What AFR's are you guys seeing with pump gas?
05-10-2010, 04:26 PM
#1
What AFR's are you guys seeing with pump gas? My tuner put me right around 12 N/A and then I was about 11.5 on spray.
What are you guys shooting for full throttle AFR's N/A and on spray?
I see some guys in magazines and online tuning at 12.5 or even 13.1 N/A and on spray how much of a difference is there between 12 and 13 AFR ?
Anyway, what are you running on pump gas for AFR's ?
What are you guys shooting for full throttle AFR's N/A and on spray?
I see some guys in magazines and online tuning at 12.5 or even 13.1 N/A and on spray how much of a difference is there between 12 and 13 AFR ?
Anyway, what are you running on pump gas for AFR's ?
. I thought 13.0 was for na and 12.0 was for the spray. Then too much fuel will hurt the motor and too lean will hurt the motor too right? 
05-10-2010, 05:04 PM
#5
I dont even understand what you are trying to say....
around 12.0 on spray could be fine but many include myself run it leaner then that and dont tune of the afr's we tune based on what the plug reads and verify with afr after, so where you said it will "blow **** up" that is not the case.
around 12.0 on spray could be fine but many include myself run it leaner then that and dont tune of the afr's we tune based on what the plug reads and verify with afr after, so where you said it will "blow **** up" that is not the case.
05-10-2010, 05:40 PM
#6
LOL... Mine reads between 12.9 and 13.1 on the bottle (wideband is still in the car because there's no sense and taking it out and it gives me an extra data point) on a clean pull. I don't advise everyone to tune that lean, but if you know how to keep the timing out of it and read plugs, they make power that way...
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05-11-2010, 02:11 PM
#8
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05-12-2010, 11:42 PM
#10
There are many different opinions on what is the best airfuel. This is my opinion.
For an average street/strip car the ownder will never re look at the tune up nor pull plugs. For this type of application we tune the nitrous in at no leaner than 11.8 and no richer than 11.5. This is a great over all area that will make good safe power.
For a race application I am a firm believer in the fact there is no set airfuel to target. There is a starting point and a finishing point. This is how we do it.. Keep in mind we are constantlyt pulling plugs and watching our tune up.
We start off with a target airfuel on the wideband of around 12.0. Reading the plugs we take the tune up two ways.. Once the plug is clean, and the heat range and timing is where we want it we give it more fuel. If the car gets faster we give it more fuel again. We follow this path until the car slows down. Then we back it up to where it was happy. Now if in the begining we give it fuel and it does not like it we go the oposite direction. We take fuel out. We will only take out fuel to a certain point and we justify that point by reading the plug. We do it this way because its safer to give it alittle fuel to find its happy point than to go lean and burn it because we went the wrong way.
I am a firm believer in the fact that if you run your application extremely lean for every ounce of power it is harder on parts and over a period of time it takes its course on parts and they break.
The spark plug tells all but the wide band is a great tool to use and we use it on every one of our cars.
For an average street/strip car the ownder will never re look at the tune up nor pull plugs. For this type of application we tune the nitrous in at no leaner than 11.8 and no richer than 11.5. This is a great over all area that will make good safe power.
For a race application I am a firm believer in the fact there is no set airfuel to target. There is a starting point and a finishing point. This is how we do it.. Keep in mind we are constantlyt pulling plugs and watching our tune up.
We start off with a target airfuel on the wideband of around 12.0. Reading the plugs we take the tune up two ways.. Once the plug is clean, and the heat range and timing is where we want it we give it more fuel. If the car gets faster we give it more fuel again. We follow this path until the car slows down. Then we back it up to where it was happy. Now if in the begining we give it fuel and it does not like it we go the oposite direction. We take fuel out. We will only take out fuel to a certain point and we justify that point by reading the plug. We do it this way because its safer to give it alittle fuel to find its happy point than to go lean and burn it because we went the wrong way.
I am a firm believer in the fact that if you run your application extremely lean for every ounce of power it is harder on parts and over a period of time it takes its course on parts and they break.
The spark plug tells all but the wide band is a great tool to use and we use it on every one of our cars.
05-19-2010, 12:29 PM
#19
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That's about where I'm at also, 12.5-12.8 NA & 11.8-12.2 on the kit. I'm running a fogger with a stand alone on my 99 Z28 & tune my AFR's with the Fuel pressure regulator on the stand alone, of course that was after we set up the jetting pattern on the dyno with a set pressure, after that since I run a low pressure fuel system, I can just adjust the fuel pressure at the stand alone when T&T'ing. Seems like I have a different set of jets in each nozzle.
11-25-2010, 08:13 AM
#20
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With cathedral port heads I run 12.3-12.5:1 NA. I found(on our fuel) I make a little more power richer.
With square port heads I found I get better results 12.7-13.0:1 NA and like 5 hp less with 12.4ish.
This is consistent with all the cars I have tuned and I have experimented a lot, the gains are small but noticable. I run as rich as I can till power drops off then lean a touch and run as less timing as I can till power drops then raise 1 to 2 degrees. Safe as possible and most consistent track times this way.
With square port heads I found I get better results 12.7-13.0:1 NA and like 5 hp less with 12.4ish.
This is consistent with all the cars I have tuned and I have experimented a lot, the gains are small but noticable. I run as rich as I can till power drops off then lean a touch and run as less timing as I can till power drops then raise 1 to 2 degrees. Safe as possible and most consistent track times this way.