Safe A/F Ratios

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Bigdough666

Picture Me Rollin
Apr 4, 2005
367
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0
41
Corpus Christi, TX
Alright guys, Ive been tuning my car on my own using an S-AFC II and a AEM Wideband. I need to know, what are relatively safe A/F ratios? Im gettin 11.9 - 12.5 in 1st, 2nd, 3rd, and it gets up to 13.0 - 13.3ish in 4th and 5th. This is at WOT. So, is this bad? Am Im running a lil too lean? Or am I cool? I want it to make power, but I dont want to lean out a cylinder and kill a piston or anything.

Right now Im running on 93 pump, but I will be on 109 race gas from here on out.

A lil info on my setup:

60-1 upgraded CT
20 psi
550s, Lex AFM, Walbro, AFPR
Ebay special IC and custom hardpipes
3" exhaust

So if this is dangerous, let me know how to fix it. Add more fuel back in with the AFC? Bump up fuel pressure? Any help will be appreciated, thanks.
 
R

rumptis

나는 제프가 당신을 사랑
Aug 16, 2005
814
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47
North Vernon, IN
I would keep it around 11.5 thru out to be safe. Doesn't really matter which gear you are in you want to be in this area.
 
B

Bigdough666

Picture Me Rollin
Apr 4, 2005
367
0
0
41
Corpus Christi, TX
Alright, update time.

Fuel pressure:

~25 with vac on
~32 with vac off

AFC settings:

I had it like this:

RPM -- Amount taken out

1600 -- 2
2200 -- 9
2800 -- 12
3400 -- 14
4000 - 6400 -- 17


I added 4 back in across the board since it was way lean

Did a pull in 3rd, eased into it, ended up at 12.5

Decided to add 1 more in across the board, was about the same and I am now all over FUEL CUT. If I slowly ease into the throttle its cool, if I go WOT immediately,all over fuel cut.

So, now what do I need to do? Its still lean, and Im all over fuel cut. Lead me in the right direction please.

Thanks in advance.
 
B

Bigdough666

Picture Me Rollin
Apr 4, 2005
367
0
0
41
Corpus Christi, TX
Well, I just noticed something this morning driving to work. The temps outside have been in the low 50s at night (when I was tuning) and in the morning. It seems when I get on it, the boost spikes, thats when I hit fuel cut. If I get into it gradually, its fine. So maybe its just the weather.

But the A/F ratios are still a lil lean, as low as 12.0 but pretty much holds at 12.5 when I ease into it and get a full pull.

I hit fuel cut as soon as it spools, Id say ~3500, so the AFC is around -10ish at that point.

I'll try to test it out this afternoon when the weather warms up a bit and see what happening.
 
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