boost adjustments effect on jetting. turbo xp 800R.

[Bendy]

Elevation

Badass, at what elevation do you unload your sled, and what is the average elevation you ride at with the 360's. I run 400's at 2000-2500ft. I do most of my riding in the Rockies with the exception of this year, good snow here, 2 week vacation way down south and switching to a larger Turbo hasn't given me any time to really ride. I was running 370's with my Aero 53. We unlaod at 3000 and ride up to and around 6000ft. In the spring we ride as high as 8000ft in some areas. Very rare though for my area.

 

[badass1000]

I unload as low as 5,000'. head up the mountain from there. most actual riding is 6,500 to 8500 or so. sometimes as high as 9800.
Lately I have ben just leaving the power jets and not touching any thing at all. Just ride all day. If I wanted to I could turn in the power jets a 1/2 turn at the really high elevations, but it doesn't effect performance enough for me to care. just a little lower egts. I don't do any long climbs at low elevation or have it pined for a long time. if I do I just feather it once in awhile and watch egts. It is not very often that I have it pined for a long time during normal riding. Once in awhile making a long climb I do. If the egts do happen to get much above 1250 I get on and off the gas a few times and it drops.
I ran strait pump last year at 7psi. once in awhile the gas station would get bad gas. my friends NA xp's would have problems on the same day as my turbo xp. I got a good deal on a 55 gal drum of 107 mon gas this year and have put in one gallon of 107 in per tank at 7psi. just turned it up to 10 psi and runing 25% 107. I have only rode it 3 days at 10psi now and good so far. 10psi really rips compared to 7psi. way better then expected.

 

[Bendy]

10 PSI

Ya, 10 PSI kicks a$$. I won't ride this weekend. I'll put the sled back together and test it here at home tomorrow. I work tomorrow, then its gonna be cold Sunday. Next weekend looks like its gonna be cold too. The weekend after that is looking like sunny and warm. "Turbo Time" in the hills. Can't wait!

 

[badass1000]

ok. I found the E6000. it is in the office/school supply section. right by the hot glue guns. I usually don't go in that section to look for glue/adhesives/epoxy. I looked in automotive, hardware, and arts and craft sections first. they all have their own adhesives section, but the office/school section was the only one with the E6000.
I covered the boots and girdles as good as I could. Bolted it all together. Made a big mess. Hopefully it works. Going riding tomarrow.

 

[SMPERFORMANCES]

XP Turbo jetting

Whats up guys!

Just trying to finalize the tuning of my Turbo XP (carbed). Im running at sea level and generally below 3000feet.

I have been trying different jetting and powerjet configuration. I broke a piston with 350s in and jet opened at 2&half turns but the sled was really pulling hard.

Whats you guys are generally running on the mains? all the guys are running at high elevation and it seems to be way different around here. I tried 450 mains this weekend and powerjets opened close to 3 turns. It was the most I could close in order that the check engine light didn't come on! Pilot jets at 15.
On the trails was ok but not like I want it. still rich on the wideband!

The main issue is that the sled has the tendency to sputter around 6700rpm and seem to hesitate before going on the boost. Am I just too rich ?

Boon docking the sled to the turbo side (right) makes it sputter a lot. like no more air entering the turbo. The engine is not reving up at all. it just dies! I guess a cold air intake will be a solution or is it simply my jetting?

Im looking for advices on carb tuning for that garrett turbo kit of mine!

In deep powder the throttle response is not so good. the sled gets a hard time reving up and seems to hesitate around 6700rpm before the boost jumped in

I m presently running 22 grams with 2mm overside rollers on the primary and clickers were at 5 this weekend and sled was kind of ok on hard surfaces hitting 8200rpm but maybe a bit to loaded for the powder as the throttle response was not there at all. Clutching is probably just a bit too heavier but not really an issue for now compared to the carb tuning. Can you guys help me?
I am definitevely sure that I am too rich right now. Im just trying to figure everything on that beast!!

thanks for your advices!1

Will probably try 370 mains and see how that works !! Any suggestions?
Also, If I close the powerjets too much, the check engine light come on all the time. NOrmal? don't want to break another piston, every other components is alright (reeds, boots..)

Looking forward to read your advices

 

[Bendy]

Wow!

That seems like a pretty small main jet for sea level. I run 400 mains, stock 17.5 pilots, needles on pos. 3 and fuel jets open 2 turns at 2000ft. It is an 04 REV, but it seems to me this motor and the 800R work relatively the same as far as jetting. I run 23g pin weight with 1mm oversize rollers at 8300RPM. Runs awesome.

 

[studsrsx]

First off, what kind of fuel are you running? What boost? What timing? Head work at all? Sounds like you are running rich to compinsate for det, hence why your check engine light is coming on. Also why you broke a piston possibly once you felt in was running good. I run at sea level so I may be able to help. Gus bohne is a guy that can definatly help as he runs all kinds of turbos on the flats.

 

[SMPERFORMANCES]

Im running 95 to 97 octane fuel, 6 psi boost spring and stock timing. compression on the head is 120 pounds. still don< t know why that engine light always come on if I close the powerjets too much even with the 450s in...

 

[badass1000]

I do not have any sea level experiance on turbo snowmobiles.
try runing 30%-40% of 105 motor octane fuel. At 6lbs it should be enough octane to not have any detonation at sea level. You might need even more, but it will be alot better then pump. See if this takes care of the check engine light comeing on from detonation and the knock sensor.
95-97 octane? is that pump gas? if so you are probably overseas and the 95-97 octane is research octane only.
usa 93 octane pump is R+M/2. it is say 95 Research octane + 90 Motor octane devided by 2= 93 octane pump gas.
Are you runing a 1:1 fuel presure regulator and 4psi base presure? if so try 400 mains like bendy recomended at sea level.

 

[swrev]

I've got 390 mains in my T-XP, anything over 6000' the powerjets pretty much have to be closed unless she starts to cool down, at 4000', I still have powerjet left to open. I am going to try 360's see how that works. The only time I've had the det sensor go off is due to a torn carb boot.

 

[SMPERFORMANCES]

Hey guys, not too much goods news

First, lets start by that engine light that never stop flashing up while on boost. I don't know why that engine does so much detonation?

After reading all your advices and talked to different people. I've decided to try 50/50 race fuel to prevent from detonation.
The only way I found to eliminate that engine light was to run the sled super rich: like 450's in and powerjets opened 2 turns. Obviously, It s way to rich to enjoy the ride. Throttle response sucks and sled won't pull that hard.

So yesterday, I dropped the main to 390 and powerjet opened 2 turns. 50/50 race fuel and 94 octane just to be sure that engine light was not going to show up.

Guess what: Now it felt like a turbo sled. pulling up some crazy turn and wheelies. But not for really long as that engine light starts to show up again. As I was opening the powerjet to compensate for detonation, the performances decrease.

The sled is definitively always on the rich side on the A/F and never really heats up over 1150F or so. which tell me that we are still rich. But that engine light ...... **** Im tired of that light! By the end of my ride, I did one last pull which was too much I guess. Broke two more piston. The top of the piston broke like last time. One on the intake side and the other one on the side.

Just ordered a full box of piston.... haha just kidding! Better laugh at it than cry.

I know that Im pretty close to the jetting but Im not able to control that engine light.
The only way is to run super rich which sucks.

Does the timing of my sled need to be readjust or what???? 50/50 race fuel, components are good. boost at 6psi, head 120pounds, fuel pressure ok 4psi at idle and stays pretty much there.

TIMING IS MY QUESTION HERE??????

THanks

 

[Wheel House Motorsports]

your only running 6 pounds on 50/50 race fuel??? thats a **** ton of octane, you shouldnt be getting det at those levels, even considering your low elevation...

You should start your own thread, give a detailed description of the sled, the setup, pictures etc and im betting there will be more help, right now your info is kinda scattered among others and not totally complete, and without pictures, its hard to diagnose your failures.

 

[Bendy]

Detonation

That det sensor is obviously doing its job if you're breaking pistons. Who machined your head? Is the squish band correct? I run stock compression, 140 PSI w/ straight 110 at 2000ft. I'd try a stock head w/ straight race fuel. I bet that light doesn't come back on. And if you have 15 pilots, In my opinion thats too small. I run 400's, 17.5 pilots, needles on 3 and fuel jets 2 turns open. When I go to the Mountains for a sled trip I run 360's, 15 pilots, needles on 2 and fuel jets open 1 1/2 turns. Less air, less fuel. Even with a Turbo, you still have to adjust for altitude and temp. Air does have a weight density and it does change. Just my opinion.