I guess this is the part I can't get my head wrapped around/ can't accept. Does your dyno result have to be a WOT measurement? Or can you gradually add throttle across... 5 or 10 seconds to get your peak results? Honest question.
And maybe i'm wildly off base with this, but simply putting a Two stroke on a dyno would yeild some sort of data would it not? And if you changed something... porting, pipe, timing curve, and stuck it back on the exact same dyno, you would see an improvement or the opposite correct? I mean the percentage of gain may not be accurate on the water, but still you would have an idea that you're headed the right direction.
I guess it gives a base line.
TNT, I feel like you're over here arguing about 10th's of a degree in EGT's and IMO, the "dumb" public just wants some relative idea of:
A. How their engine performs, and
B. How product ____ improves that performance.
I just can't believe that you can't quantify that information on a dyno somehow. Even if its not real world/ in the water etc.
Picture this. Add water injection multi port to a dry pipe on the dyno. Gain 23hp over your standard dry pipe average power curve, be super stocked thinking you have hit the mother load.
Then take it to the water to find out it's a total pile of crap.
Search for months kill 5-6 sets of Pistons in simple wear trying to make this magic dyno number even remotely show it's face.
Only to remove the water and go faster and hit harder. ???
All because you can't sustain enough load in the water to build the heat inside the pipe to match the load heat the dyno allows the motor to develop.
Keep in mind your talking hundreds of BtU's different in heat generation do to load difference.
You are instantly into over rev on Jetski and you just need enough fuel to make the low torque respond and then your done making power and into over rev.
Bike, car, prop driven boat, plane, sled. All have a veritable engine load. Meaning pitch or gears so the dyno load is very similar to what you run in those vehicles.
Dyno is very useful tuning tool.
Picture this.
Can you take two steps on a 110 deg day on the black top without burning your feet?? Most likely you just say hot hot quickly jump off the hot surface.
Well now stand in one spot 10 seconds tell me if your feet burn!!
BTW, what do race boat guys do? Because those are 4 strokes does it make it a complete apples and oranges comparison? Don't those guys have the same struggles working on the water? Or do they go though 15 props and 4 exit nozzles and test by timing their runs to find the sweet spot?
It's not a tenth of a degree it's hundred of degrees in internal pipe temp.
Picture this. Add water injection multi port to a dry pipe on the dyno. Gain 23hp over your standard dry pipe average power curve, be super stocked thinking you have hit the mother load.
Then take it to the water to find out it's a total pile of crap.
Search for months kill 5-6 sets of Pistons in simple wear trying to make this magic dyno number even remotely show it's face.
Only to remove the water and go faster and hit harder. ???
All because you can't sustain enough load in the water to build the heat inside the pipe to match the load heat the dyno allows the motor to develop.
Keep in mind your talking hundreds of BtU's different in heat generation do to load difference.
You are instantly into over rev on Jetski and you just need enough fuel to make the low torque respond and then your done making power and into over rev.
Bike, car, prop driven boat, plane, sled. All have a veritable engine load. Meaning pitch or gears so the dyno load is very similar to what you run in those vehicles.
Dyno is very useful tuning tool.
Picture this.
Can you take two steps on a 110 deg day on the black top without burning your feet?? Most likely you just say hot hot quickly jump off the hot surface.
Well now stand in one spot 10 seconds tell me if your feet burn!!
![4155603[1].jpg](https://www.x-h2o.com/data/attachments/203/203194-8f2fb2a1ee6d543f136706e0f3f6b477.jpg "4155603[1].jpg")
