We're contemplating changes for this December.

This is Shootout #19. Amazing, since it seems like yesterday that Jerry  Bassett and I created this concept of me dyno certifying stock sleds then us doing some sort of field shootout with guaranteed stock sleds. Shootout #1 was held in a farmer's field in central NY, Tim Bender was the shootout test driver, handheld stopwatches and a radar gun provided data. Tim caught our first cheater that year, noting that the carbureted 650 Indy accelerated like a dragster, impossible to be box stock! Turns out somone had compromised the sled hood seals and installed dragrace clutches. Jerry Bassett deleted that sled's data from Shootout #1.

Eighteen years and a few caught cheaters later, here were are again.

But this past few years with SnowGoer awarding a Shootout Trophy for "most improved" performance for stockers out-of-the-crate to "dealer prep", there seems to be some finger pointing about detuning box

Here is PTM Stan's full dyno session for everyone's perusal. Stan had threatened to slander me on the internet if I didn't agree to send him the $700 he paid for this particular dyno session, which is what he has been doing on the internet after I refused to pay him off.. I don't understand why he did that, other than perhaps he has limited resources to run an asphalt sled, and is under financial stress.

Stan was supposed to be at the dyno early, 9 AM. I waited for several hours for Stan to show up to tune. Glenn Hall had been scheduled to test turbo stuff in the AM, but since Stan had acquired experimental high RPM race pipes from D&D to go along with his custom ECU with the 8000 RPM rev limit removed, Glenn wanted to see how it worked out, so he offered to let Stan PTM dyno tune first. So Glenn planned accordingly, showed up at noon expecting to see Stan's final tests. But by noon Stan had just gotten to DTR and we were still getting ready to fire up Stan's sled.

The Blue line A is off the trailer, just the way Stan suggests it ran the best all motor 1/4 mile. 175 HP .85+ BSFC But the problem is the violent vibration from Stan's bent crank from test A surely ate up 15-25 HP lost to vibrating the sled, vibrating my 2000 lb hydraulic lift table and framework, the concreted floor, and my shriveled testicles, and even popped loose the ancra ratchet straps that have held, firmly, 1000 sleds. So the HP and BSFC was skewed due to the energy that was diverted before making it to the dyno absorption unit. The skewing is how much HP is lost to vibration from a crank taper running out many thousandths, shaking my steel dyno coupler and CV driveshaft. The BSFC is really lower than indicated, perhaps by .10 lb/hphr or more.

Next test shown is the Green line B, after correcting Stan's woefully rich up off-the-trailer Boondocker settings to make max HP with his low RPM pipes. A great improvement, but those vibes surely ate up lots of the HP.

Next the gold line C resulted after Stan installed his experimental high RPM pipes. Power was down, probably because the vibration was even worse. The violence of vibes increases exponentially as the square of engine RPM. We needed to tweak the Boondocker even more to optimize.

Purple/ Green D&E is with the Boondocker optimized for the high revving pipes, but that vibration was becoming even more violent. Even with the ancra straps sinched tight, the back of the sled would vibrate sideways an incredible distance. Imagine the force necessary to slide the asphalt track, squeezed tightly over the steel diamond plate nubs, several inches sideways during a five second dyno run!

Finally, we tested with the Boondocker N2O energized. What I always do is set the nitrous oxide system (whatever brand) for the base setting. I have our copper tube deto sensor attached to the engine to listen for knock and quickly abort whenever detonation is heard. I stab the throttle, hold it steady state with exhaust valves open, the sled owner [Stan] holds the nitrous button and I record one second of data and stop immediately to look at the BSFC and fuel flow. If fuel flow is off either way, boondker is adjusted. I did that several times, and in this case Stan was able to tweak his Boondocker N2O to perfection, and create optimal nitrous/ fuel flow before we ran the final red N2O test that was climbing to the moon. The N2O/ fuel ratio was dandy, no clicks of deto, all was good except that violent vibration. Here, I believe that Stan's bent and beat up crank went out of phase at 8900+ RPM causing the test to end at that point.

After this, Stan realized that the high RPM pipes were going to cause his engine to peak at too-high RPM, so he reinstalled his original lower RPM pipes. But then as I recall his engine failed to fire. We though it was bad reeds, but his subsequent assessment after autopsying at home was the crank was out of phase (besides being woefully running out). I didn't charge Stan for the time we spent after the high RPM N2O run switching pipes and troubleshooting, trying to figure out why it wouldnt refire on two cylinders.

After he got home and discovered his crank malady,  and being a pal since he has been a multi-time dyno tuner and many year DTR subscriber I suggested he come back to verify his all motor and N2O tunes with those optimal lower RPM pipes, no charge. But Stan instead since he knew he had a perfect Boondocker all motor and N2O tune, strangely, demanded a full refund for the time I spent tuning his sled.

But now he's got a new crank installed, things are once again smooth, and he has a perfect Boondocker all motor and N2O tune with the correct low RPM pipes so he thinks he doesn't need DTR anymore. So he threatened me with slander if I didn't refund the dyno time we spent tuning his sled. Those vibes, surely, ate up lots of HP and it would have been good to see the real HP/ BSFC with a straight crankshaft. I offered to retest to document that.  But that, sadly, won't be happening. I refuse to be bullied, even if paying off a sociopath bully might be a good business decision.

After Stan left late afternoon, we finally got going on Glenn Hall's big turbo sled. The same driveshaft that Stan PTM is claiming hurt his crank ran smoothly with way more HP than Stan's, and we wound up testing until 3:00 AM because of the late start. And four months later that same dyno shaft still is as perfect as the day I built it. Next Friday we will be spinning that same drive system to 10,000 RPM with a Vmax 4 gonzo turbo looking to achieve the first 600 HP DTR test.

Recently, Sean Ray concluded the 700th dyno test on his Hentges Racing Polaris 600 mod engine. Same shaft system, more revs than Stans and that same engine after all that dyno testing here is retained as a spare for the pro snoX racers.  My dyno drive shaft system is designed to absorb torsional vibrations and is easier on the engine than driving a sled. There is zero side load on the crank/ crankcase like the engine experiences when the drive clutch engages on a belt drive.

But if you have a beat up whore of a crankshaft, with pressed and repressed joints, abused with years of violent N2O stress and snapped drive belts then buzz it 1000 RPM beyond it's design limit (factory rev limit) with 2x stock HP please expect problems.

Here it is: