Speedzilla Forums banner

1 - 20 of 54 Posts

·
V4 CyclePath...
Joined
·
6,827 Posts
Discussion Starter #1
Free Ducati... no more weight or intake restrictions... let Ducati get all they
can out of the old V2 workhorse before they decide to homologate a new
V4... first Honda and then Aprilia have found that Gp inspired machines
make great WSBK machines...

Quote Crash.net
"Twin-cylinder bikes gets their second weight break in just four rounds after
a second review of the points' standings.

The FIM has confirmed it will give twin-cylinder bikes a further weight
reduction of 3kg for the final four rounds of the World Superbike
Championship following another review of regulations – bringing them
directly into line with their 4-cylinder rivals.

The new weight rules were introduced at the start of 2008 due to Ducati's
decision to bring the larger capacity 1200cc 1098/1198 to the
championship.

This minimum weight has already been reduced by 3kg ahead of the
seventh round of the series at Miller Motorsports Park by virtue of the
'average value of event' that currently favours the 1000cc 4-cylinder bikes.

A second review has since taken place over the last three events with the
FIM agreeing that the twin-cylinder machines – which solely affects the six
Ducatis on the grid – should receive another 3kg weight break as stipulated
in the regulations.

It means Ducati, despite having a larger cubic capacity, will now be able to
have minimum weight of 162kg, the same as its Aprilia, Suzuki, Honda,
Yamaha, BMW and Kawasaki rivals.

A statement read: "The new minimum weight for 1200cc 2-cylinder
motorcycles shall be 162 Kg, a reduction of 3 Kg as stipulated in Article
2.4.4.2 (Minimum Weight Adjustments) of the FIM rulebook.

"The minimum weight for 1000cc 4-cylinder motorcycles shall remain
unchanged at 162 Kg."

The average points difference between the twin and four-cylinder machines
over the last three events was 9.5 points in the favour of the latter. This,
however, would have been lower had Carlos Checa been able to complete
his two wins at Miller Motorsports Park."
 

·
He with the senior member
Joined
·
5,671 Posts
errr...... you quoting that the twin's intake restrictions are also removed, Larry...or just wishing?
 

·
V4 CyclePath...
Joined
·
6,827 Posts
Discussion Starter #3
errr...... you quoting that the twin's intake restrictions are also removed, Larry...or just wishing?
I'm wishing... darn rules rules rules... over rule the rules markers...
 

·
He with the senior member
Joined
·
5,671 Posts
I'm wishing... darn rules rules rules... over rule the rules markers...
I hear ya, but unfortunately, rules are required to allow totally disparate configuration street based machines to compete with each other. In this case, it was necessary to add extra penalty to the twins to safeguard against a 1200cc twin whitewash, even though we know that the basic formula is probably very close for 1200cc twins with limited revs and much limited valve area to compete against the fours on a relatively equal footing.

If the fours continue to dominate the results as they have done, I'm hoping that the intake restrictions on the twins will be fully lifted, but I think it's too late in the season for (a) that to be fully implemented within the rules and (b) for it to make any difference with the loss fo form from Haga and the lack of consistency from his team mate.

An extra 61% throttle body area (63.5mm stock TBs vs. the Restricted 50MM intakes) would make a tremendous difference - not only to top-end power, but more importantly, to consistency of throttle response.
(PS Ignore the funny comment from one of the riders that they thought the difference would only be 1-2HP..that is clearly mind-games at work when you have a 61% increase in throttle area!)
 

·
V4 CyclePath...
Joined
·
6,827 Posts
Discussion Starter #5
I
An extra 61% throttle body area (63.5mm stock TBs vs. the Restricted 50MM intakes) would make a tremendous difference (PS Ignore the funny comment from one of the riders that they thought the difference would only be 1-2HP..that is clearly mind-games at work when you have a 61% increase in throttle area!)
What??? if your TB was opened 61% extra it would be around 80mm... a 50mm
intake opened up 63.5mm is only 27% extra... not a tremendous difference so
maybe Checa wasn't playing mind games...

Quote Carlos Checa:

We have air restrictors that this will be also next step in six races
probably for next year already. But, from my information, air
restrictor is making smaller and smaller difference in the power. Now
maybe we need talking a little bit-- maybe 15 or 18 or 20 horsepower
to be close to the others. And maybe air restrictors can give you 1.5
or 2, maximum. Then we need to find the power in other area.
 

·
He with the senior member
Joined
·
5,671 Posts
Dear, oh dear, Larry. Been some years since you did science class at middle school, eh? :)

Hint -it's the AREA of the intake venturi that limits flow, not the diameter. The difference is 61% in area between a 50MM and a 63.5MM venturi.
That's a HUGE difference.

Like I said...ignore the Checa comment...it's mind games.
 

·
V4 CyclePath...
Joined
·
6,827 Posts
Discussion Starter #7
Hint -it's the AREA of the intake venturi that limits flow, not the diameter. The difference is 61% in area between a 50MM and a 63.5MM venturi.
That's a HUGE difference.
Show me the math and show me your source where it says 61% increase in
intake venturi area...
 

·
Registered
Joined
·
4,632 Posts
Dear, oh dear, Larry. Been some years since you did science class at middle school, eh? :)

Hint -it's the AREA of the intake venturi that limits flow, not the diameter. The difference is 61% in area between a 50MM and a 63.5MM venturi.
That's a HUGE difference.
Nah, it`s more likely his attempt at re-writing the rules of physics to suit his bent V4-obsessed mind....
 

·
Senior Member
Joined
·
2,737 Posts
Baldy fer chrissakes.......

Now we're going to get the fuzzy crank drawings and the stars on the wheels pics again.
 

·
I'll fix it.
Joined
·
2,249 Posts
Busy Little Shop said:
Show me the math and show me your source where it says 61% increase in
intake venturi area...
Larry, you really dont understand the math? its middle school geometry!

Area of a circle: Pi * Radius squared

50mm restrictor = 25mm radius
3.14 * 25 squared = 1963.4 mm2

63.5mm throttle body = 31.75mm radius
3.14 * 31.75 squared = 3166.9 mm2

3167 - 1963 = 1204 (Im rounding off here for simplicity)

and 1204 just happens to be 61.3% of 1963. :rtfm
 

·
Registered
Joined
·
4,632 Posts
Larry, you really dont understand the math? its middle school geometry!

Area of a circle: Pi * Radius squared

50mm restrictor = 25mm radius
3.14 * 25 squared = 1963.4 mm2

63.5mm throttle body = 31.75mm radius
3.14 * 31.75 squared = 3166.9 mm2

3167 - 1963 = 1204 (Im rounding off here for simplicity)

and 1204 just happens to be 61.3% of 1963. :rtfm
but where is the magical engine configuration variable in all of that?????? Take it away Larry!
 

·
Registered
Joined
·
2,868 Posts
crickets , crickets ... as he searches for his abacus . The twins would fvcking storm if unrestricted ! The stock SP-2 is 62mm for Christ sake .
 

·
He with the senior member
Joined
·
5,671 Posts
Larry, you really dont understand the math? its middle school geometry!

Area of a circle: Pi * Radius squared

50mm restrictor = 25mm radius
3.14 * 25 squared = 1963.4 mm2

63.5mm throttle body = 31.75mm radius
3.14 * 31.75 squared = 3166.9 mm2

3167 - 1963 = 1204 (Im rounding off here for simplicity)

and 1204 just happens to be 61.3% of 1963. :rtfm

Thanks for saving me the time to write this down for our friend.

Larry, if you're not comfortable with the pi * r squared formula for the area of a circle, and knowing you're a hands-on kinda guy who draws things out on paper, then I suggest you get some very fine grid graphpaper, take your compass and draw a circle with the stock 1098R throttle body venturi size of 63.5MM (31.75MM radius)...and then draw the 50MM (25MM radius) W/SBK restrictor size inside that circle, and count the little squares. You'll likely be amazed at the 61% increase in area that the stock circle provides compared to the tiny 50mm restrictors imposed on the 1200cc twins.

And then you will recognize that without the restrictors, a little more power may be forthcoming. I would suggest that the current Aprilia speed advantage would disappear if the twins could run unrestricted as you have said you prefer...
 

·
Stares at Goats
Joined
·
81 Posts
Just to throw my half a cent in, there are ways around restrictors...Yamaha did it with their 750's and actually increased power w/ the restrictors in place. It has a lot more to do with the "quality"' of airflow than just size difference. And, stock, I think the RC51's inlet's are a tad on the over-large size for the displacement, cams, piston shape and compression ratio.

Though, in this case, I'm sure the 1200's could easily handle the full size inlets, considering the design in place.

but whatever...
 

·
V4 CyclePath...
Joined
·
6,827 Posts
Discussion Starter #16
Thanks for saving me the time to write this down for our friend.

Larry, if you're not comfortable with the pi * r squared formula for the area of a circle, and knowing you're a hands-on kinda guy who draws things out on paper, then I suggest you get some very fine grid graphpaper, take your compass and draw a circle with the stock 1098R throttle body venturi size of 63.5MM (31.75MM radius)...and then draw the 50MM (25MM radius) W/SBK restrictor size inside that circle, and count the little squares. You'll likely be amazed at the 61% increase in area that the stock circle provides compared to the tiny 50mm restrictors imposed on the 1200cc twins.

And then you will recognize that without the restrictors, a little more power may be forthcoming. I would suggest that the current Aprilia speed advantage would disappear if the twins could run unrestricted as you have said you prefer...
I would be amazed if a 50mm restrictor is removed from a 63.5 venturi
means 61% increase in breathing area... and I think so would Ducati...
however I do recognize without the restrictors a little more power may be
forthcoming... someday soon we shall find out if the unrestricted Ducati V2
can match the Aprilia V4 in speed... because its no secret the riders aren't
happy about the level of power in the restricted state...

I've emailed Ducati Corse Racing Support about the restrictors and if it
means a 61% or 27% increase... standby...
 

·
V4 CyclePath...
Joined
·
6,827 Posts
Discussion Starter #18
Larry, you really dont understand the math? its middle school geometry!
I never had geometry in High School... I took it geometry after I
retired from the USAF during college studying engineering... I can do
it but I really struggled with math... I don't have a mind for math...
 

·
V4 CyclePath...
Joined
·
6,827 Posts
Discussion Starter #19
Im amazed that a so-called machinist cant wrap his head around 6th grade math :rolleyes:
I'm not a so called machinist... I'm just a dumb guy with a lathe and mill..
 

·
Registered
Joined
·
651 Posts
What??? if your TB was opened 61% extra it would be around 80mm... a 50mm
intake opened up 63.5mm is only 27% extra... not a tremendous difference so
maybe Checa wasn't playing mind games...

Quote Carlos Checa:

We have air restrictors that this will be also next step in six races
probably for next year already. But, from my information, air
restrictor is making smaller and smaller difference in the power. Now
maybe we need talking a little bit-- maybe 15 or 18 or 20 horsepower
to be close to the others. And maybe air restrictors can give you 1.5
or 2, maximum. Then we need to find the power in other area.
Let's think about this logically, besides the overwhelming empirical evidence. Why would they restrict from 62mm to 50mm if it only meant 1-2hp :wtf
 
1 - 20 of 54 Posts
Top