bb dyno results for 940 & ski-doo bb

[slyrydr]

finally got my 940 on dyno....dyno at 5k, very experienced shop and operator, does LOTS of dyno work for all brands and hp configurations, up to over 300 hp....my engine, bikeman 940 with his y-pipe and pipe, diamond ti can, stock fuel system with commander v....184 hp at 7900 rpm, interestingly, at same rpm as stock engine, total surprise; stocker was 155 hp, 14 800 m....my '10 put out 163, but of course there was a pipe change...operator said that i would need to run it about 8050 for riding elevations of 9-11k...experience says i should run it at slightly higher rpm so that in changeable snow conditions it pulls down to max hp rpm rather that trying to accelerate back up while under load, a little more testing when we get more snow....to put it in perspective with the bb 800 etec, the best bb, over a dozen tested, pulled 162 hp; stock normally 149-150, not naming which ones, but you would recognize them...this shop specializes in rotax and polaris engines and is very experienced in getting the most out of rotax engines.....most pump gas turbos are in the 175-180 range, with race gas mixes going up to about 205....my '09 m 1000, ported with exhaust got 189. but had 137 ft/lbs of torque, which pulled hills really well...anyway, not trying to upgrade or downgrade anyone else's ride, just an unbiased look at results of different engines that have come thru the shop in the last year.... just to add the info on the '14 cat, light weight, lost 46 lbs; ti can, c-3 belt drive, 16 front end, 3" track, bdx rear suspension, oil delete, bdx hood & intake, cat mesh side panels, led strip light on rear and front, hcr steering post, mohawk skiis, bdx boards, other small stuff, but that's most of it, cost some, yes....beating the poo's, priceless..

 

[Thunder101]

Thanks for the info. Nice to hear some numbers at are not at sea level.

 

[ranger12]

Thanks for the info!! Interesting numbers.

 

[knifedge]

--So basically the Cat 940 BB has the top end HP of a pump gas turbo and the low end response
and torque of a big bore without the added weight of a turbo or supercharger

 

[slyrydr]

--So basically the Cat 940 BB has the top end HP of a pump gas turbo and the low end response
and torque of a big bore without the added weight of a turbo or supercharger

...yes, and it pretty much plays that way on the hill....most 800 turbos have to run about 10 lbs of boost to run faster, which they do...however, they are running half race gas at that point for the engine to live....the 940 with the same race gas, can advance the timing about 6 degrees and handle the turbos except that on a long, open pull the turbo will come by the 940 if the hill is long enough...

 

[scratley]

--So basically the Cat 940 BB has the top end HP of a pump gas turbo and the low end response
and torque of a big bore without the added weight of a turbo or supercharger

At 5k yes. But at 10k those numbers would flip flop. I don't think I even unload as low as 5k. Great info though, nice to see some real world all on the same Dyno. Hard to argue those numbers being in such a controlled environment..

 

[boondocker97]

So if you figured 3% loss every 1000' above sea level you are looking at 216 sea level and 151 at 10,000'. Turbo definitely has top end advantage there but lacks on the bottom end til it spools.

 

[WyoBoy1000]

You can't compare to a turbo, there is something about boost that just flat pulls away. I always had one of the best running m1000 mods around, lightweight and maxed out on everything without doing engine work. But a 09 pg turbo on 6lbs still keeps pulling where it would slow down. Not sure what it is but boosted flat pulls track speed

 

[rulonjj]

Elevation dosent affect boosted sleds as much as n/a. With that being said those are pretty good numbers.

 

[madmax]

So you have stock throttle bodies and stock reeds? How much and what did you do to advance timing?

 

[swrev]

160ish on doo at 5000 is about 190 sea level, correct? Think that is what most of the builders are claiming so that is not an inflated number and doesn't surprise me. How come you posted corrected to sea level hp numbers on 800s? They should have closer to 135-140 range. Impressive numbers on 940 and and shows how pump gas turbos are a waste unless really running some elevation IMO.

 

[bradburck]

Turbo vs. BB... I have had several of both at this point... and 9k plus there just is NOT competition.. in the trees the BB is awesome, but there is a reason dudes like Burandt and others run turbo's. It just matters THAT much IMO. I went turbo.. then to BB and now I'm back to turbo. I just prefer the turbo and they have advanced so much that lag is much less of an issue these days, at least with my newest one. I also understand HP is HP, but not loosing as much at elevation is the real deal. Both are awesome, but from my experience, a BB isn't going to ever outrun a pump fuel turbo at higher elevation. Cool to see the numbers for sure.

 

[slyrydr]

So you have stock throttle bodies and stock reeds? How much and what did you do to advance timing?

..i have stock throttle bodies and reeds....the commander with timing control does the timing advance...i elected not to do the timing advance commander on account of several reports of the box having dependability issues, maybe later...

 

[slyrydr]

You can't compare to a turbo, there is something about boost that just flat pulls away. I always had one of the best running m1000 mods around, lightweight and maxed out on everything without doing engine work. But a 09 pg turbo on 6lbs still keeps pulling where it would slow down. Not sure what it is but boosted flat pulls track speed

..don't disagree with most of what you say...my m-1000 was very light weight, lighter than the poo's, the engine mods i did emphasized torque at 7200 rpm...in my area of the country, there are some hill-climb races held every year near Fairview, Ut....lots of fast sleds show up, and I don't usually compete...mostly just line up and race what you ride stuff..the last year i rode my 1000 was in '13 and went to the races just to have fun...the race day was warm and sunny, early April, the course was close to 10k, snow heavy, wet, and the way they lined up, put the skis right at the start of the steepest part...i watched the turbo's for a while, noticed they didn't get off the line all that hard, finally decided to give it a shot and lined up with the 3 turbo's that had pretty much taken everybody else....raced twice and beat them off the line so hard, about 5-6 lengths, that they couldn't catch me and ended up 3-4 ahead at the top...they went over to the trees, popped hoods and came back for another try, the fastest one closed to just 1 sled length at the top, and sure with a little more hill, would of passed me...but hey, it was their hill, but my day....i'm sure you've been there too, some days you're the bug, somedays the windshield...

 

[madmax]

..i have stock throttle bodies and reeds....the commander with timing control does the timing advance...i elected not to do the timing advance commander on account of several reports of the box having dependability issues, maybe later...

So you don't have the timing advanced? Just stock timing? Who did the dyno?

 

[kiliki]

well set up 1k will cause a turbo a lot of headaches at 8k or less. above that the turbos have the game.
3 years plus time to prove this.

 

[scratley]

Yes you can run up to 6 degrees timing at 10k on good fuel.. 91, 92 octane. The vipec setup I run advances as you go with just a slight advance at 5k. Be nice to see the 940 on good fuel, timing bumped, reeds and 50's

 

[Bacon]

Yes you can run up to 6 degrees timing at 10k on good fuel.. 91, 92 octane. The vipec setup I run advances as you go with just a slight advance at 5k. Be nice to see the 940 on good fuel, timing bumped, reeds and 50's

Well, you have had some time on a real big bore and before that had a Doo big bore. What's your opinion on the two setups? I kind of know the answer but it's more credible coming from someone who has had both.

 

[BBP]

160ish on doo at 5000 is about 190 sea level, correct? Think that is what most of the builders are claiming so that is not an inflated number and doesn't surprise me. How come you posted corrected to sea level hp numbers on 800s? They should have closer to 135-140 range. Impressive numbers on 940 and and shows how pump gas turbos are a waste unless really running some elevation IMO.

I assumed all of the HP numbers were corrected to sea level. Maybe the OP will confirm.

 

[slyrydr]

I assumed all of the HP numbers were corrected to sea level. Maybe the OP will confirm.

...yes on hp corrected to sea level...shop is custom pipes inc...he's been in the power business a long time, and is winding down his business, closing shop in next month or so...