Urba Centurion Update - (Kubota diesel, 100+ MPG in mixed driving - Fall 2012 on)

[changzuki]

2014 Green Grand Prix - Finale'
In the last GGP entry, Team Centurion shared a few lanes with smokey442's Chevy S/10 (recap: 37.7 mpg ).
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The extreme joy of driving a finely tuned, precision motor car on the legendary Watkins Glen Raceway would now be concluded with a formal checkered flag and a free-fingering!
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Yes, that's right, all driver's and navigators got fingered .
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Hearing it but not feeling it? Have a look, watch the guy in the tower on the left:
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So, that was the finish and as you may have guessed the "free-fingering" was actually our visual queue to stay right and exit the track.
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Getting off the track and back into the garage area was somewhat of a procession but did give another photo op:
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Cars were directed to the garage per specific bays corresponding to the car's Official GGP assigned number:
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With roughly 43 cars, some did not get an inside bay and were located in a small group outside.
Yes, in the land of misfit toys they were:
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And all the little Whos in Whoville cried boo-hoo-hoo!
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Sniffle, sniffle, nobody wants a Charlie-in-the-box :
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It was during this time, before the Stage 2 Rally, that the week's pre-race schedule and so much more would come home to roost. The lack of sleep, caffeine diet, over-stimulation of the Stage 1 driving, the checkered finger, and wondering if the Centurion could even make the 250+ mile trip home. ...
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With no jack, no spare, and no Kubota roadside assistance program, tension started to weigh in - the GGP was about to get ugly, really ugly.
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And that's just the beginning.
The straw that broke the camel's back happened at the Start of Stage 2 - the tank fill-up at Valero.
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An hour before Centurion was headed back to Colton, NY, CrazyJerry was like Mr. Creosote. And Watkins Glen was like the restaurant Mr. Creosote was in.
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Here's a re-enactment (specifically at 1:10 into the clip):
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Mr. Creosote
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So rewind, back at the garage area, although the Stage 1 MPG competition was over, a lot was still on the table.
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And to add to the misery, it was starting to rain...
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Sooooo, what happened at the Valero re-fuel?
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~CrazyJerry

[mikeyjd]

Originally Posted by changzuki

Sooooo, what happened at the Valero re-fuel?



~CrazyJerry

Well?

[changzuki]

Post Stage 1 / Pre Stage 2 fuel refill...
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Around 12:30 in the Watkins Glen Raceway garage, there was a gathering for instructions about the Stage 2 Road Rally.
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For this portion, several pages stapled together were found in our race packets. There was a rule sheet, narrative, scoresheet, Sherrif's letter, and this amazing paper full of hieroglyphs called a "Tulip Map" (...wonderful..) In the 288 mile trip down to the hotel south (of the racetrack), there were a grand total of 5 turns and I screwed up the 2nd to the last one.
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What do you suppose I was going to do with a Tulip Map? So now, the Stage 2 Rally wasn't looking too hot.


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During the next half hour of batting this around, the prospect of arriving home before nightfall was looking better and better, so much so that I and asked Sheepdog 44 if he would be ok with my friend Pete staying with me for this Stage 2 portion just in case.. Taking one for the team, he agreed and Team Centurion had officially split-up; Sheepdog 44 found a Stage 2 ride with Aerostang, and Centurion remained at the track. After the cars started Stage 2 (leaving the garage for Valero) I had a lengthy discussion with Pete who encouraged we go for it and do Stage 2. I agreed to make a final decision after the Valero fuel up, so off we went. Being maybe only 10 minutes away from Valero didn't give me a lot of time, and it started raining a little harder.
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As we made the descent to Valero, the 1st omen showed up only a couple miles from the raceway.
Weeebooo - weeeeebooo - weee-booooo!!!!!
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Then 15 minutes later, we were on "The Endless Road to Nowhere"... The "Curse of the Tulip Map" had kicked in and now we were lost... Luckily a traffic light was in sight, but there were no clues as to where we were. With cars in the rearview, we pulled over to let them pass...
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BINGO! WE JUST GOT LUCKY!!! The cars behind us were sporting their Green Grand Prix numbers and likely took the same wrong turn we did. We were saved and only had to follow our new tour guides to the gas station!
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As quickly as we got lucky, we got unlucky! Seems the other cars wanted to makeup time for the bogus turn and even barreling along against the Kubota's governor (65 mph) we couldn't keep up - and that convoy faded out of sight..
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At least 15 minutes later we ran across civilization and in the distance was a "Burger King"; we had hope!
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Looking beyond burger world, it appeared there was a gas station and as we wheeled a little closer there it was - VALERO!
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Upon entering the Valero station there was one of the two cars we saw earlier (the Mini) so maybe timewise we weren't too far in the hole.
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We had to wait for the cars to clear to gain access to the one and only diesel pump. Moving 10 more feet it was now time to remove the 2 gallon tank for the official fill-up. I remember saying to Pete that we must be on a little slope or something because there was still plenty of fuel visible in the sight glass.
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Recap: This was after driving up Mt. Ararat to the track, driving 100+ miles on the track, then making a wrong turn onto the scenic route back to Valero, and we still had what looked to be roughly 3/4 of a two-gallon tank of fuel remaining!
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Really?.....Really!
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As I removed the filler cap and the fuel Marshall was approaching the tank, I remember saying to Pete, "This is going to be really interesting. There's still a lot of fuel in there."
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Remembering fuel-fill #1, the goal was to fill the tank to the top of the sight glass just like before. As the fuel Marshall squeezed the trigger the fuel began to flow. As the pump's digital display sprung into life we watched and held our breath - but not long enough to turn purple. Or even red . In fact, not really long enough to qualify as holding our breath - the pump handle just clicked. The fuel was even with the full line on the sightglass and the pump's digital display showed less than half a gallon.
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Actually, it was approaching the "neighborhood" of having used a measly 1/3 gallon. We all just stood there like we had been slapped . I asked the fuel Marshall if I could rock the tank to make sure there wasn't an air bubble and he said sure. This made no difference; the fuel fill was over. Pete ran some quick numbers on his iPhone, the fuel Marshall laughed, the scorekeeper wrote down the odometer and fuel numbers and said "Nice job", and I went into thermal shock....
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At the counter I told the clerk I just filled up on the diesel pump. She laughed and said, "Is that all it took?" It was her statement that began the repeat of exactly what the last couple of years have been like when folks respond to the mpg numbers affixed to the front of Centurion's fender.
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This was bittersweet news at best. The idea that not just a car, but this car, could pull those kind of numbers seemed very surreal..
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But it just did...
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How?.... The Devil is in the details.....
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~CrazyJerry

[johnathanf1lm]

I dont know diesel motors all that well but a 3 cylinder 800cc engine pushing out around 18hp doesnt sound very efficient compared to a smaller less cylinders and cc motor putting out the same hp at like 8000rpm. I think there is improve s that can be made to the engine to increase power on the same amount of fuel.
P.s ik at 8000rpms its using more fuel but the amount of fuel going into a smaller engine has to be about the same as this motor at 3600rpm

[changzuki]

Originally Posted by johnathanf1lm

I dont know diesel motors all that well but a 3 cylinder 800cc engine pushing out around 18hp doesnt sound very efficient compared to a smaller less cylinders and cc motor putting out the same hp at like 8000rpm. I think there is improve s that can be made to the engine to increase power on the same amount of fuel.
P.s ik at 8000rpms its using more fuel but the amount of fuel going into a smaller engine has to be about the same as this motor at 3600rpm

Interesting idea. I'd love to hear more details on this. The Centurion's engine would likely fly apart at 8,000 rpm. It's rated at just 2600 rpm and currently governed at 3210 rpm....
~CrazyJerry

[johnathanf1lm]

I didnt mean put the diesel motor up to 8000k but more swap in more like a water cooled motorcycle like motor thats way smqller but has the same output as the diesel at 3200 rpm

[BobS]

Jerry,
If you don't mind, what numbers did you pull there? RQRiley says 200+ so what's the plus? Just curious.

[some_other_dave]

I think that even a tiny motor running at 8K RPM will still produce more power than is needed to push this down the road. You also do lose efficiency to friction at higher revs, I believe in a geometric fashion. There is a definite sweet-spot--see the BSFC graphs for multiple evidence of that.

-soD

[johnathanf1lm]

Yeah but a single or dual 250+cc engine would put out the same output as this diesel engine (with a complete change of gears) so how is a 3cylinder 800cc more efficient (yes ik a diesel would have more torque to it in the long run

[sheepdog 44]

I think diesels are bit deceptive when you're comparing cc's. That 800cc at 3,000rpm max has the same power as a 250cc gas engine at 6,000rpm? Despite higher displacement, it's being loaded just as efficiently because it has such a low max power. And it's a diesel, so bsfc is probably the highest you'll ever see. A 250cc diesel eliminating 500cc's of pumping losses would have an unusably low max hp. Even diesel motorcycles are in the 800cc range. You're car as is, is as efficient as it gets.

I think how to make the centurion more useable in the real world is a more pressing topic. If you put in a Honda IMA system, you would add maybe 200lbs. But you would have a faster 0-60 with 30hp instead of 17hp for accelerating.

Or just off the shelf electric conversion parts for a motorcycle would give you a plugin hybrid like the XL1. Attach a motor by half shaft to the rear wheels. The XL1 has 5kwh for 31 miles. 5kwh is about $2,000 in batteries. You could do 3kwh for $1,200 and maybe 20 miles of electric range. If you installed it right, you might get the weight addition to 170lbs +-20lbs. That would make the car perform 200% better.

Any engine with decent hp would give you 100mpg and make it useable at freeway speed limits.

We've already discussed an electric conversion.