Loss of Power [Dyno inside]

[TYSHO]

Here are the mods: K&N, P&P'd Intake, BBB's, UDP's, LW Tensioner Pulleys, Fidanza, and High-Flow Catted Y

I'm running original AGSP32PP spark plugs and a fresh set of Motorcraft spark plug wires.

Found out my front crossover coupler has a small leak, but I don't think that's the cause of at least 15+WHP. All other vacumm lines are new.

Compression results were good, 219-235 for all cylinders.

Here's the dyno:




Any clue? I'll be installing my headers, catless y, and hopefully some stg 1 camshafts I bought, then going back to the dyno. But that won't be until maybe late December through January, and I'd like to pick up the power before that.

 

[Toolman]

Strange, you are leaving 20hp on the table. A/F looks good. Hard to tell what is up just from the dyno sheet. Any issues lately? Any driveability problems? That car should for sure be dyno'ing higher than a stock SHO.

 

[SASHO91]

The axles are new, no sticky brakes, and no codes....

we were trying to figure something it out last night...

 

[Ishodu]

Have you checked the throttle cable?

 

[shopartsnw]

Have you used this dyno before? I see it is a Dynojet, and if the loading factor / multiplier (or something like that) is wrong, it can overinflate or reduce your stated power.

 

[TYSHO]

Any issues lately? Any driveability problems?

The clutch is acting up and the clamp load on the disc changes from time to time, sometimes engaging rough than other times. I had to manually adjust the cable because before it wouldn't engage any gear. The clutch now has about 10k miles on it in the past 2 months. It also started slipping real bad after about 5 passes down the track, but fixed itself on the way home.

Aside that, I use to feel a kick of power come in around 2-3k rpms. And when it was bone stock besides the y-pipe, I couldn't hit over 130mph. After the extra mods, it would go over 130mph and it actually hit 144mph on the dyno.

Have you checked the throttle cable?

Sure did. I checked that when I was doing the compression test.

Have you used this dyno before? I see it is a Dynojet, and if the loading factor / multiplier (or something like that) is wrong, it can overinflate or reduce your stated power.

No, but my friend dyno'd the same day with his Mustang GT and put down 254whp & 290wtq with a tuner, offroad h-pipe, cai, plenum, and UDP's.

We also dyno'd right when we got there with hot motors, if that matters.

 

[RStalveyARFF]

it shows your secondaries opening up early. Also looks like the spark is a little erratic.

 

[TYSHO]

Also looks like the spark is a little erratic.

How do you determine that? Is it from all of the little waves in the chart? I use to have a problem with my coil pack, but I changed that out.

Can something be clogged up in the exhaust from an old converter falling apart, and causing this much of a loss? I ask because the car had a fairly new y-pipe on it when I bought it and maybe it was replaced because of that.

 

[TYSHO]

it shows your secondaries opening up early.

Now that I'm looking at the dyno in my hands, the dip you see came from the first run with the K&N filter. On the second run, I removed it and the dip went away, I also ran leaner and made less power and torque.

I'm going to go outside and see if my secondaries even open!

 

[RStalveyARFF]

they may be stuck open... you usually get that distinctive dip at 4k

 

[TYSHO]

Secondaries open and close correctly.

 

[AREA 91]

 

[1slickRED89]

I also ran leaner and made less power and torque.

how are you adjusting that? you should make 1-2% more torque at 12.5:1 than 13.5+:1. not to mention it is much safer to run at 12.5:1 or richer.

peak power is still at 6100 with a nice flat torque curve so I think your car is running OK, I think something other than the engine output is amiss. and if it drives OK, maybe the dyno was setup incorrectly.