4.8l 13.5 PSI: Tuning, IAT/Intercooler, 1/4mile time question

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Nov 2, 2015 | 11:46 AM

#41

fastjweb

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From: NewBern NC/Lake Havasu City AZ

Quote:

Originally Posted by stock48

Thing needs the stock intake on it and some meth injection or E85 and 15~16 deg of timing to start with. The triple 12 cam will rev to 6800 RPM in a 4.8L long as the springs are set up right. Single pac's will need a .030''~.-45'' ship to reach that rpm, BTR duals should be fine at std height. If you want to make power on low boost like 13 psi the thing is going to need some timing and a leaner AFR. That turbo is pretty small on the exh side but still should reach goal or faster if things are right. The reason the converter slip is so high is because there is not enough RPM there for it to couple with that gear ratio and mph. Get mph up around 130+ with more power and it should couple a lot better.

Smart man!

Nov 2, 2015 | 08:54 PM

#42

lycominghunter

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From: Richlands, NC

Thanks Jarrett, as well as everyone's else's inputs. I'll be going to dragging rights this weekend on the set up I've been running - hoping to get a high 11sec out of it. But after Saturday it'll be 4.10s and a stock intake. I'm interested to see the difference!

Thanks again gents!

Nov 3, 2015 | 01:17 AM

#43

stock48

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From: Colorado Springs, Co/ Central, Ca

Easiest thing to do right now is mix some race gas in it and bump the timing to 17 deg and don't let it pull any for iat. Meth inj or E85 would be better but I bet the timing will be worth huge power and it will have a lot more top end as well. Id prob shift it around 6500 RPM if the springs are not shimmed.

Nov 15, 2015 | 06:02 PM

#44

lycominghunter

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From: Richlands, NC

Thanks for all of the help gentlemen. Just wanted to get back to y'all and close the loop on this issue. I wrapped the up-pipe and Turbo Inlet pipe in 1/8 foam insulation and then covered that in foil tape. Next I built a head shield for the air filter. Now, the temps have gotten cooler since I last ran, however I think the insulation helped to keep IAT's to 122 degrees by the end of the run, so I'll consider that a win.

The truck is running around 10.8AFR and is currently on 15 degrees of timing. Currently shifting at 6800rpm.

Stock48, the springs are shimmed per your recommendation back in 2013 when I bought the triple 12.

Results: 11.67sec@117.1mph, 1.74 60ft leaving at 3500rpm and 10psi. DA ~ -500ft

I'm pretty impressed. With those numbers, the negative DA really helped. 4.11s should be done tomorrow, but wont know any improvements or track times until December.

Thanks again for all of the help!

-J