hawkins6423

I've had the car for a few weeks now, and just installed the Eurocharged V5 tune today. Otherwise, its stock to my knowledge (I bought it slightly used).

I went to a Detroit "muscle car shop" today to see if they had a mandrel bender to do a cat delete, lo and behold there was a dyno - so I asked the guy if I could do a few runs.

I'm not sure if the whole procedure was done correctly. Here are some talking points:

• They had to remove the rear control arm covers to weave a link chain over the control arm in order to strap it down. The chain was then attached to a nylon tow strap.
• It took them a good hour to try to figure out the tach settings. They found out it was the red wire, but it was unstable past 4000rpm. The dyno screen would jump to like 11000rpm randomly.
• After another hour he said. Oh I forgot that we can clock your car via its speed because you have paddle shifts (Which I guess you cant do this with an automatic). So I hopped in the car and steadied at 2000rpm, he "calibrated" the dyno at that point. Did a pull or two, and I was hesistant that we were just using speed rather than tach so I wanted a recalibration. So we recalibrated at 3k rpm, same result.
• He used a Mustang Dyno. He said these typically read lower than other dynos because they take into account wind resistance and other factors.
• I just installed the V5 tune an hour before doing the dyno

Here are a few questions I have:
1) Are these numbers reliable?
2) Is it normal to have a 10 ft. lb. fluctuation between 3.7k -5.2k rpm in torque?
3) Is "dynoing" your car with the practice I described (not using a tach signal) known to degrade the quality of the test? Is is more inaccurate?

Here are two graphs of the same test. He ran out of ink while printing so its kind of hard to read. The first one is based off time, the second is based off RPM. Both copies refer to the same run. The first pull was some BS he was doing. The second pull was what I got fairly consistently. The following run was 445 hp, unfortunately I don't have the graph (when he gets more ink next week I will post it.)

In case it is hard to see, the best run was 451 rwhp/420 tq. This is a 2014 C63 with a V5 tune. Thoughts?





BASED OFF TIME





BASED OFF RPM

Here is a link to the video:

INS1GNIA

Dynos lie...this topic was discussed a bunch, just do a search. It could be a number of things, location, type of dyno, weather, what you had for breakfast....don't worry too much about it.