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      03-04-2013, 07:41 PM   #34
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Drives: McLaren 650S Spider / 991 GT3
Join Date: Jan 2013
Location: Marietta, GA

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Originally Posted by Boss330 View Post
What's the reason behind not dynoing the M5 with the hood open (cooling/heat soak?)

Here are Hartge's info on their M5:

Order form:

Their M5 demo car for sale (with 10000km on it):

Obviously I have no idea if the Hartge car is reliable or if it can go 3000miles without problems, but it seems strange that Hartge is advertising their own M5 with 6200miles on it if it isn't reliable...
Agreed. That would be very odd. This is interesting for sure. I had "HEARD" (disclaimer here: I do not know this as FACT and you should do your own investigating and form your own opinion on anything I write and not ever take my word for anything :-) that Hartge used a piggyback and it did have this increase in power and that one subsequent runs it lost power and gradually shut the car down after 10 hours. The DME shut it down. Now agian, this is what I HEARD and I have no idea if it has any truth behind it. I wold be very interested to see a Hartge piggyback on a car over her ein the US and have feedback form the owner.

As far as the Dyno on the F10. The freaking manual is literally 26 pages. :-) I am no engineer so I cannot speak to why you have to do things like have the hood closed but I know the car has very specific parameters that must be followed and precise logging that needs to be done and compared to certain tables. For one thing if the wheels are moving fast enough to represent 150 mph then the wind has to be detected as flowing at 150 mph into the intakes (true 1:1) or the DME plays tricks. Also the gear must be true 1:1 (which means 5th gear and the US cars cannot actually do that due to the limiter.) Again, I am no expert. I don't know how the car works beyond a lot of discussions with people who do know when I was doing the research for my own knowledge after seeing my DME doing strange things during some actual logging. It all seemed to line right up with what I was hearing.
Would be very cool to get some real world feedback on the Hartge from an end user. btw..I think they were reporting 4.2 second 0-62. Not entirely faster than stock no? I thought that was weird.

Last edited by ColdList; 03-05-2013 at 03:12 PM.