i had my car dynoed(mustang dyno)recently and i put down 159hp 121tq and my A/F ratio was a roller coaster.The torque seemed a bit low to me, could this be a cause of the horrible a/f ratio?or could it be my secondaries not opening or what?I know , i know a pic of the dyno would prolly help alot but i dont have a scanner .

A/F ratio ranged between 12.39 and 13.89

setup:aem CAI,ebay header,random- tech cat,Tanabe cat back ,aem pullies

 

you would lose low end torque if the secondaries were open all the time...see if the vacuum going to the valve actually has vacuum.....

 

I've seen higher torque numbers on a automatic.

 

Keep in mind that a mustang dyno will read lower than the Dyno-jets that most people use. IMO the mustang dyno is the better dyno but most shops don't fork out the cash for them. Also if you were in 3rd gear you will see lower numbers than if you do a run in 4th gear. Still your a little low even for a mustang dyno. I got 128 tq when my car was bone stock on a mustang dyno in 3rd gear.

might be the E-bay header, but I don't know....
maybe check the secondaries like you said.
How many miles do you have on the car?

 

miles : 95,xxx
and almost postive it was a 3rd gear pull, so the A/F ratio wouldnt have anything to do with it? i mean its really bad.Up, down,up, down just like a roller coaster.I also had a vafc2 untuned(vtec@ 5000) installed when i did the pull and recently i took it off and it seem to pull alot harder, so could that might have somthing to do with it also?

yes, the header is horrible but i just wanted somthing better looking then rust.The shop told me to check and see if the secondaries were opening , so that why i asked, Thanks for the replys

 

That looks about average to me, considering it's a Mustang dyno.

 

why dont you flatten out your A/F? if anything that will help it.

 

I would start with new spark plugs, plug wires, dist. cap and rotor. Also check the fuel pressure at idel and while reving to see if it's within spec. Maybe also try the seafoam trick to clean things up a bit. You can get seafoam at NAPA. Do a good tune up. Then go back to the dyno and tune in the VFAC.


Modified by 577HondaPrelude at 2:38 PM 10/27/2004

 

Your valve seats could be shot or maybe your rings causing a loss in compression. But that is speculation. take it to a shop and get a leakdown test to make sure everything is in order. Have you sprayed that engine? Just wondering becasue of your username.

Pirate

 

ive changed , plugs, wires, car, rotor, and checked compression , everything checks out good. after taking off the vafc2 the car felt alot more powerfull (switching to hondata). I mainly think it was the untuned vafc and the god awful ebay header.Thanks for the input.