EFI 2-stroke snowmobiles - Snowmobile Forum: Your #1 Snowmobile Forum

ZillaFreak · 02-03-2011, 05:50 PM

To start out, I am new here. My name is Nick. I am only joining to find out all I can about the fuel system/intake systems on twin cylinder 2-stroke with EFI. I do not own a snowmobile and most likely will never because of the lack of snow we get where I live.
I do own a Yamaha Banshee. That is why I am here. I am a MET student at UC and I want to make my banshee EFI.
My plan is to use the system of a snowmobile.
Some questions I have
1) What snowmobiles run a twin 2-stroke with EFI. I would like one that uses a MAF and wideband O2 sensor or one that can be modded to use them.
The smaller the engine the better. Because I need the throttle bodies to be as close as possible.
2) Is there any that use a single TB for a twin?
3) Is there ECU/CDI that are programmable?
Pretty much, I want to be able to use an O2 sensor and MAF sensor to control the A/F ratio. I would like to be able to program to get the most out of them. And I need the TB to fit inside the banshee frame. A single TB for a twin would be best.

I would need all the electronics and intake system too if anyone has this.

Thanks for your help

jKsled · 02-03-2011, 06:10 PM

what size throttle bodies are you running?
What size engine are is in your banshee?

There are numerous models that use efi on the twins, I do not know how much you are looking to spend because newer parts from newer models=more cash

is your banshee 2 or 4 stroke?

yes you can reprogram/tune the computers. But certain ones will need certain mapping software or aftermarket custom mapping capabilities.

also, no, i do not know of ANY efi that uses a single throttle body on a snowmobile.

The systems I have experience with are this...
Throttle bodies with tps, airbox with barometric pressure, temp sensor, etc. i have not personally used an engine with MAF. someone else will have to chime in if some sleds do in fact use that.

ZillaFreak · 02-03-2011, 06:17 PM

the yamaha banshee is a 350cc twin 2-stroke. stock they run twin 28mm mikuni carbs.
the reeds are roughly the same distant apart as the yamaha exciter 440. to give you an idea of how close i need the TB to be.

ZillaFreak · 02-03-2011, 06:24 PM

here is what my banshee looked liked october 2009

this is what it looks like now

Spun222400 · 02-03-2011, 07:01 PM

so much to say.... I'll start with welcome and nice shee, you need to get rid of those fmf's and get some t-5's

tire of jetting? iv always wanted to do this but never got around to trying it so keep me posted! arctic cat have had efi twins since the early 90's so there would be an abundance of parts on ebay, the problem is first they need a battery and second 550cc would probably be the smallest engine they had efi on, I don't think they ever made any programable ecu's but boon docker Make a controlet that modifies the singnal from the ecu on a +/- normally used to add more fuel when adding a turbo or pipes but I don't know how much you could drop the map, another thing I was thinking was could the injectors handle premix at 24:1- 32:1? that's as far as I thought into it, hope this helps

jKsled · 02-03-2011, 07:11 PM

I've seen software to create custom mapping, it looked good albeit very pricey. the way it came wouldn't change the stock map, if you just installed it, but once you program it it has the capability to change how much fuel is being injected by +-100%. I can look it up in my magazine when i get home from work.

there was batteryless efi from arctic cat. the thing is most efi systems that i know of don't use a MAF and most earlier systems did not use 02 sensors in the exhaust.

so you may have to change the way your going about this, unless you want to spend a lot more for newer parts from more advanced efi systems on the newer sleds.

ZillaFreak · 02-03-2011, 07:11 PM

1) I love my fmfs, great for the low end power i am looking for. that is one reason for the EFI to help increase low end power and increase the efficency of the motor.
2) I plan on doing the DC conversion.
3) I want to be able to control the map and also timing.
4) I plan on getting a vapor that will allow me to moniter the coolant temps and EGT.

ZillaFreak · 02-03-2011, 07:13 PM

I do want to use the O2 system and there isn't any newer ones using MAF?
I would be willing to spend some more money to get better.

I am already like 6-7K deep into it now.

jKsled · 02-03-2011, 07:19 PM

I don't have any experience with any efi machines past the 2000 year. So sorry guess i can't help you at this point. I will look still for the controller in that magazine when I get home. It would suit your purposes well.

EGT gauges/sensors are readily available at many aftermarket retailers. you'd need weld-on bung, sensor, gauge.

ZillaFreak · 02-03-2011, 07:24 PM

Ya, I might change the exhaust to a 2-1 pipe for that. or do two seprate sensors one for each side.

one big question i have. how does the injector know when it should squirt fuel into the intake. i know it is told to by the CDI/ECU, but is there a sensor that know the right time to do it.

ZillaFreak · 02-03-2011, 07:26 PM

pretty much i want to know as much as i can about how the EFI works on a twin. the more i know the better i can do this.
any info you guys have i will take.

i just had a thought that maybe run two seperate EFI systems, one for each side, but not sure if that would be good.

600RacerX · 02-03-2011, 09:22 PM

probably not a good idea to run two separate systems (too hard to control and keep in sync); it would be better to just buy a dual gauge and run dual sensors in an EGT gauge, so you can keep your twin pipes.

jwaldmann89 · 02-03-2011, 09:27 PM

Just an idea, you may want to look into MegaSquirt ecu tuning to make your own ecu mapping and such. I'm not 100% sure that it will work on a 2 stroke but it may be worth a shot. Then all you need is the TB's and fuel rails ect...

DIYAutoTune.com Megasquirt Kits / Assembled Engine Management Systems, Wideband o2 Sensor Systems and tuning products

jKsled · 02-03-2011, 09:53 PM

heres the controller i was referring to
Power Commander V, Power Comander 5, Powercommander
This is a pretty in-depth unit that requires a lot of knowledge. but it would do what you're looking to do. it would have to be integrated into the system. heres the key phrase i saw

Analog input (allows user to install any 0-5 volt sensor and build an adjustment table based on its input such as boost or temperature)

not sure how in-depth your looking to get with this project but where there is a will (and funding to back it) there is a way

ZillaFreak · 02-03-2011, 10:39 PM

that power commander V looks great, but looks like it is for 4-stroke.
I will get in touch with them and get more info from them
but looks like what I would want.
mainly they said it can adjust each cylinder, something that i would like to have. one reason i was thinking the dual system but i also thought it would be a bitch.

thanks for the help for far guys.

**BC_Dan** · 02-03-2011, 11:51 PM

The guys that are turboing their 2-strokes are using the Power Commander with good results. It works well on the new 800 RMK, which is EFI.

ZillaFreak · 02-04-2011, 08:26 AM

thanks, that is good because i know the owners of the local polaris dealer, maybe they can help me get parts.

Spun222400 · 02-04-2011, 11:27 AM

RZ/RD 350 & Misc. 2-Stroke Tech BBS :: View topic - RZ350 EFI... Done!!

this guycoverted his rz to efi I'm sure he would have a ton of info for you

ZillaFreak · 02-04-2011, 12:11 PM

ok, that is something to look into. i always wanted to do the rz swap for the PV. but another project another time lol. or maybe all at once. boy do i need some money and sponsers for this lol.

Spun222400 · 02-04-2011, 04:40 PM

Quote:

Originally Posted by ZillaFreak

ok, that is something to look into. i always wanted to do the rz swap for the PV. but another project another time lol. or maybe all at once. boy do i need some money and sponsers for this lol.

they are hard on the pocket book aren't they