Carbed 2 stroke turbo guy's !!!

[Tonysnoo]

Is anyone still around? Gus, devil, Tony??

Been away for a while due to an eye injury. Maybe I can help with a few of the above questions.

Andreas83: Fuel pump question.....more than sufficient. Actually kinda big, but the current draw isn't too bad at low pressure.
Powerjets: The Jack Harris Auto Body(clippard style) work excellent. very affordable too.

vendetta: Ditto on what Bryter said. I was able to set my idle pressure down to 2-3 psi and things worked just fine. If you are still flooding then your float needle/seats may need to be replaced or may be too large. I was able to hold 8psi with 1.8mm needle/seats under calm test conditions.


Also a few suggestions on getting DC out of an AC system. I agree with the bridge rectifier concept. I love em!

However, I personally do not ground the DC because most AC systems in sleds have been grounded somewhere and when you ALSO ground the DC side of a bridge rectifier, then you will short half of your AC wave form. You meter the correct voltage but the bridge and or stator can get overheated. Worst than that you only have 1/2 the electrical power to run pumps or?

One other suggestion is buy a bridge that seems to have stupid high voltage specs. I like to use a 25-40 amp, 600-1000 volt(PRV). The high voltage spec is not required for our circuits, but it takes a bigger static hit that will pop a lower voltage rated bridge. I never worry about it once it's installed/heat sinked.

I suggest connecting pumps to positive or negative wires directly and do not rely on chassis connections. With that being said, I do like to run a wire between the engine, airbox, and chassis to help with any static high voltage type charges only. Electrons are interesting critters and can and will get you into any trouble they can.... if not managed well.............LOL



As always, I do enjoy this thread as I am always learning from the folks willing to help us out. (Gus, Brycter, Outlaw, etc)

 

[Spaarky]

As always, I do enjoy this thread as I am always learning from the folks willing to help us out. (Gus, Brycter, Outlaw, etc)

WTF you talkin about Willis, I have probably learned way more from reading some of your info than you probably ever got from me... thanks, though.

 

[Tonysnoo]

Paid for a membership just for this thread! I have an old Mach Z that used to be a nitrous lake racer sled. Want to put it on asphalt this summer! Would a T3/T4 be suitable for this application? If not, have any good ideas? Cost effective is the name of the game, I don't want to go pro or anything, just have a little fun bracket racing. Stock pipes? I have a set of CS 1025 trail pipes also. Best thread I've ever read, PERIOD! Thanks Guys!!!

I paid for three year last year when I got into this thread. Gus was really active, and what a help he was. Plus, he is pretty dang funny when he gets going on something.....LOL

I do believe he talked about some of the older Doo stuff like yours earlier in this thread. I think he mentioned some huge turbos were much more appropriate than any of the smaller ones. Take a peek back about 10 pages to see if you get your answer.

You might try to PM Gus if you can't find it.

One thing to remember, it isn't very cheap to turbo anything(but I had to find out for myself, too!)! It's just one heck of a challange and a lot of fun. Be prepare to be more broke(financially) than at any time in your snowmobiling life.............LOL

Good luck!

 

[Ztiggi]

polaris 800 TM40 fuel problem

I just test ran my vertical edge 800 with TM40 carbs and turbo,
it seems to run very rich, but on long pulls it seems like my bowls get empty

the vent lines form the carbs goes to the air box like before, is there anyting else i should do to the carbs?

initial fuel pressure is 4psi, pipe reference.
fuel pump is walbro 190L/hour (50gallon)
fuel fressure regulator is malpassi for carbed turbo.

 

[brycter]

what is your fuel pressure saying when you are boost? is your fuel pump seeing enough voltage to run the pump?

 

[Ztiggi]

what is your fuel pressure saying when you are boost? is your fuel pump seeing enough voltage to run the pump?

I'll add both voltmeter gauge and fuel pressure gauge to check it out,
only got fuel pressure gauge under hood.

 

[brycter]

you need to know what your fuel pressure is doing on a carb sled. because fuel pressure tells most the story. if your fuel pressure is rising then you have boost pressure. and all is good. but if your boost is rising and not your fuel pressure then you have a problem. either in the tank pick up, fpr, or the fuel pump.

now if your down on boost and your fuel pressure has risen to the same level then you have a boost leak some where. either pipe, intake boot, air box came off, exhaust valve of some where.

hope this helps a bit

 

[Doug30racer]

I was wondering on carb venting if you have to vent them seperate. one line from the airbox for each one?

 

[Wheel House Motorsports]

yes, dont t- them into single lines off the airbox.. doing that can cause strange flow issues depending on how they are hooked up. just route each on there own and rock and roll.

 

[Doug30racer]

What fuel pump are you guys running if you are using 15+ lbs boost? I am using a aeromotive 13301 regulator and would like one that works well with it.

 

[PJ-Hunter]

Gus,

I'm seriously contemplating going the way of boost on my 2009 XP. Since the place where I live does not have easy and affordable access to race fuel, I'm wondering what else I can do.

I plan on running between 8-10 psi of boost and I ride at 8500' and up. Nothing lower than that. Can I run straight 100ll (av-gas) or run a mixture of pump 91 (we are now stuck with ethanol) and 100ll, or a mixture of 91 plus some tolulene to increase octane, or a mix of 100ll and tolulene. I will also be pre-mixing at 32:1 because of an oil injection delete.

Also, would you happen to know what would be the best oil that one could use a pre-mix? I just bought a case of Legend (the good stuff) but I have heard that Legend and pre-mix isn't the greatest. Any truth to that or just hearsay?

 

[Ztiggi]

I just test ran my vertical edge 800 with TM40 carbs and turbo,
it seems to run very rich, but on long pulls it seems like my bowls get empty

the vent lines form the carbs goes to the air box like before, is there anyting else i should do to the carbs?

initial fuel pressure is 4psi, pipe reference.
fuel pump is walbro 190L/hour (50gallon)
fuel fressure regulator is malpassi for carbed turbo.

I found that I had no pipe pressure, used air box reference instead, and the fuel system works well,
why don't I got pipe pressure?

edit: stupid me, I forgot to drill the hole in the pipe after welding the coupling there,
now it works with the pipe reference

 

[Ztiggi]

compression, squish and octane

Now i got my turbo sled running,
800 vertical edge, I am using 93 octane (98 european)
running at sea level to 2000ft,
boost is 7psi now, but off course I want more, maybe 10.

should I lower the compression?

and if I machine the head, should I try to get a specific squish?

 

[the sled shop]

best site ever

i love this site-please keep up the great work-ill need help probably

 

[ilovemyeg6]

91 polaris indy rxl 650 triple

so im new to the whose snowmobile engine thing. and i have a few questions for you. if you could please take the time to answer them i would really applicate it!!

1) turbo or no? motor appears to be really clean inside and out i bought the sled wrecked with 2000 miles on it.
i also bought a crossfire150r go kart (lol) im replacing the motor that comes on the crossfire with the rxl650 triple and im thinking about turboing it. i have a stock audi turbo off of my 1998 audi a4 (1.8t) and its really small all im looking for is like 8psi or something like that it has an internal WG and i will get a BOV. i dont think that im going to need a FMIC. so there is no issues there i know about the oil feed just not sure what PSI that i need to go into the turbo i know that it is gravity feed back into the tank (separate oil resavior with a pump to feed the turbo) so my question is can i turbo the motor?

2) efi or carb? it looks like that they have taken off the EFI because they dont have the fuel pump hooked up to a fuel rail or anything like that. so im guessing that they dont have the EFI thing going on. there is a small distributer thing that one line comes from the fuel tank and goes into 4 lines 3 of which go into the carbs and one goes into the back of the block, keep in mind this is a 2 stroke and it has the thing on the back of the block that mixes the oil and fuel automatically. i was also wondering if it would be better to keep that or if it would be better to mix my own oil..?

3) tuning? i really am not sure if there is a way to tune this? please please please help me out i dont know if you need a FMU (fuel pressure rising unit??) anything would help id really appreciate the help

if you can call me or text me that would be awesome i dont get on these sites but i will be checking in case you dont want to call or msg me thanks so much

Bruce 8019201737

oh yeah im from utah hah

 

[Tonysnoo]

Bruce, with so many unanswered questions on your project, I would suggest you get it running, without boost in your cart first. Get your carbs, and pipes working. Sounds like that will be a great learning experience, then maybe tackle a turbo

Good Luck!

 

[Tonysnoo]

Well still like to visit this thread. Kinda slow this year, but summer may bring some new projects to watch.

Gus thanks again for a nice head start. You got me hooked on boost with my old big bore. Even with all of the unknowns I only had one failure.

All of that led to my latest turbo project. I finished out the season really good. I learned a ton more, made lots of power and 0 failures.

Even with EFI fuel management is totally where it's at!

I also got a chance to play with some different sized turbos. I had some serious help from the guys at OVS so now I have two excellent resources.

Looking forward to next year and maybe going back to a carb...er......a propane carb????

 

[CockDiesel]

What an Awesome thread!

 

[Kerstinglane]

hey guys i am turboing an 2001 800 mountain cat, and have a few questions,
what should i do for power for the oil and fuel pumps sense the sled has no battery at the moment.
how are the kits putting pressure to the carbs
and if i pressurize the top and bottom of the carbs do i need a bov? thanks

 

[Ztiggi]

hey guys i am turboing an 2001 800 mountain cat, and have a few questions,
what should i do for power for the oil and fuel pumps sense the sled has no battery at the moment.
how are the kits putting pressure to the carbs
and if i pressurize the top and bottom of the carbs do i need a bov? thanks

Actually I think you find those answers earlier in this thread,
but I'll answer my opinions on this.

I used a 50A/1000v rectifier from ebay, and a capacitor, I like that better than battery, because there is no pump switches to remember/forget,
when the engine stops, everything stops, and high rpm=high voltage/current to the pumps.

I pressurized top and bottom of the carbs but still got a run-on sometimes,
so on my sled I need a BOV.