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5th & 6th VFR 800 Header build

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1 hour ago, Stray said:

Unfortunately that dyno didn’t provide torque values. 

 

We could calculate that. If someone was prepared to enter the power figures (read from the dyno graph) into a spreadsheet that could then be used to calculate and show the torque curve.

 

Further, if other data from other dyno runs with different exhausts was also entered, we could build up a set of torque/power stats that would provide the perfect comparison chart. The only issue with that would be differing parameters like actual bike and dyno used and atmospheric conditions etc. However, it WOULD be better than nothing.

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To address what you think about what I make of the lextek:
The primaries make a big difference in the midrange to where the cross of HP/Torque  happens.  

You can SEE the effect of enlarged primaries in Delkevic's own dyno results.  a pretty decent midrange bump,  and then the awful merges of it's POS 4-1 hodge podge cause a net loss of 5 hp or so on the topend.

They used to have the dynosheets up,  and they've since taken them down.  lol.  If you do a search around here you'll find them.  I might have one,  but I have to go to work.  to be continued.
 

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1920548509_product79307_5-600x600(2).jpg.2cebb0615da7c12c6e5f20eaefb1072d.jpg
Case in point.  This is the '14 VFR with a Delk header.  Stock muffler.  picks up great in the midrange,  and then the complete shit merges and collector design causes it to LOSE high rpm horsepower to even the stock header and it's T junction merges,  if that tells you anything.

I'd have no issues recommending a delk header except:  it causes the VFR to completely fall on it's face after 9 grand.  

it's why I roll my eyes at delk headers,  it's why I'm actually very very angry about the BW/Ali/Lextek headers.  they're so close to nailing every aspect that it would've been likely cheaper,  to run the 36-38mm ID primary the whole way.  and make more power.  but they didn't.  It comes out of the header with the same squashed down ID as the stock '14 VFR,  which you see here get LEFT in the midrange by even 98 spec primaries.  Because that's what delk is running here,  32mm ID vs 30-29mm for the vtec era.  

They left (lots of) horsepower on the table.  for what,  so you could use the stock exhaust gaskets?  So they could save 10-20 dollars a header instead of doing a decent set of merges and slip joints?

lmfao  goddamn these companies.  
 

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All fiddling and speculation and likelyhood aside,  How's the SoCal header doing?

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4 hours ago, Voided76 said:

All fiddling and speculation and likelyhood aside,  How's the SoCal header doing?

 

Here is the thread for the US header (up to date info / pics / dyno ) : https://www.vfrdiscussion.com/index.php?/forums/topic/88463-new-5th6th8th-gen-performance-header-now-in-production-in-usa/&page=9&tab=comments#comment-1093004

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Hello All, 

 

Looks like interest in the Lextek group buy has gone badly south. There are only have two names on the list of willing buyers. 

 

On Tuesday I will ring Jeff and give him the final tally so we can put this thing to bed. If anyone else is interested in a very well-priced replacement header please get in touch with your contact details ASAP. 

 

Hopefully Jeff will honour the original discount but no guarantees as it has been so long and we are significantly below the number of units requested.  

 

Best, 

 

Stray 

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On 2/3/2019 at 7:31 AM, Voided76 said:

The lextek isn't that encouraging at all,  TBH unless you're ready to buy a budget header than start hacking and mandrel bending it and re welding the first 8 inches of all 4 primary tubes.  

Pretty obvious that the multi-stage primary tomfoolery evident in the lextek/bw/alibaba header isn't working.  I'd say it's in way better shape than any of the delk/black widow/sbs/motad crap headers,  because for around 100 bucks at a legit speed shop they can be turned into something very much like what we're designing here.   But again.  as it sits it's yet another OEM replacement with a few perks until you chop it up.  

But at least it has that going for it.

Proper primaries on these bikes pick up power just off idle.  The graph you've provided is great testament that they got the merges right.  it's 90% there but they fucked up the primaries.  which is what I've been saying since I saw them/aquired some data through email about them.  at the outlet of the head they're no different from Vtec/8th gen pipes.  and it's why they aren't making More power until later more than likely.

They pick up that immediate 3.5-4 ponies similarly but they don't do it from 3 grand on like the 35.5mm inners do.  

 

1269798220_Attackmidrangecomparison1012619.thumb.jpg.d9a7af5620ee8ed849ca46ea206d50d6.jpg

 

 

The reason why I just bought Lextek headers for my 5th generation.

Below explanation is Copied from internet.

"The concept that maximum power is obtained by zero pressure in the exhaust is only partially true. There should be absolutely no back-pressure from the collector rearward, but the diameter of the system beginning with the exhaust valve is a compromise. The highest efficiency for the system requires a minimum speed for good exhaust gas velocity to insure that gas does not “back up” into the chamber during overlap at low engine speeds, and that the “suction” (negative pressure pulse) effect of a resonant (tuned length) and/or collector (overlapping exhaust pulses) system is optimized. 
    To predict what primary size will be best for a specific motor, you must know where you want the engine to develop peak torque. If the existing torque peak is at bit lower RPM than you prefer (typical in under-cammed or stock motors), it can be “bumped” a bit by increasing the primary diameter. If the torque peak is too high (motor is “peaky”, with no range and poor recovery from gear changes), the peak can be adjusted down by using a smaller pipe. A change of 1/8” in the primary diameter will raise or lower the peak torque RPM by 500 or so.

    This factor slightly overlaps the effect of primary pipe length, but the pipe length generally will not change the peak torque or the RPM at which it occurs. A length change has the effect of improving the torque on only 1 side of the peak by “borrowing” it from the other side. A shorter pipe improves the torque after the peak (reduces it at lower RPM), preventing the curve from flattening out so quickly as speed increases. A longer pipe extends the torque curve backwards to improve the engine's flexibility, at the expense of after-peak torque. Less stall speed is required, and the motor will pull taller gears; this re-tunes a 4-speed motor for better operation with Torqueflite, etc.

    For best effect, the gas speed in the primary tube at the peak torque RPM should be about 240 feet per second. The formula to calculate pipe size is:"

Area of Primary Pipe = RPM × Cylinder Size ÷ 88,200 

 My comments; The area of the Lextek primary pipe is about 1.02" (ID 29mm),  Cylinder size is 12.2" (200cc), RPM for max torque (prefer low torque ) is 7500

Area of primary pipe = 7500 x 12,2 /88,200

Optimal Area of primary pipe = 1.04 compared to Lextek 1.02, but lektex primary pipe area expands from 1.02 " to 1.5 rapidly so I can now understand why Lextek made the primary pipe area smaller at the start to ensure higher gas velocity when you have exhaust from the two front cylinders together and the same for rear cylinders and you move max torque to lower rpm which I prefer.

I hope my calculations are correct and I would like to have your comments.

 

 

 

 

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I am actually very interested in at least one Lextek system but currently not really in a position to do much about it having been knocked off my bike and only just returned from hospital. Uppermost in my mind right now is suing the idiot in the van who tried to execute a rapid U turn right in front of me, throwing me to the ground and puncturing my lung - not to mention the damage caused to my beautiful eVo4. Anyway...

 

A couple of question about this system. First of all, what is Jeff's special price for us on this and is it suitable for 8th Gen bikes? Specifically I want 2 systems for what will be 5th Gen motors with front rads and high level exhausts. So that means 8th Gen front headers with 5/6th Gen collector and outlet. After all the discussion, I'm no longer sure if the Lextek caters for the 8th Gen front rads?

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I sent Simmi/ Jeff an email to see if I could still get a set sent to the US, since I haven't been able to find a supplier over here, but have yet to hear back from them.  If I can get a hold of a set, I plan on getting it on the dyno for tuning.  Might as well do a before and after too  (05 with 7k miles on it at sea level).

 

 

 

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14 hours ago, Stobl said:

I sent Simmi/ Jeff an email to see if I could still get a set sent to the US, since I haven't been able to find a supplier over here, but have yet to hear back from them.  If I can get a hold of a set, I plan on getting it on the dyno for tuning.  Might as well do a before and after too  (05 with 7k miles on it at sea level).

 

If anyone needs help with forwarding a system to the US (or elsewhere), I would be prepared to have it delivered here to me in the UK and send it on to the buyer who would have to make the arrangments and any payments as I'm not currently fully mobile. Obviously it would be simpler for the seller to ship it direct, but if that proves impossible I would do what I can to help.

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Not sure if I am allowed to hijack this thread but here goes anyway. Apologies for TYGA taking so long to getting around to making the VFR system. Those pesky KTM RC390 owners butted in front of the queue. Something to do with them needing to go racing in 2019...Anyway, we are now on the VFR system full time so the prototype is only a few days away from completion. The starting point was the TBR  system as requested but we've made some changes, some for better flow, some to suit our tooling, and some changes for better installation and clearance so the final result will be somewhat different but hopefully what owners want. We took a bit of a guess on the configuration and based on what owners had told us, we decided to make two versions. One will be a left exit, high level so will require removal of passenger pegs. The other version, will also be a high level but on the right and be tucked behind the passenger peg hanger for those wishing to  keep the passenger carrying capabilities. If there is another configuration, (toying with the idea of dual exit right and left) then let us know. We would also like a bit of input on the silencer (muffler) design. We have a few ideas but welcome input on materials, dimensions, shapes budgets etc. Anyway, I guess photos will be nice and they will be coming soon 🙂 Appreciate your patience!

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Welcome TYGA, awesome news. I thought you had abandoned this project, so looking forward to see what you have done.  

 

As an FYI I checked with a colleague in Japan what dimensions the Ladybird HRC RC45 uses. Turns out they are 38mm OD & 36mm ID albeit in Titanium, same as the TBR I have fitted to mine. I'll be interested in your dyno results . 

 

Keep up the good work 👍😀

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5 hours ago, tyga said:

Not sure if I am allowed to hijack this thread but here goes anyway. Apologies for TYGA taking so long to getting around to making the VFR system. Those pesky KTM RC390 owners butted in front of the queue. Something to do with them needing to go racing in 2019...Anyway, we are now on the VFR system full time so the prototype is only a few days away from completion. The starting point was the TBR  system as requested but we've made some changes, some for better flow, some to suit our tooling, and some changes for better installation and clearance so the final result will be somewhat different but hopefully what owners want. We took a bit of a guess on the configuration and based on what owners had told us, we decided to make two versions. One will be a left exit, high level so will require removal of passenger pegs. The other version, will also be a high level but on the right and be tucked behind the passenger peg hanger for those wishing to  keep the passenger carrying capabilities. If there is another configuration, (toying with the idea of dual exit right and left) then let us know. We would also like a bit of input on the silencer (muffler) design. We have a few ideas but welcome input on materials, dimensions, shapes budgets etc. Anyway, I guess photos will be nice and they will be coming soon 🙂 Appreciate your patience!

🍿

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Left and right high mount? 🤔

Is this a 5g only version?

 

Yay TYGA :cheerleader:

more options for vfr

 

Like Mohawk said, I thought you abandoned us...it's been a minute

 

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Oooh, left high mount would show off my lurid green 1098s rear wheel nicely...

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Tyga yes !!! Right side dump that will work with undertail exhaust for 6gen please and perhaps a true dual under-tail exhaust with proper splitter or dual piping 🤤. Here is a picture of my Make shift Panigali undertail exhaust. 

9D21D697-EAC9-4AAB-AE8B-D32484CAD74F.jpeg

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Left side dump for single high mount and custom subframe and tale section would also be amazing 😉 

Also pleas keep us posted on progress 👏

Edited by PetoRC
Forgot something

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5 hours ago, PetoRC said:

Tyga yes !!! Right side dump that will work with undertail exhaust for 6gen please and perhaps a true dual under-tail exhaust with proper splitter or dual piping 🤤. Here is a picture of my Make shift Panigali undertail exhaust. 

 

As a 6th gen owner this is my vote as well.........

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7 hours ago, jim v said:

As a 6th gen owner this is my vote as well.........

Same here - standard position right side outlet for 5 & 6th gen.  Also interested in an 8th gen setup with standard right side outlet if available.  Seems like there could possibly be other 8th gen interest particularly if the "Wade Brand" headers will no longer be produced. 

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My boys from Tyga 🙂

I'm proud to see you guys back in the discussion.  It's been 2 years since I've even owned a 6th gen but I have admired and wanted your work since probably 2014.  
 

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A left-exit 5th/8th gen exhaust system would certainly be unique.  It's probably the best way to show off the SSSA--but I'm not sure there's enough room for the link pipe to pass under the beefy swing arm.  I believe HRC had to deform the link pipe and bevel the swing arm on the RC30 to get enough clearance.  

 

Ciao,

 

JZH

 

 

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I’m really keen to see what Tyga come up with. Have seen a few custom left exit 5th gen systems so it’s doable. 

 

Some splayed 8th gen style front headers would be great for front mount radiators. 

 

Whats the progress report, please? 

 

Stray

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Yes please keep us posted 👍👍

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