Gruppe-S

iTrader: (206)

Hey guys,

Just wanted to let eveyrone know despite popular belief, not all Mustangdyne dyno's are created equal!!

Case in point I took my WRX, which @ 1.5 bar of boost makes 310whp on our dyno. I put down 354 on the other mustang dyno, no changes in modifications (A full stand alone computer so no parameters changed). Here's the dyno graph below. The first pull was at 1.3 bar, second @ 1.5 bar. It's a WRX stock motor GT30R turbo. For comparison an HKS 3037 EVO on this dyno made 358whp. Cheers!

Gary
Gruppe-S

gsujeff55

iTrader: (4)

that on pump gas?

David Buschur

iTrader: (53)

I agree not all Mustand Dyno's are equal, they were created equal until the owners messed with the settings. I notice yours are wrong at your shop actually.

HP@50 on the dyno sheet from your own shop says "1", that isn't even close to right and will not load the car properly on the dyno. I believe off the top of my head it is either 14 or 15. Check it out.

What model dyno do you have and what model was the other shops? What roll weight do you use for an input in AWD mode on your dyno?

David Buschur
www.buschurracing.com

jkim2001

iTrader: (8)

Dave,

What are the implications of a 1 setting? Higher or lower numbers?

2hot2handle

i am curious as well........

blueo4

iTrader: (11)

its about time someone shiked the false dyno.

jkim2001

iTrader: (8)

Are you talking about Gruppe S dyno? Care to explain?

scherejs

iTrader: (12)

15.1 at 50mph is what my dyno sheet says.

tke_413

iTrader: (27)

I still don't understand this "HP at 50" thing. Mine (on a mustang dyno) was at 11.5 at 50.

Ted B

iTrader: (6)

Apparently that setting is a user specified value that affects the applied loading. Unless that setting is the same between two different Mustang dynos, you're not comparing apples to apples.

And where loading is concerned, when properly set, a Mustang dyno (and Dyno Dynamics as well) will give very realistic loading. In other words, when you tune your car on the dyno, that tune will apply to the street with no changes. The same cannot be said for inertia dynos (Dynojet).

dsm95hybrid

iTrader: (14)

I believe it represent the aerodynamic characteristics of wind resistance which is power needed to maintain 50mph. This will differ from car to car.

Gruppe-S

iTrader: (206)

Hmmm I just noticed that too.

The HP @ 50mph represents a combination of the drag co-efficent as well as the estimated drivetrain loss at 50mph. Essentially how many HP is required to keep the car going at 50mph. Mind you this is a very crude estimate, as a front or rear spoiler would alter this value. Keep in mind also that the numbers between 1 and 15 represents only a slight difference (less than 1%) in the actual dyno numbers provided the loading weight is set correctly.

I also agree with the statement that unfortunately these days it seems many dyno owners are modifying their settings. We for one have never made any changes to our dyno settings since day one. In fact when our Mustangdyne arrived, we were never even given the nice PDF sheet with the HP @ 50 for various vehicles (as apparently it did not exist at the time). When we asked Mustangdyne about this their response was "uh try 10", which we were using for quite sometime.

I decided to post this dyno comparison because I was told by the owner of the particular dyno in question that they were having their Subaru and EVO customers complain of excessively low numbers compared to the dynojets in the area (no surprise there), and needless to say I was quite surprised to see such a large difference between the two Mustang dynos!

Cheers,

Gary
Gruppe-S

David Buschur

iTrader: (53)

I don't believe the difference in setting the number @50 mph differently is as meaningless as it has been explained. That number is important because while at 50 mph there is only a 15 hp drag at 100 it is much more and the dyno applies more load as the speed increase. So the multiple of the number inputed would make a huge difference. For example, if you input 1 hp @ 50 mph and at 100 mph the dyno is applying 4 times that load you would only have a 4 hp load, if you input 15.1 like it is suppose to be at 100 mph if it applied 4 times that you would have a 60.4 hp load. This would simulate the load better and make the tune the customer received better.

When did you guys get your MD? (Gruppe-S) Also what is the roll weight in AWD mode on your dyno and what model?

David Buschur
www.buschurracing.com

Drews_WRX

round 2.....fight........










bump for more discussion on the topic, as Gruppe-S is probably ProTuning my WRX when I get the funds....

Gruppe-S

iTrader: (206)

Hi Dave,

I 100% agree, the HP @ 50 is definitely not a meaningless number. Having spoken with Mike today (our tuner) the large variation of this number does effect how rapidly load is applied to the vehicle (such as from 1 to 15), and often if this number is changed drastically it will shift the peak torque and power about 250rpm. The difference in peak HP output is usually less than 2whp where the differences in peak torque is a bit more at 5. So in terms of pure numbers, the HP@50 does not cause a huge variation (like 20whp or what not). But it is essentiall for proper tuning as it does effect the graph. I guess that's why I'm not allowed to operate the dyno and tune customer vehicles.

In answer to your question we have a a MD 500 SE (which we have had for I believe 18 months now), and we've been setting the EVO's at 12.0 loading weight. I know MD's pdf says 15.1, but for tuning we vary the loading weight in order to simulate a broader range of loading parameters for a more expansive tune, generally from 3400-3800 on the EVO.

On another note for those that participated in our EVO dyno day a month ago, you'll note that HP@50 is 12.0, which is our standard settings.

Cheers,

Gary
Gruppe-S

BTW, if we could just change the load parameters and yield higher HP numbers without affecting the quality of our tuning and/or the accuracy of our dynos we would have - it isn't that beneficial to have one of the lowest reading dynos in the bay area.