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Old 05-04-2014, 07:30 PM   #93 (permalink)
Changfa diesel + Suzuki
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Join Date: Jul 2012
Location: Northern, NY
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Centurion - '74 FIAT X1/9 Centurion Full Race DNA
Last 3: 143.5 mpg (US)
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Originally Posted by 93hatchDX View Post
That is interesting about the ear plugs for the sound. I've watched the youtube vids and it did seem a bit loud. I'm sure that can be modified if the owner wanted.
Kubota diesel in a Fiero? - Pennock's Fiero Forum
This guy here was wondering about the Kubota planted into a fiero.
Great to see the progress of this car. Thx for sharing.
Hi 93hatchDX,
Most of the time the earplugs aren't really needed especially if you're hearing is not as sharp as it used to be (hand raised here!) The noise is more of a vibration throughout the entire structure - really more like a resonance. I believe it mainly stems from very stiff mounting of the engine and transmission. The highlight of it is when there is a steep hill and the rpms are around 1800-2000 rpm. For a tiny engine the Kubota has impressive pulling power at that speed and its fury manifests then.
Previous to the Green Grand Prix, I had looked over the elevation maps and applied the worst of the course (turn #1, the uphill that extended most of the way in some form to the horsehoe) and found an existing stretch of road here that falls very close to it. After countless runs I was able to narrow down the best speed of approach, then the climb, that would yield max mpg and still allow for the target 45 mph to be met. I was off a little and my test course was actually worse than the track. The downside to the resonant vibration was a quick easy fix: earplugs. They take the edge right off and still allow one to hear for the most part.
I did check out the Fiero/diesel thread many years ago. I almost went that route myself but the deciding factor was the mid-engine layout and the limitations of it. With a few remnants of the 1973-74 energy crisis (and then another surge in 1979),there was somewhat of a mpg revolution brewing. Going back prior to the Fiero/diesel idea, was the infamous Smokey Yunick Fiero that appeared on Hot Rod magazine's cover 2 years after Mechanix Illustrated ran the Urba Centurion on its cover. Here was a lackluster Iron Duke four-banger that could now produce some get-up-and-go and return some impressive mpg's.
I've resurrected those magazines years ago and it's funny how in principle, they are still in keeping with today!
At some point after this GGP write-up I am hoping to go into some technical details that helped to really push this project and those mpg numbers over the top past the original Centurion's.
Have a great day and thanks for taking the time to read this endless-thread!

Last edited by changzuki; 08-04-2018 at 11:04 PM..
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