Dynojet numbers on 80* day

[jordanvraptor]

Terminatrix had a date with a dyno this afternoon. Ok, granted an 80 degree day with not much of a cooldown isn't optimum conditions for getting numbers, but I wanted to see what she had in her under "real world" conditions that kinda simulate when she is running hard at the track.

1st run 442 RWHP 461 RWTQ
2nd run 430 RWHP 453 RWTQ

We then waited about 15 minutes till the third run.

3rd run 441 RWHP 464 RWTQ

A/F ratio was was around 13 till 4500 then it dived down to the 11's. Remember, this car has cats and they used a sniffer up the tailpipe.

All in all, I'm very happy with the results considering it was a hot day.

 

[ALA G8R]

Not bad, but you can do better. If you drop the low end A/F to 11.8 you will maximize your peak torque. Conversely, if you raise your high end A/F to 11.8 you will maximize your peak HP.

 

[jordanvraptor]

How many percentage points should I add in fuel in the 2-4K range?

 

[Chonger]

Originally posted by ALA G8R
Not bad, but you can do better. If you drop the low end A/F to 11.8 you will maximize your peak torque. Conversely, if you raise your high end A/F to 11.8 you will maximize your peak HP.

Exactly what he said. I would go 12:1 straight across if measured at the tailpipe and 11.5:1 straight across if measured in the 02 bung. You have about 15+ HP to safely gain up top because you went rich.

 

[Todd03Blown]

from 2500-4500 that A/F is way to high for my liking...from 2000-redline on my tune the A/F is between 11.4-11.8....others may feel comfortable with something around 13 but to me that is way to high.

 

[Sonic03inSC]

I hit the dyno yesterday with very similar results. It was 89* out and may A/F looks just like yours. Are you using a custom tune or the stock predator pulley tune?

 

[Swervedriver]

Originally posted by Todd03Blown
from 2500-4500 that A/F is way to high for my liking...from 2000-redline on my tune the A/F is between 11.4-11.8....others may feel comfortable with something around 13 but to me that is way to high.

Remember it has cats, and the sensor was sniffing at the tailpipe. I don't think 13:1 is too bad but I'd try to get it to 12.0

 

[Todd03Blown]

Originally posted by Swervedriver
Remember it has cats, and the sensor was sniffing at the tailpipe. I don't think 13:1 is too bad but I'd try to get it to 12.0

Very true....good point.

 

[jordanvraptor]

I am using the stock Predator tune but have maxed out the timing adjustment in both ranges 2-4K and 4-6K. I'm still only at 21-22 spark advance at WOT. I added 5% fuel in the 2-4K range to richen it up there a bit and I took out 5% in the 4-6K range since I was rich. I'll check for any pinging, but don't know when I'll dyno again. Is there any ratio of Predator % adjustment to A/F ratio?

Thanks for all the input.

 

[Swervedriver]

Originally posted by jordanvraptor
[snip] Is there any ratio of Predator % adjustment to A/F ratio?

Thanks for all the input.

5% should be about 1 full point.

 

[jordanvraptor]

5% = 1 point A/F... Hmmm, well I changed it to 3% leaned out on 4-6K range. That should do it to give me a little more insurance on the A/F ratio and probably won't affect the numbers that much. The truth will come out in the times at the track.:burnout:

 

[Swervedriver]

Originally posted by jordanvraptor
5% = 1 point A/F... Hmmm, well I changed it to 3% leaned out on 4-6K range. That should do it to give me a little more insurance on the A/F ratio and probably won't affect the numbers that much.

An in-car Wideband is a wonderful thing. No Probably about it.

Fact is your car is making a LOT of power for such a small engine. This is possible due to high cylinder pressure (forced induction) making an extreme combustion environment. Works great when everything is right, but if things go wrong in such an environment it usually melts or breaks parts...

Fact 2: Most people will say re-dyno after making any changes to tune or pulleys. If you plan on changing things around often an in-car Wideband will pay for itself in saved dyno money. But then the liability is in your hands (not like the majority off tuners will cover your engine if they Eff it up anyhow).

 

[jordanvraptor]

I've looked into a couple of widebands. For now, I have the baseline and am making only small changes for safety sake.