Turbo HO rev bogs/dies with jumps??

rotaxhippie · Nov 5, 2012

The pipe is sealed much better now. Any miniscule soap bubble that was forming when pressure testing can be filled if needed. The greatest leak is around the Y-pipe connection, which will be a problem if the new donut does not seal up. I installed heavier springs which took 2 people to install. Is there any other trick to sealing up the Y-pipe connection? Aerocharger warns to not use any silicone/rtv.

brycter · Nov 6, 2012

I sell a product that will fill a 1/4 gap. It is like a putty with fiber in it.

Or you can cut your grayfoil flange off and install some 3 bolt flanges with a flex bellow made for turbo application.

aerocharger does not reccomend silicone because most people live by the antage " if a little works alot works better" and then the squished out silicone goes through the turbo bending all the little veins. after that they get pissed because a turbo repair is needed. :jaw:

rotaxhippie · Nov 6, 2012

Interesting. The putty you sell may be the ticket. How many rides does it hold up for? The other flex option sounds good to, though I've never seen what it looks like. Even if I could replace the donut with another similar shaped silicone or rubber that wouldn't melt would be perfect.

Kerstinglane · Nov 13, 2012

have you checked your base fuel pressure? i have a custom built trubo rx-1/ apex and with the carb motor with vaccume regulated carbs, when first got it done it was doing the same thing, my fuel pressure could be to high, i havent looked at my sled yet but thats my guess, all because of the mix of the fuel pressure regualtor and fuel pump and loosing boost pressure to the regulator so quickly.

turboxp · Nov 13, 2012

Stinger

Cant remember if you wrote that your rev is a 06 or 07 the 06 didnt have a stinger in the pipe the 07 did make sure if it is a 07 that the stinger did not come lose that will screw everything up.

rotaxhippie · Nov 14, 2012

I have been running the fuel pressure at 3.5-4 lbs. Maybe my cheap fuel pressure gauge isn't all that accurate though and it needs dialed down a bit. I know when my o-ring was leaking around the float assembly the sled ran terrible, for obvious reasons. It hasn't had anything similar to that condition, so I imagine the pressure is good. Although, jumping does slam the floats which goes back to my original statement and maybe too high of pressure would give that rush of fuel past the needle.

xp, thanks for the stinger info. When I cut the '03.5 pipe apart again I confirmed no stinger.

Any other solutions to sealing the Y-pipe connection? It's looking like TP's putty is the solution. Unless my new donut will seal up completely once I fire it up and get some vibration going.

Oh, I got aerocharger's wire dome filter, and it is incredibly well built. Far superior to some concoction I would have created.

turbo800 · Nov 15, 2012

rotaxhippie said:
I have been running the fuel pressure at 3.5-4 lbs. Maybe my cheap fuel pressure gauge isn't all that accurate though and it needs dialed down a bit. I know when my o-ring was leaking around the float assembly the sled ran terrible, for obvious reasons. It hasn't had anything similar to that condition, so I imagine the pressure is good. Although, jumping does slam the floats which goes back to my original statement and maybe too high of pressure would give that rush of fuel past the needle.

xp, thanks for the stinger info. When I cut the '03.5 pipe apart again I confirmed no stinger.

Any other solutions to sealing the Y-pipe connection? It's looking like TP's putty is the solution. Unless my new donut will seal up completely once I fire it up and get some vibration going.

Oh, I got aerocharger's wire dome filter, and it is incredibly well built. Far superior to some concoction I would have created.

I've had good luck with the orange Permatex high temp silicone with copper. As far as longevity, dunno, I open my often but its always sealed up.

rotaxhippie · Dec 5, 2012

I took the sled up Monday and it is a whole new machine. I am building boost now, 9 lbs with 50/50 110. The bog issue is still there when I dump off the throttle, jumping (hard snow) and even hillclimbing. Does a blow-off valve take care of this issue, since I don't have one? It seems to run well everywhere except when I dump (release) the throttle under boost.

Thanks for everyones help thus far; the sled is so much more fun to ride and my fuel mileage even improved now that I'm always on the pipe.

Octanee · Dec 5, 2012

rotaxhippie said:
I took the sled up Monday and it is a whole new machine. I am building boost now, 9 lbs with 50/50 110. The bog issue is still there when I dump off the throttle, jumping (hard snow) and even hillclimbing. Does a blow-off valve take care of this issue, since I don't have one? It seems to run well everywhere except when I dump (release) the throttle under boost.

Thanks for everyones help thus far; the sled is so much more fun to ride and my fuel mileage even improved now that I'm always on the pipe.

id put a bov in, they are good to have, especially with that boost, atleast in my opinion, but heres what i think happens in a "reaction",

now IDK about your going uphill bogs, but this is when you let off the throttle after drops or something, basically letting off the gas while boost still there....

you let off throttle, flaps in carbs close, you got 9 psi that has to go somewhere, your boost gauge and fuel pressure reg reads 9 psi continues to flow for that, engines not receiving much air.... and then the turbo starts to slow down quick because its got no exhaust keep the exhaust turbine spinning fast to make boost and the boost has to escape....., so in a nut shell, back pressure goes up moreless, you got boost probably escaping out of the turbo intake,

so that being short, no air in engine, getting fueled for 9 psi any ways?, open it up, its running real rich from all that fuel thrown in, then it spits it out and goes again,

so where a BOV comes in... is it essentially keeps the turbo spinning, you build boost, shut flaps, dump boost, turbo spins freely, you open throttle up, wastegate closes and you have boost almost instantly again, if your playing with the throttle like climbing in and around trees

now i could be wrong, idk how your SETUP is, but my guess on it all is what i have said, but a BOV never hurts, and you can only have gains from it

rotaxhippie · Dec 5, 2012

Everything you said makes sense and follows everything else I've read thus far. I have read a bov can hurt performance though if not installed properly. Beyond obvious goofs like leaks or the bov pressure release set too low, is there a certain distance the bov needs to be placed away from the turbo? The best place I have to install it is over the airbox between the two pipes (refer to previous photos). Any bov brand recommendations?

Octanee · Dec 6, 2012

rotaxhippie said:
Everything you said makes sense and follows everything else I've read thus far. I have read a bov can hurt performance though if not installed properly. Beyond obvious goofs like leaks or the bov pressure release set too low, is there a certain distance the bov needs to be placed away from the turbo? The best place I have to install it is over the airbox between the two pipes (refer to previous photos). Any bov brand recommendations?

lol, if you want a cheap one i run, its the HKS squential blow off valve, it lets off a high pitch sound when blows off with enough boost, at 5# it was OK,

i ran the bov with no spring, which yeah led to problems lol, the spring it came with was too stiff, so i took my keychain ring, and pulled it out Into a spring, just stiff enough to close it and return the valve if you want to call it that, return the valve to close position when theres no vacuum,

the hks works on basically, which im sure others are the same, vacuum to suck open, then when its closed, boost pressure keeps it closed by the force of air

its cheap, and it works, otherwise you could get into ones ran by say powder lites, or well anyturbo company and pay like 150-200$ or was it like 250? cant remember now

but yeah as said, no downside to a bov really, and only the upsides...., and if you want to get rid of the bog that is a good place to start in my opinion

this is a decent vid of how it sounds when blowing off, or atleast in a car

https://www.youtube.com/watch?v=Np0Ms5HFA2Y

rotaxhippie · Dec 16, 2012

I ordered a bov from Silber due to its size and quick response, but Justin couldn't tell me if I'd need to plumb it to both carbs or just one for vacuum operation. I hope it's adjustable enough to do it either way.

Finally, I got to put the sled on a hill with some load and I found out my gearing is far too low. My track speed caps out too quick. This pretty sweet little calculator has me at 74.24 mph: http://www.turboaddictionparts.com/catalog/snowmobilecalculator.html

Anybody want to share what this calc gives them for their mph and boost? I'd rather not pour a bunch of $ into chains and gears I can't use. I was thinking about trying a 26/43 which would bring that calc up to 96.19 mph. Sadly, all I have here are two 74p 15w chains and two 72p 13w chains.

turbo800 · Dec 18, 2012

rotaxhippie said:
I ordered a bov from Silber due to its size and quick response, but Justin couldn't tell me if I'd need to plumb it to both carbs or just one for vacuum operation. I hope it's adjustable enough to do it either way.

If its plumbed to just one carb, sometimes you will get a pulsing action as its opening and shutting with the cycle of the motor. T the two carbs together for the BOV.

swrev · Dec 18, 2012

According to the calculator, mine tops at 75.21 mph with 21/49 gears. Think I am going to try a 45 bottom, should bring me up to 81.9 which still seems low. Do you know if the there is a calculator which would show the speed at the 1:1 ratio of the clutches.

swrev · Dec 18, 2012

Forgot to use the overdrive portion, 21/49 ends up w/ 88.49, 21/45 would be 96.35. I usually run around 10lbs of boost.

Octanee · Dec 18, 2012

rotaxhippie said:
I ordered a bov from Silber due to its size and quick response, but Justin couldn't tell me if I'd need to plumb it to both carbs or just one for vacuum operation. I hope it's adjustable enough to do it either way.

Finally, I got to put the sled on a hill with some load and I found out my gearing is far too low. My track speed caps out too quick. This pretty sweet little calculator has me at 74.24 mph: http://www.turboaddictionparts.com/catalog/snowmobilecalculator.html

Anybody want to share what this calc gives them for their mph and boost? I'd rather not pour a bunch of $ into chains and gears I can't use. I was thinking about trying a 26/43 which would bring that calc up to 96.19 mph. Sadly, all I have here are two 74p 15w chains and two 72p 13w chains.

tbh id get vacuum from both carbs, also make sure its after the paddles going into the engine of course lol so you get vacuum ha ha, more vacuum is good just so then your bov will act quicker and be more responsive and/or shut in time

i personally got 2 nipples on my throttle bodies as it is, so all i did was take 2 clear hoses and put them up into 1 T, then from that T i run a line to another T that connects my EFI controllers boost sensor, then from up that T i run another hose to ANOTHER T lol for my BOV and my boost gauge

and that gearing calculator, no real idea but it puts me at 106.74, but i just wish there was a better calc for boosted sleds...

also i run a 23-49 gearing ratio and 10 tooth drivers on my 1000 sdi, works good, id try the 23 because it is like half the price of your bigger gear down low, not to mention your increasing your chains slack that needs to be tightened up

rotaxhippie · Dec 22, 2012

Thanks for the heads up on the bov plumbing. I plugged it into both primer fittings. The bov eliminated my bog issue, both climbing and jumping. Although, I only got to jump it a couple of times in powder. Still, hands down better.

I was told to not gear less than a 1.95 ratio, which limits me to a 23/45. I tried a 23/43 on Wednesday and I couldn't pull it to a full shift out. My track speed did increase a lot though. My 7T drivers are holding me back if I can't run a lower gear ratio.

Then my PTO bearings grenaded. Not sure if the boost took out the seal and blew out all the grease or if the bearings just gave out. This crank/engine only had like 500 miles on it, 100 of which running more than 4lbs of boost. Is there a better seal available than stock?

gus bohne · Dec 22, 2012

FWIW, I have an 03 800 with 6 yrs of 23-28 psi boost on the bottom end and its the original NO SEAL plate unit. never once have I seen a seal fail from boost. IN fact, you can remove the crankseals on a turbo and it will NOT GO LEAN. You will blow fuel all over the place and loose power from the boost LEAK but it will NOT GO LEAN on boost. Off boost yes, but on boost absolutely not.

As for your bearing. deto, or more likely out of true. doo cranks are super strong but a little wled on the pto end goes allllongggg way when your jumping.

you are loading and unloading the drive hard, maybe youve broken a few belts ? all this will do in a pto end bearing quickly.

have to give props to Seadoo clinic for building me some solid doo cranks. he aint cheap but he is dead nutz on. the worst I have gotten back from them was .001 total included runnout. thats the total sum of all the measured runout from pto end all the way to mag end .

The aero's are little heaters and do induce deto far sooner than a higher flowing / seperated housing garrett turbo. dump the vacuum cup line too. its THE bog creator on those units. there is no reason to use it . everytime it moves under vacuum to dump drive engergy it has to see positive pressure to flip the veins back into drive mode. we found that out back in the 80's.

good luck and stay boosted.

rotaxhippie · Dec 22, 2012

My original OEM crank lasted over 5,000 miles and that was when I jumped a lot more and bigger harder landings. My last crank in a factory built core gave out (rod bearing) at 1,200 miles, no boost then. So I'm inclined to agree that this crank wasn't true or some issue with the bearings. I bought it as a rebuild from JJ Machinery in UT. I have no way to measure if it's straight or not. But thanks for confirming that a OEM seal works fine.

Is it Hildebrand's See Doo Clinic (517)-238-5955 (eBay name sea_doo_clinic) in Coldwater, MI you're referring to for a good crank? Looks like they offer a Fatty bearing? I don't want to rebuild this engine and be here again in two months, any other engine longevity tips?

gus bohne · Dec 22, 2012

Yes, that is the one. Mark is a cool guy, He also did the crank in steves RT 1000 turbo that has been at 25 -30 psi for 2 yrs and still staight and true, heading to dynotech in january to try for 600 hp. already at 500 now.

as for life, 32/1 spectro semi synth oil. good real turbo cut heads, not just squish jobs. and always, good fuel. vp is my choice.

you can do yourslef a huge favor and get NON ho cylinders. night and day better than HO stuff on boost. instant difference. no guessing. dont go with super stiff reeds, use HO reeds doubled up and get the best response and life.

dont let it run over 150 degrees coolant temp. and have fun.

find a garrett and see the light, and reduce the tuning headaches and gain power too.

Turbo HO rev bogs/dies with jumps??

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