DynoTech on the Poo 800-Some thoughts

[AKSNOWRIDER]

Spence, Jim, Ron and all the rest who have contributed to this thread...thank you..We are all so lucky to have both private individuals as well as major companies that are willing to help us joe average guys out with getting the most from our hobbies.....thanks mike

 

[sled-werx racing]

Appreciate that Mike, I will tell you at times it seems we're whizzing into a fan here but it doesn't stop us from at least 'trying' to help.

Talked to Rich this morning, will be talking to him later tonight again, have updated our site for now.



have a good day
Spenc

 

[steepndeep]

a reply from Polaris

154 HP is the published number for our 800 SDI. Our engines are tested on our dynamometers following very specific processes. I can’t comment on measurements made by other testers because different dyno’s, setups, calibrations, temperatures, gas, etc. can lead to different results. Comparative measurements on a particular dyno’s are more important than absolute measurements. In other words they are good for comparing calibrations, setups, our 800 to Ski-Doo’s 800 and so on. All that said the most important measurement is the real world performance of the snowmobile. And this sled is awesome.

Consumer Services
Polaris Industries, Inc.




This the the quote from polaris about the motor HP #'s.
I think some of you who are getting down on the numbers are jumping the gun, Why doesn't one of these dyno companies do a side by side same fuel, same air, same everything comparison with a ski doo or Cat. That's all a dyno is truly good for it's a tool for tuning and comparing. No one I know rides a dyno on the flat's or up a hill. Yes in perfect conditions this motor probably makes 154 hp. How often do any of you ride in perfect conditions? I also believe there is probably a little left on the table for the aftermarket companies to go after, but that is normal, He-- doesn't cat leave like supposedly 8HP on the table with just a Y Pipe. The point is this is good info as far as dyno #'s but to get a true comparison dyno another brand same day say conditons non biased then go ride them side by side see what works on the sled, guarenteed what works on the dyno will not be perfect on the snowmobile. Some of you I think have made Ref. to Carls 910 doing cirlcles around the PSI 990 and the PSI had 40 more HP on the dyno. Again the the 990 might make that in perfect conditions but no one rides perfect conditions.

If I remember correct when some of the companies dynoed the Ski doo's last year weren't they down in the 146-7 range? Just going by memory have not looked it up. We all know they worked good last year as well as the D8's I'm fairly certain Polaris did not detune the sleds. They do still have to meet EPA standards.
Take the #'s for what there worth get them out on the snow and then make changes if need be. Just my opinion!!!!

 

[Ron]

Thanks for the info Steep. Note too that some of the naysayers are a little late to the party, the sleds been out a year. SLP had an engine in early 08 yet didn't release their single pipe until late 2008 after testing it in the snow. I didn't find a better performing XP (dyno'd more HP) last year but there are lots of variables in consumer sleds. To date, Polaris has the most efficient drive train between Poo, Cat & Doo. Many Doo guys are putting on Polaris Drive and Team driven clutches, still might be the best performance mod for the XP.
Sure hope these aftermarket goodies get a good test in the snow.

 

[BCB]

Extreme Performance in Longmont and Castle Rock CO does. They sell all four major brands of sleds. They are unbiased and actually may lean a little Polaris being that is what they started out selling. Check out their website for all their comparisons.

http://www.xtreme-performance.com/custompage.asp?pg=dyno_results_polaris

Their dyno was also featured in Snowest last year. I did post about this last year and was almost flamed to death for it. Believe you me I am totally biased toward Polaris. That is the only brand I have ridden since 1990.

 

[R44guy]

Dyno Information

I want to thank all of you guys who have contributed to this thread. It gives alot of information and shows more than just one side to the power verus performance in the snow. We all know some performance companies sell performance products that dont perform the way they say they do. Also some performance products do work ast stated. With out talking about the obvious changes in the hills to the flatlanders. I also have to say that I think when you play you pay! So if you blow it up or you get to agressive we have all learned you can never have enough information to help avoid any other educational lessons we have all learned along the way more so with mods but even with stock motors. The only question that remains is why is there so much poo on this thread?

 

[thefullmonte]

Extreme Performance in Longmont and Castle Rock CO does. They sell all four major brands of sleds. They are unbiased and actually may lean a little Polaris being that is what they started out selling. Check out their website for all their comparisons.

http://www.xtreme-performance.com/custompage.asp?pg=dyno_results_polaris

Their dyno was also featured in Snowest last year. I did post about this last year and was almost flamed to death for it. Believe you me I am totally biased toward Polaris. That is the only brand I have ridden since 1990.

So, that's 3 companies showing peak hp at 7900rpm
Just out of curiosity. Those of you that clutched for 8300. What was your sled doing at 7900 that you felt it wasn't right? I'm not doubting or bashing, just curious as mine worked amazingly at 7900. Thanks Monte

 

[allblowdup]

Well the one thing that I see is the water temp is a little low. This could represent a shorter dyno run. The factory pipe would be fairly loose at the higher altitude and would take more pipe heat to rpm higher. Afr is rich also and that would slow the pipe from heating also and give peak at a little lower rpm. Having said that it still looks like a good real world dyno run.

Are these the same guys that do the extreme pipe mod for the d8's?

 

[sled-werx racing]

thefullmonte wrote: So, that's 3 companies showing peak hp at 7900rpm
Just out of curiosity. Those of you that clutched for 8300. What was your sled doing at 7900 that you felt it wasn't right? I'm not doubting or bashing, just curious as mine worked amazingly at 7900. Thanks Monte




Have always clutched to peak torque over max HP . Yes every tunner is different perhaps and to each their own but we have had success clutching this way. Sleds alway feel and pull strong and never fall off the power curve. For the novice you will see what we mean by looking at any dyno chart...watch for max HP and pay attention to where max torque lays in relation to where MAX HP lays and where MAX HP falls off.

part reason we're so interested in what Rich is working on and that is to hopefully provide a very strong single pipe that provides more torque at lower rpm's , in comparison to what we've seen to date that is. I will say this, Rich was VERY impressed with the SLP single pipe - in comparison tests to what he's been working on

enjoy the day.... snowing here in Eastern Ontario for the first time this year!

 

[Clark]

Enough said, the D800 doesn't have the torque. The 06 700 has more torque Why, longer stroke. Longer stroke = greater piston speed. The problem is keeping the longer stroke motor together. Thats why Pol built the D8 short stroke, quik revs, and probably won't fly apart, but 154 HP that is phony and no torque for the hill lugging. INDY DAN Said big volume cases made power the old 600 triple had huge cases. Indy Dan knows.

 

[BCB]

Here is the post from last January when I first brought this topic

up.http://www.snowest.com/forum/showthread.php?t=56909&highlight=dragon+dyno

Don't get me wrong I love the 800 Dragon. The chassis is great, I do have it clutched for 7900- 8000 RPM. That is where it pulled hardest for me at 9-12k feet. That's with Carl's clutch kit including helix. I ride with XP's and think overall this is the best chassis out there. It will trade marks with any 800 out there. If it is really down on power then that should be a testament to how good the RAW chassis actually puts the power to the track. Just imagine this sled with another 10 HP.

I just think you should be able to verify the numbers Polaris is claiming with any stock 800 Dragon without a fuel controller or pipe modifications. Just how they sell them and just how many people ride them -stock- within the EPA regulations. If they can't do that then don't hype the numbers.

 

[Ron]

Enough said, the D800 doesn't have the torque. The 06 700 has more torque Why, longer stroke. Longer stroke = greater piston speed. The problem is keeping the longer stroke motor together. Thats why Pol built the D8 short stroke, quik revs, and probably won't fly apart, but 154 HP that is phony and no torque for the hill lugging. INDY DAN Said big volume cases made power the old 600 triple had huge cases. Indy Dan knows.

The 800 has 2mm longer stroke than the 700. The monoblock design has a lot of flow up top. The engine pulls better with more R's....that's a fact at 5-8000'.
The leader in aftermarket engine mod for the 800 is SLP....by a huge margin, yet their dyno numbers are not taken seriously??? Like I said to start with....most dyno numbers are almost always from someone wanting to sell you something. Why doesn't SLP claim low numbers and a bigger gain from their mod's? We are all in the same boat here, just some seem real hung up on dyno numbers as the answer. I didn't need a Power Commander on my 08! These discussions can be healthy but they don't prove a thing until dyno tests are supported by real world "in the snow" results.
I'm beginning to see why some mod shops like Carl's Cycle don't play the dyno game. They just get it done in the snow.

 

[sled-werx racing]

Rich should have the new set up at the Adirondack Shootout - we'll all see the REAL WORLD results at that time. Remember, he was very impressed with the SLP combination stating it was VERY strong, however he's hoping to bring a little more torque to the table - time will tell, and we'll provide the dyno sheets on our site for all to see/judge

What's been great for guys down in the East here is DTR and DYNOPORT putting this sled to the test pre-snow for all the flatlanders. If nothing else it's kept us all 'interested' and given the over hyped stock #'s I personally think Polaris has come out 'ahead' with all this information both good & bad

 

[thefullmonte]

Ron,
Thanks for this great post. And thanks to all of you who have contributed info and knowledge to this as well. These forums are about questions and answers, but this thread has been exceptional.

Have always clutched to peak torque over max HP . Yes every tunner is different perhaps and to each their own but we have had success clutching this way. Sleds alway feel and pull strong and never fall off the power curve. For the novice you will see what we mean by looking at any dyno chart...watch for max HP and pay attention to where max torque lays in relation to where MAX HP lays and where MAX HP falls off.

Does anyone have a graph showing the torque curve for the D8? This was a really good comment. When was the last time we referred to a a clutch as HP sensing? These are more commonly thought of as torque sensing.
I'm really not trying to steer this thread off course. BUT.......
Spenc,
Would you care to elaborate on this a bit more? You definitely have my attention.

 

[Ron]

FMonte,

I noted earlier that peak torque was even lower than peak HP on the stock engine-DynoTech chart. I don't have the DT info in front of me but I believe peak torque was 7600 RPM on the stock 800. Gets even further away from what most of us actually clutched our 8's to run. Why are the DTR results so far from our actual?
Peak torque is always? lower than peak HP. Torque in a 2 cycle is similar to that of a diesel truck or any other working engine...it's what provides the power to pull a load. If you are drag racing on hardpack or ice you might clutch to HP, but for most snow conditions you clutch to torque because of the load. You might buy a diesel truck for torque but a Porsche for the HP.
Here is the torque quote from my earlier post:
Normally many use torque for clutching rather than HP, DTR reported peak torque even lower, 97.6 @ 7400 & 96.7 @ 7900 & 88.6 @ 8100.

 

[dynotechjim]

To clutch for maximum acceleration in good traction conditions, you should be shifting at the engine's HP peak from 400 degrees CS temp (maybe 7600) at clutch engagement to maybe 1250 on the longest run (maybe 8300) (steel turns red at 1250). Knowing exactly where the HP peak occurs makes that possible.

We used to think that we were getting best acceleration shifting at torque peak (a few hundred revs lower than HP peak on a typical 20 second dyno run). But eventually, after 20 years of doing this dyno testing and converting that data to best possible field/ track performance we realized that we were really shifting at cool pipe HP peak. The HP peak RPM is a constantly moving target, moving up and down as pipe gases heat up and cool down. That's why I thought it would be good to create a pipe CS temp/ peak HP RPM chart or map, to be useful for hotrodders to achieve best possible acceleration by measuring their own CS temp.

Now for revelation #2, today we dyno tuned our first Dragon 800 Switchback. This was a whole new ballgame--instead of 110 lb/hr peak HP fuel flow this one was in the mid-nineties lb/hr! With cool coolant to eliminate midrange knock we made exactly the same peak HP as the Dragon 800 SP with PCIII yanking a pile of fuel, 152-153 A/F in the 11's and mid .60s BSFC. According to Polaris-savvy people the Switchback has the same ECU programming as the RMK. If that's the case, then the question that must be answered is how does the Switchback/ RMK ECU calibrate at high altitude? For you mountain guys that information may be provided by Bill and Donavan at Xtreme. And for mountain guys, the fuel flow/ HP/ coolant temp graph I posted here is useless for you, and only needs to be an eye opener for the flatlanders who own D8 SPs.

In order to use the BMP pipe mod on the Switchback, we had to add fuel heavily in the midrange to keep it knock-free, and some on top end, whereas with the SP we were able to reduce fuel flow for max HP. Everyone needs a wideband.

 

[sled-werx racing]

Good post Jim!


here's some udpated info for whoever's interested

http://www.hardcoresledder.com/forums/index.php?showtopic=361120


It's snowing like crazy here in Eastern Ontario!!!!

 

[AKSNOWRIDER]

well more good info, when I first put my sled on the snow last year new stock it pulled 8250 and while it ran good it wasnt spectacular up top..since then with adding the slp single ,carls clutching and such I have played around with rpms from 7700-7800 all the way up to 8450...with on the hill changes results went from 7800rpm 3/4 climb up the hill to 8450 rpm and easily going over the top...I imagine this has to do with pipe cs temp..on flat and hardpack it pulls harder at lower rpms....clutched for 8450 it is slower on hardpack...again...my guess is pipe cs temp is lower....

 

[Tdubbs]

To clutch for maximum acceleration in good traction conditions, you should be shifting at the engine's HP peak from 400 degrees CS temp (maybe 7600) at clutch engagement to maybe 1250 on the longest run (maybe 8300) (steel turns red at 1250). Knowing exactly where the HP peak occurs makes that possible.

We used to think that we were getting best acceleration shifting at torque peak (a few hundred revs lower than HP peak on a typical 20 second dyno run). But eventually, after 20 years of doing this dyno testing and converting that data to best possible field/ track performance we realized that we were really shifting at cool pipe HP peak. The HP peak RPM is a constantly moving target, moving up and down as pipe gases heat up and cool down. That's why I thought it would be good to create a pipe CS temp/ peak HP RPM chart or map, to be useful for hotrodders to achieve best possible acceleration by measuring their own CS temp.

Now for revelation #2, today we dyno tuned our first Dragon 800 Switchback. This was a whole new ballgame--instead of 110 lb/hr peak HP fuel flow this one was in the mid-nineties lb/hr! With cool coolant to eliminate midrange knock we made exactly the same peak HP as the Dragon 800 SP with PCIII yanking a pile of fuel, 152-153 A/F in the 11's and mid .60s BSFC. According to Polaris-savvy people the Switchback has the same ECU programming as the RMK. If that's the case, then the question that must be answered is how does the Switchback/ RMK ECU calibrate at high altitude? For you mountain guys that information may be provided by Bill and Donavan at Xtreme. And for mountain guys, the fuel flow/ HP/ coolant temp graph I posted here is useless for you, and only needs to be an eye opener for the flatlanders who own D8 SPs.

In order to use the BMP pipe mod on the Switchback, we had to add fuel heavily in the midrange to keep it knock-free, and some on top end, whereas with the SP we were able to reduce fuel flow for max HP. Everyone needs a wideband.

Jim, I am curious as to why Polaris would calibrate the switchback with the same fuel mapping as the RMK?? Surely they wouldn't think this thing was going to be used at altitude all the time...It's designed as a crossover sled...why would it be so lean on top and the D8SP so rich?? The sled ECU theoretically should compensate for altitude via the barometric pressure sensor correct?? Now I am even more confused than ever....why would poo make the switchback so lean and the SP so rich....if anything the motor on the switchback will be loaded harder for longer periods of time through offtrail deep snow and pulling a longer track than the SP ever would be...

Do you have more SP's scheduled on your dyno?? What were dynoports fuel flow numbers?? Were they just as rich up top??

 

[indydan]

Clark

Enough said, the D800 doesn't have the torque. The 06 700 has more torque Why, longer stroke. Longer stroke = greater piston speed. The problem is keeping the longer stroke motor together. Thats why Pol built the D8 short stroke, quik revs, and probably won't fly apart, but 154 HP that is phony and no torque for the hill lugging. INDY DAN Said big volume cases made power the old 600 triple had huge cases. Indy Dan knows.

CLARK, As Ron said the new D800 has 70mm stroke.

The bore and stroke on both, the old 800 and the new 800 TWINS are exactly the same. the new 800 motor is just alittle shorter between the spark plugs.

CLARK, You mixed things up alot in that post. " INDY DAN Said big volume cases made power the old 600 triple had huge cases. " I didn't saying anything like this, please re-read carefully and think carefully before you " quote. " your getting different motors and cylinder numbers all mixed together.

Dan