First off, mods if wrong section I apologize, please move to proper spot. A cursory search did not reveal to me the correct place for this.

I needed a baseline before mods, and local club had a dyno day today. I had been to this dyno one other time and did 3 pulls on it, but on those 3 pulls and both pulls today, the dyno had problems picking up tach readings.

Several cars before mine today, several cars after mine, no issues on the other cars. I watched the guy hook up other cars, and watched him hook up mine. Seemed no different.

Additionally, I exported all of the files for the run, put them in excel, lined up the RPM points, then averaged the results to get a "smooth" graph.

Attachment is excel file with all data... I only massaged data for A/F on the second run, as it was throwing curve way off with an almost straight across reading of 18, so I figured A/F wasn't reading correctly for that run. All other data is untouched.

Here is what I came up with:

Peak HP: 247 @ 6200
Peak TQ: 218 @ 5100

Specs:
06 Track, Rev-up, V2 (replaced with newer motor due to oil consumption)
No mods, except Pop-Charger

Dyno: Dynojet (from what I read, not exactly conservative)
Correction Factor: between 1.21 and 1.24 (don't forget, we are at 5200 feet here)
4th gear pull.

So, my actual questions:

1) What could be causing my car to not give good tach readings? He tried both the #1 plug wire, and the #3 plug wire, with similar results.
2) Is my methodology sound for establishing a baseline?
3) 247 hp seems pretty good for a revup... is it? A non-revup pulled 232 on the same dyno about 30 mins before me.

 

WOW! You put a lot of effort into this.

SAE correction takes care of elevation and other factors. Makes dyno runs on the "same dyno" comparative.

Base line: Do 3 runs. Base line is the best of 3.

Common tuner trickery: 3 pre-mod runs. 3 post-mod runs. Compare the worst pre-mod run to the best post-mod run. Gives BIG numbers. Terribly misleading.

 

Yeah, I HAD to go thru this much effort just to get a usable baseline! of the five runs I did, each one had "holes" of missing info because of the tach pickup issues.

Anyone experienced this, or know of a solution? Or, show I just try a different dyno shop?

I don't think this guy is an idiot or anything, because as I said he dyno'd several cars both before and after me with no issues.

 

Moved...