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Thread: E-tec fits on sst45 mid

  1. #21
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    Default ETEC on Stinger Tower

    Quote Originally Posted by Powerabout View Post
    yes but long exhaust is all about low end power, perhaps run a rotax pack as the sled guys have full access to programing an e-tec
    No, this is a pipe that is tuned to high power. For optimal power in a single pipe resonance (as this pipe is tuned for) you need a long pipe. If you look up the introduction of the 2 cylinder ETEC's in 2006 there is not only the curves I've shown below, but also how the geometry of the tower was modified for this later version.

    For midrange they inject water into the pipe to increase midrange power. The pipe when dry is tuned to provide a power increase in the 5000 to 5500 rpm range. You can see clearly what the power curve looks like dry, the engine comes "on the pipe" above 4500 when dry and that tuning is for max power. When they inject water it provides more power in the range of 3500 to 4500 rpm.

    Here is the power curve for the 60 ETEC as published by Evinrude. As you can see the pipe when water isn't being injected is tuned to give max power at high rpm, it isn't tuned for midrange. If you take the pipe off you're going to take a beating at high power. Tuned pipes work over a range of power. The pipe with water injected is still helping at high power, but its gain is rolling off over 5000 rpm. If you took the pipe totally away you'd get hurt pretty badly at high speed.Name:  Slide1.jpg
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  2. #22
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    sure injection cools and slows the exhaust for mid range
    common on modified jet skis

    the 45 is a 45ci engine that makes 70hp at 7000 but based on 50hp at the crank before higher comp and modded exhaust.
    the etec 60 with 52ci and has vastly more airflow capability wont be far behind and with a rev limit removed and modded exhaust even closer

    but your saying without its long pipe it will make less max hp than in factory form?

  3. #23
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    Quote Originally Posted by Powerabout View Post
    but your saying without its long pipe it will make less max hp than in factory form?
    Yes, exactly.

    You could shorten the pipe and get it to work at higher rpm, but if you took it off the existing tower and ran it without a pipe it would not make the 60 hp it does now at 5500 rpm. Look at the power curve. The pipe it has now is tuned for max power at about 5500 rpm. If you take that pipe off you sure a heck aren't going to make 60 hp anymore.

    If you want it to run to 7000 rpm then of course with a bit shorter pipe than it has now you could likely make more than 60 hp, because you're turning it more than 25% faster so if you tuned it and it didn't blow all to hell, you could probably make 75 hp, but what I'm saying is that if you put it on the stinger tower it isn't going to be tuned properly and at 5500 rpm you won't make 60 hp.

    I have a ETEC two cylinder that we're doing a different lower unit for the military and while it's a good workhorse engine, it's not a thoroughbred. It vibrates a lot and to tune it you're going to have to get in and redo all the maps. I don't know anyone who's doing that right now, but here could be someone who has access to the tools to tune it. Maybe there is someone out there, but I'm not aware of it.

    If you bolt it onto the Stinger tower it won't be tuned properly. Just because it can bolt on doesn't mean it will work on that tower.

  4. #24
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    Quote Originally Posted by Yellowjacket View Post
    Yes, exactly.

    You could shorten the pipe and get it to work at higher rpm, but if you took it off the existing tower and ran it without a pipe it would not make the 60 hp it does now at 5500 rpm. Look at the power curve. The pipe it has now is tuned for max power at about 5500 rpm. If you take that pipe off you sure a heck aren't going to make 60 hp anymore.

    If you want it to run to 7000 rpm then of course with a bit shorter pipe than it has now you could likely make more than 60 hp, because you're turning it more than 25% faster so if you tuned it and it didn't blow all to hell, you could probably make 75 hp, but what I'm saying is that if you put it on the stinger tower it isn't going to be tuned properly and at 5500 rpm you won't make 60 hp.

    I have a ETEC two cylinder that we're doing a different lower unit for the military and while it's a good workhorse engine, it's not a thoroughbred. It vibrates a lot and to tune it you're going to have to get in and redo all the maps. I don't know anyone who's doing that right now, but here could be someone who has access to the tools to tune it. Maybe there is someone out there, but I'm not aware of it.

    If you bolt it onto the Stinger tower it won't be tuned properly. Just because it can bolt on doesn't mean it will work on that tower.
    interesting project you have there, what the story with the vibration?

    PS its going on a sst45 mid not a stinger as the etec has the 2 cyl bolt pattern which is completely different than the 3cyl

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