Dynos and MS3...

[AutoXRacer]

Hey guys,

What gives with all these dyno sheets and claims I see on the net...?
Stock dyno runs range from 231 to 250ish... Then you have guys with CAI, down-pipes, exhausts, etc putting down 250, 265, etc...

Are the dynos not being done on a specific gear? I thought to correctly do a dyno run you had to be on your closest 1:1 ratio gear...usually on a 5 speed thats 4 gear...

I just don't understand the inconsistent data (I know location, weather, altitude, etc have something to do with it)...

 

[SwampAss]

Different types of dynos, alt, inconsistencies in cars.

Comparing dyno sheets with other cars is pointless. Comparing your own dyno sheets before and after mods is what dynos are used for.

The actual numbers on your dyno read out are largely moot.

 

[ZooZoom]

very true about judging dyno sheets only on a same car (and same dyno) basis. I'm heading back to another dyno day next Saturday. It will be my third dyno run on the same one. New mod is a Cobb SF intake. Looking fwd to proving what gains it offers at near sea-level conditions.

 

[AutoXRacer]

But shouldn't a dyno be somewhat consistent to other dynos...?
A 100hp car should register the same on different dynos, +/- 5hp I would imagine...?

So what you are telling me is that comparing dyno runs from different dynos is pointless since they are inaccurate. They are only good for comparison on multiple runs... Get a baseline run, then get another run with changes to the vehicle and compare the difference in data...

So how do you measure the horsepower that your car is making?
If Mazda states that the MS3 has 263hp at the crank which would correlate to about 233 at the wheels; how can you prove that the car is making that stated horsepower if different dynos are going to give you a different result?

There has to be some kind of standard calibration in dynos... ???

 

[haze20]

That is true but you have to look at all the conditions. The temperture outside plays a large role. Also with the TMIC the placement of fans can be a factor.

 

[numbnuts22715]

But shouldn't a dyno be somewhat consistent to other dynos...?
A 100hp car should register the same on different dynos, +/- 5hp I would imagine...?

So what you are telling me is that comparing dyno runs from different dynos is pointless since they are inaccurate. They are only good for comparison on multiple runs... Get a baseline run, then get another run with changes to the vehicle and compare the difference in data...

So how do you measure the horsepower that your car is making?
If Mazda states that the MS3 has 263hp at the crank which would correlate to about 233 at the wheels; how can you prove that the car is making that stated horsepower if different dynos are going to give you a different result?

There has to be some kind of standard calibration in dynos... ???

There are a few different kinds of dynos... Dyno jets, mustang dynos, and some other dyno that reads even lower than a mustang dyno. These are the kinds I know of.
From what I've gathered talking to different tuners, is that Dynojets figure out horsepower, and then use all kinds of mathematical equations to find out the torque, and the AWD dyno I was at, the guy said it figures out the torque, and uses an equation to find out horsepower.
Simple answer to the question above about proving the hp.. you cant.
Different altitudes, temperatures, and the kind of dyno used can differentiate results big time.
To measure your horsepower, get on the dyno. It won't necessarily mean you have more or less power than somebody else that got their car dynoed based on their results.
There isn't one dyno that can be used universally because of differnet methods of calculatingthe power.

I know some of that was redundant, and I apologize for that. but I hoped it help you figure something out.

 

[AutoXRacer]

So basically, the only way to confirm Mazda's claim of the 263 hp output is to remove the engine and place it on an engine dyno with a controlled enviornment...?

OK, I guess I've give up on this...

That was an issue I had with dynoing my Miata... Over the course of three years I had to go to three different tuners due to one going out of business, the other raising his prices too high, and finally found a reasonable one.

Two of them used Dyno Jets and the other a Mustang Dyno... I got three different results... This was very frustrating!!!

I'm just planning to go to the dyno jet place and running a baseline (ignoring my results) and then going back once I install the MS CAI and taking the difference between both runs... I hate the thought of not having a consistent reading with regards to Mazda's HP claim...

Does anyone know the closest 1:1 ratio gear in the MS3?

 

[SwampAss]

4th

 

[Mocoso]

I "think" the torque/hp formula yer thinking of is the following:

HP = rpm x T(torque) / 5252(constant)

 

[palerider]

I know power would be different between dynos, but what about A/F? This should be rather constant, right?

And also.... why isnt there a place on this board where everybody with a Speed3 dyno, has posted. There is only that one thread for stock runs... searching dynos on here sucks.

 

[aaronc7]

I thought 5th was? from car and driver:

Gear: Ratio: Mph/1000 rpm Speed in gears
I 3.54 5.3 36 mph (6700 rpm)
II 2.24 8.4 56 mph (6700 rpm)
III 1.54 12.2 82 mph (6700 rpm)
IV 1.17 16.0 107 mph (6700 rpm)
V 1.09 20.4 136 mph (6700 rpm)
VI 0.85 25.9 155 mph (6000 rpm)

 

[BLACKMS3]

Not only do different dyno's put down different numbers, but the ambient temperature and relative humidity of the specific day you dyno is put into play as well...

There are a ton of factors....

I was dyno'ed in 4th as well and I thought it should have been 5th.. but it doesn't really matter as long as it's consistent with future runs..

I'm sure that attributed to my 267HP/279TQ dyno with only and intake and test pipe...

 

[meha11]

As stated above by everyone else there are tons of variables.
I’m confident that if i went back to the same shop that dynoed my car at 273.9 whp, i would now have more hp just because it’s now much cooler with little humidity providing much denser air to mix with the fuel. I actually thought about doing it just for s**** and giggles but talked myself out of it as I’m not as rich as I used to be.

 

[AutoXRacer]

I thought dynos corrected for altitude and weather conditions...?

 

[hellcat]

Wouldn't the fact that putting parts on without tuning for them to gain the full potential have something to do with lower than expected dyno numbers on a modded car?

 

[BLACKMS3]

False... when you buy aftermarket parts, they usually don't say xHP gain with (insert part) and a tune!

They say (this part) has shown a gain of xHP and that's what I expect. Install the part and that is the gain I should be expected to see......no additional effort on my part. And in the MS3's case a tune means an aftermarket Engine Management in the range of $600+....


As for dyno's, yes they do compensate for variables, but those variables are exclusively in their environment... although a series of the same dyno's... (ie same manufacturer) setup in the same way with the same software, hardware, etc, should read similarly, however that is rarely the case.

 

[CTGrey02]

Stock vs CAI. Both cars were done on a Dynojet, you can see from the sheet they were the same day, about an hour apart and similar temps. Both cars were run in the same gear, although it was a while back. Like previously stated, different dyno's give different readings as do various correction factors. Different gears didn't make as much of a difference as people would think either. We did that as well.

 

[bkw]

I dyno'd my car on two different dyno's, but both being dynojets. The first one was at ICS which I put down 266/306, and the second was the same one CTGrey02 went to in Bristol where I laid down a 269/302 pull.

I thought the first pull at ICS was an anomaly so just to be sure I got a second opinion and it came very close to the original pull.

Oh, and both times were done in 4th gear.

 

[AutoXRacer]

I dyno'd my car on two different dyno's, but both being dynojets. The first one was at ICS which I put down 266/306, and the second was the same one CTGrey02 went to in Bristol where I laid down a 269/302 pull.

I thought the first pull at ICS was an anomaly so just to be sure I got a second opinion and it came very close to the original pull.

Oh, and both times were done in 4th gear.

Is your car stock...? How could you be putting down crank stated HP?
You have to have some kind of drivetrain loss; at around 30 HP loss due to drivetrain...? I've seen as low as 231 HP...?

 

[Jays07MS3]

I dyno'd mine last month on a Dynojet and was disappointed with my results (225 HP/ 254 TQ). And thats with the CAI.

I'll probably be going back on 11/11 to do another pull but this time I'm going to bring some ice for the IC and see if that helps.