I'm not a push turbo guy- but very cool

[av8er]

www.pushturbo.net new web page- very cool information on new turbo kits

the future is looking bright, assuming boondocker, twisted, and cutler can develop stand alone kits also no more damn fuel boxes to monkey with.

 

[CO 2.0]

I'm so stoked on this. Standalone will be the reason I finally pony up and buy a turbo. I would like to know if it's self compensating for high elevation 12Kft or if push would have to custom tune it for you to begin with.

 

[hypnotoad]

very interesting looking kit

 

[Rprecision]

Thats a good start and all but the real question remains, is it closed loop ? Otherwise, its no better or worse then what we got now, just you cant adjust it in the field

 

[knifedge]

----Looks very interesting. Seems like a 2871 with 70 A/R would have more volume of air to offer at altitude and maybe get same HP with less boost. TBBT and the rest of the system Really looks AWESOME!!!! Must check this system out! It is a new era in snowmobile turbocharging. If this works as advertised, Systems less than this will be very outdated. It is like comparing carburators to fuel injection.

 

[backcountryislife]

Thats a good start and all but the real question remains, is it closed loop ? Otherwise, its no better or worse then what we got now, just you cant adjust it in the field

Well, the fact that it takes det, EGT, and other things into account, and controls fuel, boost, and timing...

Makes it NOTHING like anything else out there right now. Not even close.

Even if you can't adjust it in the field (it's like a PCV with 2 maps from that perspective, not "adjustable" but you can swap maps) the fact that it takes these things into account makes the exact tune much less important than it was in the past as it SOUNDS like it will keep you from damaging the machine.


Closed loop hasn't worked very well so far, and this is a system that's pretty darn close to that, but seems like it will be a better system.

 

[polemite.productions]

if its monitoring air going in (mass air sensor?), and exhaust going out (o2 sensor?) and makes adjustments accordingly, then there is no need to adjust for altitude or temp. its about damn time! very cool.

however, i'm skeptical about the tb before turbo setup... seems like a recipe for cavitation to me. i guess time will tell.

 

[polarisfornow]

the fact that you can adjust timing in the map will be the biggest power maker/engine saver of anything out there. when i used to do imports we could only run 4-6 lbs safely on the b series honda motor. when AEM came out with a stand alone ecu that could handle boost and pull timing with added boost we almost over night could run 10-12 on the same stock motor on 91 oct fuel. anyone that doesn't see how big this could be needs to take another look.

 

[knifedge]

--I believe I would like three power settings on the handlebar instead of two. Pwr setting 1 -- Pwr setting 2 --- and then the economy setting 3.

 

[knifedge]

if its monitoring air going in (mass air sensor?), and exhaust going out (o2 sensor?) and makes adjustments accordingly, then there is no need to adjust for altitude or temp. its about damn time! very cool.

however, i'm skeptical about the tb before turbo setup... seems like a recipe for cavitation to me. i guess time will tell.

--If the engine is creating a vacuum in the intake, when the throttle body is opened to whatever degree, the pump will be primed. The compressor will be at a fairly high RPM due to vacuum(no load)-- then the throttle is opened and the vacuum is filled going passed the compressor -- compressor draws down or speeds up under load, building boost depending on settings and/or throttle position. --It is cavitating in a on then off throttle situation with the throttle body near closed and the exhaust spooling up the turbine due to the cavitation(vacuum) on the intake side. No BOV either, cool. The BOV is replaced by the throttle body ahead of turbo creating vacuum instead of excess boost and wastegate. If it did not cavitate or create vacuum, you would need a BOV.

 

[Insaneboltrounder/sjohns]

Sounds like someone knows turbos

 

[Rprecision]

Well, the fact that it takes det, EGT, and other things into account, and controls fuel, boost, and timing...

Makes it NOTHING like anything else out there right now. Not even close.

Even if you can't adjust it in the field (it's like a PCV with 2 maps from that perspective, not "adjustable" but you can swap maps) the fact that it takes these things into account makes the exact tune much less important than it was in the past as it SOUNDS like it will keep you from damaging the machine.


Closed loop hasn't worked very well so far, and this is a system that's pretty darn close to that, but seems like it will be a better system.

The ECU will support some stock dashes with RPM and MPH only. There will be a new dash available that is water proof, heated and visible in all light conditions. The dash is programmable by PUSH TURBO to display some engine functions, such as RPM, MPH, BOOST, EGT, WATER TEMP, AIR TEMP, ALTITUDE, HP, FUEL, OIL, O2, TPS, INJECTOR DUTY CYCLE, MAP 1 or MAP 2, KNOCK SENSOR, SENSOR FAILURE, PERSONAL MESSAGE WHEN STARTED,(ie. your name etc...) and much, much more. There will be ECU and DASH kits available for most existing PUSH TURBO kits.

PUSH TURBO will be the only OEM to have this system.

I suppose this is a bit ambiguous; after reading this it was my understanding the new ECU/Dash would display these items, not necessarily utilize them.

Maybe I am misunderstanding the concept

 

[turboless terry]

What about the head? They are claiming pump gas to 12 psi. with the stock 12 head. All other kits were married to some form of race fuel unless you went back to the 09 head. Sounds like it is what everyone has been waiting for or more. if it works like they say it does.

 

[branix]

the ecu is pre-configured, with two maps, sea-level and 5000+ft and not changeable, it is optimized to 2012 m8 with push turbo and 2 elevations.

there will be a ecu for 2008 - 2011 (push, BD, cuttler,...) but in that case you have to contact jeff from dakota performance to talk about the setup.

egt is a nice way to control the 2 stroke engine, very effective. 02 sensor is also a good way but very problematic on 2 stroke, readings are not working all the time and the ecu can't use it to adjust it self.

the hp output is the "max possible "save" hp output" there are always people who want more and more hp, but there is a good match between power/reliability an this is the line where push is walking with his product.


the OEM dash sucks, you pay 15k for a snowmobilie and you get a dash with 5 functions? rpm, speed? (who care about speed on M series?) temp, trip, ...
IMHO that is a joke. The new dash is available mid- end october ans is plug n play replacement of the OEM ACat dash. but with all necessary informations. Honestly, who is watching his dash all the time? i take a look to rpm, egt, and maybe sometimes to water temp. that's all.


Throttle body before turbo, is definitely thinking out of the box, there is no other way "technically" to have a quick response 2 troke with a turbo, and we all know what you need when you do side-hilling, boondocking and all those burand/rasmussen style stuff. you need quick response. Also, We all know those problems with fuel/leaning out engine/ stock injectors, ..... nearly all those problems are solved,

finally it is time to make a step forward,

 

[TurboMatt]

Very cool stuff!!!!

 

[polemite.productions]

--If the engine is creating a vacuum in the intake, when the throttle body is opened to whatever degree, the pump will be primed. The compressor will be at a fairly high RPM due to vacuum(no load)-- then the throttle is opened and the vacuum is filled going passed the compressor -- compressor draws down or speeds up under load, building boost depending on settings and/or throttle position. --It is cavitating in a on then off throttle situation with the throttle body near closed and the exhaust spooling up the turbine due to the cavitation(vacuum) on the intake side. No BOV either, cool. The BOV is replaced by the throttle body ahead of turbo creating vacuum instead of excess boost and wastegate. If it did not cavitate or create vacuum, you would need a BOV.

how on earth will the pump be primed with the inlet closed off? your description of the cavitation happening at the inlet during on/off opertion of the throttle is both obvious and exactly why i don't like the idea of the throttle body ahead of the turbo inlet.

since when has pump cavitation been a good thing? right off the bat, i'm predicting premature turbo failure due to the shocking of the turbo during cavitation.

and from a performance standpoint, why would anyone want to stop the turbo spool when you're not on the throttle? when you get back on it, you are starting fom zero again. to me, this spells out lag.

now, having the throttle body in the stock location can also cause cavitation, on the outlet side, when the charge slams into the closed butterflys. but this is the purpose of the BOV.

it seems to me that most people have this idea that the purpose of a BOV is to sound cool and keep the charge tube pressures down so that they don't blow apart. both of these functions are true, but the 3rd and most important function of the BOV is to avoid cavitation of the turbo.

with the BOV open, the turbo doesn't loose as much rpm, (stays spooled up) which brings on the boost much quicker in a throttle on/off/on situation. and also, it extends the life of the turbo itself by eliminating the shock of the cavitation. for this reason, i don't know why EVERY turbo kit, including pump gas kits, aren't equiped with a BOV. my guess is that it is to keep the cost down. but to me it seems like cheap insurance and performance.

 

[knifedge]

--With this setup, the only thing holding back the intake charge will be the reeds.

--Clearly, by Push description of the setup, he is counting on turbo spool-up in a on /off throttle to provide the quick response to ON throttle again. He is counting on the reduced load of the compressor due to limited throttle opening and limited airflow to increase the RPM of the compressor. This is clearly starving the compressor for air--increased compressor wheel speed and reduced air available. Then whack the throttle open ---Engine draws air through compressor housing and wheel loading it and building boost, wastegate closes till proper boost achieved.

--It will be interesting to see this all come together and work.

--I still want a bigger turbo for higher altitude(based on what I think I know).

 

[mynewuseddoo]

how on earth will the pump be primed with the inlet closed off? your description of the cavitation happening at the inlet during on/off opertion of the throttle is both obvious and exactly why i don't like the idea of the throttle body ahead of the turbo inlet.

since when has pump cavitation been a good thing? right off the bat, i'm predicting premature turbo failure due to the shocking of the turbo during cavitation.

and from a performance standpoint, why would anyone want to stop the turbo spool when you're not on the throttle? when you get back on it, you are starting fom zero again. to me, this spells out lag.

now, having the throttle body in the stock location can also cause cavitation, on the outlet side, when the charge slams into the closed butterflys. but this is the purpose of the BOV.

it seems to me that most people have this idea that the purpose of a BOV is to sound cool and keep the charge tube pressures down so that they don't blow apart. both of these functions are true, but the 3rd and most important function of the BOV is to avoid cavitation of the turbo.

with the BOV open, the turbo doesn't loose as much rpm, (stays spooled up) which brings on the boost much quicker in a throttle on/off/on situation. and also, it extends the life of the turbo itself by eliminating the shock of the cavitation. for this reason, i don't know why EVERY turbo kit, including pump gas kits, aren't equiped with a BOV. my guess is that it is to keep the cost down. but to me it seems like cheap insurance and performance.

I think by "primed" he means that the compressor will be running at a higher rpm before the throttle body is open.

If the turbo has minimal air feed with the throttle body closed before the turbo, it will be running in a near vacuum state and the compressor will have no resistance from air mass, this will keep the compressor spooling faster at idle than a traditional set up, not at zero speed like you suggest.

When the throttle bodies are closed they aren't fully closed as the engine still needs air to idle. The engine at idle also provides some suction down stream of the turbo and helping expand the gas moving through the compressor.

The cavitation you are attempting to describe is relevant more to liquid moving through a pump than a gas. The air moving through the turbo can be expanded with the pressure drop through the throttle body plate. If it were water moving through a reduced inlet orifice the liquid would build up, move, build up, move etc, giving you the cavitation you are thinking about. Don't get inlet cavitation and compressor surge mixed up.

 

[Dam Dave]

I dont think some of you guys know what cavitation is
When we are talking about cavitation we are generally talking about liquids in a pump.

I see it all the time in pumps I have never seen it in a compressor.


Cavitation is the formation of empty cavities in a liquid by high forces and the immediate implosion of them. (A liquid is a continuum and repairs itself if it is torn apart.) Cavitation occurs when a liquid is subjected to rapid changes of pressure causing the formation of cavities in the lower pressure regions of the liquid.

Cavitation is a significant cause of wear in some engineering contexts – when entering high pressure areas these bubbles collapse on a metal surface continuously, causing cyclic stressing of the metal surface. This results in surface fatigue of the metal causing a type of wear called cavitation. The most common examples of this kind of wear are pump impellers and bends when a sudden change in the direction of liquid occurs. Cavitation is usually divided into two classes of behaviour: inertial (or transient) cavitation, and non-inertial cavitation.

Inertial cavitation is the process where a void or bubble in a liquid rapidly collapses, producing a shock wave. Inertial cavitation occurs in nature in the strikes of mantis shrimps and pistol shrimps, as well as in the vascular tissues of plants. In man-made objects, it can occur in control valves, pumps, propellers and impellers.

Non inertial cavitation is the process in which a bubble in a fluid is forced to oscillate in size or shape due to some form of energy input, such as an acoustic field. Such cavitation is often employed in ultrasonic cleaning baths and can also be observed in pumps, propellers, etc.

Since the shock waves formed by cavitation are strong enough to significantly damage moving parts, cavitation is usually an undesirable phenomenon. It is specifically avoided in the design of machines such as turbines or propellers, and eliminating cavitation is a major field in the study of fluid dynamics.


http://en.wikipedia.org/wiki/Cavitation

This is what cavitation looks like where I work

 

[Dogmeat]

Decent description of compressor stalling and surging. Cavitation applies to liquids and pumps as dave stated.

http://en.wikipedia.org/wiki/Compressor_stall