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Discussion Starter #1
Hey Kevin...

I am back to running a stock ECU and stock map. I have the open
exhaust, and a 17 but that is all my mods right now. My EGTS go off the scale at 6000 rpms, and the scale stops at 1600 degrees!!!!

I remember you saying that you found bikes to be rich, and my is
so lean I can't even ride it until I map again...the center two cylinders
are almost always 100 degrees hotter then the outboards...

Tomorrow I'm going to run it up and see where things go at WOT. When
I'm at 6000, with no load, you know running in a lower gear, the temps
go way high, but if I roll it on, they immediately drop to normal.

Question, do you think I might use the TPI to adjust out the lean
midrange? I just don't know why I'm so lean when everyone says
they go rich...but I think I'm the only one to run a really open pipe..

Thoughts???
Jere
 

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Jere, I've seen your pipe, and I think it would be safe to say that you are as close to zero back pressure as humanly possible.

But more importantly, you are running the stock header (if memory serves me correct).

So, we have an extremely low back pressure system with no pulse cross-over pipes to help equalize the scavenging.

My opinion here is that you are trying to treat the exhaust on your 12 like a V-8, and they don't follow the same rules.

I have seen alot of guys try to really open the exhaust up on an inline four, and I have never once seen an instance where the bike ran better above 5k rpm.

Some back pressure is mandatory for an inline four with an extremely efficient valve config. In fact, I would say that by running your exhaust as open as it is, you are endangering your exhaust valves.

Just my thoughts, not a slam on your pipe. Have you considered an Akra?
 

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Hey Jere,

On my bike and most other ZX12's with a pipe, they run rich in a majority of places. The only place on mine where I have to add any significant amount of fuel is from 6000 to 9000 RPMs and only at 10% and 20% throttle. Most everywhere else, I subtract fuel.

I think you & blitz may be on to something with your pipe being basically no backpressure whatsoever. It probably flows so much more than a traditional pipe and has much different characteristics. How does it run below 6000 RPMs and at what throttle positions? You say it runs way lean starting around 6000 RPMs under a light load(5%-10% throttle I assume) and then gets back closer to stoich when you open the throttle? I've got a good idea about what it may be but can you give me details like how it runs at all RPMs and throttle positions, or at least what you recorded so far? I'll check back later.

Its curious that your middle two cylinders would run 100 degrees hotter than the outer two. Maybe something to do with their placement??? What would swapping injector leads with the outside cylinders do I wonder???
 

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Discussion Starter #4
Hey Blitz...good points...I'm still experimenting...but the bike runs
really good, especially at high rpms... I ran a 9.27 @ 151 with this
pipe, and no map. But I'm concerned about cruising with my egt going
so high...I know I'll cook some valves, so I'm not riding the bike until
I sort this out...

Kevin.. I'm going to test more tomorrow and I'll record my findings...it
must be the pipe, and I'm happy that it sooo lean, because I can toss in
more fuel and make the power. As for the scavenging, it will only come
in to play back at the collector, so my question to you and Blitz, what does
Blitz mean about the crossover? Do other pipes link the tubes next to
each other with a pipe...if so, that's easy to do, as I have a TIG, but I
thought those created disturbed air rather than a clean flow....

Thanks guys!
 

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Discussion Starter #5
Hey Blitz, I never take offense, I just try to pick other's brains
and learn. But I was never much one to go with what everyone
else runs, because 1) it's more fun to build your own, and 2) if
I come up with something better, it gives me the edge!!! So, I
usually do my own thing, and if it doesn't work, I can always but the
Akra, which by the way has beautiful workmanship...awesome...

But my pipe must be making big power, the time in the 1/4 is great, and
all I've done is a 17t, bones, and a few simple things...I weigh 210lbs.
I wish I was like JadeGreen...'lil bastard weighs 135lbs ...

The throttle response is quick, and it will lift the front with a blip, so
I don't think I lost bottom end... I know I should have.
 

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Yes, a 9.27 is smoking for sure..... So she's obviously making good power.

The cross-over pipes are exactly as you thought, on the Akra they are about 3/4 of an inch in diameter and are maybe 6" down from the head flange.

I have heard that the inside cylinders on the 12 run hotter, because of how closely they are siamesed together. If you've ever seen the cylinder block on the 12 (or 9), they are really, really close.
 

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Discussion Starter #7
I had an interesting conversation with a big name tuner today, and
he tells me the reason the ZX-9 center cylinders are hotter is because
they map it from the factory that way on purpose...and that I should
not trim the cylinders to run at the same temp for the following reason...
Here goes...if all the cylinders run at the same temp, that means all
the pistons are pulling equally...sounds good to me...well, that's not
what they want. To reduce harmonic vibaration through the crankshaft,
they want the center two cylinders to "pre-stress" the crank, with the outer
cylinders then applying their work to a crank that is already "loaded".
According to Mike Keivers, this makes for a stable crankshaft, with much
less vibration, and reduced twisting which makes them fail.

So, that is the reason that the center two run hotter, they are mapped to
make more power than the outer two, which helps the crank.

Caught me off-guard, so I just said "hmmmmm".

I'll read up on some of the other high-rev engines to see if I can find
anything...not that this is so important etc...just sort of interesting.

I didn't get to ride today...a long list of honeydo's...honey do this,
honey do that....honey get my sandrail running!!!!
 

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egts.......... etc

would just like to mention

keep in mind in your air box......... the firing order of the cylinders
sometimes a void is caused in the available air
sometimes a vortex that actually diverts air away from the next
cylinder thats gasping for air

me thinks the floor meets the stacks in the z toooo flush
of course would have to test on a dyno
havent had a chance to email BEAR & discuss

in addition some in 4 exhausts scavenge on the sonic dynamic
some on the length of the pipe
thats why you have the balance pipes so soon in the downpipes
the 4 into 2 into 1's
the x pipes
the stacked pipes
blended collectors
radial collectors

finding one that hits in the rpm range you desire is the way top go

only real conclusion i have is the sonic pipes
tend to be much more peaky
also drop off more if any changes are made
 

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Pre-stress the crank huh? I'm still trying to get my mind around it but am having difficulty. :roll: But then again, you never know. I think I would have to call the guy out on that one though.

Got to thinking about the lean spot. If it is only lean from say 6000 RPMs and up at partial throttle, then that is more or less, just like mine. Sounds about normal, really. I don't think the TPI will fix it though because it will cause problems other places. I've got a friend that will make you a good deal on a Yosh EMS.
 

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Discussion Starter #11
Workman, can you tell me the diff betwn the yos and the pc3 boxes?

I'd like to know if the software has any adv on one vs the other...


J
 

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Jere, I'm not as familiar with the PCIII as I am with the yosh EMS but here are the differences that I know of.

You can by a accessory kit for the Yosh that does several things. You can get an integrated shift light. You can get a "clutchless shifter". There is also a map switch that allows you to change between 3 different maps on the fly which is good for those with NO2. In the software, it allows you to offset the mixture between different gears. These are the main things that you can do with it. The accessory kit cost almost as much as the EMS itself but it would cost as much or more to do all these things seperately anyway.

Probably the thing I like about the EMS the most is that I have never heard one thing negative about it or about Yosh. No failed units and no customer service issues. But it does cost about $75 more than the PCIII.

Call Brett at pro-flo.com and tell him I sent ya. He will make you a good deal. Match anyones price on just about anything.
 
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Jere,

Told you, you should of got digital units... lol..

1600 on the Westach analog unit can be anything from 1575 - 1625.. the analog downfall..

However.. 1600 is still "ok"..

When I tune I see peak stable power at about 1650 or 900C. Anything more then that and things get a little risking... run some bad gas and get some detonation and say bye bye..

However.. I have run as high as 1725 (race motor, race fuel), but on the street I would not even consider it... just to many variances.

But if you are running 100deg hotter in the two center cylinders then I would defiantly be concerned about that.

If we ever get together I have an EGT calibration unit that I can through on and get an accurate reading for you.

Its interesting that allot of people out there have varying opinions on the max "temp" that can be run. I have heard everything from 1250, 1400, 900, to 1750.. when in all reality the true melting point of aluminum is closer to 1100 deg... cast is twice that.

Pretty scary when you take into consideration the temps we actually run, but we have to remember that we are talking combustion temp and not actual piston or head temp for that matter.. Get a CHT gauge if you want the best of both worlds.

If low melting point is the negative to aluminum pistons, then there ability to disperse heat quickly (and there weight) is the positives. They dissipate heat very rapidly through the piston skirts.

So melting a piston is a pretty hard thing to do, you have to really hold it in the dead zone for quite awhile. 1700+...

Chances are you will see detonation long before you melt a piston... and it will be the detonation that kills the piston, no the heat..

The deal about pre loading the 2 center cylinders is one of those things that makes you go "huh"... Not sure I would buy into that..

"preloading" can really only be done by advancing the timing on the middle cylinders. Adding more fuel will only make the cylinders produce slightly more thrust or torque during the crankshaft rotation, but should not effect the actual rotation process or balance it for for a smoother idle...

If this was the cause I would think that many other manufactures would of jumped on the band wagon. Almost all "well allot" of inline 4 turbo engines and standard motors for that matter contain a balance shaft...


Holy crap.... didn't realize I was typing a book.... I will stop now... LOL

Must be all my none posting catching up with me...

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If anyone is thinking of trying digital, I can tell you that the SPA gauges are the catsa$$. I run a pressure/temp. gauge in my truck, use the pressure to monitor fuel (lift pump) psi's and the temp is currently being used for coolant temp, though I did use it to monitor fuel temp. pre-injection pump for awhile. They areen't the cheapest gauges but you get two gauges in one face, somewhat similar to the Westachs. Here's a link to their website and I have a few buddies that sell that if you are interested in a price.

http://www.spatechnique.com/instruments.html

A dual egt gauge runs about $445.00, but you get the senders with the gauge. I believe they are 1/8" NPT.
 
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Yes SPA makes some sweet stuff....

Hope yout not paying 445.00 for that unit...

I have been a dealer for about 2 years and can smoke that deal... ;)

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