Turbo Theories and Myths

[Justin_sane]

ah, Thanks for the clarification brad. Didnt even think about that lol. I guess a sled spends a lot more time at or near redline than a car, so you dont have as much shifting around the map as with a car.

Im interested in the variable geometry turbine setup too. Ive read about them, but ive never run one on anything yet.

 

[NM]

NM,
I tried to explain why a turbo that is too big will have higher charge temps, but let me break it down at little bit more. I do love explaining this stuff so, here it goes and please anybody feel free to ask questions.

A compressor map is like a topo map. The top of the “mountain” is where you want to operate the turbo. Like a mountain there is a ridge, and as you go up in altitude or increase boost, you move along this ridge. You always want to operate as high on the “mountain” as possible. If the turbo is matched correctly you will always stay on the ridge as you change boost and/or altitude. By using a bigger turbo, you will be operating lower on the “mountain” than is best. The lower on the “mountain”, the lower the compressor efficiency. The lower the efficiency, the more heat the compressor makes at a given boost or pressure ratio. The higher the heat, the lower the air density is - therefore less oxygen to burn with the fuel. Less oxygen and fuel = less hp.

Engine load has nothing to do with compressor size as we do not care about compressor efficiency anywhere but 100% throttle on a CVT. A bigger turbo would only perform worse at less than 100% throttle, because it is even less efficient at part throttle then 100%.
With over 300 Aerocharged E-tecs, we can recommend 12.5-13 AFR - any more fuel than 12.5 and the E-tec is not happy. Your Pro will take more, but not the E-tec.

You said your AFR starts at high 12’s and creep down to low 12’s to save the motor... Does the boost-it box have a timer and add fuel as 100% tps is maintained? What if the pull is longer then you planed- does it keep adding fuel? We have run 30hrs straight at 100% with no issues. My guess would be your system is heat soaking and that is the cause of the creeping AFR. As the system heats up, the system has less oxygen and needs less fuel.

174 x 3 is a popular upgrade and we have many systems running this combination, including some in Revy without issues.

The race circuit is where I get to play with new technologies that do relate to back country riding weather at 11,000ft in Colorado or in Revy. Carl Kuster will be servicing and stocking kits at his CKMP in that neck of the woods. He puts on about 4k miles a year…lucky dog.

I can only say what we have experienced in real world testing, and the etec pulls harder on a long pull if you can get the 02s down in to the mid to low 12's on a long wot pull. I agree the RMK can take more and we run them in the high 11's at Wot.
I have seen a few Aero etecs in Revy and have seen them run and talked with the owners, and it is all interesting feedback. I talk to a lot of Aero Polaris guys too.

 

[Boostmonkey]

I don't have much turbo experience (Impulse t-nytro); does the variable vain turbo adjust itself on the fly? If not can it be set up to do so? If yes then in theory it should spool faster and be more consistent than a fixed vain correct?

 

[Justin_sane]

They apparantly control the turbo speed by adjusting the vanes, eliminating the need for a wastegate, as i understand.

 

[deaner]

I can only say what we have experienced in real world testing, and the etec pulls harder on a long pull if you can get the 02s down in to the mid to low 12's on a long wot pull. I agree the RMK can take more and we run them in the high 11's at Wot.
I have seen a few Aero etecs in Revy and have seen them run and talked with the owners, and it is all interesting feedback. I talk to a lot of Aero Polaris guys too.

Not a boosted sled......but I found the same thing on my 2010 when I put my 14:1 head on it. Found the jetting where plug color was just perfect.....right on the line. Added more fuel to where plugs look a little rich and it pulled WAY harder. Had to add a little more pin wieght. Dont know the science behind it, but that was my experience.

 

[NM]

Not a boosted sled......but I found the same thing on my 2010 when I put my 14:1 head on it. Found the jetting where plug color was just perfect.....right on the line. Added more fuel to where plugs look a little rich and it pulled WAY harder. Had to add a little more pin wieght. Dont know the science behind it, but that was my experience.

Max horsepower is generally made right on the edge before the sled would be considered lean. For max torque, the motor needs to be richer.
Torque is king in the mountains.

 

[dlux]

I think that big picture is real world riding and and products that work. I personally own a aerocharger etec and have yet to see one that works 100% in deep snow riding. each and every time I have contacted aero charger to get advice or try to come up with a solution to their problems I was told that they had never experienced these conditions before. now I understand as a consumer in the performance snowmobile market I have opened myself up to Issues and will have to deal with tuning etc, but I am sick of spending 30-40-50 grand a year on products that fall short and I as the consumer to be tossed aside after the sale is final. I think its time for aerocharger to step up and put your money where your mouth is, rather than worrying about selling more kits and making yourselves try to appear brilliant online why not get the kits you have working 100% why not address your existing customers issues and make them happy. At this point Aerocharger has become a negative name in the etec turbo world, do your homework look at the amount of unhappy aerocharger etec owners. Companies like boost-it have zero unhappy customers from what I have found. sure they are a small builder and may not have 300 kits on the snow but at least their success rate is 100%. I'm not sure about you guys but personally Id rather have one product at 100% than 50 products at 50%. From my experience you can put as much make up on a turd as you want but its still a turd, AEROCHARGER you have a turd on your hands and if you have any corporate integrity at all you will admit your faults work with your existing customers and turn this thing around because if you keep it up these smaller companies will destroy your market share. I cannot dispute one way or another which turbo itself is better but I do know that aerocharger as a turbo kit manufacturer is not working maybe its time to go back to your roots and just build turbos, do what you do and do it well, there is probably a reason you don't see Garrett manufacturing turbo kits.

 

[Aerocharger_Brad]

I think that big picture is real world riding and and products that work. I personally own a aerocharger etec and have yet to see one that works 100% in deep snow riding. each and every time I have contacted aero charger to get advice or try to come up with a solution to their problems I was told that they had never experienced these conditions before. now I understand as a consumer in the performance snowmobile market I have opened myself up to Issues and will have to deal with tuning etc, but I am sick of spending 30-40-50 grand a year on products that fall short and I as the consumer to be tossed aside after the sale is final. I think its time for aerocharger to step up and put your money where your mouth is, rather than worrying about selling more kits and making yourselves try to appear brilliant online why not get the kits you have working 100% why not address your existing customers issues and make them happy. At this point Aerocharger has become a negative name in the etec turbo world, do your homework look at the amount of unhappy aerocharger etec owners. Companies like boost-it have zero unhappy customers from what I have found. sure they are a small builder and may not have 300 kits on the snow but at least their success rate is 100%. I'm not sure about you guys but personally Id rather have one product at 100% than 50 products at 50%. From my experience you can put as much make up on a turd as you want but its still a turd, AEROCHARGER you have a turd on your hands and if you have any corporate integrity at all you will admit your faults work with your existing customers and turn this thing around because if you keep it up these smaller companies will destroy your market share. I cannot dispute one way or another which turbo itself is better but I do know that aerocharger as a turbo kit manufacturer is not working maybe its time to go back to your roots and just build turbos, do what you do and do it well, there is probably a reason you don't see Garrett manufacturing turbo kits.

Please give me a call asap. I do not know of any issues from last year other then snuffing in deep power on a hard turn to the right. This has been taken care of with a new muffler design. Some customers in Canada have not used the correct reeds and caused a bog. This to has been corrected, we now ship reeds with all our kits.
If you had any other issue plaese let us know so we can work on it. When you call be sure to have to name of the dealer if you did not buy the kit i want to pull any tech call records and see why you still an issue. Something does not sound right.
No need to wait until monday to call.
Cell 913.940.1193

 

[Aerocharger_Brad]

dlux,
PM sent as well. We have to many happy customers not to make them all happy. Garrett, turbonitics, and Procharger does make kit

 

[Aerocharger_Brad]

Here is a cool video of deep powder with old muffler.
Felker Motor Sports Pump Gas Turbo - YouTube

 

[E-Zmoke]

dlux,
PM sent as well. We have to many happy customers not to make them all happy. Garrett, turbonitics, and Procharger does make kit

LOL

 

[dlux]

Brad, I have talked several times to yourself and your crew, Andrew Tyler etc. And up until this point my questions have went unanswered and seemed to fall on def ears, I will contact you again but please don't give me the same old song and dance that you've never heard of my problems. Every aerocharger etec I've ridden does the same thing. It hesitates and studders on the bottom end, and it is also very inconsistent. I should be able to stab the throttle from a dead stop or any other position and I cannot, none of the ones I've seen can. So if your going to tell me that you've miraculously came up with a real world solution than I am all ears!

it is to bad I had to make waves on here to get any attention, and I do apologize to Neil hijacking your thread but I think people need to know what's really going on out there I have no affinity to anyone mfg. I ride what works and am sick of being the industries ginny-pig show me a product that works and back it up with a no bs if your not happy we make you happy policy. I think the small players in this market are doing the right thing to protect their longevity in the industry they are testing in our conditions and making sure they have it nailed before selling product. Also not shipping kits to any dummy with a toolbox, by doing their own installs they know exactly what they are working with, it comes down to quality vs. quantity for theses guys and I'm glad someone's finally taking the initiative.

 

[NM]

Brad, I have talked several times to yourself and your crew, Andrew Tyler etc. And up until this point my questions have went unanswered and seemed to fall on def ears, I will contact you again but please don't give me the same old song and dance that you've never heard of my problems. Every aerocharger etec I've ridden does the same thing. It hesitates and studders on the bottom end, and it is also very inconsistent. I should be able to stab the throttle from a dead stop or any other position and I cannot, none of the ones I've seen can. So if your going to tell me that you've miraculously came up with a real world solution than I am all ears!

it is to bad I had to make waves on here to get any attention, and I do apologize to Neil hijacking your thread but I think people need to know what's really going on out there I have no affinity to anyone mfg. I ride what works and am sick of being the industries ginny-pig show me a product that works and back it up with a no bs if your not happy we make you happy policy. I think the small players in this market are doing the right thing to protect their longevity in the industry they are testing in our conditions and making sure they have it nailed before selling product. Also not shipping kits to any dummy with a toolbox, by doing their own installs they know exactly what they are working with, it comes down to quality vs. quantity for theses guys and I'm glad someone's finally taking the initiative.

It's an open discussion so I don't consider it a hijack. I do appreciate the positive comments, and people will eventually understand why we don't just take anyone's money and ship out a kit.
It is very important to us that our customers are happy.
We actually have a guy driving all the way from Southern Oregon to get a kit installed because I wouldn't send him one.

Based on how many fuel control systems we a really selling for Pro RMK turbo kits sold by other turbo kit manufacturers, there are many unhappy customers out there, and not a lot of help.

 

[jpgmtech]

The biggest problem with any two stroke turbo kit is the tuning. Even OEM's fall flat at times with this, although they are much better now in recent years. Meshing an etec direct injection system with a supplemental fuel system is not easy - the etec system does not produce a consistent 'baseline' fuel curve. It is constantly moving things around. The only etec turbo kits I saw working well in the snow last year had carefully tuned boost-it fuel controllers, along with a few clutching tricks.

 

[teeroy]

I think there are lots of turbo'd sleds out there that aren't 100% but I will bet some owners are reluctant to say so.

 

[Shadam]

my sled shop told me not to turbo my 2stroke sled. they said it will take a best part of a year to set up/dial in properly and they didnt want to be blamed for "issues"
that and I would squeak the motor shortly. is 4 stroke the future ???

 

[deaner]

Yeah its funny how many shops will keep selling kits and marketing the piss out of them when they dont really work that good to begin with. Rode a BD setup and holy cow was it gross. It pulled like a raped ape up on top.......I mean WAY harder than their pros. But man was it gross on the bottom end. You always hear how flawless the M series are supposed to run. I had two of them and did not like them one bit. They are fine for some things, but definitely not my type of riding. When I was riding in tight trees it seemed like every time I NEEDED some juice the frickin thing would burble and fart and I would get stuck. Could have lit the stupid thing on fire.

But, lets hope that the kit builders keep pushing things until we have a 2 stroke kit that truly is all around rideable. I sure havent been on one. But I havent been around any of the new kits like TSS, boost it, and the ones with the standalones. Just mainly boondocker and twist it crap.

 

[drew562]

Yeah its funny how many shops will keep selling kits and marketing the piss out of them when they dont really work that good to begin with. Rode a BD setup and holy cow was it gross. It pulled like a raped ape up on top.......I mean WAY harder than their pros. But man was it gross on the bottom end. You always hear how flawless the M series are supposed to run. I had two of them and did not like them one bit. They are fine for some things, but definitely not my type of riding. When I was riding in tight trees it seemed like every time I NEEDED some juice the frickin thing would burble and fart and I would get stuck. Could have lit the stupid thing on fire.

But, lets hope that the kit builders keep pushing things until we have a 2 stroke kit that truly is all around rideable. I sure havent been on one. But I havent been around any of the new kits like TSS, boost it, and the ones with the standalones. Just mainly boondocker and twist it crap.

I ride with 3 m8 turbos and they are boondocker kits. They run flawless but the guys that own them spent countless hours on the boondocker box cleaning them up. If I had one I'd be ok because the guys I ride with know them so well.

 

[dlux]

one thing I have come to realize is that everyones opinion of a good running sled is different, id say most of the sleds that I've ever had would be perfect to 95% of the people. A lot of people hate to admit they spent money on something that doesn't work worth crap so they try to make everyone believe the hype! Ive never owned the perfect sled yet maybe this year is the year?

 

[jpgmtech]

one thing I have come to realize is that everyones opinion of a good running sled is different, id say most of the sleds that I've ever had would be perfect to 95% of the people. A lot of people hate to admit they spent money on something that doesn't work worth crap so they try to make everyone believe the hype! Ive never owned the perfect sled yet maybe this year is the year?

Agreed