Tunnig Question

[Larrygto]

I had my car Dynoed Yesterday and the afr is 12 to 1. If I were to get the afr's were they should be what kind of gain would I see?

[BAD LS1]

On motor or spray? Leave it alone of its on spray, you want 13.0 on motor. maybe 10-15 hp at best would be the gain??

[Larrygto]

No spray only motor, But when they tuned it I had a bad catback that was banging everywhere and give false knock reading so they didn't want to give it much timing. No that that's fixed is it worth getting it retunned?

[BAD LS1]

Yeah probably, throw 28 degrees at at and a 13.0 AFR.

[Larrygto]

[/IMG]This is a LS1 with headers Shouldn't it be doing better than this

[Poncho]

ls1s are usually around there stock, maybe a little higher.

[BAD LS1]

The AFR isnt gonna kill it that bad. Unless it has like next to nothing for timing or the tune is just rediculously out of whack, which is quite possible by the looks... But This is an auto witha loose ass converter... Its not gonna dyno well unless you lock the converter and do the pull in 3rd.

[Larrygto]

From what I understand there is very little timing every time they tried to add timing the knock sensors would make them take it back out. I just don't know if it's worth $300 for a few hp?

[2SLOW]

From what I understand there is very little timing every time they tried to add timing the knock sensors would make them take it back out. I just don't know if it's worth $300 for a few hp?

It is not, unless your looking for that extra .001 at the track.

[BAD LS1]

From what I understand there is very little timing every time they tried to add timing the knock sensors would make them take it back out. I just don't know if it's worth $300 for a few hp?

Something is really wrong then if it wont take timing. I can whack mine with over 30 degrees of timing and not see one bit of KR.

Here is my conclusion:

Possible causes

Stock thermo still in, shitty gas or not 93 octane, Lots of oil vapor being drawn into the intake (reduces octane rating) or as you mentioned false knock, but it takes a rattle close to the motor it self to do that. And it usually spikes and drops off instanty. Real knock slowly tapers down on the scanner...

[Larrygto]

They asked about the gas it had Top Tier 93 in it. It was the mid pipes hitting the frame are they close enough? Should I get a diferent stat and a catch can before I get it retuned?

[BAD LS1]

Yeah you should have a 160 in there for sure, and the fans tweaked to reflect it. Catch can is alwaysa good idea, im sure if you removed the throttle body its covered with oil on the back side as well as the intake is nice and shiney inside im sure.

[Larrygto]

Just talked with the tuner he said they didn't log them, But from what he could see it has 22-24 degrees of timing at the most.

[BAD LS1]

Just talked with the tuner he said they didn't log them, But from what he could see it has 22-24 degrees of timing at the most.

Thats not horrible, thats about stock timing.

[Larrygto]

So I should be happy with 305rwhp and save my money?

[BAD LS1]

So I should be happy with 305rwhp and save my money?

Thats about all you will get out of it for #s because of that converter. If you want better #s have them manually lock the converter and do the pull in 3rd gear. Prolly will be closer to 340ish

[Larrygto]

I'm not really looking for dyno numbers I'm 1/10 away from a 12 and I'm not sure I can get there on this tune? Also 1 other thing this thing idles like crap I've changed the plugs cleaned the MAF could the knock and the idle problem be connected?
Thanks for all the help Larry

[BAD LS1]

No thats just in the tune up. RAF table nees to get bumped.

[BadAzzGTA89]

I say have Tom tune it FTW!

[Berettaspeed]

it would matter more at what load your timing was set. 22-23 is most GMs.. it matters when it starts to taper off or where is starts to gain. adjusting those will help maintain alittle more power thats all. and your A/F would help more than the timing. get it more lean and you will have a much better gain.