two turbo's on a shee?

[streetshee]

question why is it that most people who turbo a shee only put 1 turbo on? why not leave twin pipes on with a small turbo on each pipe? instead of the 2 into 1 pipe set up. the local turbo expert here reckons that they will distruct because of the negative wave in the exhaust chamber will try and suck the turbo backwards therefor "shocking the bearings ect,but in a 2 into 1 system you have allways 1 cylinder fireing which is greater than the negative return wave and so the turbo is spun more evenly,not pulsed,hope i explained what i have been told.can anyone enlighten me? would love to use the two smart turbos my m8 has in wkshop!!!! thanks.

[HotCarl]

I think you answered your question right there. When the piston is in it's intake cycle some exhaust gas flow back intot the cyclinder which is a negitive direction. this short period of vacum would not make a turbo very happy.

[FireHead]

I think you answered your question right there. When the piston is in it's intake cycle some exhaust gas flow back intot the cyclinder which is a negitive direction. this short period of vacum would not make a turbo very happy.

I don't think you would ever break the turbo, but certainly keeping enough gas flow through it would be a challenge. Besides, two turbos are heavier than one........ :geek:

[streetshee]

yeh but i think the 2 into 1 pipes are gayasfcuk!! look like little jonny made em at school,lol.

[streetshee]

i love my dmc916's wouldnt swap em for anything,wood be soooo sweet wiyh a smart turbo on each pipe,yehman :happy:

[RZBansheeMan]

Yeah, 2 into 1 pipes look super fuckin' GAY on a Banshee, maybe you could " Y " your stinger tubes together into a big single stinger tube and run a single turbo off that.

 

Just a thought :geek:

[shanYE west]

Yeah, 2 into 1 pipes look super fuckin' GAY on a Banshee, maybe you could " Y " your stinger tubes together into a big single stinger tube and run a single turbo off that.

 

Just a thought :geek:

 

Kinda what I was thinkin too Mike.

[streetshee]

the mans not wrong! thats a good idea,anybody else have any thoughts on that? i think it could work,how do uget around the problem of pressuring petrol out the carb overflows? because the carb will be under pressure from the turbo,do u simply block em up??

[Wildcardracing]

the mans not wrong! thats a good idea,anybody else have any thoughts on that? i think it could work,how do uget around the problem of pressuring petrol out the carb overflows? because the carb will be under pressure from the turbo,do u simply block em up??

I've got a turboed snowmobile (2 stroke), I'll have to look at the carbs and get back to ya. They are just VM40 mikunis, but they have been modded a bunch for the turbo setup. My sled has rotary valve instead of reeds, my question is what effect would placing poitive preasure on the back sides of the reeds at all times have?? Would they close like they are supposed to? Has anyone successfully turboed a banshee?

[FireHead]

I've got a turboed snowmobile (2 stroke), I'll have to look at the carbs and get back to ya. They are just VM40 mikunis, but they have been modded a bunch for the turbo setup. My sled has rotary valve instead of reeds, my question is what effect would placing poitive preasure on the back sides of the reeds at all times have?? Would they close like they are supposed to? Has anyone successfully turboed a banshee?

There are several folks over on Planet Sand that have turbos on their bikes. :thumbsup:

[streetshee]

i dont think the reeds will be under constant pressure because one cyl will allways be suckin the boost in.thinking about it two turbos couldnt work because the reeds would then be pressured open by the turbo? that would be cool slobanshee06 if you can check ur sled,thanks.

Edited December 30, 2007 by streetshee

[Wildcardracing]

i dont think the reeds will be under constant pressure because one cyl will allways be suckin the boost in.thinking about it two turbos couldnt work because the reeds would then be pressured open by the turbo? that would be cool slobanshee06 if you can check ur sled,thanks.

OK, sorry it took so long but I took a good look at the sled. Here's what I got: It has dual carbs, just regular VM 40 round slides with a fabbed aluminum intake box (dual out single in) fed directly by the turbo. As for your question on the vent lines, they have been clamped and plumbed into the intake box so the bowls are under the same pressure as the venturi. The carb caps have also been drilled/tapped and have lines to the intake box, to also provide equal pressure on top of slides so they will close. The carb flanges (manifold side) have been tapped into as well, Right one is plumbed into the wastegate (one of three lines on wastegate, other two go to hi/low switch and intake box) Left line goes to over-boost warning light and aux fuel pump switch (turns on electric pump when turbo spools). There is a small 12v battery to supply power for the pump and warning light. There have been two gages added one measures crankcase pressure and the other is fed off the intake box to measure boost pressure. I need to research it some more for how significantly the jetting was changed (low speed is stock, needle has been changed, and the mains are huge) I'll have to dig further and let you know. The waste gate opens at 6psi (any more and crank seals/base gasket start failing). I have to run 100+ octane at 7,000-10,000 ft. elev. The engine is a 583cc rotax otherwise completely stock, it dynoed at 155hp to the crank at 6psi. I'll try to research how much the jetting was changed from stock (might help give you an idea where to start). Hope this helps a little.

:thumbsup:

Edited December 31, 2007 by slobanshee06

[Wildcardracing]

Another idea is to do like the automotive guys with turbo/carb setups. Enclose the carbs in a box that is pressurized by the turbo. This would save space and aleviate the headache of drilling and tapping the carbs. you could make the box so it bolts right to the cylinders with your manifold bolts. Have a lid that bolts on top to get to the carbs, would look kinda trick I think.

[streetshee]

thats a very big help slobanshee06,i thank anyyou imensly.keep the info comming if you get any, circa how many cm across is your sled turbo? my mates got 2 smart car turbus but im going the 1 turbo route,1 smart car turbo would be too small i think,my woman sez my shee dont need a turbo,yeh itd be the bollocks on the street!! yeh man,hail the banshee!!!

[Wildcardracing]

thats a very big help slobanshee06,i thank anyyou imensly.keep the info comming if you get any, circa how many cm across is your sled turbo? my mates got 2 smart car turbus but im going the 1 turbo route,1 smart car turbo would be too small i think,my woman sez my shee dont need a turbo,yeh itd be the bollocks on the street!! yeh man,hail the banshee!!!

It's an Aerocharger model # 114N250A, it measures @ 40mm at the intake impellor and 50mm at the mouth of the intake. A small turbo would spool up a hell of a lot faster (build more bottom and mid power) A larger one would have a lot of lag, but hold on when it finally spools. 2-strokes consume a lot of air, I've seen guys using turbos off diesel pickups on larger sleds (700+cc) for hillclimb competitions where they are wide open the whole time. guess turbo size would depend a lot on what kind of ridin u do. you might try one of those smart turbos and see if it spools enough in the top end, you might be surprised. I'll let ya know more if I can.

SLO