Carbed 2 stroke turbo guy's !!!

[heinracing]

Gus... I know your the "moderator" of this thread, but I would like to hear the explanation of how they are doing it first off... and then you pick it apart or say yeah that might work.

Frankly... I am a newbie to the turbo world and what MM is saying doesnt sound possible to me.

*note.. I dont want to start a pizzin match though either.

it is possible..

one way of doing it would be having the vents of the carbs going together to a line in the charge tube.

a line is then inside the charge tube with holes in it and the other end of the line exits out the side of the charge tube with a jet in it. the jets change the pressure inside of the carbs to add or subtract fuel by pressure

here is a few pictures
and thats not my welding either

 

[gus bohne]

its the same pitot tube and principal I mentioned on page 1 of this thread for use on slide tops and for bowl venting.
Outlaw addict, His opening statement exposed his animosity and ignorance, thats why I asked him to delete..


Maniac's,, opening statement of BAD information on this thread,,,, was ignorant. drop it and please move on.



Differential pressure managment is the correct terminology.


Holzman uses that method as did bender on their first year 4 stroke turbos, they abandoned it for their own reasons and are back to the more conventional method.

Hein, you can accomplish the same thing by machining the vents to access the bell area, plug off the external vent outlets and use dynamic pressure as we did on the outboard engines with butterfly style carbs..

Oh and the bov is recomened for mountain riding I agree, Voodoo is not he is speed running ,, no need for it, I am drag racing and still no need for it.

That has its drawbacks too, around 2 bar things go wrong and it stops pulling fuel and begins pushing it back into the bowl going lean again. don't know why but we tried for months to get around it without any answer.

( note, they were butterfly bowless carbs so its moot )

Even with the old external vent, just using the pipes pressure to control the rising rate of the regulator does away with rejetting for boost changes.

Tony them doo valves are thin,,, the cat valves are mans valves ,,huh !!!

I'm all for learning but not for bashing.. Try the diiferential method and let us know how it works for you .

Gus

 

[maniac mechanic]

Maniac's,, opening statement of BAD information on this thread,,,, was ignorant. drop it and please move on.



I'm all for learning but not for bashing.. Gus

It is funny how you say this yet you are calling me names. I will stand behind what i stated as some of the info I read on here is bad. But I never called anyone ignorant nor did I state who was giving the bad info. I simply was stating my opinion and observations. It appears to me the one doing the bashing is you gus. I made some claims on here and you were not even willing to give me the chance to explain them or prove them. I guess here its your way or not at all.
I guess in 22 years of turboing you have learned enough and have decided not to listen to any new ideas that are not your own?

 

[Spaarky]

*note.. I dont want to start a pizzin match though either.

as I stated, I just wanted to hear the theory behind it... lets get back to some good info!!!!!!!

Outlaw addict, His opening statement exposed his animosity and ignorance, thats why I asked him to delete..

Sorry, I didnt see it, and didnt mean to open a can of worms. Sorry, curiousity was going to kill the cat.. hahahahaha

I understand the theory... just dont think that it will create a completely in tune system in all the situations listed. I run a system similar to Gus's and all it takes is a simple turn of the power jets and I am where I need to be.. takes 5 seconds...

 

[Team Voodoo]

Maniac how can you explain and prove your system if your not allowed to disclose or divuldge the info.This is a D I Y thread for people who like to build their own systems and understand its functions. If I was looking for a kit I would not be here and would buy from a reputable company. But as of now I'm leaning from a reputable guy.

Just my 2 cents no disrespect intended.

MIKE

 

[Tonysnoo]

it is possible..

one way of doing it would be having the vents of the carbs going together to a line in the charge tube.

a line is then inside the charge tube with holes in it and the other end of the line exits out the side of the charge tube with a jet in it. the jets change the pressure inside of the carbs to add or subtract fuel by pressure

Hey Hein,

I've been studying the pic and been wondering why/how that setup would work. Seems to me that with the bleed off of the jet, you would always have some value less than boost pressure in the float bowls(slightly lean) If I'm thinking correctly the more boost the less loss(with the same jet) and so this setup would richen(be less lean) slightly with more boost. Am I looking at this correctly????

However, I'm not sure I see how that setup would compensate for different altitudes. er...... wait.......less pressure outside the tube more flow through the jet, less pressure in the bowl, leaner yet. Is that enough to lean the carb bowl pressure the correct amount at altitude?

Wouldn't you accomplish the same thing with a T in the carb bowl pressure line and a jet in the T?

Interesting to ponder!

 

[gus bohne]

Its a functional system Tony, the leak is Neccesary because dynamic pressure is much higher, the VELOCITY is whats creating the signal changes in the carb.

the leak changes with pressures and density..

you still change the leak jet from time to time at least the sytem bender used needed that..

does your application still need jet adjustment Hein ? or does it have enough margin for the altitude spreads you ride at ?

Gus

 

[rsaint]

Just wondering why nobody has turboed a tripple i have a 809 and a spare s body chassis to put it in do they not work. Looking at a garrett 3071 to try it are there any advice ya or na.

 

[gus bohne]

Its a little small for it.

3082 is better overall choice . .
It will work like stink with the formula 3 800 touring single on it. simple fun..

should produce a sweet 300 under 20 psi.

If you had to use the 71 it won't be bad just not as responsive and torquey.


Go for it..
Gus

 

[heinracing]

Its a functional system Tony, the leak is Neccesary because dynamic pressure is much higher, the VELOCITY is whats creating the signal changes in the carb.

the leak changes with pressures and density..

you still change the leak jet from time to time at least the sytem bender used needed that..

does your application still need jet adjustment Hein ? or does it have enough margin for the altitude spreads you ride at ?

Gus

Thats a bender system that i took a picture of.
you change the jets for different temps and altitude. works nicely faster then pulling carbs to change jets.

 

[Team Voodoo]

Its a little small for it.

3082 is better overall choice . .
It will work like stink with the formula 3 800 touring single on it. simple fun..

should produce a sweet 300 under 20 psi.

If you had to use the 71 it won't be bad just not as responsive and torquey.


Go for it..
Gus

Wow this turbo stuff is getting to me I really like the idea of a 300 hp tripple . I would do my renegade 1000 twin but I use it for stock radars. I will be building a turbo charged trail sled just not sure which 2 stroke to go with yet but that 809 sounds sweet.

 

[extremedesigndave]

What The Hell Is Going On

So i have been reading some of the posts on changing the pilots! I dropped my pilots from 45 to 35 dropped my mains from 320 to 280 and figured i would be in a good place to screw with the power jets!
Two other things that i have done was put my plugs in the VES ports, and installed a Arctic Cat regulator for and electric start model ( 22 bucks ). The regulator works great, i have very stable ac voltage and even vary stable, not higher than 14 volts, dc voltage.

OK

NOW THE PROBLEM,, ran the motor today, DUMPING FUEL and I mean DUMPING fuel out of the pipe! tried un hooking the PJ's because i did notice the fuel gets to them way faster with the VES un hooked.. STILL DUMPING FUEL ... hooked back up the VES,, STILL DUMPING FUEL..

AND WHEN I SAY DUMPING FUEL I MEAN AS SOON AS YOU GET IT TO MAYBE 4K RPM IT BOGS AND DIES.

I even unhooked the new voltage reg and SAME....


Should I put the old pilots in?

The air screw is at 2.5 turns out, and it idles great!

I am about to put my 45's and my 320's back in,,

oh yeah and the third jet in the bowl i did not mess with and i think it is a 140?

Give me some ideas?

Thanks

 

[devilrmk]

You got something else going on there. Leaking float or something. Sounds like its leaking once the fuel pressure comes up. Are you sure something didn't happen with your regulator?

I am running 410 mains with my powerjets 1 turn at 4-6000ft. Stock 02 needle in on the second clip, stock P8 needle jet. Pilots 2.5 with the air screw at 1/2 turn. Mine runs awesome.

 

[gus bohne]

Dave take them back off, you got something in there, maybe pressure reg moved and pressure is way up..

Nothing you did would cause it to do that. its too rich down low now, your pulling the carbs to far up for the giving rpm, thats why its pulling on the pwerjet so early ,, or at least thats how it seems, in reality your just so rich on low speed its making pull the slides up to far to lean it back out..
somethins amiss..


Gus

 

[snowlovers]

turbo of course

Gus
one question for now, many to follow.
Is there a very good reason everyone seems to run the 2871 turbo, i only want to add about 30 hp at elevation, 10000, can i use a smaller turbo, say a 2052. thanks Dave

 

[devilrmk]

For what motor snowlover?

 

[snowlovers]

turbo

Will be turboing the 800 xp 163 track, kept all the cats cause you dont get much for trade in, still good sleds , let our friends ride them with us, thanks in advance

 

[rsaint]

Its a little small for it.

3082 is better overall choice . .
It will work like stink with the formula 3 800 touring single on it. simple fun..

should produce a sweet 300 under 20 psi.

If you had to use the 71 it won't be bad just not as responsive and torquey.


Go for it..
Gus

Actually the 3082 is cheaper and are you saying a single pipe is better than the tripple jaws mountain pipes i have. Been looking for a y pipe and single pipe but have had no luck. Enjoy reading this post and Gus you are so helpful to so many.

 

[gus bohne]

THe small turbo theory only works on 4 strokes,, sorry.

You need a 71 compressor minimum,, 2 strokes need lots of air.especially the overported R motor.. lots of leak in the R engine.

remeber this ONE RULE Under 200 exhaust duration..UNDER 130 transfer duration..BEST overall power and performance for a 2 stroke turbo.

Triple pipes are THAT much more airflow, and that much more CONSTANT pipe heat LOSS.. they work better in the dyno room than in the field.

turbo's are torque multipliers.. You can still buy the pipe new..cheap easy power.

Gus

 

[Tonysnoo]

I figured a little update on my project might be in order.

Since I started this project I have found that this motor likes fuel. Yesterday was a big green light day for me. I have it now where it appears safe to hold wide open, the transistion is clean and quick. Its stupid fast even with only 7psi boost. I gotta get it on a big pow day or a big big slope and see if I still say that. Until then I'll share what I've done:

Gus made the intitial recomendation to run the 2876 on this motor and it works nicely. I have 1-2 pounds of boost just after engagement and it increases in a nice linear fashion to where I have 4 - 5lbs just as I slide into the 6000 rpm range. After that hold on cause you don't seem to spend any time in the 7000 rpm range it just gets it on right up to shift rpm.

It has great boondocking manners. I can drop into a tree infested gully and work my way through the creek bottom and back out the top without any ill effects.....just a little off idle rich burble(that seems to be a trademark of my Cutler carbs) and never have to get out of the 6000prm range...er maybe a few burps of the throttle for grins...yeah baby!

So here is my calibration to date:
M7 with Cutler 1000 big bore, GT2876, 110lt pump, mod injector pump for oiling, powervalves pinned open.
Low compression domes with .020 cut out of the squish and the dome opened up a bit and Stock timing
D&D monster single(reinforce seams) and Y pipe with the internal stinger cut out..(that might go back in)
48mm Cutler carbs with 10 pilots, AA5needle jets and cutler #5 needles(raised to max) and 620 mains with harris powervalves at 3turns.
Mallory reg at 5psi with Gus's pipe port system so I see about 16psi fuel at boost.
Guages include: fuel pressure(my favorite), O2, avenger with all the tricks including boost built in. and a couple of idot lights for the idiot in me.....LOL

Still in the works: I need to build a better way of keeping the airbox attached. Also want to work the calibration to see if AV gas will work or maybe a mix of race and pump or????? Just some better mileage might also be a focus too (about 4mpg right now) ouch!.......LOL

Hope this helps, and many many thanks to Gus for keeping me on the path!