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? MTNTK Turbo ?

T
Jan 4, 2011
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Polaris engine is not DI.... Rotax Etec is. Running 4 injectors you have to run a piggy back, then you are getting away from the simplicity and control of the reflash. Early turbo 2 strokes were all the the secondary injector system. Some still use that system. I currently own a Boost-it Pro running basically the same system your referring to. Have you owned both systems?

No, I haven't. I ordered a MTNTK kit but haven't received it yet. That's true on the Polaris motor not being DI only port injected (SDI). Definitely not as fuel efficient or as precise control of fuel delivery as DI setup. SDI is still better for fuel economy, and I suspect throttle response vs throttle body fuel injector location.

How do you think moving the injectors back to the throttle body location effects throttle response?

How do you like the Boost-it turbo setup?
 

tdbaugha

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Nice logical justification of an out dated injection method... Anyway, I don't care about emissions so much as maximizing my time on the mountain without having to drive back to the trailer to refuel.

Why would the Corvettes, Porsche, Audis, Mercedes, etc. be making more power out of the same displacement motors and induction methods if direct injection did not allow for more power in addition to more fuel efficiency?

I agree that the cooling and lubrication on the rod bearings is a good thing. Are you saying this could not be accomplished using the throttle body injectors as secondary injectors?

Yeah I understand it's not ideal. But we're talking about alpha -n controlled, stupid simple, really dirty 2 strokes. Not exceptionally complex, closed loop 4 strokes.

You will not notice fuel economy or throttle response difference between the transfer port injection vs TB injection mountain riding with a turbo charged 2 stroke. If you're gonna go burn 200-300 mile trail days out east where you're partial throttle most of the time then yeah you may see a difference in fuel economy.

All I'm saying is I think the pros far out weigh the cons to TB injection vs transfer port injection.
 
T
Jan 4, 2011
58
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Why???

I bet dollars to donuts a NEW Silber kit walks on MTNTK...

I do like that their intercooler has a closed loop cooling system separate from the engine cooler and that it's placed in the bulkhead. I also like their carbon fiber intake tubing.

The problems I see with the Silber kit are: the turbo they use is inferior to the MTNTK EFR, you have to send in your ECU for reflash and if you want to up the boost you need new injectors with the Silber.

It is a very nice kit this year and I'd love to try one.
 
S
Nov 7, 2015
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Rigby, Idaho
Why???

I bet dollars to donuts a NEW Silber kit walks on MTNTK...



I haven't seen any kit walk on a MTNTK kit. You cant make a kpa run as hard as the EFR turbo will, just take a look at the maps... and before you start talking tuning realize that there are a lot of silber guys running Shawns tuning on their silber kits to fix the mid range bog.
 

AKFULLTHROTTLE

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I haven't seen any kit walk on a MTNTK kit. You cant make a kpa run as hard as the EFR turbo will, just take a look at the maps... and before you start talking tuning realize that there are a lot of silber guys running Shawns tuning on their silber kits to fix the mid range bog.

Mid range bog?? Are you talking about a Pro? I have never has a bog EVER on my Axys.. And my Pro bog was very rare.

Elevation may take part in this.
 

AKFULLTHROTTLE

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I do like that their intercooler has a closed loop cooling system separate from the engine cooler and that it's placed in the bulkhead. I also like their carbon fiber intake tubing.

The problems I see with the Silber kit are: the turbo they use is inferior to the MTNTK EFR, you have to send in your ECU for reflash and if you want to up the boost you need new injectors with the Silber.

It is a very nice kit this year and I'd love to try one.

Stock injectors are handling 10-12 psi.
 

sledhead9825

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I do like that their intercooler has a closed loop cooling system separate from the engine cooler and that it's placed in the bulkhead. I also like their carbon fiber intake tubing.

The problems I see with the Silber kit are: the turbo they use is inferior to the MTNTK EFR, you have to send in your ECU for reflash and if you want to up the boost you need new injectors with the Silber.

It is a very nice kit this year and I'd love to try one.

The intercooler in the bulkhead is a nice idea but the wrong location. You need it covered in snow when you are under boost. How well do your heat exchangers work with no snow on them?

I agree the carbon fibre intake is nice.
 
T
Jan 4, 2011
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The intercooler in the bulkhead is a nice idea but the wrong location. You need it covered in snow when you are under boost. How well do your heat exchangers work with no snow on them?

That's a good point. What do you think of the closed loop cooling system idea vs how MTNTK does it by integrating into the stock cooling system?

Would a closed loop tunnel cooler be ideal, or would the water temperature difference be negligible?
 

sledhead9825

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That's a good point. What do you think of the closed loop cooling system idea vs how MTNTK does it by integrating into the stock cooling system?

Would a closed loop tunnel cooler be ideal, or would the water temperature difference be negligible?

I have closed loop on my Boost it system. Works awesome air box is always ice cold. Closed is more complicated and requires a circulation pump. I'm sure it's better but how much I don't know. Easy test. Do a big pull and then stick your hand on the air box. Would be nice not to have any extra electical draw.
 

Justified

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Feb 21, 2010
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Just curious if you have to pull the can to change the quick drive belt?
Thanks
 

mountainhorse

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www.laketahoeconcours.com
How I feel in many "Turbo" threads...

<iframe width="900" height="506" src="https://www.youtube.com/embed/MMngRRwFPYU?rel=0" frameborder="0" allowfullscreen></iframe>





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Last edited:

Sunvang

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That's a good point. What do you think of the closed loop cooling system idea vs how MTNTK does it by integrating into the stock cooling system?

Would a closed loop tunnel cooler be ideal, or would the water temperature difference be negligible?

The MTNTK intercooler gets the coolant straight from the tunnel coolers before it goes into the engine, so it should be as cold as it possible can get in the stock cooler and the extra cooler. A closed loop cooling system needs to have a pretty large coolant capacity to compare to MTNTK solution in my opinion.
The only downside i see with the MTNTK solution is when riding in very bad snow conditions, but hopefully the extra cooler will take care of most of that problem.
 
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