Had the ride dynoed at Speed Inc, for the MFBA dyno day. This is my first time ever dynoing it. So I dont have anythig to compare it to. The car ran strong, to and from the dyno. Weather wasnt too hot or anything.Somewhat cool. Was a little humid out, because it rained the night before. But it didnt seem that it effected the car at all, because car ran strong the way to the dyno.

Here is my graph . http://www.v8havoc.com/dynorun7-17.jpg

I have some questions.

1. Is it normal for it to be so jagged like that? Looks like it dips up and down to much. When I looked at LS1's sheets, they're didnt get no where near as jagged like that.

2. Air/Fuel seem about right for a untuned bolt on car right?

3. I was told if it was a bad opti, there would be a difference or spike in the A/F #'s. That true?

Well here are the mods.

97 Formy, A4. 80k on the clock. Jet-Hot LT's, 2 1/2" trueduals, Moroso CAI, 3.73's.

Here is a vid of the 2 runs. In the first one, if you listen you can hear like a miss or somthing. Could of been the camera, but I dunno. But I didnt notice it, while it was running. Sounds mean though lol. http://www.v8havoc.com/dyno.wmv

 

anyone?

 

If it was your opti, your dyno graph, not your A/F graph, would be extremely choppy (Think Seismograph during a 5.0). I honestly can't think of what could be the cause of your wavering power lines at this time in the morning though. My suggestion would be to start checking the basics.

 

Look's like you have a ignition issue.. If you notice it's at the same area in the graph for both run's. your A/F look's pretty flat as well. So i'd check your plug's, wires and what not.. other wise not really that bad...

 

Plugs and wires are in great shape. Ill go take a look at them tomorrow.

Thanks,
Mike

Also,
How much flywheel hp would that be for an auto?

 

So is there anything else I should look into?

And do you think a tune would clear this up?

 

264 RWHP with an A4 works out to ROUGHLY 312 FWHP.

My 96, with CAI, 160* thermostat, Magnaflow cat-back and 3.42 gears did 264 RWHP and 290 RWTQ with the stock manifolds, so I wonder if you've got something going on there that needs to be fixed. Not sure though. My car is also a Formula, had about 80k on the clock at the time and is also an A4.

Scan for knock retard during driving. See if you're getting some knock retard. 2 degrees of retard can cost you 10 ft-lbs of torque (which then affects horsepower). If the PCM pulled timing, then worked it back in, pulled again, and worked it back, like that it would cause the wavy graph you had.

 

would I need to get a scanmaster to do that? Because I dont own a laptop.

 

That, or find someone with a laptop that can scan it for you while you drive... The place where you dyno'd at might be able to do that too.

 

It might be that your wheels were slipping a little. Did you notice any wheel spin on the drum?

-Dave C. '97 Z28

 

nope no wheel spin. I've only heard of big powerfull cars doing that though.

 

I had the same thing and heard everything from a slipping trans to ignition ect. But likely thats not ur problem if it runs fine. Did they strap it down real loose or did they pull the suspension down some? On their computer there is a SAE trend smoother did they use it? I have seen graphs that look perfect (No spikes) but before they smoothed it it was worse than yours. Don't get paranoid if it feels ok than it probably is.

 

Get rid of the true duels and you will see a gain, they are over kill for your stock car.

 

I actually gained good topend from the true duals. I wont dump them.

Well thanks for the input. Could some of you guys post your bolt-on dyno run graphs? I would like to compare.

Mike

 

oh and the car was strapped down really well. You can see in the vid too.