stock 5.3 tahoe except 2.9L whipple with 3.75" pulley and aem x gauge for logging (after primary cats). the 4.375" pulley made 450whp . wanted to make around 550whp so i changed the pulley. i read alot on here that the stock fuel could support right at 600whp before needing lt4 parts and or cams with fuel lobes
maxed out the SOI
added the max and desired HPFP up higher just to see if it would work
the IPW is pushing 8ms its maxed and the HPFP is falling off
any suggestions before i add meth?
Not sure how you plan to make any power at 2 to 5 degree's of timing. You're about 12-15 degrees short of where it should be. Your EGT's must be sky high.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
How does that address the fuel pressure issue?
If it made 450hp on that timing, think of what it could have made on that same pulley with more timing and you still would have had the fuel there.
To me it needs more injector if you want to continue.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
It had 10-12? at that power level. I was warned that with this new gen 5 11:1 and pump 93 is best to leave it there and about 12.20s afr.
Also most i have read advise to replace the lt1 pump first. I plan on just using meth for now
It will make more power at 24 degrees and less boost therefore solving the fuel issue. FYI you log clearly shows 2.9 - 4.6 degrees of timing. Also makes your blower last 3x longer.Originally Posted by volcomstone550
Last edited by jsllc; 05-28-2020 at 10:08 PM.
2012 ZL1 - Maggie Heartbeat, Port & Polish Heads, Custom Cam, Custom rotating assembly, steel sleeved LS9, No NOS and No water meth. 16psi
810rwhp and 820rwtq 91 Octane 6400 rpm
948rwhp and 951rwtq 105 Octane 6400 rpm
999rwhp and 997rwtq on 60% Ethanol 6400 rpm
People run 24 degrees of timing on these motors with boost???
That log is the 3.75" pulley not the 4.375" pulley. I took timing out when i swapped pulleys.
I'm fairly certain the stock tune in LT4 cars asks for 24* at redline. But those engines also have lower CR than the L83 (10:1 vs 11:1). I'm no expert, but I would think you could still run at least 15-18* and not have any issues, and make way more power without needing to up the boost and spend thousands on a fuel system. Just my amateur $.02
If the goal is power the limit is fuel type. Not boost. Until you hit the 20s in timing there is more to get. I have won the bet many times. I can always make more power with timing than with boost. 7psi boost with 22 degrees of timing will make more power than 12 psi or 14psi with 8 to 10. Parts last longer. Boost is heat. Heat is loss of power. Timing to a point creates better combustion. Less heat and better combustion equals more power every time. AND no extra money required. Creates more TQ as well. All around winner.
810rwhp and 820rwtq 91 Octane 6400 rpm
948rwhp and 951rwtq 105 Octane 6400 rpm
999rwhp and 997rwtq on 60% Ethanol 6400 rpm
9.7-1 cr
16psi boost
810rwhp and 820rwtq 91 Octane 6400 rpm - 14 degrees
948rwhp and 951rwtq 105 Octane 6400 rpm - 20 degrees
999rwhp and 997rwtq on 60% Ethanol 6400 rpm -29 degress
10psi
850rwhp and 848rwtq 91 Octane 6400 rpm - 20 degrees
810rwhp and 820rwtq 91 Octane 6400 rpm
948rwhp and 951rwtq 105 Octane 6400 rpm
999rwhp and 997rwtq on 60% Ethanol 6400 rpm
The L83 in my tahoe is 11:1. I am not running 24? of timing on pump 93. And i have a free meth kit so 15? of timing on this 3.75" pulley is going to be faster than any version of the 4.375" pulley. I invite you not to comment anymore on this thread
I didnt realize the iat was pulling out some timing. I put the timing back to 15ish and fixed the iat to pull timing at 120ish? F im going to add the meth and see if i can get the rail pressure back. 7psi is only going to make 500 max without any other engine mods.
7-8 psi and 17 degrees on timing is the sweet spot for l83, l86, lt1 on 93 octane. Headers, no cats opens up the tuning window for a little more timing. Once you're over 5.6-5.7 ms of pulse width it's hard to make anymore power with boost.
you will never make your desired HPFP of 3300psi
even if you did your pushing the fuel system to the max. and maxing our SOI doesnt help either
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Found some threads saying it can help some.
Thanks for the input
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