highest redline?
06-30-2007, 12:18 AM
#22
Junior Member
Join Date: Oct 2006
Posts: 14
Originally Posted by heretic' post='876417' date='Jun 27 2007, 07:21 PM
That's pretty impressive then, considering that, according to the SAE paper submitted by Mazda, the horsepower curve was nearly a straight line from approximately 405kw at 6300rpm to roughly 500kw at 8500, then flattening to 515kw at 9000. For it to build so smoothly, then taper off, then shoot up by over 150kw in the space of only 1500rpm is an incredible feat of engineering.
If the sarcasm isn't obvious, I believe the 900hp claim to be complete and utter bullshit.
Normally, I would agree that something is wrong with such a non-linear increase.
I read somewhere that the Lemans adjustable intake rated 40hp? lower than some peak HP intake as the Lemans intake was geared towards a wide power band.
The hidden assumption(s) here is that this was exactly the same engine/intake.
Different porting and/or a tuned (peak) intake might do it.
06-30-2007, 10:08 AM
#23
Senior Member
Join Date: Jun 2004
Posts: 524
Originally Posted by trydis7' post='876631' date='Jun 29 2007, 09:18 PM
Normally, I would agree that something is wrong with such a non-linear increase.
I read somewhere that the Lemans adjustable intake rated 40hp? lower than some peak HP intake as the Lemans intake was geared towards a wide power band.
The hidden assumption(s) here is that this was exactly the same engine/intake.
Different porting and/or a tuned (peak) intake might do it.
So, the engine that won LeMans could have made much more power with only a little more RPM (indicating a large torque increase as well), but only if it was a different engine. Got it.
That's like how the engine in my Rabbit can make 250hp, assuming that the cylinder head and intake manifold were different. It's not and it doesn't.
08-15-2007, 09:21 AM
#24
Junior Member
Join Date: Aug 2006
Posts: 1
I think its unfair to compare the redline of a rotary vs. a bike engine. Its like comparing a Scania 14L diesel against a rc engine with a normal redline around 30-40000rpm. The smaller things get, higher it can spin due to lower rotating mass. Atleast compare engines with similar displacement, poweroutput and/or materials (rotarys are mainly cast iron, bike engines are mainly all aluminium).
And ontopic:
I belive the biggest problem is eshaft-flex which causes the rotors to crash into the side irons and the flex also destroys the stationary gears. There are three ways i can think of to minimize the flex at higher revs.
A two piece 'GURU TYPE' eshaft with a center support bearing.
An eshaft which is 'pre-stressed' and under heavy loads the stress reaches its 'normal' state. I think some of the dragracing boys do this to their crankshaft.
And finally lighter rotors.
Any opinions?
And ontopic:
I belive the biggest problem is eshaft-flex which causes the rotors to crash into the side irons and the flex also destroys the stationary gears. There are three ways i can think of to minimize the flex at higher revs.
A two piece 'GURU TYPE' eshaft with a center support bearing.
An eshaft which is 'pre-stressed' and under heavy loads the stress reaches its 'normal' state. I think some of the dragracing boys do this to their crankshaft.
And finally lighter rotors.
Any opinions?
08-15-2007, 09:44 AM
#25
Senior Member
Join Date: May 2002
Location: California
Posts: 22,465
Originally Posted by Eson' post='880326' date='Aug 15 2007, 07:21 AM
I think its unfair to compare the redline of a rotary vs. a bike engine. Its like comparing a Scania 14L diesel against a rc engine with a normal redline around 30-40000rpm. The smaller things get, higher it can spin due to lower rotating mass. Atleast compare engines with similar displacement, poweroutput and/or materials (rotarys are mainly cast iron, bike engines are mainly all aluminium).
And ontopic:
I belive the biggest problem is eshaft-flex which causes the rotors to crash into the side irons and the flex also destroys the stationary gears. There are three ways i can think of to minimize the flex at higher revs.
A two piece 'GURU TYPE' eshaft with a center support bearing.
An eshaft which is 'pre-stressed' and under heavy loads the stress reaches its 'normal' state. I think some of the dragracing boys do this to their crankshaft.
And finally lighter rotors.
Any opinions?
And ontopic:
I belive the biggest problem is eshaft-flex which causes the rotors to crash into the side irons and the flex also destroys the stationary gears. There are three ways i can think of to minimize the flex at higher revs.
A two piece 'GURU TYPE' eshaft with a center support bearing.
An eshaft which is 'pre-stressed' and under heavy loads the stress reaches its 'normal' state. I think some of the dragracing boys do this to their crankshaft.
And finally lighter rotors.
Any opinions?
this is backwards...
you're right about the e shaft flex, and the 3 and 4 rotors are better, because they have more main bearings.
and some bike engines ARE comparable. i was looking at a 1198 ducatti sport, with the 3" sport exhaust, its 160WHEEL hp, its good for 9.7's @140 mph in the stock bike, which has all kinds of "race car" features like digital dash, and datalogging. it redlines around 12k... which seems to impress nobody.
i dunnno 9 second quarters for 20k seems like its not even that much money
08-15-2007, 05:53 PM
#26
Senior Member
Join Date: Jun 2004
Posts: 524
Originally Posted by j9fd3s' post='880328' date='Aug 15 2007, 06:44 AM
this is backwards...
you're right about the e shaft flex, and the 3 and 4 rotors are better, because they have more main bearings.
and some bike engines ARE comparable. i was looking at a 1198 ducatti sport, with the 3" sport exhaust, its 160WHEEL hp, its good for 9.7's @140 mph in the stock bike, which has all kinds of "race car" features like digital dash, and datalogging. it redlines around 12k... which seems to impress nobody.
i dunnno 9 second quarters for 20k seems like its not even that much money
you're right about the e shaft flex, and the 3 and 4 rotors are better, because they have more main bearings.
and some bike engines ARE comparable. i was looking at a 1198 ducatti sport, with the 3" sport exhaust, its 160WHEEL hp, its good for 9.7's @140 mph in the stock bike, which has all kinds of "race car" features like digital dash, and datalogging. it redlines around 12k... which seems to impress nobody.
i dunnno 9 second quarters for 20k seems like its not even that much money
You can go about as quick for a LOT less money in bone stock trim. Plus, Ducatis seem to be the Ferrari of motorcycles: you rub them with a diaper, taking them out only for rare and special circumstances, at which point they break and require a second mortgage for repairs.
This doesn't prevent me from WANTING a Ducati.
08-16-2007, 09:48 AM
#27
Senior Member
Join Date: May 2002
Location: California
Posts: 22,465
Originally Posted by heretic' post='880366' date='Aug 15 2007, 03:53 PM
You can go about as quick for a LOT less money in bone stock trim. Plus, Ducatis seem to be the Ferrari of motorcycles: you rub them with a diaper, taking them out only for rare and special circumstances, at which point they break and require a second mortgage for repairs.
This doesn't prevent me from WANTING a Ducati.
This doesn't prevent me from WANTING a Ducati.
yeah, it was cool.
mom was shopping for this.. https://www.nopistons.com/forums/ind...howtopic=69832
08-30-2007, 02:10 AM
#29
Member
Join Date: Aug 2007
Location: Alliston, Ontario
Posts: 47
I'd rather an Aprilia RSV1000, but anyway.
Wouldn't it be possible to run higher RPMS with a hardened Eshaft (heat up orange with torch, lob in bucket of oil), makes it hard but not as brittle if you chucked it in water. But yeah, wouldn't it be possible? Or would it just snap in half like a damn connecting rod?
Wouldn't it be possible to run higher RPMS with a hardened Eshaft (heat up orange with torch, lob in bucket of oil), makes it hard but not as brittle if you chucked it in water. But yeah, wouldn't it be possible? Or would it just snap in half like a damn connecting rod?
08-30-2007, 05:45 AM
#30
Fabricator
Join Date: Jan 2004
Location: Central Ohio (Hebron) Zephyrhills Fla.
Posts: 1,322
Originally Posted by Electric' post='881648' date='Aug 30 2007, 12:10 AM
I'd rather an Aprilia RSV1000, but anyway.
Wouldn't it be possible to run higher RPMS with a hardened Eshaft (heat up orange with torch, lob in bucket of oil), makes it hard but not as brittle if you chucked it in water. But yeah, wouldn't it be possible? Or would it just snap in half like a damn connecting rod?
Wouldn't it be possible to run higher RPMS with a hardened Eshaft (heat up orange with torch, lob in bucket of oil), makes it hard but not as brittle if you chucked it in water. But yeah, wouldn't it be possible? Or would it just snap in half like a damn connecting rod?
The E shafts are induction hardened. Note the blue lines around the edges of the rotor bearing throws........
Have the trainees ever had an Arial square four or Arial Red Hunter to ride? How about a Clymer Mamouth
or a Vincent Black Shadow? Real motorcycles.
Lynn E. Hanover
Thread
Thread Starter
Forum
Replies
Last Post
Mazdaracer4fun
RX-7 & RX-8 Parts For Sale & Wanted
1
04-24-2008 12:32 AM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)