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4.8L 9psi Tune Advice

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Old 09-19-2015, 03:22 PM   #1
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Default 4.8L 9psi Tune Advice

Hey guys. With the help of many members on here and friends, I got my truck turbo'd on 9psi. Went to the track last night and ran a best time of [email protected] with a 2.09 60ft time. I know there is more power to be had through the tune and I was hoping that maybe some of you could take a look at it if you had a chance. I also attached my log, and config if you'd like to check them out too. Information about my set up is below.

Performance:
2003 RCSB 4.8l 2wd
Isky Triple 12 cam, Isky valve springs
Trick Performance turbo kit with 78mm Magnum Ball Bearing Q Trim
3 inch down pipe and 3 inch exhaust dumping after the cab
90mm throttle body on a Holley Hi-Ram
124lb injectors with walbro 450 pump
E-Fans

Drivetrain
Lowered 4/6
4L80E with a 3600 Circle D 258mm Triple Disc
Trutrac with 3.42 gears
Relocated shocks with QA1 single adjustables
Assassin bars
28x11.5 ET Streets

Any and all advice is welcome. Thanks in advance!
Attached Files
File Type: hpt 9psi Tune 8 12.96 pass.hpt (494.5 KB, 166 views)
File Type: hpl 9psi Track Tune 8 12.96 Log.hpl (34.5 KB, 75 views)
File Type: cfg 2 Bar Config 1B.cfg (3.1 KB, 61 views)
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Old 09-21-2015, 08:37 PM   #2
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without even looking at the tune you have A LOT more in it by cutting down your 60ft. 2.0 with slicks and traction bars? you should be 1.6-1.7, that'd make it almost an 11 second truck on it's own, you'd think?
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Old 09-22-2015, 03:34 PM   #3
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you can get away with 28-29 degrees of timing on the 4.8.. and your only commanding 14degress at 9psi..

Increase your timing 3 degrees at least and run a 0.2 richer afr.. on boosted applications, power comes from ignition timing more then it does from keeping a leaner afr.
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Old 09-22-2015, 06:00 PM   #4
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Quote:
Originally Posted by norris_83 View Post
you can get away with 28-29 degrees of timing on the 4.8.. and your only commanding 14degress at 9psi..

Increase your timing 3 degrees at least and run a 0.2 richer afr.. on boosted applications, power comes from ignition timing more then it does from keeping a leaner afr.
Did you mean 18-19?
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Old 09-23-2015, 09:37 PM   #5
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Maybe he meant 28-29 degrees on a N/A motor...

So 17 degrees base is still relatively safe at 11.7 afr? First boosted application I'm tuning so I'm going slowly, being cautious. I appreciate all of the advice I can get!

Yes, my 60ft is horrible and that's what I'll be focusing on once I get my 4" exhaust done. I did cut my best 60ft that night of 1.96 and that was launching at 4psi, but that was before I had leaned the tune up closer to 11.5 and increased the timing a degree. Even n/a I was never able to get below a 2.1, so if I am able to get down to a 1.6-1.7, that would get me deep into the 12's which would be awesome. Time will tell!

Thanks for the input!
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Old 09-24-2015, 10:49 AM   #6
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My single cab with 6.0 leaving on a 300 shot on wore out drag radials would cut 1.6-1.7 60ft with nothing done to the suspension except being lowered. If your in the 2's something's off, suspension, tire pressure, etc.. I don't think I have ever had anything with a 60ft in the 2's.
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Old 09-24-2015, 11:05 AM   #7
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what fuel?

that motor at 9 psi should have around 20* on 93 with a 11.7 afr
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Old 09-24-2015, 01:04 PM   #8
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20* is kind of a lot on 93 alone... approach that carefully. I'm not saying it cant be done, but do it a degree at a time to make sure that your motor is happy as you increase it. Don't just jump to 20 and take it as gospel that someone on PT did it once...

Also before you mess with spark make sure your AFR is dead nuts where you want it. Always play with fueling before you add spark to a tune.
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Old 09-24-2015, 03:24 PM   #9
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20 * isnt really alot for a 4.8 figuring 29 * for NA and safely pulling 1* per 1psi

My old 5.3 when was on 9 psi had 22* in it on 93
Made 575rwhp

Plugs dont lie but will agree creep up on that number but is very plausible to run

If youre on e85 you could get away with delaying pulling timing to about 5 psi then start the 1* per 1psi


Also since youre turbo you have more leg room then a Pd blower
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Old 09-24-2015, 06:23 PM   #10
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Quote:
Originally Posted by LSX Power Tuning View Post
My single cab with 6.0 leaving on a 300 shot on wore out drag radials would cut 1.6-1.7 60ft with nothing done to the suspension except being lowered. If your in the 2's something's off, suspension, tire pressure, etc.. I don't think I have ever had anything with a 60ft in the 2's.
I agree with this.

With ET Streets, you should be able to pull a 1.8 60ft easily.

Tire pressure should be 25 - 28psi.

My 2007 Mustang GT on Sumitomo HTRs pulled a 2.0 60ft and that was blowing through 1st and 2nd gears at around 28psi.
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