March 2007

Friday, March 02, 2007

DynoTech : Month of March

3/1 Got a call from Don Emery of DNE performance, that  384hp 1725cc four cylinder Mach Z he built for Tom McConkey (dyno sheet posted on Subscriber pages) set a radar record for single engine sleds at 177.0 mph. You can see an amazing video of madman Tom making that speedrun on

3/1 Justin Fuller (Full Power Performance) with stage 4 RX1 turbo drag sled owned by Tom Borges. new current record holder on this dyno, 440 CHP since dyno is idle this weekend I have that final dyno run replaying on the computer screen in the dyno control room (large HP readout) from start to finish 7300 to 10,800 RPM, click on dynocam in control room to see it. Will post full dyno run on the website with as much tech info as I can get from Justin.

Waiting for a new Lovejoy number 8 flexible rubber coupler for my dyno drive system (used in conjunction with Lord rubber coupler on driveshaft) to dampen torsional vibrations. Noticed a crack in the old one, will have new one on 3/5.

3/5 AM rebuilding dyno drive, PM private session, cameras off.

3/6 Chris Squiers and John Wilbur with two F somethings and maybe a SkiDoo. Had an F7/F8 cast cylinders, ported by Rob HTG with D&D Monster twin pipes, Boondocker,  first pull 133hp,  after maybe 4 massive, bizzare looking Boondocker tweeks made 171hp at 8600, torque was below 110 lb/ft so John surmised the guy he hired to install his Fett offset key put it in backwards, popped the flywheel and found a stock key. I just got a load of keys from D&D so John installed a 3 deg key and after a few more Boondocker tweeks made 182.7hp at 8400 and torque jumped to 116.2 at 8000 for a broad hp curve 177+hp from 8000 to 8600. Next sled was a stock 07 F8 with D&D Ypipe and D&D single with Boondocker. This one was a bit surgy on the dyno so we added some midrange and top end fuel, smoothed that out and made over 161hp on 87 octane. Something was strange about the ECU because late in the tuning session the engine became lean at low revs part throttle. After each wot run, bringing the revs back down to idle at about 4000rpm it would lean out to 18-20/1 and misfire refuse to idle and then stall. Disconnecting the Boondocker didn't help. We made one final fuyll throttle run and the engine is fine, just that mysterious leanout at light throttle. When we popped the clutches back on, the engine ran dandily and John was able to drive it into the trailer. Last sled was a HTG 1200 stroker but I didnt have a puller for the late clutch on and early style crank.. I saw that sled run at Loon lake, it doesnt look like it needs much dyno tuning, John just wanted to see the number.

3/9 Dead 1 Dave Craiglow with his HTG ported F1000,
picked up another 10hp by removing his D&D single and installing D&D twins, will post his latest numbers.

3/10 going to Loon Lake one more time with 1000 Edge this time with fresh water pump so my mag cyl wont be drinking coolant. And please don't anyone give me any free drink chips at lafalot afterwards. Those six chips hurt me last time since the bargirl was pouring about 4oz bourbons to make sure she got the big tips (6 chips x 4oz = way too much). Plus I have to be on my toes for tomorrow AM dyno session...ran great today, clutching that labored at 8-8100 last time pulled 8300 at 400 degree pipe ctr section temp, then slid to 8600 at 680 degrees, just like the dyno suggests where the HP peak occurs. Felt good, but the Sherriff put an early end to the festivities due to a complainig neighbor and a lack of a permit. Maybe we'll get an opportunity to run the weekend of 3/17 someplace. Drank two draft beers afterward.

3/11 10am Bob Jacoby and Sage dialing in their freshly rebuilt RX1 suck-through turbo. Maybe shooting for Justin's record? Bob Jiaccobe or Jiacobbe was smart--his RX1 turbo that was junk when we dynod last time had  block rebuilt with thicker sleeves, and a sleeve retainer on top to keep sleeves from ovaling when inevitable deto creates monster cylinder pressure. The needle jet extender that dyno genius Jim Czekala  recommended worked dandily. Lightning Pro saw our early post, created the needle jet hood extender that we described, his own sleds worked better thanks to Joe DiSpirito who gave Genius Jim the big hood idea. Thanks Joe I took all the credit.

3/13 AM Joe DiSpirito's Big needle jet Hood worked killer on this oversize turbo suck-through carb. Those turbo-useless 48 mikunis are now in the ballpark Now instead of main jet left out and lean A/F ratio, we had normal size main jets and FAT A/F ratio. Now we backed down on Mikuni round jets, Bob Jiacobbe owns the rights to the jet size since he paid all the money to correct a bad situation. This dyno sesssion cost him $1000 and his A/F ratio is mint and should create good reliability if his octane matches his HP. Bob will surely sell his boost only tuneup to others to defray his $1000 (over two days) tuning session.
Now with safe-for turbo 11.5/1 A/F ratio we made 300 plus easily with no intercooler  (not good to run intercooler with A/F mixture--one advantage of blow-through systems) with about 27psi boost, then backed boost down to 250 HP. With lower boost, Sage ran a small whisper of N2O injected behind the carb before the turbo scroll. This added over 50 HP and help cool intake charge and help off-the-line acceleration. So bumping up the boost to 27psi will get them 350plus, and surely 400plus is available with nitrous. But Sage and Bob will save higher boost/ bigger N2O jets for the dragstrip and only when necessary.

3/13 pm Don Malcom from northern Ontario who was struggling with deto on a HTG Storm stroker pump gas 1000 lake racer engine.. His first mistake was not buying 24 Molson XXXs at the duty free shop to help allay the pressure on the dyno operator. His second mistake in my opinion was using stiffer than  stock motor mounts on his stroker 1000cc. Stiff motor mounts have proven to be a nightmare for carbs that need to deliver smooth  fuel flow to their host engines. His fuel flow delivered by the vibrating carbs is totally useless; harmonic vibrations from the evil stroker causes the carbs to vibrate into a blurr, fuel flow foams into a vanilla-like milkshake, then fuel flow drops and rises as carbs buzz and settle down depending upon revs. Larger main jets = less fuel flow into the engine since float bowls are emptied more quickly.

3/15 Dan Cross and Dan Forte are installing stock motor mounts at their shop nearby (the heavy mounts were installed by one of Don's tech people in Ontario), will probably dyno again Tuesday.

Joe from Boyeson Reeds is encouraging me to post the results of Rad Valves on Casey Mulkins' trailmod Chuckaroo Mach Z. I've downloaded all dyno tests onto Excell spreadsheet, should have time tomorrow to assess the dozen or more dyno runs we ran on Casey's sled.

3/23 I deleted that post after Eyvind Boyesen called. Joe had threatened to sue me in Philadelphia for "theft of services [?]" if I didn't post their test results. I alluded to that threat as coming from "Boyesen" in my DTR subscriber pages post. According to Eyvind, Joe, who is an independent consultant, made that threat without  Boyesen or his company's knowledge or approval. Those test results are the property of Boyesen (they paid for the test time). When a company uses my facility to independently assess products, those test results are private. And if the testing is done properly, and results positive I'm glad to post the dyno numbers.

3/27 Dan and Dan are bringing Don Malcom's 1000 HTG storm trail stroker with stock motormounts, hoping to smooth out that unusable fuel flow curve.

3/24 AM Kim Stout coming from PA with F1000 with update ECU map, also Speedwerx Ypipe and single pipe. Kim also bought a D&D Ypipe and D&D single to compare to SW and Bikeman mod stock pipe vs stock exhaust.

JD Powersports is now shipping their T660 HP upgrade kits. Took many months to acquire factory style electrical connectors, their upgrade ECU now creates 130hp on low boost, toggle switch takes you to a separate map with richer mixture and timing adjusted, 150-160hp, just like they did on DTR dyno pages. Now plug and play. 585-458-0620.

Dennis Richards from Richards Machine in Buffalo [716-683-3380] races an XCR/ HTG 1200 stroker lakeracer with 280hp and 175 lb/ft torque. He invented, patented and sells the ultimate torque arm that mounts outboard between the drive clutch and driven clutch. Each end has an adaptor to fit to the bores of the clutches, high speed bearings and an adjuster to obtain the desired center distance. Todays monster engines create huge torque, and spindley jackshafts must be bending horribly (changing center distance and fatiguing jackshaft metal). My simple math on Dennis' sled is at clutch engagement and prior to shift the belt is about 2" from the center of the crank. If he's making 175 lb/ft (175 lb of force 12" from crank center) we can multiply the torque pulling on the drive belt  by SIX  (12" divided by  2")  so  6 x 175 = 1050 pounds of pull on the outside of the driven clutch! This load is exerted on the jackshaft, cantilevered over the belly pan supported only by the small drive end bearing, then unspported for about 18" then supported by another bearing in the top on the chaincase. Would you imagine hanging an iron big block chevy engine with a turbohydromatic transmission from the driven clutch on the jackshaft? How much does the jackshaft bend x number of inches from the jackshat bearing, then unsupported for 18"? And if we mounted our chainfall at 9:00 on the outside of the driven clutch how many degrees of twist would the weight of the big Chevy engine create on that tiny jackshaft?

Taking that one step further, imagine Justin Fuller's 442 HP RX1, 220 plus lb/ft, same clutch same math but add 220 x 1.19 intenal crank gear reduction = 262 lb/ft x 6 = 1572 lb of pull on Justin's jackshaft. So that's like hanging the big block chevy plus transmission PLUS an iron smallblock chevy engine. Anyone want to walk  under the sling that's holding all that iron suspended by a sled jackshaft?
I just began examining Justin's HP data to post this weekend, saw peak [crankshaft] torque really was 237 lb/ft x 1.19  reduction to  clutch x 6 = 1692 lb of side load  on rear clutch/jackshaft during acceleration. Anyone driving one of these awful things should examine Dennis' torque arms.

Being a farmer engineer, I can't figure this out accurately. How about a real engineering assessment from a real engineer, estimating materials, etc. That would be way better than standing over Dennis' sled hood up with no torque arm, watching he whacked it on a jackstand, then running to find a safe place to hide.

And it's comforting to know that drivers and onlookers are protected from all those whirring and bending parts by a thin aluminum beltguard.

It would be great if some engineer-type DTR reader would do the math for us. What is the jackshaft deflection at 1000 and 1500 pound side loads? A free subcritipon or renewal awiats the first smart guy who provides the correct data.