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      04-09-2020, 04:50 PM   #1
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Re-dyno: Stock M2C - HUGE discrepancy

First dyno - 425 whp, car in dyno mode, notice the bad power curve with huge drop off after 5500rpm, fan was not on the first run

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Second dyno - different shop - 377whp, car NOT in dyno mode, notice the nice smooth power curve without drop off after 5500rpm

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I don't know which dyno result to trust now. 50whp difference between dyno runs is a lot but much healthier power curve at the second shop and on par with other dyno results i've seen in terms of curve..

Does it matter that for the second dyno the car was not in dyno mode?
Brian from Kies Motorsports was saying in one of his videos that if the car is not in dyno mode, it "may" limit power due to the car "freaking out" being on rollers with wheels spinning at different speeds. I also did get a bunch of errors during the run.
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      04-09-2020, 05:34 PM   #2
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This is why dyno's are only good for before and after tune analysis. Dyno to dyno is a crap shoot.
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      04-09-2020, 06:49 PM   #3
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Quote:
Originally Posted by infinitekidM2C View Post
This is why dyno's are only good for before and after tune analysis. Dyno to dyno is a crap shoot.
Agreed, only reason I got a second one is because the power curve on the first one looked really bad and wasn’t sure if the car has issues or it was the dyno.
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      04-09-2020, 08:38 PM   #4
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Quote:
Originally Posted by McLaren720s View Post
First dyno - 425 whp, car in dyno mode, notice the bad power curve with huge drop off after 5500rpm, fan was not on the first run

Attachment 2280280

Second dyno - different shop - 377whp, car NOT in dyno mode, notice the nice smooth power curve without drop off after 5500rpm

Attachment 2280285


I don't know which dyno result to trust now. 50whp difference between dyno runs is a lot but much healthier power curve at the second shop and on par with other dyno results i've seen in terms of curve..

Does it matter that for the second dyno the car was not in dyno mode?
Brian from Kies Motorsports was saying in one of his videos that if the car is not in dyno mode, it "may" limit power due to the car "freaking out" being on rollers with wheels spinning at different speeds. I also did get a bunch of errors during the run.
This is my dyno sheet

Mustang dyno
Car on dyno mode
Untuned
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      04-10-2020, 11:39 AM   #5
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Hasn't it been proven that the M2C has a flat line after 5500 just to make sure it doesn't break big brothers legs?

You tune and that flat line goes away..
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      04-10-2020, 11:58 AM   #6
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It's best to use the same dyno for delta comparisons. Also Dynojets "IMO" are the best as they can't be easily manipulated like a mustang. Dynocom read higher from most I've seen. Regardless it's just a tool.

See my dyno comparison before/after tune at the end of this vid:
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      04-10-2020, 12:36 PM   #7
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I can concur Dynocom's read very high. I won't waste my time on those anymore.

DynoJet is a good "standard" for comparison. Just make sure the numbers are displayed in SAE calculations. STD calculations tend to fluff numbers slightly due to the correction factor.
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      04-10-2020, 01:37 PM   #8
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Quote:
Originally Posted by infinitekidM2C View Post
This is why dyno's are only good for before and after tune analysis. Dyno to dyno is a crap shoot.
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      04-10-2020, 03:15 PM   #9
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But the point was, would the car not being in dyno mode lower the reading?
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      04-10-2020, 03:27 PM   #10
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Quote:
Originally Posted by McLaren720s View Post
But the point was, would the car not being in dyno mode lower the reading?
I don't know the answer definitively but I would assume it would make a difference given they went through the trouble to include that setting. Would love to know for sure.
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      04-10-2020, 03:35 PM   #11
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How does one set dyno more?
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      04-10-2020, 03:47 PM   #12
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Quote:
Originally Posted by robertm View Post
How does one set dyno more?
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      04-28-2020, 06:07 PM   #13
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Dynocom is junk and reads high

My car dynoed stock 377 whp on a mainline dyno same as almost everyone else using a mustang dyno
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      05-03-2020, 12:17 AM   #14
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Different dynos read vastly different.

There is absolutely no value to do any other dyno than dynojet if you don't do before and after.

Dynojet reads high albeit not the highest, but the point is it reads most consistent across different conditions, by far.

M2C puts down 370-380whp stock on dynojet (DCT on the higher end), which sounds correct.
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      05-06-2020, 12:47 PM   #15
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Any dyno that gives consistent results is useful in tuning an engine. You do a Before, make an adjustment, then do an After. Iterate until happy.

Everything else is just Bragging Rights.

OP, that first plot just looks like the ecu was backing things off as the temperatures rose. The blue and green traces look good.
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