Turbo XP-four stroke or two?

[DenverR1]

I'm hoping to put a turbo on an XP in the future. From what I've heard, a four stroke is easier to turbo and probably will have less maintenence? But a two stroke e-tec probably will be better in the trees yet because of the turbo lag. Any truth to this? I'd like opinions on what would be the best option to turbo. Throw the carbed XP's into this conversation as well as I know there are quite a few kits being offered already. Thanks

 

[Doo37]

cant wait for that e-tec but it sounds like the xr 1200 could be a yammi killer people are finding that its easier to make pow with the doo im in the same boat as you denverR1 which motor should i turbo

 

[DWHalverson]

If you don't know, I will have kits available for the XP hpoefully by the end of June. I will be offering a kit for the 1200 when I feel Ski-Doo has refined some things on the sled first. That and I need to get the coin to buy a sled to build off of. Four stroke to four stroke, I feel the Ski-Doo will have the advantage, based only on what I have "heard". I know what the boosted Yamaha has to offer. If it is a desicion between two or four stroke, the thing I would look at would be how much power do you want? The 800R turboed makes very reliable power and is very forgiving even with carbs. The e-Tech will still be a few years for the 800. If the four stroke Ski-Doo has the reliability of the Yamaha then that will be great, but as of now I feel another season under boost will be a good indicator. I'm sure it is better than the two stroke, but the maintanence on the two sroke really isn't bad if you keep the boost under 15 psi. 200 plus hp at elevation on the XP is truely an expierence . Carpletunnle (sp), muscle cramps and spasms from trying to hold on at full tilt are all good .

Dave Halverson
R&D Custom Turbo Werx
605-791-2291

 

[triple7]

Well I am planning to try a carb 800 turbo setup from Dave. I am sure it will not be a totally trouble free setup but it will DEFINATLY work better than the E-tec. I have been working around a turbo e-tec 600 and it is a total pile. It has big name industry folk working on it and it continually burns down, loses power, wont run etc. I just got a report of an mcxpress 1200 with a 163 running over 90 mph trackspeed in heavy powder on 16 pounds. My buddy rode it and said it pulled close to his 1010 twin turbo. If it will hold together that should be an insane setup.

 

[SilverGriz]

I really think the 1200 will be the way to go for a reliable turbo set up. What clutch are the T1200 guys running?

 

[triple7]

A comet on the mcx sled. Not sure on powderlites and turboboyz. The guy that rode it said it felt like a tank compared to his xp though...and thats what I dont want.

 

[Reeb]

800R turbo. I've kinda lost the Yammi hardon the more I ride the XP. 50 more HP would be IDEAL. 200 at elevation.......I can only imagine how wide my grin would be.

 

[H20SKE]

From watching and talking to the guys from powderlites and their show at Yamafest--the XP1200 is less money and requires less boost than the rest of the turbo's for the same or more power. The 1200 up at Yamafest was only running 10lbs of boost and went up everything--and fast with no issues all weekend. If I was to put a hairdryer on a sled--it would be the 1200. I hear that some have put over 25lbs of boost on it and no issues.

My .02

H20SKE...

 

[DenverR1]

How about the turbo lag on the 1200? Is it much of a problem? And I'd like to hear from some guys who have ridden the 1200 (turboed or not) and compare it to the XP 800 chassis. Is it quite a pig? What's the longest track they are coming out with stock so far on the 1200? Thanks for all the responses.

 

[Doo37]

longest from doo is 137 renegade hopefuly next year they go longer! the powderlites videos and others on u-tube make the 12 look like it has min if any lag but i havent rode one yet

 

[triple7]

Same deal, I havent ridden it but what two of my buddies who did ride the mcx boosted setup a bunch told me was that there was no lag. They said the thing came on so hard by 4500 or 5000 rpm that the pull was extremely hard and instantaneos. Just what I was told. They said it pulls way different than a yammie because the yammie comes alive a good 3000 rpm later than the doo.

 

[WatchThis!!!]

Well I am planning to try a carb 800 turbo setup from Dave. I am sure it will not be a totally trouble free setup but it will DEFINATLY work better than the E-tec. I have been working around a turbo e-tec 600 and it is a total pile. It has big name industry folk working on it and it continually burns down, loses power, wont run etc. I just got a report of an mcxpress 1200 with a 163 running over 90 mph trackspeed in heavy powder on 16 pounds. My buddy rode it and said it pulled close to his 1010 twin turbo. If it will hold together that should be an insane setup.

I have to ask, who's is it?

 

[triple7]

Boondocker

 

[MtnMaster]

Word on the street is (From some VERY knowledgable people) is that with the Propane conversion like some of the Yammy guys are doin, the XR12 will produce up to 500+ ponies! Who knows how it will hold up, but could you imagine!
The T-XP isn't without a little bit of tuning, but if you just run moderate boost, and don't try to get too crazy, the things is an absolute blast to ride! And will suprise some of the T-4st boys, thats for sure!
Long live the 2 stroke!

 

[gus bohne]

Due to the extremely short fueling cycle of the D.I engines it is almost impossible to inject the volume needed for turbocharging.

The only dependable method will be to either add an injector to the charge tube/airbox or just use throttle body mounted units .

D.I. by its nature is a system that strives to deliver the smallest amount of fuel needed for safe combustion and low emmisions. To do this the fuel is LATE as in its introduction to the cylinder,,ie after ALL ports have closed,

the pressures used as well as the ultra LOW volume of fuel needed to run is just NOT geared toward hi power output levels.

I fail to see the D.I. engine in its current form being a candidate for PREDICTABLE, DEPENDABLE turbocharging.

The heat increases alone would tax the bottom end even more than a turboed RT with the dreaded SDI system ,,

that too is a poor but USEABLE sytem to boost, .

For all 2 stroke turbo worshipers,, keep the mix going thru the reeds, you need to keep the base and rotating assy wet and cool it aids in avoiding deto and helps you run a cleaner fuel curve to boot..

My RT turbos are all carbed, no issue with cranks rods or realted intake side piston scoring.

RT piston scoreing on the intake side IS injector Position related.
It completly goes away when the feuling is thru the reed and the injector is removed..

pardon my spelling as I am using a laptop and have fat SAUSAGE fingers !!

Gus

 

[triple7]

Ya man, that sounds just about right on the money. Boondocker could get like 4 percent extra fuel out of the DI unit. So, they added a throttle body system. So basically, you have two entirely separate fuel curves. The electronics on the sled are absolutely insane and we (along with they) have failed to get control over them. It can change timing, lean stock fuel delivery, remove all timing, close exhaust valves ect and pretty much make it an impossibility to tune consistently and safely. When it runs, it is bad to the bone. The trouble is it will rock for 7/8 of a gnarly chute, bog due to timing, fuel, or exhaust valve change and you role down. Or it may not make it that far. Or it may go out the top no problem. You never know.

 

[Doo37]

sounds like the 1200 is the way to go! (for now) thanks for all the info