so bigger injectors and anything else guys, i at least wanna see 17*'s of timing if possible ay suggestions

 

The reason why his truck can't run anymore timing is because it starts to produce audible ping. Plus, with that small pulley we saw as much as 13psi, so 12degs of timing on a hot radix is just fine.
11.4 a/f ratio is perfectly normal for 13psi! Why would it be need to be leaned out more?
I run my Av at 11.0 and it sometimes hits 10.8 and there is not much difference in running it at 11.8 a/f ratio.

Unfortunately, some trucks just can't take as much timing as others.

Let's lower the boost to about 8-9psi and I'm sure we'll get 18degs.
With 13psi, I think it's just overturning the charger.

see you soon,
allen

 

not to jack the thread,
i get audible ping but no KR [otc scanner] and only 16 deg timing.
low iats, 110-120 on a 3.4 pulley and a full 9psi at wot on a 5.3.
is the pcm doing something with the ping even though i get no kr????

 

great points allen, i just can't imagine with the 2.75 versus my 2.8 there'd be that much of a heat increase. I felt he shouldn't chase his tail if the heat was do to a mechanical issue, not a "normal" accpeted issue. but your right, never even thought about him being a 5.3, overspinning and too much that way is obviously a concern for him.

as far as lean to rich and rich to lean. All trucks like different #'s. seems lately I am noticing turbo guys have more success with richer afr's. What's that have to do with the tea in china? idk, but you know ever one is gonna suggest 11.8, ESPECIALLY if they are pushing big IDC numbers at >11.4AFR with a radix, not a STS'ed avalanche.
You and Wilde Racing has me believing you STS guys love fuel. LOL

you're in good hands whoop.

 

I agree. Throw a 3.1 pulley on there and run more timing. I was running 18 degrees of timing with no meth on my 5.3. I was running about 8.5psi. 60# injectors are a good idea, but less boost will need less injector. I was at 91% duty cycle with the 3.1.

 

Well, having a 5.3 makes more sense. His sig says "10lb pulley" and he mentioned he had a 2.75" pulley. I have a 2.75" and a 6L and see 9psi. If hes seeing 13psi then thats a different story. I wouldn't even run that on a stock bottom end but thats just me. From what I've seen anything over 10psi requires a fast trip down in the timing table. So 12*'s @ 13psi is not unusual. If youre getting audible ping then it doesnt really matter what you "Should" be able to run. When it pings, its too much.

Downsize the pulley and up the timing. I bet you make more power with less strain on the hard parts.
I keep my AFT at 11.8-12.0 while in boost but @ WOT and 9psi it stays about 11.5.

 

thanx allen for clearing that up. that answered or my question's but 13psi WOW!! never knew i would get that high of boost, but i'm definitely down sizing to the 3.1 and this morning i pulled up against a 04vette at a redlight and smoked him and i saw 9psi with 3.1. the guy on the vette just gave me the thumbs up. chet and at 13psi no wonder the differential went out lol, cuz damn thats alot of boost for a 5.3l with radix i/c,275pulley