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tuning a naturally aspirated car - 6G Celicas Forums

Topic #46921 13 posts Started by 6strngs
so. I have an APEXi AFC Neo and an AEM UEGO wideband O2 both on their way. should have them by the weekend (hopefully) or early next week. I'm going to be using them for once I have a turbo, but I was hoping to squeeze a little more power out of my car in the meantime. I'm a total newb to tuning though. I figure that what I want to do is just add/subtract fuel as necessary to maintain a steady air/fuel ratio. But what ratio should I aim for? also, what should I do with my timing. I'm currently advanced to 18 degrees, should I just set it back to 10? any advice and tips would be useful.

94 GT - Sold -------- 69 Pontiac Lemans - Sold88 Alltrac - Sold ---- 04 WRX - Sold00 GT-S - Sold ------ 91 Miata - project/drift car95 GT - Sold -------- 96 GT - New Daily Drive
let the ECU handle closed loop, in open loop shoot for 12-13:1 AFR, as for timing just watch the knock monitor on the SFC Neo.

2000 Celica GTS 'slowest gts evar'1998 Mazda 626 FS-DE/CD4-E
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QUOTE(Bitter @ Apr 4, 2007 - 8:33 PM) [snapback]543307[/snapback]
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let the ECU handle closed loop, in open loop shoot for 12-13:1 AFR, as for timing just watch the knock monitor on the SFC Neo.

at idle and part throttle cruising, the car should stay at 14.7 right? (assuming the car is in good condition, which I do my best to make sure that it is) and for full throttle, I should stay between 12-13:1 with 13:1 yeilding more power and 12:1 being safer, correct?

I know th SAFCII has a knock monitor, but I don't know if the Neo does or not (it's not mentioned in it's list of features).

94 GT - Sold -------- 69 Pontiac Lemans - Sold88 Alltrac - Sold ---- 04 WRX - Sold00 GT-S - Sold ------ 91 Miata - project/drift car95 GT - Sold -------- 96 GT - New Daily Drive
I think you can go leaner than that. 14:1 shouldn't be too bad.

Live Free, Be Happy
better to err on the side of caution if the neo infact does not monitor knock. generally leaner than about 13:1 doesn't yield much more power but does make things alot hotter. closed loop will bounce around, but the average will be around 14.7, but it will jump around between 14 and 15.

2000 Celica GTS 'slowest gts evar'1998 Mazda 626 FS-DE/CD4-E
14.7 is ideal for emissions... not power

"It's ok to be naked girl... I'm an artist!"1995 AT200 Celica ST:stocked out daily driver...1984 AE86 Corolla GT-SR5:silvertop 20V 4AGE project car jacked up with goodies...1991 SW2x MR2 n/a:bare bones hardtop model soon to be...
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QUOTE(Kwanza26 @ Apr 5, 2007 - 8:52 PM) [snapback]543778[/snapback]
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14.7 is ideal for emissions... not power

yeah, but in closed loop mode in part throttle cruising I'm not really looking for power, I'm looking for economy (could care less about emissions....) if I want power, I will put my foot down, which is why I agree I should only tune the open loop mode. which I will probably tune for about a 12.5:1 or so.

94 GT - Sold -------- 69 Pontiac Lemans - Sold88 Alltrac - Sold ---- 04 WRX - Sold00 GT-S - Sold ------ 91 Miata - project/drift car95 GT - Sold -------- 96 GT - New Daily Drive
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QUOTE(6strngs @ Apr 6, 2007 - 4:35 AM) [snapback]543800[/snapback]
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yeah, but in closed loop mode in part throttle cruising I'm not really looking for power, I'm looking for economy (could care less about emissions....) if I want power, I will put my foot down, which is why I agree I should only tune the open loop mode. which I will probably tune for about a 12.5:1 or so.

That's probably too rich... The best way is to get on a Dyno... cause engines are all pretty different depending on condition and stuff...

"It's ok to be naked girl... I'm an artist!"1995 AT200 Celica ST:stocked out daily driver...1984 AE86 Corolla GT-SR5:silvertop 20V 4AGE project car jacked up with goodies...1991 SW2x MR2 n/a:bare bones hardtop model soon to be...
but the whole point of buying the wideband was to avoid getting on the dyno! tongue.gif it's not so important to me to squeeze every single HP possible just yet. It's not going to remain an NA car for long, so as long as I can feel a slight difference with my butt dyno I'll be happy.

So, what A/F ratio do you recommend for WOT?

94 GT - Sold -------- 69 Pontiac Lemans - Sold88 Alltrac - Sold ---- 04 WRX - Sold00 GT-S - Sold ------ 91 Miata - project/drift car95 GT - Sold -------- 96 GT - New Daily Drive
12.5 is a little rich, but every tune is a little different. the stock tune goes way rich, ive seen mine dip into the 11's nearing 10 at WOT. start slowly pulling fuel at WOT till you're near 13:1 if you have no knock. if you get knock then retard timing from 18 (you'll need to when you go FI) and add back a little fuel. just have to play with it, it helps to have someone to ride with you to watch the gauges.

2000 Celica GTS 'slowest gts evar'1998 Mazda 626 FS-DE/CD4-E
the SAFC neo does not display knock count.

Former Team 5SFTE pro member ;)13.6@108MPH, 5SFTE Powered
install the wideband and install the safc. set your timing back to 10tdc. the drive around and just watch the wideband for a few weeks while you do more research on tuning and a/f ratios. then when the time comes, youll know what to change and why.

15PSI - 30MPG - Megasquirt Tuned
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QUOTE(presure2 @ Apr 6, 2007 - 5:23 PM) [snapback]544101[/snapback]
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the SAFC neo does not display knock count.

well that toads the wet sprocket.

2000 Celica GTS 'slowest gts evar'1998 Mazda 626 FS-DE/CD4-E