Unless dyno runs are done on the same day, with the same dyno, under the same conditions, the numbers mean nothing and you cannot compare one to another. I find it quite comical that people post dyno charts without having a before and after chart from the same day, same dyno and same conditions. I find it twice as comical when people do a baseline dyno run, make some mods, dyno it weeks later and then try to make comparisons between dyno runs.

 

That's not true. I recommend using the same dyno but it's not always possible to get a baseline dyno and post mod dyno on the same day. Mods can take days/weeks to install depending upon what's being done to your car. You can get a good idea of power gains even if you have to dyno on different days. It's not perfect but it's typically close enough.

 

you could have two of the same motors, but putting out two different power ratings, in saying that it doesn't have to be a drastic difference between the power it could be a few hp to 15hp.
Just because its the same car doesn't mean its going to be exactly identical because that's theoretically impossible and with supercar motors they are hand built as well.

If you are rich enough buy two c63 amg, same build date etc etc etc,
put both of them on the same dyno 3 runs each and I can promise you they will not put out the same power.

 

Agreed. Using the same dyno is a good idea but even the temperature and barometric pressure will typically change through out the same day. Then we can debate the effectiveness of the dyno weather stations. And I won't get started on the effects of heat soak on dyno numbers.

 

Okay, I'll concede the point G55K made about not always being able to dyno on the same day, and your point about atmospheric conditions changing within a day. However, using a different dyno (even if they are of the same model and brand) render results completely incomparable.

My whole view of dynos is that the absolute numbers the produce are irrelevant, but that the change in numbers for the same car on the same dyno are useful tools. My $0.02.

 

anyone keen on seeing my done exhaust set up ?

 

did it make any power or was it just for show like the air box?

 

it made close to 40whp, I posted a thread up of the set up check it out or heres the link.
https://mbworld.org/forums/w212-amg/...st-set-up.html

 

got my dyno results back and pick up my car tomorrow >