What Gains have people seen going from 13.8 AFR to 12.7????
09-29-2008, 10:11 PM
#1
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What Gains have people seen going from 13.8 AFR to 12.7???? As the title says. I am just wondering what kind of horsepower gains have been seen from going a full point Richer. Trying to get a feel of how much power a point of AFR is worth. I know it really depends, but I am just trying to get an idea.
Last edited by 1fstGM; 09-29-2008 at 10:49 PM.
09-29-2008, 11:38 PM
#4
I personally think 13.8 is on the edge. You are probably not going to see gains unless you are detonating (knock). Depending on your combo n/a likes 13.0 to 13.2 at the most. W/ afr that lean I would hope your running lower timing ie. 24d at wot.
With that said every car is different. W/o scanning you wont know.
Doug
With that said every car is different. W/o scanning you wont know.
Doug
09-30-2008, 07:58 AM
#7
The only way to know it to strap it down on the rollers and get some numbers. Personally I saw very little gain from 12.7 to 13.2-13.4 so I run on the safer side at 12.7 with about 25* at VE peak, 27.5* at max rpm. IMO, aim richer and see what the benefit (if any) is to leaning on it little by little, you'll probably be supprised.
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09-30-2008, 09:26 AM
#8
That blanket statement does not cover the scope of N/A. I have had many cars that make next to nothing when leaning out past 12.6-12.7... and a select couple that wanted to be around 13.2-13.3.
The right AFR for an N/A setup is where it makes the most on the rollers. If all you have is the street, 12.8 is a good place to be.
/end 2cents
09-30-2008, 01:06 PM
#9
That blanket statement does not cover the scope of N/A. I have had many cars that make next to nothing when leaning out past 12.6-12.7... and a select couple that wanted to be around 13.2-13.3.
The right AFR for an N/A setup is where it makes the most on the rollers. If all you have is the street, 12.8 is a good place to be.
/end 2cents
The right AFR for an N/A setup is where it makes the most on the rollers. If all you have is the street, 12.8 is a good place to be.
/end 2cents
Just saying Most n/a cars we've had on our dyno worked best at or around 13.0. + - .2
Doug
09-30-2008, 01:12 PM
#10
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That blanket statement does not cover the scope of N/A. I have had many cars that make next to nothing when leaning out past 12.6-12.7... and a select couple that wanted to be around 13.2-13.3.
The right AFR for an N/A setup is where it makes the most on the rollers. If all you have is the street, 12.8 is a good place to be.
/end 2cents
The right AFR for an N/A setup is where it makes the most on the rollers. If all you have is the street, 12.8 is a good place to be.
/end 2cents
09-30-2008, 03:03 PM
#11
It's true that many of the cars that I tune on an unloaded (dynojet) will make the most at 13ish, but getting the cars on the street or track and making pulls through all 3-4gears and having cylinder temps rise causes knock in most of the cases. There is a somewhat local shop that I regularly get retunes from and the cars all have very high timing and are at 13-13.3:1 AFR. They made good numbers on his dyno for the most part, but actually racing the cars is something else.
10-01-2008, 07:01 AM
#13
Sorry, not trying to be a *****
It's true that many of the cars that I tune on an unloaded (dynojet) will make the most at 13ish, but getting the cars on the street or track and making pulls through all 3-4gears and having cylinder temps rise causes knock in most of the cases. There is a somewhat local shop that I regularly get retunes from and the cars all have very high timing and are at 13-13.3:1 AFR. They made good numbers on his dyno for the most part, but actually racing the cars is something else.
It's true that many of the cars that I tune on an unloaded (dynojet) will make the most at 13ish, but getting the cars on the street or track and making pulls through all 3-4gears and having cylinder temps rise causes knock in most of the cases. There is a somewhat local shop that I regularly get retunes from and the cars all have very high timing and are at 13-13.3:1 AFR. They made good numbers on his dyno for the most part, but actually racing the cars is something else.
this is exactly how mine did. It made the most power on a dynojet at 13.2/1 and 30 deg timing. at the track it was faster with 26 deg and 12.8/1
These changes were worth 1.5 mph
