On my dynojet wideband I see a high of 13.4 as I go through the rpms, it seems to start off at 13.1 or so gets to 13.4/5 then drops back down to 13.2 or so. I have a 255 and 42lb so I dont see why fuel would be a problem. Do you read lean or richer at the tail pipe cause when I got tune just a few weeks ago I only showed a high of 13.1 Is mid 13's to lean. Im about to spray it and worried I will be to lean??

Here is my graph where you can see my A/F, its pretty straight.

 

You will read the same at the tailpipe since you dont have cats. 13.4 may be a bit lean for WOT but if you arent knocking I wouldnt sweat it too much. You can tweak on the dyno to get it where it makes max power, all engines will react differently to different air fuel ratios, find what makes your car happy and stick with it.

 

That is a little close to the lean side, but still safe for NA if there is no knock. I know tony from AFR likes to run in that range - some set ups seem to like.

I'm not a nitrous person - but I'd be concerned that its way too lean for a shot. Someone who knows more will chime in.

 

I run 12.5:1. You should test for your optimum AFR on a dyno because some cars actually make more power with more fuel. The difference between 13:1 and 12.5:1 for my car was -2hp. So, I'd rather be safe than sorry and run the 12.5:1. I also have seen a car gain 10hp going from 13:1 to 12.5:1.

 

yeah its lean for nitrous but there are ways to make it richen up on spray such as using the right size fuel jet to achieve desired AFR.

 

where do you put the fuel jets on a dry shot?

 

There are ways to add extra fuel when hitting a dry shot yet still run ity leaner N/A, it is in the tuning though rather than a simpe jet. There a few different ways to do this.

 

Thanks for the good info. We did try to hit the spary on the dyno but my n20 selenoid would not hit, only my fuel. Im still working on that problem. Anyway like I said I did try to spray it on the dyno to make sure I was at a safe A/F. I'll just have to see what she does when I do hit it. Whats the best way to go up fuel jets? Im only gonna spray a 100 shot. Thanks.

 

Start a little high on the fuel jet and come down till you are happy with AFR.