Guys bottom line is we can sit here and debate as to what dyno and drivetrain loss is accurate until we are blue in the face.
We have a Mustang AWD 500SE with a fully enclosed and dedicated test cell.
Porsche Motorsport North America is directly across the street from our facility (no more than 20 yards away). We have engines built by PMNA for our race cars and have literally taken them off there dyno(each engine is dyno tuned and tested prior to being delivered to a customer) installed in one of the Cup cars be it in stock trim or World Challenge trim and the numbers are considerably different.
The variables and the drivetrain loss are all relative to the car you are testing at that time.
There are several other variables to consider when dyno testing a car, you want repeatabilty and the enviorment needs to be consistently controlled for correct and true results.
Each car is different regardless of what anyone is going to tell you.
As advice to any consumer I would tell you to look for the "improvement" in performance and not just the final number HP. Regardless if you by GMG products or anyone else's.
It doesnt matter what the car makes in the end.
As a company we have always been very conservative on the numbers we claim to make and our Mustand Dyno is also very conservative as to the numbers it puts down.
In the end the only way to really get an accurate "real" hp number on any engine is to have it dyno'd on a true engine dyno that has been certified.
It would be great to line up all the tuners who ever they maybe.
1 engine dyno and dyno everyone in the same enviorment using the same equipment to see what the "real" power gains are
but that will never happen.
For your viewing pleasure here is a picture of our dyno test cell:
Our dyno is available for rent for "consumers" and "tuners" in the so cal area.
We currently work with several of the OE car makers that have headquarters in the area as well.
The topic of what the "true" numbers are will be debated for decades to come.
To make a statement that one dyno is better than another because its sanctioned by a racing organization is not fair either.. Just because they are sanctioned or that they are the official dyno means nothing.. We are also involved in professional racing and we all know the "deals" that are made when it comes to be the "official this or that". Its all a matter of business in the end.
Maha and Superflow are one of the OE suppliers of dynomometers to major european
car manufacturers does this make them better than any other ? Not really its just that those suppliers of equipment offer that manufacture certain features and costs that work best for them.
Why did we go with a Mustang Dyno? GIAC is a development partner to GMG and they have used the Mustang Dyno for years, in order to maintain reliability and consistency when developing products it was our decision to have the same equipment. In the end it made sense to go that route.
Why did we go through to the extent and cost $$$ of having a true "test cell" the answer is simple. We wanted to maintian the most consistent enviorment for the best repeatability throughout the development process.
Dont get me wrong "Every Tuner" and "Every Company" is entitled to there way of coming up with HP numbers. Most are reputable, stand behind what they claim and offer a reliable product that improves performance overall.