I wouldn't personally run more than 11lbs (91 octane) on my daily driver 5.3l. The shorter stroke of the 4.8l helps those engines stay together longer.
As for the boost level, I wouldn't personally run more than 11lbs (91 octane) on my daily driver 5.3l. The shorter stroke of the 4.8l helps those engines stay together longer.
and yes, these lil engines do take a beating.
i was out tuning mine earlier today on 16 psi and 93 octane, usually have it at 18 psi but went to fuel up and they were out of E85 FML (good thing i had my laptop lol)....so had to put 93 octane and still pulls pretty good. left it at 15*...im running meth though also.
Last edited by La Chochita; Dec 10, 2012 at 11:11 PM.
Dec 11, 2012 | 12:04 AM
#16
I'm running anywhere from 12-15psi on my lq4, 93 octane and no meth for the time being. In the process of upgrading my fuel system a little to handle 15-18psi on pump gas and add meth. I'd go e85 but it isn't available in my neck of the woods yet. I'd say constantly I'd feel safe with 12 on pump gas and no meth on the 5.3, depending on compression and how much you trust your tuner. I just like to see how far I can push things
Dec 11, 2012 | 02:31 PM
#17
Staging Lane
Joined: Sep 2012
Posts: 55
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Theres an article on Truckin where they took a 150k mile 5.3, stock bottom end, cleaned the rings, gapped them a lot and put in a turbo friendly cam, some decent heads and 70 pulls at the max 23.9 pounds of boost. made 1300hp. they wanted to find the limit to boost, and they stopped because there was zero compression on the back cylinder. popped a valve cover off and a rocker just fell off the valve, like twisted, so they took the charge pipe off and the engine still ran with the broken rocker. over 70 pulls and they stopped at 23 pounds and it still ran. IIRC they used an air to water intercooler but im not sure they used meth. still trying to figure out why they obtained 500hp N.A with a cam, heads and LSXRT intake... but anyhoo max boost around 23 pounds got the 03 LM7 block 1300hp and 1100tq. read it yesterday. it made me wanna buy things.
Dec 11, 2012 | 02:51 PM
#18
Dec 11, 2012 | 03:10 PM
#19
Staging Lane
Joined: Sep 2012
Posts: 55
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