Im not running 15 psi at about 12.8 to 13 air fuel and im hardley seeing any knock at all. Most of the time any. This is ok correct? it feels like running 20 on 11.5 a/f. Also spraying windshield washer fluid.
even if im not getting any knock??? Why would it blow if im running high octane?
Its running so good how i have it now. Im even hitting 17 psi and its not misfire how it was before. Before i had it at under 12 the whole time and it would get up to 15 and start spark blow outs and stuff and would run bad. Now that its like this Its a beast. I will give it a little more try to get it to 12.5. But when you say KABOOM. Is that just going to happen all of a sudden or is there a way i can tell like spark knock. Im not getting any spark knock. I was going to leave it but now you got me worried. I'll aim for 12.5.
I've done alot of searching the only thing that i see that running 12.5 to 13 under boost is that it can cause melted pistons. Is that what you meant by kaboom? please explian!!!
You need to aim for ballpark of 11.5-11.8 ... You keep it where its at you will blow it.. They usually say "the leaner the meaner".. As you can see it is true, but it won't last... You said you were getting spark blow out, what are the plugs gapped at??
P&P Tuning
420.5whp / 359.8wtq
I will take it back down to correct air/fuel. I had plugs gapped at all sorts. From .040 to .025. They are at .025 right now. It was misfire when it was at air fuel 11.5. Stoped misfire when i wen up to 13. Maybe plugs are fouled out. I wish i could keep it at 13. Its running so strong. How bout 12.5 with meth?
BOOSTED BABY wrote:Its running so good how i have it now. Im even hitting 17 psi and its not misfire how it was before. Before i had it at under 12 the whole time and it would get up to 15 and start spark blow outs and stuff and would run bad. Now that its like this Its a beast. I will give it a little more try to get it to 12.5. But when you say KABOOM. Is that just going to happen all of a sudden or is there a way i can tell like spark knock. Im not getting any spark knock. I was going to leave it but now you got me worried. I'll aim for 12.5.
Hate to say this and do not mean it to be rude, but sounds as if you do not totally know what your doing. Spark blow out is going to happen (if it is going to happen) regardless of air/fuel. It is due to boost pressure (airflow) blowing out the spark. You probably had something else going on that you were not sure of.
As stated lean does feel good (until you blow it up). Lean can make great power, but at a cost. Richen it up and get a good tune on it.
FU Tuning
Just because you don't see knock doesn't mean you are damaging your engine.
not agreeing that 13's are good, but extra fuel does add extra resistance to the spark trying to jump the gap, its not 100% the boost pressure
208whp 239wtq
13.7 @ 102mph 2.19 60'
get real meth! and put better gas in it
Running lean will only make more power to a point and 13's are beyond that point. 12.5 is about max power lean, although as stated at a cost. Running lean will also create more heat thus damaging the engine. There's a reason suggested afr's under wot are between 11.5 and 12.0.
Anxiously awaiting the "I blew my @!#$ and don't know why." thread.
Edited 1 time(s). Last edited Saturday, July 19, 2008 6:30 PM
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
Heres a good breakdown for reference
Air/Fuel Ratio Limits
6.0:1 Rich run limit
9.0:1 Low power, black smoke
11.5:1 Rich best torque at WOT
12.5:1 Safe best power at WOT
13.2:1 Lean best torque at WOT
14.7:1 Chemically ideal
15.5:1 Lean light load, part throttle
16.2:1 Best economy, part throttle
18-22:1 Lean run limit
Joshua Dearman wrote:Heres a good breakdown for reference
Air/Fuel Ratio Limits
6.0:1 Rich run limit
9.0:1 Low power, black smoke
11.5:1 Rich best torque at WOT
12.5:1 Safe best power at WOT
13.2:1 Lean best torque at WOT
14.7:1 Chemically ideal
15.5:1 Lean light load, part throttle
16.2:1 Best economy, part throttle
18-22:1 Lean run limit
And this came from where?
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
^Quoted from a BMW racing forum....sorry dont have the link anymore, just remember saving the .txt file. It matched pretty close to what I've noticed in my experience tuning formula SAE race cars.
uhh at 13psi my WBo2 says 10.5
Built&Boosted moar
04 Cavalier Turbo r.i.p my baby
2nd place 2009 GM tuner bash qwick 8--holla
I had setup table switching in megasquirt for the target AFR numbers between 11.1 and 12.3 depending on the gear I was in, 1st-2nd 12.3 and 3rd-5th 11.1 for the targets. I've done alot of AFR tuning since I had a Superflow engine dyno(crankshaft dyno) at my disposal and lots of time to use it.
with my saab kit/GMSC reflash i see 10.5 AFR @ WOT@ 7-8psi. torques like a champ, but i dont believe AFR #'s are the only thing that needs to be tuned.
^Your right about AFR's not being the only, but it is a good 90% and the rest is pretty much trivial once you get the proper fueling (AFR). Throw down a few advance vs. knock to find the sweet spot and your damn near done....Well, at least for the MS, which auto tunes the accell, decel and idle and does and VERY good job of it when your on a dyno.
Liquidplamsa wrote:with my saab kit/GMSC reflash i see 10.5 AFR @ WOT@ 7-8psi. torques like a champ, but i dont believe AFR #'s are the only thing that needs to be tuned.
wow pig rich for such a tiny turbo and such low boost....
