Carbed 2 stroke turbo guy's !!!

[heinracing]

Never tried square tube, I'm curious ???

seems like it could work just as well on the intake tract, that would make fitment better too..

hummmm


Gus

Was curious because we see around a extra 20lb of torque and 15 hp with it on open tube headers in racing

 

[Tonysnoo]

only thing i could see would be the fins would disrupt flow on the inside or cause a turbulance.




gus have you ever tried square piping for charge tubes?

in the race car world square tube headers create more hp because the flow is better as it causes a perfect flow.

Im going to build a square tube header for the apex and do some squre tubing into the airbox and put on dyno to see if there is a difference

Wouldn't interior fins tend to straigten the flow, no more swurly curly flow streams??? Maybe why square tube works too??? No doubt you would need to run a slightly larger diameter to makeup for the slight loss of area from the fins????

Oh Oh, if it works, maybe we will have to knife edge the leading edge of the fins..........LOL


t

 

[gus bohne]

Extrudehone !

Tony, its a fawkload of fun at 25 psi..made 2 full pulls then brought her home for delivery..430 ish grams , STM weights..
I weight 245,, porker !!!!

Gus

 

[heinracing]

Wouldn't interior fins tend to straigten the flow, no more swurly curly flow streams??? Maybe why square tube works too??? No doubt you would need to run a slightly larger diameter to makeup for the slight loss of area from the fins????

Oh Oh, if it works, maybe we will have to knife edge the leading edge of the fins..........LOL


t

i do like knife edges

 

[RIDECATS]

Hey Dave the pic makes them look thin. Are they?.........I was worried about filling the voids, so for now I just pinned the stock ones and removed the cables.

After reading this I saw a deal on power valves delete at fastlane for AC power valve delete

Great thread guys....lots of info

 

[extremedesigndave]

Power Valve Delete

WOW, I can build those for way cheaper!!!!!
You want some

 

[Tonysnoo]

After reading this I saw a deal on power valves delete at fastlane for AC power valve delete

Great thread guys....lots of info

Great price! I wonder if the M8s are the same width as the m7?

 

[Tonysnoo]

Extrudehone !

Tony, its a fawkload of fun at 25 psi..made 2 full pulls then brought her home for delivery..430 ish grams , STM weights..
I weight 245,, porker !!!!

Gus

Congrats Gus, sounds like a handful!....and I'm in awe swinging half of that weight....LOL

 

[canucklehead]

lean bog

Ok, contrary to what others have seen when blocking the exhaust valves fully open my sled is leaner now. I richened the fuel screw a full turn and shimmed the needle up half a clip.(there are no slots for you non-doo guys) It idles ok now but if I wick it to the bar it bogs so bad that it almost stalls, after a second or two it will finally wind up and go wfo no problem. This is at 3000'. My question is... I ride at 6000', will the bog still be there or is 3000' gain enough for it to be gone. My next step is to shim the needle another half a clip, that's all I can do with it. I just don't want to shim it here and then get up to riding elevation and it be rich. So, any experience with a lean bog and how many feet before it goes away? Thanks

 

[devilrmk]

With mine, 2000ft makes a world of difference as far as the low end.

 

[Spaarky]

x2....... I was amazed when we were in Cooke tuning last year the difference between just going out of town, to the first little tuning hill we hit

 

[devilrmk]

My custom ground helix worked wonderfully. I ground a 30/36(polaris button clutch) helix.

I have a little blurble at engagement until it starts boosting. Acts like its really rich. I was starting to mess with tuning it yesterday when I noticed I had a loose exhaust valve(no loctitite) that blew the gasket. So I was done tuning at that point.


Not sure where to go with it. I am sure its in the needle/needle jet, I just don't want to get it too lean while in the cruise/higher rpm/slight boost range it runs really clean once it starts boosting or in a bit higher rpm range. It seems to respond the best if I am light on the throttle until the turbo spools then its game on.

On the trail ride down I messed with it just a bit and closed off my powerjets to make sure it wasn't pulling some fuel from them. That didn't make a difference.

I might need to start looking at changing my needle profile.

Would dropping my mains make much of a difference in the lower rpm ranges? Like dropping 5 jets sizes or more then richening the top end back up with the powerjets? Currently running 410 mains, which seems to be much richer than most guys I talk to.

Its tough to see the wash with avgas.

 

[gus bohne]

you will see a difference with just 3-4 size reduction.
don't be scared to trim the powerjet tubes either,, your burble is tunable in multiple ways//


Gus

The RT promod went home with Steve Bueti, aka "Driveline" this am....like a loosing your best DOG...
Shop feels like a ROBBERY took place and I feel SAD !!

gotta fly to Michigan now to be close to the beast..lol

Its in very good hands..

 

[devilrmk]

Thanks Gus. It doesn't appear to be related to my powerjets. They are trimmed to come on about half throttle right now.

Just went out and measured my needles and compared them to a set of 01 needles I have and the 01's are a bit leaner so I will try those then maybe start jetting down the mains.

 

[thejhcowboy]

cpi xp turbo help please!!!

hey guys i just got my cpi turbo kit and i am installing it now and i have ran into lots of problems like the instructions don't say what the two other holes in the oil res are for and i didn't get lots of parts that should have came with it and cant find anyplace that sell these parts and i cant get a hold of cpi they never answer there phone or emails can anyone help me. thanks you can pm me or call me 307-699-1230 or email me at codymulligan@gmail.com thanks so much i hope to get this running by wed this week

 

[Todd H]

Power jet for bottom / mid range?

Have been thinking about installing another set of jets in the lower half of the carb intake to allow adjustment for the bottom, mid-range. Anyone tried this? and how did it work....

With the 4500' elevation change it makes it difficult to jet it properly on the bottom and mid.

Just a thought....

 

[Summit Guy]

hey guys i just got my cpi turbo kit and i am installing it now and i have ran into lots of problems like the instructions don't say what the two other holes in the oil res are for and i didn't get lots of parts that should have came with it and cant find anyplace that sell these parts and i cant get a hold of cpi they never answer there phone or emails can anyone help me. thanks you can pm me or call me 307-699-1230 or email me at codymulligan@gmail.com thanks so much i hope to get this running by wed this week

There are two threaded holes one for the oil pump feed (the bottom one) and one for oil return (top one) and two barbed fitting at the top for venting. Just get the appropriate sized hose and tie wrap them way up in the console area. When you get time get one way breather valves in case you end up upsidedown

 

[thejhcowboy]

There are two threaded holes one for the oil pump feed (the bottom one) and one for oil return (top one) and two barbed fitting at the top for venting. Just get the appropriate sized hose and tie wrap them way up in the console area. When you get time get one way breather valves in case you end up upsidedown

Thanks so much for your info this will help out a ton.

 

[canucklehead]

hey guys i just got my cpi turbo kit and i am installing it now and i have ran into lots of problems like the instructions don't say what the two other holes in the oil res are for and i didn't get lots of parts that should have came with it and cant find anyplace that sell these parts and i cant get a hold of cpi they never answer there phone or emails can anyone help me. thanks you can pm me or call me 307-699-1230 or email me at codymulligan@gmail.com thanks so much i hope to get this running by wed this week

Man can I relate. This is definitely a do-it-yourself kind of kit. The good thing is... there's lots of great guys around here that can help. Like already mentioned the extra two fittings on the oil reservoir are for vent lines, did you get those? About 18" long 1/2" heater hose. And like already mentioned you will want to put in some sort of breather/check valve in the ends of those.

 

[Tonysnoo]

Have been thinking about installing another set of jets in the lower half of the carb intake to allow adjustment for the bottom, mid-range. Anyone tried this? and how did it work....

With the 4500' elevation change it makes it difficult to jet it properly on the bottom and mid.

Just a thought....

Hey Todd,

I don't see anyone jumping on this question. I was curious too. I just can't imagine that it wouldn't work. My cutler carbs have three power jets. The side ones use a metal tube directly into the float bowl, but an extra power jet with a long tube down toward the bottom of the bore should work just the same. I wonder if there might be any kind of problems with the long tube in the air stream? Vibrations, turbulence, etc? I guess you could mount it sideways without any big problems?