October 2008

Sunday, October 19, 2008

DynoTech : Dragon cooling improvements revised

Xtreme Performance Dyno has been simply removing the Tstats from last year's RMK800 and this years Dragon 800s. This allows unrestricted coolant flow in parallel through front and rear heat exchangers. Bill Davis reports that this drops coolant temp to max of 100-110 deg F on hard running, albeit with way less HP (high altitude) creating engine heat.  It's been suggested by Polaris techs that plumbing the heat exchangers in series like the SnowX racers (as the following link shows) might cause coolant flow to be restictive, lower than the 22 gal/ minute flow they say is necessary to do the job. The easiest thing to do is pop the Tstat out, just run the oring gasket. Check coolant temp and we're hoping that in reasonable snow it will run 100ish. But if on hard pack, high speeds if it climbs to 125+ you will just lose HP from the hotter coolant/ lower airflow and the increased liklihood of knock that will result in less timing/ richer fuel flow. Surely some are doing the series plumbing like the similarly powerful 600 SnowX mods, that run on-off-on throttle but never see much over 80 degrees F. We can report how this does work out.

Dragon owner Doug Meyers (thanks Doug) sent us this link to show how to put D8 heat exchangers into series.This is how the new IQ race sleds are plumbed:

http://parts.polarisind.com/PrintAssembly.asp?assemblyID=38095&AssemblyName=ENGINE, COOLING SYSTEM - S09MX6JS/JE &ModelYear=2009&LineName=SNO&Print=Yes&ModelName=600 IQ RACER/EURO - S09MX6JS/JE

Wednesday, October 15, 2008

DynoTech : Selling PCIIIs for Dragon 800 EFIs

I have a batch of Power Commander PCIIIs w/ factory-style plug-in ECU connectors for Dragon 800s coming in on 10/17.

Currently I have maps that we created here for max pump gas HP for stock pipe (drops fuel flow from 110 to 95 lb/hr and adds 10 HP), BMP stock pipe mod, SLP pipe, and SLP pipe w/ Xtreme pipe mod (if that becomes available).

After this initial testing/ tuning with the PCIII I believe this is as precise as a factory remap, so I believe a max HP map we created to achieve close to 154 HP with the stock pipe is applicable to all Dragon 800s operated below 3000 ft altitude (testing will be done soon to see if this identical mapping is ideal at 6500' at Xtreme dyno).

The PCIIIs we ship to DTR subscribers will be pre-loaded with the map of their choice (and that can be altered or changed to a different DTR map by the user with supplied software and PC cable), so it will be a plug-in and go deal.

I have sold Boondocker boxes for years to people who come here to dyno tune, and will continue to do so. Boondocker surely deserves a Nobel Peace Prize for developing this great EFI tuning device that not only adds fuel, but can also reduce fuel! This has enabled EFI sledders to do whatever they like to hotrod their machines, including pressurecharging, and tune as nicely as carbureted engines. This is great for individual dyno tuning here. I've done many hundreds of Boondocker tunes. But I have seen in most instances that each sled, seemingly identical requires a different Boondocker tune to be precisely spot on.  Perhaps this has been in some instances due to vast difference is base tune of F7 ECUs. But it's been varying enough that I wouldn't sell a Boondocker over the mail with a preloaded map, and expect the buyer to be pleased.

But the PCIII is different in that it uses very precise steps in RPM and throttle position to add or subtract fuel. So I'm as comfortable sending out a preprogrammed PCIII to a Dragon 800 owner as Polaris might be doing a remap of fuel flow.

I plan to maintain an email database of people using these preprogrammed PCIIIs, and as subtle tweaks/ improvements etc are developed those will be shared instantly.  

The current user price is $350, and when I receive the boxed PCIIIs on 10/17 I will take one to the PO to  find out the cost of shipping/ insuring. Preloading the PCIII is fairly straightfoward, done with a cable from the dyno computer to the PCIII (either on the sled, or off). Map upgrades can be done by the user, and new maps are e-mailable. Lots of PCIII info is on their website.

Twenty years ago, for $5.00 I  used to put two 320 main jets in an envelope and send them to Arctic Cat Wildcat owners to replace the 400s they came with. Times have changed, but the HP % increase available  from proper performance tuning is still the same.

Also for those interested in the SLP single pipe mod, Xtreme Polaris will do those for $220, or sell a new SLP pipe kit w/ mod for $850 (normal unmodded price is $630) 303-654-0867


Sunday, October 12, 2008

DynoTech : Dyno Over-Correction factors and agendas

There's a good post on HCS Polaris IQ forums by an educated guy requesting correction factors used by OEM and aftermarket companies, and independent dyno testers like me regarding HP results on the new 09 Dragon 800.

When I borrowed $50,000 22 years ago to acquire this SuperFlow 901C (and C was a huge option because it came with a computer to remember things). That computer was a $5000 option. Very cool. How about printing plots of the computer generated graphs? Another $2000 got me an incredible plotting machine that grabbed tiny felt tipped pens out of a six-gun-like cartridge, held the pens and slid each pen side to side, and the machine slid sheets of shiny paper up and down to create very cool looking cartoons of the HP graphs.

I threw that stuff in the trash years ago, replaced it with a $500 computer that is 100x faster than that old pre-288 $5000 slug. New software has come along from SuperFlow (another $5000) to enable us to utilize the more powerful $500 computers, now we have real-time graphs (show up on the monitor as they happen live) and instant readouts of the Corrected data.

The Corrected data from the dyno is the same today as it was 22 years ago.

We have always had two Correction factors to select from--Standard and SAE.

The actual dyno test on any given day is listed as "observed" data. That is the actual torque and HP made on that day. If we test in August with high humidity, we get low observed HP, and correction factor will increase that number. Conversely, if we test in Feruary, -10 F in the dyno room, high baro, the correction factor will reduce the observed  HP to a lower, more realistic number..The corrected data should be the same whether the engine was tested in Aug or Feb.

Standard (STD).  is the expected HP the engine should make at 60 deg F dry air, sea level 29.92 in hg (inches on mercury baro pressure).

SAE is more conservative, some engineers say more realistic as a continent-wide average. That correction factor uses a higher altitude, 29.38 in hg, and 77 degrees F.

When I figured out how to run the dyno in my shop, on a brand new 87 Yamaha Exciter I saw quickly that SAE HP was no good, because it was lower than STD. We wanted big HP, and if it took the most optimistic correction factor to get that, why, that's what we'll use! STD was the official DynoTech (C&H Dyno then) correction factor.

This goof-ball decision would have enduring impact upon aftermarket and OEM data that would be released to the public for the next 30 years. Back then we got zero HP data from snowmobile manufacturers, and very crude, vague info from the few aftermarket suppliers that had dynos. Some aftermarket suppliers' catalogs had awful, hand drawn graphs of before and after HP. Lots of it was complete bull. That's why I built my dyno (another story).

Knowing that I had impartial dyno infomation that the public really needed, I began publishing stock and modified dyno test results, all in the most optimistic STD, in my DT newsletter. Once I began to publish  STD HP of all the stockers, and all the mod stuff, the bar was set. Ten years later, when manufacturers began publishing their own HP numbers they wisely used STD instead of SAE, so as I like to think, their numbers would match mine in the early 90's, and they continue to do so today. So probably because of me, the snowmobile industry has adopted STD as the standard instead of SAE that's used by the automotive, boat, and motorcycle industries. Surely that's a feather of dubious value in my hat.

Over the years, as the most notorious Dyno Detective, I have discovered new correction factors. To name a few:

KJ Correction: Knob Job correction factor. My dyno has a torque correctoion knob under the console, ostensibly to zero the torque of the dyno each run. Problem is, that knob can add or subtract up to 12 lb/ft of torque for a full dyno test! I discovered that 15 years ago, when Pro Stock bike dragracer Paul Gast sent his Kaw drag engine to a big name engine builder in Florida. Paul used my dyno, with dyno driven from trans output shaft to dyno with a splined custom driveshaft. 200 HP leaned to the bone. Sent the engine to FL, the engine builder with an identical SF901 dyno baselined 200 HP. Then he did some stuff to Paul's engine, got a 218 HP dyno sheet and the engine back in a crate for something like $5,000. Dandy. 

Paul bolted his engine in the bike, drove to NYIRP drag strip and ran identical ET/ MPH as before. WTF. So Paul called me  from a pay phone (no Cel Phones back then) while I was eating dinner, to tell me of this strangeness. So I met him at 8:00 PM at the dyno (to my neighbors' chagrin), hooked the bike up an voila 200 CHP. So I looked at Paul's "after" SF901 dyno sheet from this infamous engine builder, and I noticed that there was 10 lb/ft of torque extra from low RPM to HP peak. So on a hunch, I cranked the torque zero knob to 10 lb/ft at rest, and showed Paul what I did. Next dyno run, 218 CHP. Complete B.S., the original KNOB JOB. Paul Gast is a great guy, the marketer of Lectron carbs for sleds and bikes (all PS Japanese bikes run Lectron carbs except one that's trying EFI). I'm sure his attorneys got his $5000 back.

Next correction factor is the BEB Correction factor. This is the Boat Engine Builder's Correction factor. .Sonny Hawkins is an old friend, sled hottrodder, and offshore boat racer on some national cicuit with a 30' catamaran. He told me about new engines he had built in Erie County, 500 CID 750 Holley NA 800 HP (that made my eyes roll back). But his boat was slow, maybe 110 mph instead of the 120 the Chris Cat hull should run with a true 800 HP per side. After fighting with the hull designer and prop guy, he pulled an engine out to have it "re-dyno'd" at the engine builder's shop just to make sure all was well. Sonny bugged me to go along, and being friends I reluctantly came to observe. Being savvy on electronics, BSFC etc I caught this engine builder cheating 250 HP! That 800 HP engine was really putting out 650, which is what it takes to make a 30' Chris Cat run 110.  I think the attorneys settled that issue, too. The Boat engine builder's answer was, "all the boat engine builders have their dyno's cranked up, if i don't do the same, no one will buy my engines"....

One more important one and please this is about a now-defunct company:
Unscrupulous Sled Aftermarket Company Correction: Local sledder Al S. came to DTR after a season of fighting to make reasonable performance with a huge buck PSI 1140 twin in a ProX chassis. Al paid an extra $300 to get his engine dyno tuned by the builder before he got the engine. In the crate with the engine was a dyno sheet 225 HP or therabouts. After struggling to run by stockers, Al finally brought his sled to DTR.  I think it was 157 HP. We cranked the timing to the max and it made 172 but that's all it had. So in this case the USAC correction was to add 43% to STD correction. That dyno sheet looks real. But it pays to be leery.

Bottom line is. all these modern dynamometers are computerized things, all can be tweaked at the will of the dyno operator to say what they want. I can make a weedeater on the dyno show a 987 HP dyno sheet. I have many friends in the aftermarket with instrumented dynamometers. I doubt that if they build really good stuff (which ultimately keeps them in business) they need to crank the knobs on their dynos. And also all major aftermarket players know their work will eventually show up on my dyno, and the real numbers are made here. Besides being ethical builders, knowing that their customers can make the same HP at my dyno is a feather in their hat.

Thousands of people enjoy seeing real numbers on DTR website, and the modest subscription fee pays for a lot of the high overhead and work involved compiling the data, and ensuring its' accuracy. I have no agenda other than to provide the most accurate data possible for people who follow my stuff, and for people who come here from many 1000's of miles away to test and tune, and see the real, not pretend HP numbers..

Sometimes I feel bad if we can't find the HP a dyno user is expecting, and a twist of the dyno knob can achieve temporary happiness for the sled owner. But a knobbed dyno sheet doesn't help the sled run faster. Even a modest knob twist might seem harmless to please a paying customer who, say, is hoping for 300 HP on a HTG XCR1200 triple (often achieved by those if everything is dialed in perfectly), and is tapped out at 296. But you can't do that! Case in point, my old dyno pal Gene Hurin came last year to dial in his HTG1200 lakeracer along with Rob Schooping. We tweaked timing and jetting for an hour, 296 was "all" it would make, and Gene was bummed. An modest torque knob bump could have gotten 300.0 but I can't do that. So after maxing out at 296, while pulling Gene's sled off the table we noticed lots of oil in the bellypan. Rob pulled the pipes off, and discovered a chunk of epoxy in the crankcase (used where the boring bar breaks through the case when oversize sleeves are fitted) had come loose, causing a huge crankcase leak! Gene was relieved, because he knows that leak probably cost 4.0 HP, and he plans to come back again this fall to get his 300.0 HP dyno sheet to admire. But what if I had knobbed him 300.0 with that unknown crankcase leak? Then Gene would have repaired the leak. come back to test again expecting 304.0! Once you do a compassion knob, you're destined to knob forever, just like people who lie must continue lieing. It's a viscious circle.

I hope Gene doesn't make 299 with his sealed crankcase, because he'll likely be even more bummed, like the guy with 11 3/4 inches who is bummed because it isn't really of foot long.





Saturday, October 11, 2008

DynoTech : AmSnow/ DTR Adirondack Shootout

This December, the Adirondack Shootout in Woodgate, NY, will once again be hosted/ covered this year by American Snowmobiler Magazine and the AmSnow website.

When our pal Jerry Bassett sold American Snowmobiler a few years back, the new owners opted to skip covering the Shootout, and we found a fine partner in SnowWeek/ SnowGoer Magazines. Tim Erickson and crew covered the Shootout for several years, but now that SnowWeek is no longer being published, we lost our instant publicity that our aftermarket participants/ companies desired. SnowGoer will not return as our publishing partner.

Instead, we've renewed our relationship with American Snowmobiler, who began the Adirondack/ Old Forge, NY Shootout 18 years ago with DynoTech Jim, George Taylor (then owner of Shootout Headquarters Van Aukens Inne), and the sled dealers in the Old Forge area. [Big Moose Yamaha/ Cat, White Lake Polaris, Smith Marine (again) SkiDoo]. AmSnow editor Mark Boncher suggested that AmSnow website can provide instant results of the Shootout, and the magazine article is planned to be featured in late January.

We're still finializing plans for the Shootout, but our initial concept is to run all 600 stockers, 800cc stockers, and all four strokes.

Aftermarket trail/ lake mods will be provided by aftermarket companies who agree to place a 1/6th page display ad in American Snowmobiler (that's always been their prerequisite). There is some discussion of bolting aftermarket parts on the Shootout stockers, for back to back upgrade results. We'll have awards for various categories as entrants are solidified.

 In addition, we're planning to have up to 10 consumer-owned lakeracer sleds, each sponsored by one or more of the aftermarket companies in the Shootout. This is a 660ft deal, anything goes, full body required situp style, 3" front and rear travel, full length skis. Trophies for these sleds will be best ET, and separately best MPH, two stroke NA, two stroke power adder, four stroke power adder.

This year, the Official Shootout Motel Headquarters is the North Woods Motel/ Restaurant/ Cocktail lounge in Old Forge. Van Aukens Inne is no longer part of our program. The Shootout Banquet is scheduled for Friday night at the Trail's End Restaurant in downtown Old Forge.