MAF tune

Ok guys,

Ive changed back to a MAF from SD. I looked over my tune, and thought I was good to go. I started it, and the AFR is reading 33.2 on my LM2. The spark is 35 at idle, MAP is 65 and IAT is 22. My AFR before i went back to the MAF was 14.3 at idle. What tables am I missing here? I recently installed my wideband slightly farther back in the exhaust, maybe its seeing "free air" ?

The car idles just fine, and it revs better than ever.

65 MAP kpa? Maybe raise the idle a little to get that down first?

33.2 would not run. that's free air or miswired

your idle advance is stupid high, try 28 or so

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Originally Posted by steveo

33.2 would not run. that's free air or miswired

your idle advance is stupid high, try 28 or so

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His idle advance is not stupid high. My L31 runs about 30-34* BTDC @ 700 rpm and I ran 30* with the LT4 cam.

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Originally Posted by Fast355

His idle advance is not stupid high. My L31 runs about 30-34* BTDC @ 700 rpm and I ran 30* with the LT4 cam.

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Yes but your iac counts are probably zero with that much lead at idle. Not the preferred way to tune as you probably know. Just sayin. Why would you need that much lead with an l31 at idle with a quick burn chamber and a stock cam? Are you trying to achieve the best idle vacuum and thats all?

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Originally Posted by S10LS

Yes but your iac counts are probably zero with that much lead at idle. Not the preferred way to tune as you probably know. Just sayin. Why would you need that much lead with an l31 at idle with a quick burn chamber and a stock cam? Are you trying to achieve the best idle vacuum and thats all?

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Not the stock cam, 215/220 @ .050 on a 114* lsa 4* advanced and it has aluminum e-tec heads. The vortes don't burn any faster at idle than any other head.

IAC is about 10-15 steps at idle fully warmed up.

Best idle vacuum and least fuel consumption possible.

isnt dropping combustion temps at idle a good thing?

and there's a big difference between 30 degrees (with your lt4 cam'd lt1) and 35 degrees at idle.

hell even all in WOT timing on an lt1 shouldnt be 35 degrees?? most people find no power gain past 33-34 top end

Quote:

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Originally Posted by steveo

isnt dropping combustion temps at idle a good thing?

and there's a big difference between 30 degrees (with your lt4 cam'd lt1) and 35 degrees at idle.

hell even all in WOT timing on an lt1 shouldnt be 35 degrees?? most people find no power gain past 33-34 top end

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The last one I tuned had a 232/240 @ .050 cam, 11.4:1 compression, LT4 heads and made peak power at 37* btdc. Over 400 to the tire from a pump gas 383.

I have had my L31 as high as 38* at idle while playing with the timing via 2 way control on HP Tuners. 34-35* is no problem. Some of the carbureted ebgines I have worked with had over 30* of timing at idle.

Ive read in several places that I need to smooth the MAF tables? If I need to tune the AFR, what MAF tables do I adjust?