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broken dyno drive components...

For the next few weeks or so, all 400 plus HP tuneups are on hold. The following photos show what is left of my $1000 big driveshaft.

In my blog schedule I facetiously suggested that last weekend after the Shootout, "OSP Jim and crew [were coming here] trying to break my dyno....". I won't be making jokes like that anymore!

Saturday afternoon, OSP Jim and madman driver R. Dustin came to demo the power of Shawn Burke's Adirondack Shootout record setting turbo Nytro (anyone who was at the Shootout knows it really didn't need much dyno tuning), but we never got to make any big power with the Nytro before the steel molecules in my big driveshaft got tired of holding hands. While loading the engine at 8500 RPM in preparation for our first dyno test, we felt a 1/2 second shudder followed by a loud pop and the engine was against the rev limiter for a fraction of a second before being shut down. The driveshat had separated at both ends--from the rubber vibration dampener at the engine, and the automotive ujoint coupler at the absorber end.

Fortunately, the orange colored driveshaft loop did it's job, and the roof of my building is dented by small parts but unpunctured. But there was a violent 360 degree spray of bolts, u-joint bearing caps and bearing needles that created many new holes in the ceiling tiles, walls, and light fixtures. And there are surely some IED-like steel shrapnel that I will find, rusted, in the parking lot next spring.

The taper end on Shawn's nytro is bent, but that working end, splined to the end of the three cylinder crank is replaceable from the side of the engine.

But most importantly no one got hurt. I will keep what's left of the driveshaft to explain to people that come come here why we never enter the dyno room with the engine under power.

Do I need a stronger driveshaft? Nope--it wasn't fatigue from too many high power sled engines (the shaft is designed for 500 lb/ft continuously), but operator error that created this havoc. Trying to assess this mess, like a forensic detective, I think this is what happened...

Torsional vibrations--impact gun-like forces that create havoc with crankshafts/ crank tapers/ clutches appear to be extremely violent on three cylinder four-strokes when boosted to many times their designed torque levels. Monsterous torque levels can cause those engines' cranks to wind up and unwind, creating torque spikes up to 10x higher than the engines' average torque. This can cause premature wear on clutch parts, and slippage of crank tapers creating wedging of clutch tapers or even worse fretting enough to melt and weld the steel on the crank tapers! Recently FPP Justin was here with a high-boost 4tec that after maybe five 400+ HP tuning runs, and spot welded it's crank to my SkiDoo dyno adaptor. I was able to remove the adaptor from Justin's crank, but there were some small chunks of his crank taper melted and welded into the female taper on my steel dyno adaptor. But I have had very little trouble like that with the many high boost four cylinder Yamahas and two cylinder Z1s tested with big torque. There just seems to be more torsional vibes with the big triples.

I was hoping not to do unintended taper welding with the OSP Nytro. So when R. Dustin showed me a light coating of moly lube on the crank taper (they do that to prevent stuck clutches), I decided to not clean it off, and see how that might help prevent taper galling during dyno testing. I installed the grade 8 dyno adaptor bolt with all the torque my IR 1/2" drive impact would put out, and attached the drive shaft. But when we began testing--loading the engine at 8500 there was some unhappiness with the dyno trying to control things. The SuperFlow dyno is completely automated--if you set the control to hold the engine at 8500 before beginning at test, it will try to do that regardless of whether it' 50 or 500 HP there. In this case, the dyno seemed to obtain the desired 8500, but then it would misfire like tuning was poor but Jim saw on his laptop monitoring the stand alone that it was against the rev limiter. But the dyno measures dyno speed, and Jim was measuring engine speed so that difference was probably my coupler slipping on the crankshaft taper! But that didn't register with me (never had that happen before), and it should have. Brain failure one is I should have removed my adaptor, cleaned the tapers and started over. But we tried again several more times befor the catostrophic failure, and this time I believe the torsional vibes/ slippage caused my tight crank bolt to begin backing out creating even worse slippage, and severe out of balance condition at the engine. And that perhaps created more strange, almost indescernable vibrations that were causing the four bolts on the dyno end to become loose, and eventually completely remove themselves from the adaptor and fly away. So my second brain failure was not going to check the condition of the driveshaft fasteners prior to each attempt to test. All four nuts flew, as did the lockwashers and bolts. Nothing broke, the fasters just loosened up and removed themselves in just a few seconds of operation, then flew in all directions like the square pieces of a pineapple hand grenade. I've done this so many 1000s of times without fastener issues, I ignored them at the worst possible time.

So OSP Jim will need to replace the Nytro crank end (hopefully only a few hundred bucks) and I will replace my big driveshaft. No need to redesign it, just build it again. But my cavalier assumption that what I tightened during setup will remain tight during the session is changed. And maybe now blue locktight on dyno shaft fasteners on these big engines will be part of the program for gonzo HP things.

And I must compliment the OSP guys on having the demeanor necessary for anyone who regularly races/ tests/ sells engines approaching 10hp/ cubic inch. Not everyone has that. Gaskets can squirm out, pistons can sieze, blocks can crack, rods can snap, and dyno drives can fail. I don't know who coined the calmly spoken southern drawl phrase "parts is parts", but it's appropriate.

This innocent looking small engine coupler is about $600 worth of stuff- the eight hole Lord torsional vibration damper is a key component necessary to protect the engines from their own harmonics. And that center self aligning bearing (what's left of it) is designed for the linkage of helicoptor rotor assemblies. The aluminum part is custom made on CNC machinery. New parts are on the way here.

Boost, fuel flow, & ignition timing relationship

BOOST, TIMING, & FUEL

On the dyno, we often jockey ignition timing and boost pressure levels, to enable us achieve maximum reliable power on a given octane. Do we go with more timing and lower boost, or less timing and more boost? Less timing advance and higher boost mean higher exhaust temperature (and hotter pipes) helping drive the turbo’s exhaust turbine harder and more quickly and higher intake charge temperature (less dense and more prone to deto) especially on two-strokes that have some of the intake charge spend time inside the hotter exhaust header pipe on the bottom half of each piston stroke, before the returning sound wave shoves it back into the exhaust port. More timing and less boost can have the opposite effect along with the increase in transfer of combustion heat into the heads while the expanding burning mixture spending more time there driving the pistons down instead of burning in the pipe(s), making them hotter! But what about fuel flow? We can make max HP at about 13/1 A/F, but we get the greatest combustion chamber cooling effect (and least power output) at 10/1. What shall we do? Jockeying all three about, and watching for/ listening to detonation is what we must do while we observe torque and horsepower on the dyno (or observe clutch RPM during field testing—was that 50 more RPM, or 50 less RPM?).

Some years ago DynoTech was contracted to create an optimal pump gas tune (ignition timing curve, fuel flow, and boost level) for a turbocharged Buell motorcycle that was being considered for production (details of the turbo Buell “Diablo” were made public in Cycle World, May 2010, page 44). We built five Buell X1 engines/ bikes for H-D to test with custom dished low compression pistons with tight squish band clearance to obtain the combustion chamber turbulence necessary for rapid flame speed (which results in less ignition timing required to achieve best torque). We also designed and fitted each bike with efficient side-mounted intercoolers with plastic pro-stock style air scoops (there’s a photo of one of the turbo Buell X1 test bikes on our motorcycle dyno on this website when you click on “About DynoTech”). H-D had loaned us engineering software to enable us to tune the front and rear (hotter running) cylinders individually. Their target was 125+ rear wheel HP (about 50% increase over naturally aspirated X1s). After trying 100’s of combinations of boost/ ignition timing/ A/F ratio we wound up with front/ rear ignition timing nearly identical to the stock factory curves with boost pressure and fuel flow that made over 130 RWHP! Part of the H-D endurance testing that these bikes ultimately passed included filling the bikes’ fuel tanks with pump gas and [underpaid] test riders would run in high gear, WOT (at a high speed test track in Alabama) non stop until the tanks were empty—with no electronic deto protection! According to the CW article, the turbocharged Buell X1 test bikes exhibited greater reliability than the normally aspirated high compression X1s.

The point is, people too often assume that we MUST retard ignition timing when we pressurecharge any engine. But if our goal is to achieve max safe HP on a given octane fuel, we should not be afraid to experiment with ignition timing

BMP M1000 single pipe field testing by Dakota Performance

IN RETROSPECT THERE IS SOMETHING AMISS HERE SINCE I'VE DISCOVERED THE GLITCH IN MY DYNO NUMBERS...HERE'S MY POST BEFORE I FIGURED IT OUT... Just got another call from Jeff at Dakota Performance. Last week he track dyno tested his stock M1000 with new BMP single and ypipe, said he made 32 track HP more than same sled with Speedwerx Y and single. That equates to 40-50 HP at the engine. He was amazed as I was at bizarre HP.

Jeff had taken the clutches off of his turbo M1000 with four 82 gram weights, and the stock M1000 w/ BMP pipe pulled the weight on the dyno, then in the field accelerated like the turbo sled from a dead stop. But from a steady 40 mph cruise, valves closed, whacking the throttle resulted in poor response. So today he locked the ex valves open, tweaked his fuel controller to compensate and now his M1000 is a rocket on-off throttle like his turbo sled.

I still don't get it.

Next wednesday HTG is coming to DTR with a lakeracer F1000 with a single pipe from BMP made with same dimensions as the single on the M1000. wrong, F7 chassis w/ F1000 engine, BMP pipe is same style used on M1000, but with outlet pipe rewelded to fit F7 chassis, cancelled test wed, reschedule for Fri or Sat.

After discovering the false high torque glitch in my prior testing, I'm bewildered by Dakota's track dyno test that showed similar results.

Carl McQuillen Racing Engines in LeRoy, NY has remanufactured two circa 1906 Curtiss OXX6 V8 airplane engines which are scheduled on 9/13/08 to lift off Keuka Lake in Hammondsport, N.Y. in a replicated Curtiss America 1913 seaplane. www.seaplanehomecoming.org is where you can see this amazing thing. Carl is an aviation aficionado and somehow the Curtiss Museum found him and his capabilities. They had two right hand rotation surplus OXX6 V8 engines that needed to be rebuilt, with one converted to left hand rotation to drive the other propeller. Instead of simply rebuilding, Carl redesigned the nearly century old engine with some modern technology (pistons, camshafts, valves, magnetos, etc) and instead of 90 HP as dyno tested in 1906 (and in 2006 on Carl's dyno) the rejuvinated OXX6 engines now make 140 HP, both right and left hand rotation! It was delightful to watch this project unfold, using modern-looking but century-old cast aluminum engine blocks and billet crankshafts machined in 1906 on manual lathes driven by flapping leather belts.

22 years ago, then young Carl McQuillen accompanied me to SuperFlow headquarters in CO Springs to help me assess this new computerized dyno testing equipment I saw in some Hot Rod magazine. Carl was just then beginning his engine building business, had his own dyno, and did performance stuff for street/ strip dragracers. He convinced me it was wise to borrow $50,000 for this then-new dynamometer technology "if I wanted to do it right" so I could spend another $50,000 adapting it, and creating this test cell to dyno test snowmobile and motorcycle engines. As young people are apt to type, online, "WTF?". But here we are.

Carl was helpful to me while I created this fixture/ facility for testing and tuning. When I began testing things an learning, Carl was one of many who helped me understand what was happening that had bewildered me. If you look back in the DTR archives--Volume 1 #4 Carl McQuillen explained for us, Align Justify

in understandable terms, why the "Extrudehoned" 650 Wildcat engine failed to make added HP even though airflow CFM was marginally higher.

Since then Carl McQuillen Racing Engines has invested in millions of bucks worth of equipment including CNC machining and EDM equipment, several new fully instrumented dyno cels, and is capable of creating intricate, useful things out of huge hunks of metal. This OXX6 engine project is a great example of that capability. Tomorrow will be a good day, watching the America Seaplane lift off from Keuka Lake in Hammondsport, N.Y. and fly through the air. I'll be watching with Carl, and my armpits will surely be drier than his.

Blue Marble Oil?

The Blue Marble guys just shipped me a couple of cases of oil for me to test. I've followed BM oil streams around the internet, and you DTR subscribers know our batting average for dyno testing fancy oils/ oil additives/ treatments etc.....00zero.

This time Sam DynoMan (he has a track dyno testing service) who is a local Blue Marble distibutor brought a low mileage bone stock Polaris 600 twin, with polaris oil for baseline dyno testing. His plan was to baseline on our SuperFlow engine dyno, treat his engine however they do it by soaking cylinders and parts etc, run it for a while, track dyno it and if results were positive, bring it back for an "after" test.

After we baselined the engine at about 115 HP (very typical) I checked compression and squish, wrote my initials on the CDI, and Sam took the sled home for treatment/ further evaluation and dyno testing on his DynoJet track dyno. A week later Sam called me, ready for another "pull" on my dyno. Bring it on.

This time, with Blue Marble oil as the only change (***) the engine made 117 HP on the average of two hot engine tests. Compared to the baseline test, fuel flow lb/hr was identical (= no jetting chages), airflow CFM was identical (= no airbox mods or porting). And since the HP peak occurred a hundred revs HIGHER than baseline probably no ignition timing was advanced. Very interesting.

(***)
What could be done to fool us? We're measuring fuel flow and airflow and we can expect increased torque and shifting of midrange HP and HP peak RPM to lower RPM with added timing and compression. In this case the midrange torque was identical and HP peak was a hundred revs higher! Since friction drag increases as the square of engine RPM, could lowered friction be helping us? About the only thing someone wanting to cheat our system would be to add HP increasing additives to the gas (ie: propylene oxide). But usually that stuff is noxious smelling, especially since propylene oxide is used commercially to sterilize fruit flies in fruit storage buildings (just what I want to sniff during testing). I don't think DynoMan Sam was cheating, but I have to test this for myself.

My plan is to take John T. Cowie's Polaris 600 twin that Sean Ray used in DTR (shimmed up cylinder, cut head, etc etc) and do that same Blue Marble oil treatment procedure ourselves. Very Soon.

Bikeman F7 test session

We spent all day today dynoing F7 EFI stuff-- just received my pile of D&D production Y pipes. Erich Bikeman flew in yesterday from MN, stayed overnight w/ bill DiFranco arrived here fashionably late after sled was set up on the dyno.
Bikeman stock pipe mod was good.
D&D Y pipe was good.
Bikeman stock pipe mod plus D&D Ypipe was even better.
Bikeman stock pipe mod plus D&D Y pipe plus Bikeman ported F7 cylinders = 160 HP plus, 16 seconds at WOT on 93 octane gas.
Dyno tests will be posted here within a few days.

bathtub cylinder heads vs shrinkwrapped cylinder heads

I subscribe to Cycle World magazine primarily to read Kevin Cameron's monthly one page TDC column, and to try to absorb detailed technical articles he writes that appear in about every other issue.

In the most recent issue (March?) Kevin addresses coolant velocity in cylinder heads. According to KC, turbulent high velocity coolant is vastly more effective in removing heat from combustion chamber "domes" than lazy slow moving coolant. Worse yet, is any area of stagnant coolant that rests against the domes' coolant side surfaces with slow or no movement which can create dangerous detonation causing hot-spots.

Kevin describes large coolant volume cylinder heads as antique "bathtub" design. Conversely, he describes modern sled cylinder heads (like some SkiDoo models) as having a "shrink wrapped" appearance where the diecast cylinder heads' outer covers closely mirror the shape of the combustion chambers. Shrink-wrapped covers create small but ample passages for high velocity coolant flow over the combustion chambers.

Some of the aftermarket snowmobile cylinder heads I see on the dyno look like bathtubs to me. Most "billet" head covers are large rectangular structures that appear to hold lots of coolant, exactly the opposite of what would create high velocity turbulent coolant flow over the internal surfaces of the combustion chambers.

On typical dyno tuneups especially this time of year it's more time (and cost) effective to dyno sled engines with their own coolant, letting the 7.5hp roof mounted dyno room blower cool the engine between dyno runs. To maintain consistancy, I like to measure head surface temp with an infrared gun before each dyno run. On most sleds, head surface temp runs about 20 degrees F lower than coolant temp, but this is not as important as doing each dyno run with similar engine and pipe temperature.

What I notice on some aftermarket cylinder heads is that ending surface temp (after 10-15 second dyno runs) is sometimes much higher than what we usually see with stock heads. In the past I have dismissed this difference in being caused by different material finish (shiny machined and anodized or powder coated billet instead of die or sand cast surfaces) causing different infrared gun readings. But after digesting Kevin's info I'm thinking that we may be experiencing the bathtub syndrome.

How bad is this?

My favorite example of stagnant coolant was Tim Bender's experience with an Exciter FIII oval racing engine nearly 20 years ago. Kevin Cameron had suggested to Tim that the golf-cart-like transfer ports on the Exciter engine limited its potential. So Tim decided to widen the engine to allow room for larger transfer ports that he would create out of material welded on to the sides cylinders. This meant having the Crankshop build him a wider crankshaft, then saw a crankcase and cylinder head in half, then weld in an inch or so of material to allow bore spacing to be wider, accomodating normal-size transfer ports.

Tim's problems began when the one-piece cylinder head was widened and welded back together. The Exciter 570's coolant normally enters the front of the head in the center, then is forced around each combustion chamber surface, then rejoins as it exits the rear center of the head at the thermostat housing. However the widened and rewelded head provided an unintended short-circuit for the coolant straight through the center of the head from front to back without being forced around the combustion chambers. Unbeknownst to Tim and me, this allowed stagnant water to lay on the combustion chambers instead of flowing over them. Trouble was lurking.

On the dyno, even with lots of water flowing to cool the engine, we never could create low BSFC without detonation. But the engine made more HP than before and Tim was anxious to test the engine in his race sled before going to the annual big oval race at Eagle River.

I went with Tim to a nearby frozen lake where the night before he had snowblown an oval track on the shallow end. When he began doing laps with his dyno-tuned engine Tim encountered detonation with the same jets, same gas as we had dyno'd with the day before. Jets that were dandy for 15 seconds on the dyno were causing deto on the track after 20 seconds. The 48mm carbs required about 15 sizes larger jets to be deto-free, and that extra fuel drowned the HP added by the larger transfers. This was perplexing to both of us. At the end of the day, Tim's high HP wide engine was no faster than the narrow golf-cart Exciter race engine he had run previously. Why the deto? With his other race engines, winter dyno jets were within a few sizes of what he needed for 20 laps.

That evening, one of us remembered the widened cylinder head. I like to think that I came up with the solution to the problem, but it probably was Tim. One of us called the other, and we discussed the possibility of a problem with combustion chamber coolant flow. Tim went to the shop at 10pm, and upon inspection found that there was an open passage in the widened area for coolant to flow directly from the front center head inlet to the rear center outlet! He mixed up some Devcon epoxy filler and goobered that unintended passage closed. As intended, coolant would once again be forced to the outsides of the head, pass over the chambers then rejoin at the rear before exiting the engine.

The next day back at the lake, Tim was able to jet down all of the 15 sizes (and then some) and the HP was back, deto was gone. More races would be won.

Bottom line--stagnant coolant was surely the culprit. According to KC, when coolant boils and creates a steam pocket anywhere around a combustion chamber, detonation is sure to follow quickly even with the safest A/F ratio.

I'm not suggesting that all billet replacement heads are low velocity bathtub design--in each case I don't know what sort of internal passages were created by the person who programmed the milling machine to carve out the "tub". But my opinion is that before an aftermarket head is installed in might be good to compare coolant volume between the stock head and the replacement head. If the replacement head has larger capacity than the shrink-wrapped stocker I would question the design and ask why the volume is greater. If the answer is "to help cool the engine".....

The factories' sled engine designers surely use dyno software that measures coolant flow in GPH, and that figure along with temperature rise in the coolant around each combustion chamber is necessary to correctly design the cooling passages in any cylinder head, either OEM or replacement.

When it comes to snowmobile cylinder heads, cool-looking and big is not necessarily better.

Bad octane, Gus Bohne 1080 turbo, etc

BAD OCTANE

Octane cheating either intentional or otherwise seems worse this season than ever before! Why do we suspect that? We can hear pump gas detonation on the dyno more this year than in years past! It appears that more than ever before, people come here to tune their trail sleds with their own “fresh high test” and discover here that it’s really “low test”. Often, when we experience unusual detonation we can buy 93 octane from another gas station, and the knock goes away. I often talk about the NYS Bureau of Weights and Measures who reports that roughly 10% of gasoline they test in this state is substandard. Dateline NBC took it upon themselves to test octane at California Exxon stations, and out of 85 samples of high test gas one in eight was substandard—the worst of which tested at 75 octane! Car and Driver wrote that the state of Michigan’s Bureau of Weights and Measures found that out of 2,816 samples of high octane pump gas, 217 were low octane. Is your state or province any different?

How can we hear detonation occurring on the dyno? Sean Ray learned about listening to engine knock several years ago at Delphi where he is employed as a calibration engineer. Hyundai engineers came from Korea to Sean’s Delphi dyno cel with a roll of ¼” ID copper tubing that they attached to the engine Sean was calibrating for them. They drilled a hole in the control room wall, bolted the copper tube to the Hyundai engine and inserted the other end into the control room, just dangling in the air. Delphi engineers could now hear every click of detonation—which makes a loud snapping noise that emanates from the copper tube in the control room—sometimes even before the engines knock sensors could notice it! Sean brought the copper-tube deto sensor concept from his Delphi engine dyno cel to DTR several years ago. It’s an incredible tuning aid, and has saved many hundreds of pistons to date! We now listen for detonation here and usually can abort any test before engine damage occurs. Three or four audible clicks and we quit the test. On two-strokes we will never hear more than about twelve clicks of detonation—the engine will have seized by then! Last season Sean and Tim Bender ran over 700 max power dyno tests on one mule 600 race engine for Hentges Racing, and lost zero pistons because Sean could hear clicks and abort. During similar max power testing in years prior to the copper tube, Tim used to bring a box of pistons and a jug of muriatic acid to clean the bores after seizing. Back then it was more wrenching and less testing. But today it’s much more efficient thanks to Sean’s Korean engineer pals!

Four-strokes can be more forgiving—each detonating compression stroke is followed by a piston-cooling intake stroke. This means that a few more intermittent clicks of deto can be heard and tolerated by the engine before really bad things happen. Four-stroke piston seizures from deto are rare. Instead, when continual deto makes spark plug ground straps red hot, preignition can occur which can create the worst damage! Then, peak pressure will climb to the moon, which can crack ring lands, stretch the head bolts/ studs and either blow the headgasket(s) or just lift the heads enough to allow combustion pressure into the coolant passages, spewing coolant out the reservoir overflow. Too often people try to rectify detonation problems not by increasing octane or more conservative tuning, but instead by using stronger head bolts/ studs, O-ringing combustion chambers, copper headgaskets, etc. Then, instead of blowing headgaskets we might see studs being pulled out of the crankcase threads, conrods bend or break and cylinder and head gasket sealing surfaces fried into junk as though attacked by a plasma torch! Tune those high boost engines! Don’t scrimp on octane!

With proper tuning for the available octane, stock fasteners and headgaskets will survive incredible power increases! Justin Fuller of Full Power Performance prefers stock head fasteners in his 200-400+ HP turbocharged Yamaha four strokes—noting that stock fasteners are designed to stretch and continue clamping properly as the aluminum heads grow with normal heat expansion. Heavier larger diameter high tensile strength fasteners may not stretch enough as the aluminum heads expand and can instead create severe cylinder head distortion that can cause compression/ coolant leaks even where no severe detonation occurs.

So, back to the issue at hand—what do we do about this awful situation regarding cheating on octane? To be safe and conservative, ALL HOTROD TRAIL SLEDS SHOULD BE TUNED TO BE DETONATION-FREE ON 87 OCTANE! A conservative tune for 87 octane might result in only 3-4% reduction in peak HP so it’s not a great penalty to pay. Then, leaner jetting or a second more powerful Boondocker or PCV map can be used for lake racing etc when a few gallons of race gas/ av gas can be added to the tank for safety.

It’s quite possible that when we tested Gary Berwind’s Z1 turbo with the Turbo Dynamics’ 4 stage tune, he may have had less than 93 octane in his tank even though he paid for 93 octane that day. Severe detonation made it impossible to run the high power settings without water/ methanol and lots of it! But now, after this dyno tuning session Gary can probably run his sled anywhere with any octane gas. He just needs to have his water/ methanol reservoir topped off, typically with windshield washer fluid. My opinion is that anyone with an overboosted Z1/ F1100T should run race gas, and/ or invest in a water/ methanol injection system. So WHEN (not IF) you buy 85-87 octane even though the pump sign indicates 91-93 octane you won’t need to depend upon factory knock protection to save your engine. And remember, the factory Z1/ F1100T ECU will not look for deto above 8300 RPM!

My own experience with boost and water/ methanol is with the used Whipple supercharger I bought from my pal Rusty in Rapid City SD for my 2002 Chevy Avalanche 5.3 liter V8. Based upon Sean Ray’s calibration work at Delphi we understand that the 5.3 is tuned to the edge of deto NA. So adding boost, especially with no intercooler, is almost guaranteed to create knock. With 6-7 psi boost, my Whipplecharged 5.3 would just pull lots of timing in reaction to light deto even with Sean’s reprogrammed EFI Live tune that gave us 11.0/1 A/F ratio on boost. The knock-induced retarded timing severely limited the power increase. But by adding a water/ methanol injection system the compressed charge temp is drastically cooled to about ambient temperature, and I can run knock-free now with 6psi boost on 87 octane gas. The water/ methanol condenses the compressed intake air thus dropping observed boost pressure a bit with the fixed speed supercharger.

It seems that a compact water/ methanol injection system would be a huge benefit to NA trail riders with heavily modified engines who buy gas on the trail and want max HP. I haven’t seen anyone here with that sort of system, but isn’t it about time?

ANOTHER EXCELLENT AFTERMARKET ARCTIC CAT 1000 Y-PIPE

Ted from Terra Alps Racing in British Columbia, Canada (www.terraaplpsracing.com) sent us a stamped Y pipe he makes and sells for Cat 1000 twins. Local Cat wrench Don Zuzze brought this 2007 F1000 bone stocker for a PCV tune, and we tested the Terra Alps Y-pipe compared to the stock Y-pipe as shown here. Adding 5% fuel at 100 and 80% throttle positions with a PCV, the A/F ratio was held constant. As shown in the following graph, HP is improved from midrange to top end. And note the precision of the control of fuel flow by the Power Commander.

SHRINK WRAPPED vs BATHTUB HEADS and BLOCKS

A few weeks ago I got my first close look at the Ford FR9 NASCAR race engine designed by RoushYates on an episode of “How It’s Made”. In this program, we can see how both the heads and block have that “shrinkwrapped” appearance—the external surfaces closely match the perceived shapes on the internal structures of the heads and block!

Here’s a good side view photo of the engine:

http://www.google.com/imgres?imgurl=http://image.hotrod.com/f/30726978%2Bw750%2Bst0/hrdp_0911_01_z%2BNASCAR_race_engines%2B.jpg&imgrefurl=http://www.toonutsracing.com/smf/index.php%3Ftopic%3D928.0&h=480&w=640&sz=50&tbnid=45Tpd7WlDiKwZM:&tbnh=101&tbnw=134&zoom=1&docid=QxBrKk8UckgUZM&sa=X&ei=aHw5T5KzOZK_0QGd76iwAg&ved=0CDoQ9QEwAg&dur=2099

Kevin Cameron helps describe the advantages of small volume high velocity cooling passages in my blogs of Feb 5, 2009 and January 6, 2011, as well as KC’s excellent “Turbulence Needed” tech article in the subscribers’ pages. It’s obvious that the RoushYates engineers “shrinkwrapped” the external surfaces of the exhaust sides of the heads and sides of the blocks to minimize coolant volume, and maximize coolant velocity which increases the transfer of heat from hot engine parts to the radiator/ heat exchanger.

HTG POLARIS 1080 TRIPLE w/ GUS BOHNE TURBO SYSTEM

Gus has the carb issues on Art Bass’ turbo 1080 resolved, and now we were able to tune it on the dyno. But it didn’t take long to see that the triple pipes on this sled were too short, causing HP to climb with revs until I let off the throttle at 9800! Note that torque has not yet peaked at 9800. But if I stayed into the throttle the torque and HP peaks would surely have gone beyond 10,000, totally unnecessary with a big boosted engine like his. So Gus is going to lengthen the pipes enough to bring peak power down into the 8500-9000 RPM range. Then he and Art can come back to DTR and turn up the boost!

EngSpd	STPPwr	STPTrq	LamAF1	ExhPrs	BoostP	Baro_P	AirInT	Vap_P
RPM	CHp	Clb-ft	Ratio	psig	psig	InHga	degF	InHg
7600	246.1	170.1	12.84	16.2	12.7	28.97	37.1	0.16
7700	249.0	169.8	12.88	16.5	12.8	28.97	37.1	0.16
7800	253.3	170.6	12.92	16.5	12.9	28.97	37.1	0.16
7900	258.3	171.7	12.98	16.6	13.0	28.97	37.1	0.16
8000	264.1	173.4	12.88	16.7	13.1	28.97	37.1	0.16
8100	267.1	173.2	12.74	16.6	13.2	28.97	37.1	0.16
8200	271.3	173.8	12.54	16.8	13.3	28.98	37.1	0.16
8300	275.3	174.2	12.36	17.2	13.4	28.98	37.1	0.16
8400	278.7	174.3	12.25	17.5	13.5	28.98	37.1	0.16
8500	281.7	174.1	12.17	18.1	13.7	28.98	37.1	0.16
8600	287.3	175.5	12.08	18.4	13.7	28.98	37.1	0.16
8700	297.6	179.7	11.93	18.4	13.8	28.98	37.1	0.16
8800	305.2	182.1	11.88	18.6	13.8	28.98	37.1	0.16
8900	315.6	186.3	11.81	18.7	13.9	28.98	37.1	0.16
9000	327.6	191.2	11.73	18.7	14.0	28.98	37.1	0.16
9100	350.0	202.0	11.66	19.0	14.2	28.98	37.1	0.16
9200	361.0	206.1	11.64	19.2	14.2	28.98	37.1	0.16
9300	368.1	207.9	11.62	19.3	14.3	28.98	37.1	0.16
9400	379.0	211.8	11.65	19.6	14.4	28.98	37.1	0.16
9500	394.6	218.2	11.69	19.7	14.4	28.98	37.1	0.16
9600	404.7	221.4	11.70	19.8	14.4	28.98	37.1	0.16
9700	413.4	223.8	11.77	20.6	14.5	28.98	37.1	0.16
9800	418.9	224.5	11.87	20.7	14.6	28.98	37.1	0.16

Back to the dyno this AM

Gary's brand new 05 F7/ F8 EFI is way low on torque/ HP. With new DD twins it pretty much maxed out at 109 LB/FT and 166 HP at 12/1 A/F ratio. Aiflow CFM is fine, crank has not twisted out of phase. Thinking maybe the pipes were off the mark we installed Gary's stock pipe/ muffler, at about 11/1 A/F ratio it makes 96 LB/FT and 141 HP.

This AM, we're checking compression to make sure they didn't goof and put F10 conbustion chambers on it, then if that's OK we're hoping that the 3 degree keyway is installed backwards.

If we find the missing 10 LB/Ft of torque, we'll tune the sled with the stock pipe, then maybe rerun the twin pipes on Monday.

back from the Adirondack shootout

We lucked out on the weather, could have been monsoon rain but it turned out to be very light mist so we had a good crowd of observers.

The SnowWeek guys were great to work with, they are pleased to be partnered with DTR and the Adirondack sled dealers. They'll have a full stock Adirondack Shootout issue in your mailbox in two weeks, including dyno certification test data. Trail mods to follow in the next issue.

Tomorrow we're dyno tuning Jarred's stock F7 from about 10AM to noon or so, webcams running. Expecting to tune another one into the mid 140's.

Monday is SkiDoo day, in AM a Bondi trail port 800 twin, then in PM an 830 big bore twin. Tune in to the live streaming audio/ video for all of that.

Also for new subscribers, to read the SFD (SuperFlowData) files, you must download free Windyne software at www.superflow.com. I think it's easiest if you first open the DTR article, right click on each SFD file (one at a time) left click "copy" then "paste" each test on your own computer (I use a 3 1/2 inch floppy for that). Then open Windyne, go to "file" "open saved test" from your floppy, then have at it. Remember the data opens up as the OBSERVED HP in the dyno cell that day, then to see corrected numbers click on "2" above the test data. Then if you click around, you can operate the software, do comparison graphs, etc.

Back from Shootout

This mat have been the best Shootout ever--decent temp, lots of snow, 13 aftermarket sleds. And we caught one ringer. all results will be in SnowWeek magazine. After that article is out I will post my numbers of stock sleds including that wicked SkiDoo provided Mach Z ECU. I'm still kicking myself for having Jimmy Cooper overwrite the race fuel map with an 06 fuel map. We should have reinstalled the stock retarded ECU, let it run that way at the Shootout and I could have sold that Shootout 10 HP extra hotbox on Ebay for $1000. I need to pay Jimmy Cooper for the five hours he spent here with his Doo computer getting this ECU correct, and Ebay would have made that easy. But I still have the 600SDI race box, we didn't mess with that, renstalled the original ECU in the sled. That may show up on Ebay next week so we can remunerate Cooper's Sales and Service (585-682-9707).
Curt came back today with a full N2O cylinder (please don't call it noss) and we finalized that evaluation. The newly supplied EFI Boss Noss box was fitted, now needle valve fuel flow was seemingly in range, we were able to dyno tune Curt's ZR800 into the twilight zone. Actual dyno results will be released after Curt lines up with his dad's RX1 Bender turbo stage 1 (Curt's dad has no idea what Curt is plotting).
We finished with Curt's juiced up ZR800 this afternoon, and we hooked up Mike Ziggy Zigmont (we found each other on the I90 today) to the SuperFlow dyno. Mike has a Bikeman F8 and ran blubbery but safe all last year with 58 psi fuel pressure. Now we have installed a DynoTech programmed Boondocker and we've been able to drop fuel pressure to 45 psi. In an hour we created a safe .700+ BSFC and 11/1 A/F ratio from valve opening to HP peak and beyond. Those Boondockers are great EFI tuning devices especially if you can tune on a fully instrumented dyno to utilize.
Sunday we will finish off Ziggy's F8, will try the Bikeman F7 mod stock pipe, then spend the last part of the session tuning midrange, part throttle settings, to make sure we have no lean spots. ziggy's F8 will be powerful and reliable after we dial the Boondocer in tomorrow AM.
Somtime tomorrow Erich Long aka Bikeman is supposed to show up at DTR to dyno his two Shootout sleds. I'm hoping Sunday 10 AM we'll be done with Ziggy's Boonocker/ various single pipe tuneup (3 hours total) and we can next wrench and tune Erich's two F9s, albeit after the SW DTR Shootout. I love my job.

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