When under boost ( say, 12-15psi. in a built GSR engine ) what would be a good safe A/F ratio to shoot for to produce max. power? Thanks.

 

You want to shoot for 11:1~12:1 for a compromise of good power/safety. If you want max power shoot for 12.5:1~13:1 but that is pushing it, very aggressive tuning.

 

yeah, i agree. about 12:1, especially on pump gas. 13:1 on 116 octane.

 

11.7:1 ish... these guys are pros, I prefer being safe I've lived through a couple tanks of 87 in my lifetime

 

A little OT, but what will the full rich on an autometer indicate? 12:1 or more? Less? I remember someone saying that the autometer a/f guage is real lean even at full rich display. I am going to tune it with my autometer for the time being and I am not going to be driving too aggressively. And I will be pushing like 5-7 psi on a d16a6 motor.

 

No it wont indicate if you are running 12:1. You need a wide band 02 to monitor that.

art

 

Thanks everyone! I will run 12.2 to 1 on 92 octaine Chevron pump gas and 12.5 to 1 on 101 octaine Union 76 Gas. Does that sound reasonable? Already have a Greddy A/F Guage and will be getting a Greddy EGT Guage soon.

 

Under Boost.. 12.49 will make the most power without compromising reliability.. And you REALLY NEED a wideband to read this.. DO NOT rely on any reading your OEM O2 sensor is putting out..

-Jason

 

I really would like to Make My own Wideband O2 metering device. If only is was better with electronics. Someone on here could make some $$ if they would do this.

 

My car was tuned to 11.8-11.9 under 10psi for optimum power and reliability, esp. for a stock motor.

 

i tune with high boost apps around 12.2-12.4 on race gas and 11.2-11.8 on pump gas.

 

be a baller, 14.7:1 w/ proper tuning

 

I think this question may have been beaten to death but can someone convert all of these air fuel ratios into exhaust gas temperatures, or is there maybe a chart that exists already on a website I don't know about .

Right now I'm having a really tough time still trying to figure my car out and the biggest problem is that I'm having mad fuel problems so I just need something thats gona help me out here and I'm sure all the other people around here would appriciate it....

Adi

 

you cannot convert a/f readings to EGT's because they both dictate different things. A/f is air fuel, as you would think, but EGT's are different, and can mean several things. A high egt with good a/f would tell me timing is too retarded, while a low egt with good a/f would mean ignition is too advanced. When I tune, I start with a nice, safe ignition value, and tune for a/f. Once that is safely tuned, then, based on EGT's, I'll advance or retard timing to get it to an area where max power is achieved along with safety. They are not the same thing, they are useful when used hand in hand.

 

I would also make sure the A/F ratio is right for the CR being used.

 

Ahhhhh thank you very much for clearing this up for me I never would have know this before!!
So basicly either way you look at it a/f reading are just as important as egt readings but when you put the two together they work the best in aiding for a perfectly tuned car...

Thanks for the information VaporTrail I appriciate it a lot!!!

Adi

 

Say you have a fully built GSR Engine with a Compression Ratio of 9.0 to 1. You want to boost between 12 and 15psi. What A/F ratio should you set your standalone for WOT for Power and not sacrifice Safety? Thanks.

 

I would tune for 12:1 on pump, 13:1 on race gas.

 

Me to

 

Thank you very much for your answer!

 

Do a google search for "wideband O2 project." There are some Australians that have done all the work for you and it is very cheap (relatively). It even uses a stock Honda O2 sensor.

Ben

 

I try for 12.20 when tunning at 25psi on 116 vp

 

I have been reading there site. It's very informative. I really want to buy a pre-bult unit but they are not avalible right now and probably won't be for a while. I guess I will have to take a crash course in electronic.