BigOgre
Well-known member
Italian design and military in the same sentence? Hmmm . . . .
Btw, clicking on DISCOVER MORE brings up an error code.
SPLIT: Off-Topic Crap About Diesel
- Thread starter bwv
- Start date
Help Support Yamaha FJR Motorcycle Forum:
Btw, clicking on DISCOVER MORE brings up an error code.
ionbeam
2 FUN
If it were a French military design, when started it would run backwards
All the DISCOVER MORE would tell you is to look and see if the D in diesel is capitalized or not, everything else is there on the page as you scroll down.
bwv
Well-known member
And it would drop the guns...
Old Guy
Well-known member
OK. I watched the drag race video, and I think I've spotted one downside to high-performance diesels in motorcycles 
mcatrophy
Privileged to ride a 2018 FJR1300AS
My wife's car is an Audi A3 2 litre turbo diesel. Fuel economy is better than the petrol (gas) equivalent, but this advantage is threatened to be outweighed by the higher cost of diesel. Unfortunately diesels have become so popular that the relative demand has gone up, refineries are getting unbalanced, so having to do more work to get the amount of diesel.
I consider the economy good but not exceptional, and performance is very good for a "standard" family vehicle.
There's a bit of a misunderstanding about the low-speed torque, the torque isn't particularly good until the engines reaches say 1500 rpm when the turbo begins to work, but remember the maximum engine speed is not very high, and it runs out of puff long before it gets there; short-shifting at 3000 to 3500 gives a better feel to the performance than trying to get high-end power. So you're only working over a 2:1 or so engine speed ratio in each gear.
In normal driving you learn to use it differently from driving a petrol engine, and the performance is sufficient to surprise other car drivers. Try to move from rest too quickly and the nanny under the bonnet has to wake up to stop the wheels spinning.
Pollution is another issue. All modern diesel cars have a particulate filter to filter out the particles from the exhaust. These do need cleaning out, there are different systems from different manufacturers. The VW group cars assume the car will sometimes be driven reasonably hard, say motorway cruising, to burn off the filtered particles. The downside of filters is that the very smallest particles still come through, these are the ones that go deepest into the lungs' capilliaries, and they are carcinogenic.
The clutch can be prone to failure. The power strokes seem to give rise to higher vibration than in the petrol engines. To smooth this out, you could use a heavier flywheel, but this would noticeably affect the acceleration. The design compromise is to fit a "duel mass" flywheel, essentially two light halves bonded together with a resilient glue (I simplify somewhat). These can fail if the engine is "chugged" a lot.
On the whole, very happy with it, but it bugs me somewhat that a vehicle weighing several times the FJR and with a much higher frontal area gets better fuel economy.
I consider the economy good but not exceptional, and performance is very good for a "standard" family vehicle.
There's a bit of a misunderstanding about the low-speed torque, the torque isn't particularly good until the engines reaches say 1500 rpm when the turbo begins to work, but remember the maximum engine speed is not very high, and it runs out of puff long before it gets there; short-shifting at 3000 to 3500 gives a better feel to the performance than trying to get high-end power. So you're only working over a 2:1 or so engine speed ratio in each gear.
In normal driving you learn to use it differently from driving a petrol engine, and the performance is sufficient to surprise other car drivers. Try to move from rest too quickly and the nanny under the bonnet has to wake up to stop the wheels spinning.
Pollution is another issue. All modern diesel cars have a particulate filter to filter out the particles from the exhaust. These do need cleaning out, there are different systems from different manufacturers. The VW group cars assume the car will sometimes be driven reasonably hard, say motorway cruising, to burn off the filtered particles. The downside of filters is that the very smallest particles still come through, these are the ones that go deepest into the lungs' capilliaries, and they are carcinogenic.
The clutch can be prone to failure. The power strokes seem to give rise to higher vibration than in the petrol engines. To smooth this out, you could use a heavier flywheel, but this would noticeably affect the acceleration. The design compromise is to fit a "duel mass" flywheel, essentially two light halves bonded together with a resilient glue (I simplify somewhat). These can fail if the engine is "chugged" a lot.
On the whole, very happy with it, but it bugs me somewhat that a vehicle weighing several times the FJR and with a much higher frontal area gets better fuel economy.
ionbeam
2 FUN
Man, I could smell that right through my monitor. Probably the only thing on the track that could smell worse would be the nitromethane cars, but they don't lay out the same size cloud that these cars & trucks did.OK. I watched the drag race video, and I think I've spotted one downside to high-performance diesels in motorcycles
Anything that runs under 12 seconds and faster than 130 mph is a serious performance vehicle, but damn, did you see the size of the equipment needed to run this quick/fast?
Last edited by a moderator:
RichDoyle
Well-known member
Because of issues of cost, uncertainty of future trends, and (especially) availability of avgas in the worldwide market, light aircraft manufacturers have been slowly adopting diesel engine power in their aircraft. In some countries, ONLY the diesel-powered version of certain aircraft are available. Cessna's venerable Skylane (aka 182) is currently only produced only in a turbo-diesel version - period. I the US, these diesels use Jet-A, not automotive diesel. Jet-A often costs less than 100 LL, which is pretty much the only avgas there is.
Serious teething problems getting this stuff to market (note Thielert's problems), but the worst seems to be in the past.
These engines are heavier with more complex fuel systems than the gasoline-powered engines they replace, making the planes heavier overall. But diesel characteristics (especially as they are universally turbocharged) are otherwise well-suited to aircraft requirements. But I think it's a tough squeeze to see them in any widely desirable motorcycle. And autogas doesn't have the same economic and availability downsides that avgas does.
Serious teething problems getting this stuff to market (note Thielert's problems), but the worst seems to be in the past.
These engines are heavier with more complex fuel systems than the gasoline-powered engines they replace, making the planes heavier overall. But diesel characteristics (especially as they are universally turbocharged) are otherwise well-suited to aircraft requirements. But I think it's a tough squeeze to see them in any widely desirable motorcycle. And autogas doesn't have the same economic and availability downsides that avgas does.
lnewlf
Well-known member
Yeah, but it would be great for getting the young blond gum snapping texting lipstick applying dizzy chick in the Hundai off yer ass .OK. I watched the drag race video, and I think I've spotted one downside to high-performance diesels in motorcycles
