i was getting my vafc tuned this weekend and was runing a little lean from 5500-7000 and rich the rest of the way up.

anyway i got the 7000-up range leveled out. but for some reason i couldn't get the rest(5500-7000) to richen up. no matter how much fuel i added it wouldn;t come down all that much. the guy tuning it was trying to get it to be 13.1 all the way. we got it down to 13.7 but thats about it. from what he said it isn't a bad number. but he would have liked to get it lower

anyone else have it so it won't lean out at all?

 

You CANNOT richen with the AFC. ONLY LEAN

 

What does your hp and torque curve look like? Is it linear or are there some dips in it?
Did you see any hp gains from the tuning that was done or is the person doing the tuning just checking the a/f ratios?

 

Thanks.
if you read agian. would you say that i whould get a fuel pressure regulator or does it seem ok to have it at 13.8? the rest of my graph is all in between 13.0 and 13.4.

like i said i was told by the tuner that it is ok. just want another opinion.

 

the hp and torque lines are pretty flat.

i gained like 4HP in the higher rpms and 2lbs or torque.

 

that sounds fine.
but you could probably make more power if you had an fpr in conjuntion with
the AFC.

 

A FPR is going to raise the fuel pressure according to vacuum pressure so even if you do put it on then your whole fuel curve is going to raised. All the points you have mentioned.....13.0. 13.4...etc will be raised.
What you could try is to put on the FPR and set the VAFC to zero. Tune the FPR first to get you rough tuning and then use the VAFC to do the fine tuning. This usually works the best. The VAFC has tuning ability of +/- 50%. Also make sure that the VAFC has been tuned seperately for the low cam and high cam. There is a screen to tune each one.

 

alright thanks guys. especially for the rapid answers.

oh and welcome to honda-tech SlickTech

 

to add to his response, you should increase pressure first, see if there is a gain.
if there is gain, good. where there are any losses you should lean those
areas with the vafc. keep going until you dont make anymore power

 

>>A FPR is going to raise the fuel pressure according to vacuum pressure so even if you do put it on then your whole fuel curve is going to raised. All the points you have mentioned.....13.0. 13.4...etc will be raised.<<

Don't you mean "lowered"? I never heard of an aftermarket FPR that actually caused a leaner mix than stock. His current delimma has him around 13.7:1 A/F ratio because the stock FPR does not allow enough pressure to build in the fuel rail. An aftermarket FPR (at least all the ones I've ever heard of) will allow more pressure to build in the fuel rail, thus causing more fuel to shoot out of the injectors, resulting in a richer mix and lowering the ratio of air to fuel.

If anything, he may be running a little too rich with an aftermarket FPR, but that's where he want's to be because the AFC can take care of it. (as someone already posted)

Good tips on setting a baseline for tuning.

 

I was speaking in reference to the fuel pressure being raised. I usually don't speak of a/f being raised or lowered.....just leaner or richer. I think we are all on the same page though.