E-tec 130hp

[sho305]

Sounds like it is running good, you did see the thread about the 250 etec right..

[theoldwizard]

...
We've got the news here that the V4 130 etec can't meet the 3 star regs!...

That does not surprise me !

Awhile back I had some "inside" news about the 130. It was exactly the same as the 115, but used some "interesting" adjustable exhaust port technology that BRP borrowed from Rotax snowmobile engines. Such tuning would change emissions.

A 90 degree V4 is not an optimal design (of course neither is a 90 degree V6; a 60 degree V6 is much better ). I'm a bit surprised that there is no I4 E-tec, but my guess is that it is too difficult to tune the exhaust inside the leg.

I expect that BRP will eventually fill the hole between 90 and 150 hp. I wouldn't be surprised if they dropped the current 150 in favor of whatever new engine they develop..

[waynekerr135]

That does not surprise me !

Awhile back I had some "inside" news about the 130. It was exactly the same as the 115, but used some "interesting" adjustable exhaust port technology that BRP borrowed from Rotax snowmobile engines. Such tuning would change emissions.

Just what was it they borrowed?
Was it the RAVE valve system?
I need to make my 115 run faster, not too bothered about emmissions.

I'm a bit surprised that there is no I4 E-tec, but my guess is that it is too difficult to tune the exhaust inside the leg.

What do you mean "I4 E-tec" and why would it be difficult?

I expect that BRP will eventually fill the hole between 90 and 150 hp. I wouldn't be surprised if they dropped the current 150 in favor of whatever new engine they develop..

There is the 115, last in the line of 4 cylinder models & 1800cc
The 150 is 2600cc IIRC. (Sorry don't do cubic inches)

[sho305]

Nobody cares about making a lighter than V6 at or close to 150hp.

[theoldwizard]

Just what was it they borrowed? Was it the RAVE valve system?

Yep !

What do you mean "I4 E-tec" and why would it be difficult?

Okay, I'm no expert in exhaust tuning, but what I have read is that designing an exhaust system to do a good job of scavenging I3 (or V6) 2 strokes takes shorter overall "length" than on I4 2S. To fit inside a stock lower leg requires more loops and bends. More loops = more restrictions.

If you look at the HP/cc ratio of the 90, 115 and 200 they are 0.069, 0.066 and 0.077 respectively. You will note that the 115 is the lowest.

Also, if the 90 made the HP/cc as the 200 (and why wouldn't it; they are both second generation blocks/pistons/combustion chamber ?), then it would make about 99 HP !

[waynekerr135]

OK, I see that ,,,,, but how do the snowmobiles/jet bikes make a hole lot more power with less cc?

[sho305]

A pipe supercharges the exhaust, it pulls too much fresh mixture out of the cylinder...then at the last moment stuffs it back in before the piston goes up. What you mean with triples is exhaust scavenging. It works like a pipe but not really, its more like a 4 into 1 header on a car. As one exhaust pulse goes out into the collector it makes a small wave that helps suck the next one out in the pipe next to it in the collector...where all the pipes end into the bigger one. With 120 degrees offset in a triple this works well as the pulses are in more ideal timing....but you will never get the kind of power an expansion chamber (big pipe on sled, motorcross, etc) will. It just keeps the exhaust flowing out of the pipe more or less so the next pulse has it a little easier. In that case a giant triple would work best....but a big pipe works best on a single cylinder and up to three at once for reduced output like an outboard would need. Not sure about an I4 into one pipe, one would have to get the motor to work at low rpm with the pipe before they worry about using a pipe. However an exhaust valve could be used without an expansion chamber, then the porting could be more ideal for max high rpm output and the valve could keep the low rpm power from going away.

[waynekerr135]

Phew !!!!!! Or in English terms "Blimey"
I can see here, were talking high tech.
Anybody got any info of how to get 130+ from a 115?
My brain is close to critical overload, must rest it.

Keep it coming peeps.

[sho305]

Problem with the etec is you need to be able to adjust fuel curves....just like any efi. Traditional mods should work like porting, compression, more air in and out.

[theoldwizard]

Here's the patent !

[waynekerr135]

Well done Mr Wizard!
I've got the idea of how it works ,,,,, now all I have to do is put the theory into practice on a 115.

I "sometimes" wish I worked for BRP, or at least be a fly on the wall in the design office!

[waynekerr135]

Problem with the etec is you need to be able to adjust fuel curves....just like any efi. Traditional mods should work like porting, compression, more air in and out.

I note that there is a sensor on the airbox, if this measures the amount of air flowing and adjusts the fuel input, what happens if the holes in the airbox are enlarged?
More fuel, more power?

[waynekerr135]

Anybody ????

[Jorgeparagon]

No way ,more air without more gas=nothing ,probably you'll have problem with the idle ,the TPS is very sensitive and do not forget EPA ,it's the law at least in USA .And ,of couse will voyd your warranty.
Have a nice day

[theoldwizard]

I note that there is a sensor on the airbox, if this measures the amount of air flowing and adjusts the fuel input...

I'm not an Evinrude tech, so the following are educated guesses.

The sensor is probably Inlet Air Temperature.

I believe that E-tec is a "speed density" system (i.e. no mass air meter, no vane air meter). The amount of air entering the engine is calculated by the manifold pressure (i.e. vacuum) and the engine speed. So you are correct, more air will automatically get more fuel and make more power.