Dyno sheet and air fuel ratios ...

**Stav** · 21-09-2007, 12:01 PM

Guys these are the air fuel ratios my car had on the dyno day recently.This is the exact state of tune which my car ran a 14.527. It is worse than a stock rich tune. What do you think the potential gain is from a decent tune? I am thinking another 10 to 20 rwkws...
http://www.fordforums.com.au/attachm...chmentid=35296

ratter · 21-09-2007, 01:33 PM

You will gain a little power by leaning it out, but not as much as you list, timing is where you will get your power from

**Stav** · 21-09-2007, 06:09 PM

I think you are pretty right mate. I do remember seeing an e series car with similar af ratios.They adjusted it with an adjustable regulator and their power did go from 179 horsepower to 197 hp.I believe it was Rollin from memory.

sprjenkins · 21-09-2007, 06:41 PM

nice cold intake temp too colder than the external temp

Road Games · 21-09-2007, 07:16 PM

Quote:

Originally Posted by sprjenkins

nice cold intake temp too colder than the external temp

Thats how it SHOULD be ................

**Stav** · 22-09-2007, 12:40 AM

I am not sure whos dyno sheet this is but I have kept it because their story was interesting.If it is rollins and he wants me to remove it them let me know.This is the gain from regulator pressure change only .

daz_ · 22-09-2007, 10:08 AM

Holy crap please tell me the afr's aren't that bad standard!?!?

10.5 through the midrange? THIS MIGHT EXPLAIN SOMETHING?

xr8ute · 22-09-2007, 10:59 AM

Quote:

Originally Posted by ratter

You will gain a little power by leaning it out, but not as much as you list, timing is where you will get your power from

Agreed, I was going to make the same comment.

Stav, what was your fuel rail pressure when it was last tuned? That that is really the fuel rail pressure you should keep it at.

If you need to run a higher fuel rail pressure becuase your injectors are maxing out, then set the rail pressure (say 50-60psi w/vac disconnected), and take it back to your tuner so they can at least adjust the injector slopes to compensate.

It would be better just to fit bigger injectors though, and run them at the fuel pressure they are designed for.

As for how much more power it makes? Only time will tell, but I wouldn't be betting on 20rwkw.... ;)

**Stav** · 22-09-2007, 01:27 PM

Car was tuned at 45 psi and stayed 45 psi mate.The standard injectors were removed as they maxxed out.I ran out of fuel at 120kmph and 166rwks I am running bigger injectors.Everything is the same as tune day but the pump which failed has been replaced.

xr8ute · 22-09-2007, 01:34 PM

OK. So the tune hasn't been touched since the bigger injectors where added?

What part number injectors are you running?

Mr_4.0 · 22-09-2007, 04:50 PM

with a colder intake temp then ambient, the power result will be wrong anyway. thats a bad dyno operator that did that!

**Stav** · 22-09-2007, 06:01 PM

I dont know about the temp differences. Should the result been less? Not that the numbers mean much but the air fuel ratios will need fixing. I will get them fixed soon. The full potential of the car is what I am after.If the figures look good then thats a bonus.It may even be a dead map sensor.

xr8ute · 22-09-2007, 08:40 PM

Quote:

Originally Posted by Stav

It may even be a dead map sensor.

You've changed to bigger injectors, but haven't mentioned having it re-tuned for them?

I wouldn't be too worried about a 2 degree difference in the measured ambient and intake temps on your dyno sheet....lol.

EDIT: just saw your other thread where you mentioned you had another tune after the injectors where fitted.

At what fuel pressure are those injectors rated at 29lb/hr? What brand and part number are those injectors?