July 2007

Monday, July 30, 2007

DynoTech : Dyno schedule month of Aug 07

8/1 Justin Fuller Full Power turbo Yamaha R1 streetbike this time on the SF901 dyno with driveshaft from bike output shaft to dyno. Will compare rear wheel roller HP to actual output shaft HP. Justin wants to use 901 dyno to utilize its exact control of engine speed (no tire slip) and more complete instrumentation.

8/3 Thursday AM Jim Cooper's PS1000 still trying to cure solid mount stroker fuel flow issues. Also a PS800 Jim is setting up MSD timing for a customer of his. PM maybe Rich Daly's PS1000 on my dyno. Jim Cooper came this time with EFI fuel pump and adjustable bypass regulator--that fixed Steve Bennett's vibrating CS1710 so maybe would fix the ps1000 stroker? No luck; running as high as 9 psi we were still plagued by violent surges in fuel flow even with float bowl flooding over. Hard to rubber mount the big triple in the MXZ chassis, so possibly a rebalance of the bottom end is necessary. The PS800 Doo triple was dandy, stock crank and stock rubber mounts as we expected perfect fuel flow, Jim optimized a timing curve on the MSD, wound up with 209 or thereabouts with very broad HP curve.

8/10-8/15 Fri-Wednesday, private pro engine testing, webcams turned off.

8/15 Wed 5pm Jim Cooper back again, still same stroker crank/ solid engine mounts, this time has CNC machined upper and lower brackets to connect three megatrons into a rack.  Also Jim has  a pile of lead stick-on mag wheel weights if we need more help to calm the carbs down.  I just read Kevin Cameron's new book TDC. In his chapter about Gordon Jennings  Kevin describes how Gordon added stick-on wheel weights to a  vibrating roadrace bike to pre vent top end starvation. Hoping the same will work for Jim Coooper.   If we cure Jim's carb vibes early enough we will  tune upon  Elite Motorsports  Jack G's ps800 that made 209 last time, now with custom built Dynoport pipes. Hoping for more and/ or broader HP. Jim Cooper's fuel flow was still horrible even with racked megatrons, and even with a pound of lead weight added to bells. So we tie-wrapped my now infamous 5 lb crowbar onto the racks and presto flawless fuel delivery. Rich Daly offered me $100 for the bar, I'm holding out for $150. It will be easy for Jim to add 5 pounds to his carbs by bolting weight to his new upper and lower racks. Next we dyno'd Jack Gs ps800 Skidoo and with Jim Cooper optimized timing  and new  DynoPort nicely hand fitted pipes made 226hp with a broad hp curve from 9100-9800rpm, up 18hp from the last session due to DP pipes and perfect timing. Also backpressure was spot on--making same hp from 4-8 seconds at WOT.

8/16 AM Jeff Stinson with a prostock 700 Firecat, full mod w/ high RPM Jaws pipes, also maybe with high RPM D&D pipes, Boondocker tuning. The Jaws high revving pipes made peak hp at about 9500, well over 170hp but tuners with D&D high rpm twins are reporting 10 hp gain so Jeff may be back with a better tighter head and D&D high rpm twins.

PM Bikeman Jake Jenkins with BM F1000 ported, this time with D&D twins, Boondocker tuning for grass  tuning on 50/50 93 and 110 max HP 226/ 150 lb/ft right at the rev limiter. tuning for trail riding adding 15 lb/hr fuel on top end with boondocker = 218hp at 7500-7600 over .60 lb/hphr.

8/21 Tuesday AM Jason Price w/ F1000/1200 with big fuel pump, Boondocker N2O system, looking for 300 plus (maybe 350?) for drag racing. Jason had D&D create this F1000/1200 fitted to a Firecat chassis as a sort of clone to Glenn Hall/ Jason Stoviac's D&D twin pipe F1200 nitrous burner tested here recently.
On motor only Jason's F1200 made 221 HP at dandy fat .60 plus even with low compression and stock timing (Jake's F1000 shown above had 6 degree offset key).

Using Glenn Hall's recommended aftermarket EFI pump and high fuel pressure and his Boondocker map, we easily made 330 HP  at too safe BSFC.  Bumping  n2o to larger nozzles we were up to 356  HP .64 at hp peak, but we had a lean midrange spot .52 at 7800 that needed to be boondockered before we added any more n2o.

So after assessing Boondocker midrange I mumbled to Jason that he take his 7800 rpm Boondocker settings of 12 12 12 and add 5 to each to 17 17 17. Jason misinterpreted my suggestion to mean "change 7800 setting to 5 5 5" which would prove to be destructively lean. Goof one since I did not follow up on Jason's Boondocker tuneup..

Goof two was not listening to Jason's pal Kevin who suggested one more dyno run to ensure midrange fuel was safe and fat before stepping up N2O one more time...After having dyno calibrated more than a hundred Boondocker sleds, I was certain that going from 12 to 17 at 7800 would flatten our midrange fuel curve to perfection. Let's save Jason 10 minutes of dyno time, I know 17 is perfect, lets just increase N2O and make another step in HP...But our midrange at 7800 was down to 5 maybe like the space shuttle with a missing tile....

Either way, Jason can step back and tune to 355 with new drummed race gas (Sunoco Supreme or Maximal are my gonzo BMEP favorites), and his performance will be safe and very powerful.   And from now on he will maintain his fuel freshness with Nitrogen gas head pressure to maintain the presence of his most important "light ends" in the fuel.. When it comes to buying "fresh" just opened race gas for your $30K sled Trust no one.

8/22 I've thought a lot about our n2o deto. Goof  three was  not remembering my own winter experience with C16. I was in Forrest Lake MN, Kip Campbell had a brand new sealed drum of C16 in his garage, cold from winter storage. We went to a lake, all sleds were filled with fresh C16, all cold turbo sleds refused to start. Someone suggested a squirt of pump gas in the intake of each sled, all sleds fired up. Once they were good and warm, the C16 ran fine. Turbos make hot intake charge-- it takes lots of heat to vaporize C16. So here we are with Jason's n2o 1200, blowing huge clouds of 120 below zero n2o vapor into the streams of C16 spewing out of the nearly wide open injectors! How can that [possibly old] C16 vaporize 100% in that mostly subzero atmosphere? Goof four was loading the engine at 7000 before beginning the acceleration test at 450 rpm/sec. The engine gets the same flow of n2o at 7000 and 8500. That means that at 7000 there may be 20% more n2o ingested per revolution than at 8500. And 20% more time for detonation [deto is time dependent] to create havoc, especially if net mixture is lean and hot. Gonzo n2o engines should be loaded a few hundred revs below hp peak--we enjoy observing the massive low end hp from the n2o but it takes too many dangerous seconds to record that info. Goof five was not immediately seeing that on our final real time graph the hp was below the prior (less n2o) dyno run that was left purposely on the screen. More n2o and less hp means shut the engine down now, and it took me over one second to notice hp was low before damage occurred. With detonating n2o engines we have maybe 1/4 second of hp curve dropping below prior run before plug/ piston damage occurs. I was late pulling out. That was a two-piston snooze. I spoke to Jason today, pistons wrecked but thankfully chrome cylinders are fine, so he'll be up and going as soon as he gets pistons from D&D tomorrow. He has what appears to be an excellent tuneup at 350 hp+ (the second to last run before deto stopped our session). He also has Sunoco Supreme or Maximal race gas coming in a fresh sealed drum, which will be pressurized with nitrogen for storage.

We didn't make it to 400 as I think he hoped, but he still has 80hp more than the F10 n2o engine he tuned here before going 8.8 in the 1/4 mile. Glenn Hall's n2o record still stands, just barely.

Monday, July 09, 2007

DynoTech : Dyno Schedule month of July

7/10 Tuesday AM Bill DiFranco tuning ODS Dan's Cutler F7/F10 for asphalt. Will tune carbs for max HP plus try to tune Boondocker N2O system for extra 50 HP or thereabouts. took second in ESTA Big Twin class to Glenn Hall's 400hp turbo.

7/12 Thurs PM late, MachZ big bore with NOS N2O system, results private.

7/13 Fri 5pm Tom Murphy from Indiana w/ F7/F10 1000ps twin plus tuning Boondocker N2O. left here, drove to ESTA race ran 8.85 don't know where he finished.

7/19 Thurs AM Nelson from Carlson Sports F6 stock grass racer, SkiDoo 800 triple PS

7/28 Dan Schuler ps800 triple grassracer final tuneup. Dan picked up 15 hp optimizing timing, jetting, pipe backpressure...also after fine tuning this was very high 800cc triple hp, equivalent to the best 1000 stroker PS' cc for cc, this was accomplished by Dan's use of Tom Turner's 2 stroke software with porting done to order by a local MX engine modifier.

Friday, July 06, 2007


To:  Boondocker Dealers, Distributors, and Customers
Date:  June 29, 2007


Dear Boondocker Dealers and Customers,

You will soon be notified of a safety recall by Rehvac Manufacturing that a
ffects some Boondocker nitrous oxide cylinder assemblies.  Rehvac makes saf
ety blow-off valves used on several brands of nitrous cylinder assemblies.
 This blow-off valve has a defect which seriously compromises the safety of
 the nitrous cylinder.  Because of this dangerous Rehvac defect, please obs
erve the following instructions:

he serial number of the VALVE.  If you have a Boondocker cylinder with a si
x-digit S/N number on the VALVE greater than 132349, do not use or refill t
his cylinder.  IMMEDIATELY, EMPTY THE NITROUS GAS in a well-ventilated area
, such as outdoors, using proper safety procedures.  DO NOT ATTEMPT TO USE

You will be notified soon regarding further details of this recall, includi
ng how the defect will be corrected.  

If you know of others who use Boondocker nitrous products and who haven
t received this notice, please tell them to contact Boondocker toll-f
ree at 1-877-522-7805.  We must know how to contact them with recall inform

Current products being shipped from Boondocker do not have this defect.  Th
e corrected blow-off valve has a “K” stamped on the head al
ong with the burst pressure rating of “3000”.

For questions, please see the Q&A section section below. It contains all th
e information we have at this time.

Thank you for your cooperation,

1589 Hollipark Dr.
Idaho Falls, ID 83401
1-877-522-7805 (toll-free)
Fax:  208-524-7381

Q & A for cylinders affected by this recall:

Q:  Can I use my cylinder?  
A:  No.

Q:  Can I leave my cylinder full of nitrous?  
A:  No.

Q:  Can I leave my cylinder mounted?  
A:  Yes, but the cylinder must be empty.  Using proper safety procedures, c
rack the hose fitting and open the valve to empty the nitrous in a well ven
tilated area, such as outdoors.  Remember that the gas and cylinder will ge
t cold enough to cause injury, and that breathing the gas is harmful.

Q:  How long before I can use my cylinder again?  
A:  Boondocker is working with Rehvac to quickly implement a safe plan to r
emedy Rehvac’s manufacturing defect.  For your safety, Boondocker has chosen to notify you now before all details are known.

Q:  Where do I find my valve serial number? 
A:  The six-digit S/N number is stamped on the blow-off valve body, which i
s near the knob.

Q:  What is the safety hazard caused by this defect?  
A:  The risk of a cylinder bursting is increased because the Rehvac manufac
turing defect causes the safety blow-off valve to not release at the design
ed pressure.  A burst cylinder can result in property damage, injury, or de

Q:  I am a dealer.  Should I notify my customers?  
A:  Yes, please forward this notice to them.

Q:  I know somebody else with a Boondocker nitrous cylinder.  Should I info
rm them?  
A:  Yes, please forward this notice to them.