[Rookie38]

I got my inspection a few weeks ago and when the car was on the dyno the tech told me my air fuel ratio was at 14.5. I have heard this is around where you want it to run good, But that there could be gains if it is closer to 12. Is this true? Also right now my pressure is at 38 with the engine running and the vac hose off. With the hose on it drops to around 31. Could I pick up anything by adjusting the fuel pressure and if so which way.
Thanks

 

[1 Bad 88 GT]

Unless you or someone else has installed an adjustable FP regulator it's not possible to adjust your FP.

 

[Rookie38]

On 2006-03-03 19:09, 1 Bad 88 GT wrote:
Unless you or someone else has installed an adjustable FP regulator it's not possible to adjust your FP.

I have a kirban adjustable regulator installed. I have searched on this forum and found some peole saying that this ratio 14.5:1 was very lean. and that this could lead to burnt pistons. Did I miss read this, or is this the case if running around this ratio under high Rpms as opposed to moderate to everyday driving?
Thanks for the reply 1 Bad 88 GT. I was starting to wounder if everybody left this site and forgot to tell me.

 

[thekingofazle]

14.7 is perfectly stoichiometric for gasoline enginesm - it will yield the most power per amount of gasoline - basically, it's the most efficient, and the most economical on fuel. however, that isn't the ratio for optimum power, the dyno guys are right, an A/F ratio at about 12.5:1 is optimum for power, and safer on parts.

14.7 should be what is maintained by the computer at cruise and emissions testing speeds, but it should go full rich when you're at WOT. It is possible to run into detonation at that ratio.

I would pay for a dyno tune session and play with your fuel pressure - go up a pound or two and run it, then another pound or two, check again, until it's where you want it at WOT. If its at 14.7 on the emissions dyno (just partly loaded) thats where it should be. They don't test WOT readings on the emissions rollers as far as I know.