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You got pretty aggressive port times.

I also have 1 set cylinders, ported aggressive. I just found out, my conservative higgspeed worked better with those cylinders than both my Figarolies AND Dencoes regarding performance all over.The result really surprised me.
I get home from Barents Sea tonight, and will do some measurements on my higgspeed. In fact, they work surprisingly well with heavy ported cylinders!!!!

Does your motor ping at all at full throttle on pipes? If you hear nothing at all, with a square ex port and none squish band heads, you are probably too rich. This causes even worse flat spot gurgling as far as I have experienced. And raising transfers make the whole thing even more difficult. What is your transfer duration?

Is your flat spot just as bad in every throttle openings?

Jorgen

Yup, from what I've seen 8 deg. Is fairly conservative already.
With that said, I have a 400 pipe that works fantastic in mid range with a 5.5 deg baffle... It is definitely not a peak hp pipe but the area under the curve makes up for that.
In the end, you would be able to get rid of that weak mid range but it will probably sacrifice peak hp if playing with the pipes. It's sort of a personal preference thing how you like the power curve.
I can tell you that I was Jonesing for peak HP pipes but now I have them, I'm on the fence whether I like them more than my torque pipes... It's a different bike all together!

The 400 is stock port... It really has no business being so quick! :lol:

Your exhaust port looks pretty square, any issues with ring snag?
As far as the diffuser cone goes, the most efficient shape is similar to a musical horn.
My software has a diffuser horn coefficient, which changes this shape based on belly dia and tuned length and pipe volume targets. Essentially there can be a wide variety of horn shapes it will produce based on this coefficient but it changes the complete shape right from the port to the belly to maximize the efficiency.
Look at it this way, the biggest difference I see from Wirges to Denco's is the diffuser shape, not tuned length or baffle cone angle. There are plenty here that will give you feedback on the performance differences between the 2... It's really a package deal.
When you got rid of that last tapered piece before the belly, I think that was a negative move... Maybe consider going back to 2 or 3 cones there, this will directly influence mid range.

:think: ...just wondering about the cornering clearance with those.....?! (they look great!)

Author:	h2b780 [ Thu Aug 28, 2014 5:05 am ]
Post subject:	Re: H2 flatspot issues
jyrgNorway wrote: You got pretty aggressive port times. I also have 1 set cylinders, ported aggressive. I just found out, my conservative higgspeed worked better with those cylinders than both my Figarolies AND Dencoes regarding performance all over.The result really surprised me. I get home from Barents Sea tonight, and will do some measurements on my higgspeed. In fact, they work surprisingly well with heavy ported cylinders!!!! Does your motor ping at all at full throttle on pipes? If you hear nothing at all, with a square ex port and none squish band heads, you are probably too rich. This causes even worse flat spot gurgling as far as I have experienced. And raising transfers make the whole thing even more difficult. What is your transfer duration? Is your flat spot just as bad in every throttle openings? Jorgen Yea, pretty bad at any throttle position in 5-6000 area. Intresting about the higgs, but how about peak hp vs. jolly? Please messure the jollys to when your at it.. Yes i had it pinging on pipe when i leaned out needles as a bandaid fix for flatspot but that didn't work at all.. I belive the nozzles has to be smaller to lean out that area (1/4)? And will try that when they arrives.. don't know transfer duration, will degree her out this weekend if i find time and some beer.. Btw. Flatspot is alot "smother" in cold weather and/or cold engine, that tell's me it need to be leaner..? Infact, rode it home from work around midnight last night, 9 degrees celsius and really good air.. What a rush!! Gotta love these bike's!

Author:	Walms [ Thu Aug 28, 2014 5:45 am ]
Post subject:	Re: H2 flatspot issues
Yup, from what I've seen 8 deg. Is fairly conservative already. With that said, I have a 400 pipe that works fantastic in mid range with a 5.5 deg baffle... It is definitely not a peak hp pipe but the area under the curve makes up for that. In the end, you would be able to get rid of that weak mid range but it will probably sacrifice peak hp if playing with the pipes. It's sort of a personal preference thing how you like the power curve. I can tell you that I was Jonesing for peak HP pipes but now I have them, I'm on the fence whether I like them more than my torque pipes... It's a different bike all together!

Author:	h2b780 [ Thu Aug 28, 2014 6:21 pm ]
Post subject:	Re: H2 flatspot issues
Walms wrote: Yup, from what I've seen 8 deg. Is fairly conservative already. With that said, I have a 400 pipe that works fantastic in mid range with a 5.5 deg baffle... It is definitely not a peak hp pipe but the area under the curve makes up for that. In the end, you would be able to get rid of that weak mid range but it will probably sacrifice peak hp if playing with the pipes. It's sort of a personal preference thing how you like the power curve. I can tell you that I was Jonesing for peak HP pipes but now I have them, I'm on the fence whether I like them more than my torque pipes... It's a different bike all together! Is that a triple 400, ported?? Yea it's gonna be hard to have both good midrange and a crasy topend.. But if i could get it to pull just decent in midrange i would be happy. Here's some pic's of my cyl.

Author:	h2b780 [ Fri Aug 29, 2014 4:23 am ]
Post subject:	Re: H2 flatspot issues
Here are the sledpipes, as you can see i joined them with the fbg header (way to much work to fabricate taperd header..) About finish.. let's say they are under develop On the sled pipes have alu.heatshield's on them and look really nice, without shield's it's a different story.. I was to call them "fast by Lars" but i'll guess i will go with "flatspot by Lars" instead First try with stock sled tuning length, worked really good with stock topend and vm34's: Current pipes, about 100mm. shorter and a new one step 4,5 degree diffusor (sled had a two step diffusor with a angry 10 degree last step..):

Author:	Walms [ Fri Aug 29, 2014 6:03 am ]
Post subject:	Re: H2 flatspot issues
The 400 is stock port... It really has no business being so quick! Your exhaust port looks pretty square, any issues with ring snag? As far as the diffuser cone goes, the most efficient shape is similar to a musical horn. My software has a diffuser horn coefficient, which changes this shape based on belly dia and tuned length and pipe volume targets. Essentially there can be a wide variety of horn shapes it will produce based on this coefficient but it changes the complete shape right from the port to the belly to maximize the efficiency. Look at it this way, the biggest difference I see from Wirges to Denco's is the diffuser shape, not tuned length or baffle cone angle. There are plenty here that will give you feedback on the performance differences between the 2... It's really a package deal. When you got rid of that last tapered piece before the belly, I think that was a negative move... Maybe consider going back to 2 or 3 cones there, this will directly influence mid range.

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Author:	RODH2 [ Fri Aug 29, 2014 6:18 am ]
Post subject:	Re: H2 flatspot issues
...just wondering about the cornering clearance with those.....?! (they look great!)

Author:	h2b780 [ Fri Aug 29, 2014 8:58 am ]
Post subject:	Re: H2 flatspot issues
Walms wrote: The 400 is stock port... It really has no business being so quick! Your exhaust port looks pretty square, any issues with ring snag? As far as the diffuser cone goes, the most efficient shape is similar to a musical horn. My software has a diffuser horn coefficient, which changes this shape based on belly dia and tuned length and pipe volume targets. Essentially there can be a wide variety of horn shapes it will produce based on this coefficient but it changes the complete shape right from the port to the belly to maximize the efficiency. Look at it this way, the biggest difference I see from Wirges to Denco's is the diffuser shape, not tuned length or baffle cone angle. There are plenty here that will give you feedback on the performance differences between the 2... It's really a package deal. When you got rid of that last tapered piece before the belly, I think that was a negative move... Maybe consider going back to 2 or 3 cones there, this will directly influence mid range. No ring snag yet, but you can hear them.. You may be right about the diffuser cone, but the differens i noted was for the better, not much tho.. Don't you get more suction (more fuel to gurgle when it returns) with a steeper 2 or 3 stage cone? That was my theori anyway (to smoth things out), but i'm pretty new to pipes so i could be all wrong? Wery intresting subject tho, and you seem to know alot so keep it coming, i might learn something? Btw. My nozzles arrived today, have just put them in but it's wet outside so i will report back after testride

Author:	h2b780 [ Fri Aug 29, 2014 9:01 am ]
Post subject:	Re: H2 flatspot issues
RODH2 wrote: :think: ...just wondering about the cornering clearance with those.....?! (they look great!) Thanks "mait"! No clearance prob's so far..

Author:	h2b780 [ Sat Aug 30, 2014 6:35 am ]
Post subject:	Re: H2 flatspot issues
Here are my finding's after a few testrun's: Nozzles are now Mikunis smallest avalible #N4, needle in middle position. Bike was way fat around flatspot so needle has to come down but i went home and yanked up ignition about 5*. And did another run with same carb settings, way better, now she will atleast pull when i "floor" it from 5000 Not alot but it's a improvment

Author:	h2b780 [ Sat Aug 30, 2014 1:41 pm ]
Post subject:	Re: H2 flatspot issues
Well, i set needles to leanest positon but with a thin plastic shim underneath. Bike run's even better but does it get enough fuel when on pipe?? Maybe lectron carb's are the answer to my issue? Anyone here run them and have some info to share? About ignition, a zeeltronic seem's to be a good investment as Jorgen already proved. Jorgen: what jetting (nozzle's) do you run in your vm34's (pp. vs. reed's)

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