Early dyno reports. Sidewinder and T-Cat

[ttpowersports]

Yes very respectable hp stock and budget friendly gains on a still very
mildly altered engine , it's definitely getting harder for the two stroke
engines to attain anything close to this and still have reliability of a stock
engine that this fourstroke triple will provide , i for one can't wait !!

 

[ttpowersports]

Yes very respectable hp stock and budget friendly gains on a still very
mildly altered engine , it's definitely getting harder for the two stroke
engines to attain anything close to this and still have reliability of a stock
engine that this fourstroke triple will provide , i for one can't wait !!

 

[climbmax]

its getting real.....
MCXpress Yamaha Sidewinder / AC ZR 9000 upgrade kits

Sidewinder stock power
The new turbocharged snowmobile Yamaha Sidewinder / Artic Cat ZX 9000 is the most powerful serial produced snowmobile ever build.
And it has great potential to be even stronger.
Yamaha claim the stock power to be about 180 hp.
The truth is even better.
When we test in our ASB calibrated and certfied Superflow dyno, we measure 192 to 194 every run.
The stock turbo pressure at sea level is 65 kPa. (=This is 9,4 PSI).
Very impressive for a stock snowmobile.
Boost compensation for altitude
One of the benefits with turbo is that it’s in these days possible to maintain the power at any altitude.
The ECU gets informed about the barometric pressure and controls a valve (=Turbo Control Valve) so the same total pressure enters the engine.
The baro pressure is about 100 kPa at sea level, and the turbo pressure 65. The total pressure will then be 165 kPa.
At 1000 meter elevation, the baro pressure is 90 kPa. The turbo pressure will then be 75 kPa, so the total pressure will still be 165 kPa.
At 2000 meter, the baro pressure is 80 kPa, and the turbo pressure 85 kPa ,total pressure 165.
Is it actually more relevant to talk about total pressure than turbo pressure, so we will do that in the rest of the text below.
To compare, a natural aspirated engine with 193 hp at sea level, has in best case 0,8 times the power at 2000 meter elevation (=154 hp).
MCX Stage 1 upgrade kit
The back pressure of the stock muffler is O.K, and still, the power increase by installing a less restrictive muffler is rather much.
Just by a switch to a racing muffler, the power at sea level goes up to 206-208 hp. The total pressure increase up to about 170 kPa due to that the wastegate hole in the turbine housing is a little to small for this setup.
At altitude, the total pressure will drop down to 165 kPa again, and the power will be just over 200 hp.
One problem with just installing a low restrictive racing muffler is that the air/fuel will be leaner.
The MCX Gen 5 EFI-box is specially developed for controlling the total pressure and the opening time of the injector.
The best lambda value on a turbo gasoline engine is between 0,80 to 0,85 at full throttle. We prefer to run rather rich to get as much safety limit as possible against detonation, so we aim for lambda 0,80.
If we run richer than 0,80 the power drops rather rapidly, and if we run as rich as 0,73, the engine starts to misfire.
(A natural aspirated engine is normally performing best at lambda 0,90)
The MCX stage one kit will include our EFI-box that controls the fuel and the boost, and a racing muffler that is less restrictive.
We have tested some different mufflers. All with low back pressure, but with different noise levels.
In many areas in the world, like in Scandinavia, Finland, Russia and the east of Canada and USA,

We have set the total pressure to just over 180 kPa. The engine delivers 225 hp at this point.
The stock ECU has a boost safety system that cut off the engine if the total pressure rise higher than about 185 kPa.
With our stage one kit, this safety system is still active. This makes it very safe.
https://www.youtube.com/watch?v=LpRRbHwd2rY
Stage 2 upgrade kit
The turbo, fuel pump and injectors can handle more power.
And the engine show no sign of detonation with higer boost when using pump gas 98 octane RON.
So with just some more electronics to avoid the boost safety system, we can rise the pressure more.
At just over 200 kPa total pressure, (=15 PSI turbo pressure at sea level) the injectors are fully open at lambda 0,80.
The engine delivers 250 hp at this point
https://www.youtube.com/watch?v=RZ9t1xKkCLo
Stage 3 upgrade kit
At higher altitude, the turbo will have to work harder.
The compressor of the turbo will have to pump more the higher up you go if the power shall be the same.
So if you want more power than 250 hp at sea level, or if you want to keep 250 hp or more at high altitude, the stock turbo on the Sidewinder becomes to small.
We are now testing bigger turbos and a bigger intercooler for more power. And the fuel system also need an update to reach more power.
More information will follow soon…..

 

[174mcx]

Boost compensation for altitude
One of the benefits with turbo is that it’s in these days possible to maintain the power at any altitude.
The ECU gets informed about the barometric pressure and controls a valve (=Turbo Control Valve) so the same total pressure enters the engine.
The baro pressure is about 100 kPa at sea level, and the turbo pressure 65. The total pressure will then be 165 kPa.
At 1000 meter elevation, the baro pressure is 90 kPa. The turbo pressure will then be 75 kPa, so the total pressure will still be 165 kPa.
At 2000 meter, the baro pressure is 80 kPa, and the turbo pressure 85 kPa ,total pressure 165.
Is it actually more relevant to talk about total pressure than turbo pressure, so we will do that in the rest of the text below.
To compare, a natural aspirated engine with 193 hp at sea level, has in best case 0,8 times the power at 2000 meter elevation (=154 hp).

I've had so many arguments over this over the years, its nice to hear it some where else... Everyone says boost is boost, run 12psi at sea level or 10 000' doesnt matter....

Looks like theres potential there! When do I get to test ride!?