Hey, I appreciate you taking the time to post and sharing your info (although threatening to delete the thread makes me want to say just do it and be done with it). If you've tuned and worked on a lot of cars and dynos I'm sure you already know that you can't always compare one dyno to another, and Mustang dynos generally read differently than the more common Dynojet (usually more conservative numbers which is why the "dyno queen" crowd prefers the inertia-style Dynojet vice a more accurate for tuning, loading Mustang-type dyno). I have no doubt your dyno that you used came out with those numbers but I think they're probably a little on the high side compared to what most other chassis dynos will show.

I'm not sure if you're actually operating and calibrating the dyno yourself or going to a shop as a customer, but I've seen more than a few dyno owners think their equipment is dead-on accurate when something they miss is slightly off and affects calculated power. Maybe that was the case here or maybe this particular car has something off and was putting down more power. When more cars start dynoing we'll have a better idea of the ranges they put down. What I'm more interested to see on the car you dyno'd is the percentage change from your original numbers when he starts modifying the car. As long as the dyno is consistent I could care less if it reads high or low compared to other dynos but some people won't see it that way.

And that's the only point I'm trying to make. We already have a lot of people that don't understand there are differences in dynos and some who don't understand the difference in how the factory rates power at the engine's crankshaft in a controlled test cell vice individual owners strapping a car to a chassis dyno. I can already imagine there are some people taking your one set of numbers and trying to brag about the SS Turbo and make us as a community look like we don't know what we're talking about if it turns out that most of the other '09 and '08 cars produce lower numbers in line with what other dynos so far have shown.


I personally doubt there will be differences but if there are I'd imagine them being emission or drivability related (I've noted my car surges a little when cold with the A/C on and also has an abrupt throttle tip-in at time), but you're right. The computer part number itself is the same but we can't say for certain yet that the calibration used on that computer is the same for '09. So while I'm highly skeptical there's "extra power" hiding on the '09 cars I won't completely rule it out. A closed mind is one that never learns. But it is highly unlikely.

 

I don't operate the dyno myself it's a shop upstate's I use. I've used it quite a few times and everytime the numbers I've pulled on there have matched up when I've gone to other shops. So I do believe them to be correct. And yes I do agree with you that most members on here have no clue about the different dynos (as I've seen in this and my thread already) But I've setup dyno's before and I went over the calibrations with the owner and everything was pretty much spot on from what I could see. As I stated there is a chance it was off, but the car we did right after made the power it was supposed to make, if anything it was off by 3-4whp or so.
But also look at this side. Stock sc'd dyno's If seen online, or witnessed personally:
04 redline 190-195whp
05 cobalt 198-215 whp
06 cobalt 221-236 whp
I mean look at the increase there from just different OS calibrations, they all used the same ECM. My car put down stock 227whp and 231whp on 2 different dyno's so that would put it at @250 crank hp or so when only rated for 205.
All I really care is that's our baseline and I'll be using the same dyno to tune and do the big turbo tuning with so at least I'll have consistant numbers.

 

Actually the calibration versions each have their own part number independant of the ECM version.

In the service parts application for 09 Cobalt LNF for the ECM module there are 2 entries for the ECM, but they are the same part number (one I listed above). The reason their are two entries is one is for the coupe and one is for the sedan. That part number is the exact same number as the one on the 08 Cobalt LNF, the HHR LNF, and Sky/Solstice LNF. If you buy one what you will get is an ECM that will work with all the above, you just have to put in the right calibration (it comes unprogrammed).

Trusting dynos is very hard and I don't think any shop has the capability to compare to accurate lab dynos that can control the chamber the test is occuring. (Temp, pressure, humidity, etc) What they can be used for is tuning because you can see if you are gaining/losing/maintaining power output which most people agree is their real use.