Fuel consumption, economy, modifications, etc.

[Tom400CFI]

Nothing like the 2 month later response....must be summer.lol.

What did you manage to squeeze out of a 350 with some tuning?

LOL. I hear that...b/c look at me replying now, 3 months later!

We have the 350's down to an average of 4.5 GPH which is fantastic for our resort, and right on par w/the PB 200 Edge. For us, the way we groom, that works out to about 1 gallon/acre produced.

[Canadianbombar]

That's extremely low. Is that US gallons or imperial? What RPM do you set the throttle at? Do you use any additives? I use Howes in my 3500 duramax...never used anything in cats but I think it likely wouldn't hurt to try.

[Tom400CFI]

We run about 1350-1400 RPM for the most part.

No addatives other than "winter blend" in our B20 fuel.

[Canadianbombar]

I kind of figured that's what you were going to say when you said you were covering an acre per gallon...therefore 4.5 acres per hour. 1350 is what I was told to run the 350 at a few years ago that I was getting around 12 hours out of a tank on. It is indeed the sweet spot for fuel efficiency on those. That was just fine with me..I stuck with that religously as it was only my second season in a cat and trolling along at that speed kept me out of trouble and allowed me to learn at a reasonable pace. Imagine my surprise the next season when I landed at a western resort where they yelled at me unless I was literally redlining the thing in a vain attempt to keep up with far newer PB 300 Edges. I became something of a speed demon after that season as it forced me to get used to running the cats at maximum operating speed. All of that said...my thoughts are this : Do you not have experienced ops coming in from other resorts who can't deal with crawling along after running cats at max speed elsewhere?! I'm not sure I could deal with 1350 on a continuous basis after operating at max speeds for a few years. Do you think that the wear and tear saved on the machine by running at 1350 makes up for the fact you're only covering half the terrain you could be if you were running the thing full tilt? I'd say a pretty good argument could be made for burning 1 1/2 times the fuel to keep 1/2 the hours off the machine and payroll to cover the same terrain? I wouldn't mind being able to take my time to produce the absolute best product after running the Indy 500 for a few seasons...but I think running at 1350 would probably seem painfully slow now.

[Tom400CFI]

I think running at 1350 would probably seem painfully slow now.

It is. It WAS...
I hear you, and I thought you might have a response somewhat like that.

I have experienced ops. We are a "big western resort". We do groom at a good rate and produce a lot. The reason that my acres/hr numbers, and consequently, my gallons/acre are seem so low is that unlike many resorts (not necessarily your resort), our "acres" are based on actual product groomed -not what the MP says. The acres of groomed product that our guests have at their disposal...that is what we measure. So if we go over something twice, the MP says "20 acres" for that trail. But the trail is only 9 acres; we only produced 9 (with overlap) for the guest. 9 is what we measure. So our numbers are much lower than other resorts' but I feel they are the most valuable. Whether or not you agree with that measuring philosphy, that is why our APH is so low...not b/c we are running at 1350. Our ground speed is probably pretty similar to yours, and most others.

We have modified the drive systems in our cats to allow us to operat at 13-1400 RPM, average 4.5 GPH, while still producing at the same rate that we used to produce at, burning 6.5-7 GPH in a 350. Same with the 500's where we're down to 6-7 GPH which is unheard of. This drive system modification saved us roughly 15,000 gallons of fuel last winter, compared to the winter before, yet we groomed more acres (minimally). It also makes the case for the PB a lot weaker...when a 350 produces slightly better (for us) and gets virtually identical fuel economy. When there was a 50% difference (4-4.5 GPH for the PB and 6.5-7 for the Bomb) it was much easier to justify the PB purchase. Now, not as much.

[Canadianbombar]

Oh...I completely understand the difference between acres groomed and MP computer acres groomed...we've been into that before on here. My point was....a 350 is supposed to produce around 18 acres an hour run full tilt with no overlap....therefore 9 is the number one would expect to get in the real world with turns and overlap...making your 4.5 still very low and a number that jives with running at 1350 vs bouncing off redline. It sounds like you've changed the gearing...to get more speed at 1350?!? Would that not hurt your grunt on steep climbs and pushes? Or have you mucked around with pump flows? Why would one go to these lengthes to try and get the PB economy out of a BR when a PB is cheaper in the first place? lol Don't get me wrong..I love BR's....but it sounds like you're falling over yourself to justify keeping an all BR fleet. I think an ideal large fleet has 50/50 of each. PB's and BR's both have certain conditions they excell in and it helps at new cat negotiation time if the rep knows you can go either way with your purchase.

[Tom400CFI]

Oh...I completely understand the difference between acres groomed and MP computer acres groomed...we've been into that before on here. My point was....a 350 is supposed to produce around 18 acres an hour run full tilt with no overlap

I'm not sure where you're getting that from, marketing brochure? We don't groom that way and wouldn't if fuel was free. The way we groom, we used to burn 6.5-7 GPH which seems to be a fairly common number for resorts with 350's who care about value, and now we get 4.5 grooming at the same rate, with the same quality product.

Don't get me wrong..I love BR's....but it sounds like you're falling over yourself to justify keeping an all BR fleet. I think an ideal large fleet has 50/50 of each. PB's and BR's both have certain conditions they excell in and it helps at new cat negotiation time if the rep knows you can go either way with your purchase.

I'm totally with you. We have 7 PB EDGE's and 6 BR's -I love BOTH. So am not falling all over myself for anything except waht makes sense. If I can get 33% better fuel economy from a cat, while still producing at the same rate...why wouldn't I?? We didn't change the gears or the hydraulics. Our "mods" were virtually free, and only took a few minute...once we "figured it out".

[Canadianbombar]

Sorry..I was wrong...it's 28 acres an hour. WTF?!?!?! NEVER! I'm pretty sure I had viewed 18.8 Acres an hour in some specification data previously....but the current brochure states 28/hour. See it here...almost the first thing they throw out : http://www.prinoth.com/attach/BR350%20E ... 2006ok.pdf

The reason I know it WAS once 18.8 is I'd had this whole conversation before with another ops manager a couple years ago (after seeing the posted specification on Prinoth's site) about "who in this world actually gets 18 acres an hour" out of one of these cats and we both agreed that to get 18 acres an hour you would have to be going full tilt on a field in one direction for one hour. I'm not sure where the hell they got 28/hour from. Potentially bad metic conversion! Anyways...the net result of our conversation was deciding a real world production expectation (actual acres covered) out of a BR 350 was 8-12 acres an hour depending on conditions. I know when I was running one at 1350 rpms I was covering 80 acres of actual physical terrain in a 10-13 hour night netting me 6 - 8 acres an hour INCLUDING breaks and refueling stops etc.

I thought you guys were an all BR shop...sorry for my erred assumption. Nice to see yet another diversified shop...they're truly the way to go for the previously mentioned reasons. I was netting around 4.5 gal/hr when I was running at 1350 as well. Are you basically telling me the only tweaking you guys did was to mandate running at 1350 and turning the tiller speed down a bit? The tiller speed will actually eat into fuel consumption ALOT. Even more so on the PB than the BR I believe. If I was to muck around with a cat mechanically in search of efficiencies...I think I would be looking at a way to gear the tiller to run at a higher speed than it does now when the tiller pump running at it's HP/torque sweet spot.

[Tom400CFI]

Yeah, that 18 GPH is pie-in-the-sky stuff. 28? Give me a break.

We didn't change the tiller speed, in fact that is one area where we haven't addressed at all; most of my guys run the tiller at full speed...all the time. There is some more low hanging fruit.

We basically changed the drive peramiters so that drive away occurs at 900 RPM now, and full stroke of the pump is achieved at only 1350. All "speed" after that is from motor RPM only. That allows us to groom at the desired speed -same speed we always have- at 13-1400. Impossible before. With the factory setting, at 1350, you've just barely starting to move. Ridiculous.

[Canadianbombar]

Ahhhhhhhhhhhhhhhhhhhh. Very very interesting..I did not know/think of that but I have floated thru the menu's and viewed all the different perimeters in the computer before. I thought they were basically for adjusting the speed of left track to the right if they were out of wack....but now that you mention that too me I suppose you could adjust both track speeds up using that same perimeter screen. It would also explain to me why one 350 I ran seemed to crawl at 1350... and another seemed to move along at an ok clip. If I recall right... there was a perimeter in there for tiller speed as well? You could pull it back a couple hundred rpm so the ops could still set it to 11 but it would actually be spinning slower. Where you have a few of them you could experiment with different settings on different cats running similar routes to see where the optimum setting is for that as well. I'd play the same tiller speed game with the computers in the PB units as well. I KNOW tiller speed has a HUGE effect on their operating efficiences. A 3.5 gph PB anyone? Hmmmm.