| Here's what happens when people can't post (like the R1 forum).....
and threads wander into vagaries and conjecture...... and limited in
input. Here's the link to a thread.....
http://www.r1forum.com/forums/thread
And here's the responses to some of the statements and questions.....
The Storm: Just got my new
Factory Pro v stacks in today with the new BMC Filter
and holy cow look at the size diff!
(now, skip to the bottom and see the last Blue quote, first!)
LDHR1:torque my friend torque..
unseen response: Different bike models respond to different velocity
stack lengths and shapes. In "general" shorter = higher rpm power focus
and longer = lower rpm power.
In the 04-06 R1 (and the 02-03 R1's, too), any shorter stacks made less
power everywhere - and the longer we made the stacks, the more power
the engine made, everywhere - until we got too close to the top of the
airbox. I backed off 5mm and that made best upper mid and top and low.
Shortening the stacks only made less power in the upper mid and helped
nothing more at any rpm.
Wheatman: Graves make better power in the midrange...
unseen response: And you know that... because you did a comparison test?
I DID do a comparison test. That statement certainly doesn't jive with
anything I've ever done or anything that I've ever heard from a user
who rode his bike and had the 2.
JG1: I'm so confused with the whole Graves vs.
Factory Pro thing. I have the Graves, FWIW
unseen response: Getting information from the internet where only some
people can post anything they feel like for any reason they want, will
do that.
Wheatman: Ram air on the 04/05 R1 seems to
starve #2/3 cylinders of air so the Graves design equals the air flow.
Unseen response: And that statement came from what test? As it doesn't
seem to be replicated in the real world testing. Actually - the air
properties inside the airbox is rather chaotic - BUT - the air pressure
is essentially equal at any point in time throughout the airbox - The
airflow's certainly not flow directed at a pair of cylinders. Otherwise
Yamaha would have fixed it.
D207G: Factory helped Graves design their stacks.
I had the Graves on my 2002 R1, but am going to try the Factory set
for the '04.
unseen response: Thanks for the credit, but not quite true. If I was
paid to develop something for an outside company, I would do my best
to do a good job for them or not take the job. Because we've been tuning
AND designing dyne systems AND building reasonably competitive AMA Supersport
bikes (one AMA 600cc Supersport win!).... We do development for other
companies, including some exhaust companies, camshaft manufacturers,
cylinder head gurus - and if I had decided to do a particular job, it
would have to be a job that we were also not making or planning to make
ourselves. With stacks, we started out making the velocity stacks for
Belgarda Yamaha's World 600 Supersport program. They were similar to
Yamaha's stacks (that's what they wanted), but instead of making only
1 length of 35mm, we made 20mm to 45mm in steps of 5mm for them. They
had the fastest carbureted R6's in the world at the time. The only similarity
of any of our stacks to the Graves stacks were the 03-04 R6 stacks -
and there was only 1 way to make them in one piece. We subsequently
made the proper 2 piece Superflares, which work better than the one
piece stacks (theirs and ours).
LESTAT77: Anyone have a true comparison on the two. I'm in the same situation.
Which one to get.
unseen response: Ahhh!!! Voice of reason!
Juerg: (referring to the EC997 dyno charts posted at factorypro.com
using a Yoshimura slipon) "That dyno unfortunately doesn't help at
all. You cannot compare a standard bike to a bike with exhaust AND stacks,
to tell anything on the effect of the stacks themselves. We need a dyno
showing the difference "before/after"
Unseen response: It shows a typical USA R1. The
BASE test was with stock header pipe with slipon,
stock stacks and stock air filter - and not an aftermarket full system
that may or may not have + or - effects on the stock powerband. If there
was a large difference in improvements with a stock exhaust and I saw
it at one time or another, I'd print it. Using a completely stock exhaust,
and the FP stacks, according to other people who have tested the Factory
Pro R1 stacks seems to indicate a rather huge improvement at 7000 rpm,
but it's so huge, that I won't print it. I'll let someone else print
it.
Lestat77:You have two different designs. I think the Factory pro stacks
would help a lot more with midrange and you would lose a lot more with
the top end. The graves you will gain some mid range, but only lose
a little in the top end. Guess, it depends on what your really looking
for.
From what I understand velocity stacks don't produce more HP but move
the power band in the RPM range. Shorter stacks are better for top end
power and longer stacks are better for midrange/low end. Yamaha actually
increased the midrange on their 05 R6's by making the middle stacks
longer. Just like the Graves set up, but they made up for the top end
loss by making the throttle bodies bigger. Still would be nice to see
a back to back comparison on the dyno.
Unseen response: RE the R1 stacks: logical idea, but neither the
FP stacks, nor the Graves stacks should lose power when it's measured
under load on a dyno or when riding. As far as stacks go, yes, you can
make more power. It's not always the airflow, it's the ability of the
stack to create a timed or tuned resonance of air pressure that cleverly
overfills the combustion chamber to above atmospheric pressure across
a desired rpm band (like a supercharger does across the rpm band), but
obviously, if there's "above atmospheric pressure" in the cylinder,
it's going to flow back out the intake port. The trick is to make the
stack exactly the right length and inner diameter so that it makes the
pressure boost at exactly the point in time that the intake valves closes.
Instant extra compression! Yes, for those who extrapolate from that,
you can change the cam's intake valve closing point to match the existing
stacks better, too.
snoopface: d207, where did you get this BS from. sounds like a typical
factory mark story. (this was regarding us designing stacks for
Graves from up above)
unseen response: Ouch!! Zing! :-) Since we had nothing
to do with designing Grave's stacks.... Hmmm..... Lets' do some analysis
here..... Is this a common feeling you have about others. How long have
you felt this way. If we did it, then we did it. If we didn't do it,
well, then we didn't do it. Don't feel much like saying we did it if
we didn't. I don't do everything perfectly, but what I've done... I've
done - and if I print it, I'm pretty darned sure about it. If you get
results different from what I got, then there's a reason for the difference.
You may not LIKE the reason why your results might be "different" from
my results, but 37+ years of doing this with many different engines,
quite a few different dynos, being a relatively quick, top 3 club roadracer,
being down the street from cam designers, cylinder head gurus, top ranked
AMA teams, ran our own AMA Supersport team (one win!) says that just
maybe, I might know what I'm talking about.
An open mind is a terrible thing to waste!
Juerg: This is interesting, at is would contradict the popular theory
that the dip is caused by an intended closing of the exup valve, to
meet noise emission requirements. (that's in regard to Sportrider's
dyno test of the stacks - using, in my observation, poor test procedures,
that showed a huge midrange increase in power, that we never got when
we tested using more controlled test procedures.)
The longer tubes seem to prevent a resonance problem on the intake side.
(not from my testing!)
It also is interesting because there is no gain (contrary to what factorypro
is pretending on their graph) in peak performance.
(yes, using poor test loading, they got a huge midrange improvement
and poor topend improvement and that's different from what we got or
what people who use the FP stacks when riding experience. I should send
my cousin Bruno over from Bern. He's fairly experienced! :-)
I now am curious to see a similar comparison using Graves stacks
(Factory Pro TRIED to get Sportrider to compare the stock,
Graves and Factory Pro stacks and post the results. Ask Andy at Sportrider.
I'd imagine that the Graves stacks would show less midrange improvement
and probably no loss of topend using equally poor dyno test procedures.
Of course, from rider feedback and our EC997,loaded power tests, I don't
really agree with the Sportrider Superflow dyno testing anyway, so it's
all pretty moot. Actually, Sportrider's dyno hp numbers don't relate
much to anybody else's dyno hp numbers.
Juerg: True! Almost every change will have some impact, those systems
have to be seen as a whole. Nice curve anyway! Comparing with Sport
rider however, my guess is that you are rather seeing the impact of
the air filter and not the stacks.
Unseen response: Hmm...... First, you wanted a test with the stock exhaust
and only changing the stacks - Now, you want a test with all the parts?
I change the air filter to a BMC RACE and get 1ish hp improvement after
the FP stack dyno test (it's on our site) and somehow you don't believe
that, but you believe some well meaning magazine journalist who's "whacking
the throttle on in 4th gear on a dyno test with hardly any load" dyno
chart? And your guess is that it's the air filter? If anybody reads
that, they will figure that installing a BMC RACE filter will add 4-5
hp? I say that the BMC's worth 1, maybe 2, depending on wandering dealership
level dyno test procedures.
And the Last post from the original poster??
The Storm:
I have Finally had a chance to ride the bike after the stacks and air
filter and the bike pulls like mad earlier than before and never
lets up!!
The biggest difference I've felt is that you don't get that big hit
on the power it's just a lot more smooth on the delivery NOT LESS just
earlier and SMOOTHER!!!
..........................................................................................................................................
Well, there you go. A smattering of good questions, a lot of well meaning
internet banter, some internet suppositions, a bit of internet amateur
to professional animosity, internet rumor and internet bad info...My
summation?
The Storm rode his bike and it works better - just like we said it would
and an EC997 dyno showed (but unlike what a dynojet clone dyno said)The
lowend and midrange are improved. (as predicted and we expected)
It's smoother. (that's what happens when all 4 cylinders pull evenly)
It doesn't drop off in power. (once again, proving Sportrider's R1 dyno
test procedures were funky)
Marc
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