sfdownhill

2 hours ago, DannoXYZ said:

Common 304ss isn't as ductile as 1020/1022 mild-steel which is what most muffler shops deal with.

 

Best to pre-heat pipe with oxy-acetylene torch before expanding... about 450-500C. In between stress-relieving to annealing temps. Especially if it was orginally made from seamed tubing. Need to keep heating during expansion because it will work-harden. Due to higher amount of springback, you'll want to measure as it's expanding and account for this. Do in single pass. More than one cycle with test-fit will most likely cause crack.

Thanks for this, Dano, it’s very helpful.

We’ve expanded 5 or 6 midpipes now, always done by Wade (the guy who makes our headers) in his shop, and have not had any splits. The commercially manufactured midpipes - Staintune and Yoshimura - had 3 or 4 slots where they fit over the headers. Wade cut slots into the custom midpipes too, and none of them split - not sure if it was the slots, technique, or materials that helped us avoid splits.

On 9/25/2021 at 4:45 AM, Mohawk said:

If you replace the ducati carrier with an Afam, JT or Renthal 5 bobbin Quick Change carrier

Mohawk, that looks like about the lightest sprocket carrier/cush drive I've ever seen. It looks like there's a JT logo on your carrier - is this correct? I'm used to seeing Ducati drive assemblies with an outer flange covering the cush bobbins, with bolts from the bobbins coming through the outer flange and nuts on the bolts holding the outer flange [see vfrcapn's post/photo above yours]. I love your safety wire loop [very tidy] and it appears that the cush bobbins on your assembly have female hex fittings, so I assume they thread into something that transfers drive forces to the carrier, yes? It would be very interesting if you could shed some light. Thanks!

On 9/22/2021 at 2:55 AM, Resina said:

Hurray!!!!! After waiting since April 03rd, mostly due to Portuguese customs, I am very happy to share I have received my headers 😝

Super Thanks to Darryl (Duc2V4) & Lance (sfdownhill) for making this possible!!!!

So glad they finally made it Francisco! What an ordeal it was getting USPS and Portuguese customs to coordinate...whew. Keep us apprised of your install and tuning. Cheers!

11 hours ago, zinsern said:

Great work guys! If there is a waiting list in the works for the next run, please put me down for a set of 8th gen headers 😊

Hi zinsern - there is no telling if it will happen, but will let you know if it does.

28 minutes ago, Cogswell said:

Here's a shot of the MTB installation instructions. Note that it says to retain the stock O2s and cautions that it may not work correctly without them.  It seems to imply that the Racing module needs that input regardless of whether a MTB is installed or not.   Seems like they could develop a Racing module that could read a wideband sensor directly. 

Thanks for that info Cogswell. And yikes - my headers don’t have bungs for the OEM O2 sensors. Plus they’re already ceramic coated. Dang. Well, it’s just another of those puzzles we solve when modding our VFRs.

10 hours ago, ae86andkp61 said:

I've managed to locate an unused header to buy...Mr Squiggle came through and I'm quite excited! Thanks for the help, everyone! Now I've just got to figure out how to tune it....leaning towards the My Tuning Bike as it seems to have some great features, but the Power Commander may not be as capable, but it is so well-known and well-supported, that it has some appeal as well.

Glad to hear it, ae86andkp61. I’m with you on the RB vs PC - I’m  considering going from my current PC3 to RB w MTB when I do velocity stack and airbox mods on my 5 gen. Yaman is the man at RB USA, and there are a number of members here that he’s helped with setting up AFR maps for their RB systems, so that’s a consideration.

9 hours ago, Cogswell said:

Also,  you'll be keeping your 2 stock O2 sensors (I have no idea why), so on a G6 you'll have a total of 3.  IMO the RB tune without the MTB was better,  the target AFR in the MTB map I think it's a bit lean.  Over the winter I need to learn how to create multiple maps and adjust AFR targets to get it just right.  

Cogswell, my understanding is that it’s not so

critical to keep the OEM O2 sensors with RB if you’re running MTB. Without MTB, the OEM sensors send O2 sensor readings to RB, which then communicates with the ECU to manage fueling. MTB takes over those duties when installed. What I’m not certain about is whether it’s important to have the RB connected to the OEM O2 sensor connectors going to the wire harness/ECU if you’re running MTB, or if MTB negates the need for OEM O2 sensors altogether. It’s a good question for Yaman at RB USA; as mentioned above, he’s a great resource for assistance when setting up a RB system, with or without MTB.

The only difference between the 5 gen headers and the 6 gen headers is the 6 gens have 5/8” cut off their collector exit pipe to allow the complex 6 gen midpipe/dual muffler assembly to fit.

Having just installed a set of 6 gen mufflers on these headers, I’m thinking we should have cut off 3/4”...maybe even 7/8”. Any other 6 gen owners think a little bit shorter collector exit would have been a better fit?

8 minutes ago, Cogswell said:

Read the thread - self explanatory. 

(Laughing) You probably only need to read the first 6 or 8 pages to get the gist.

5 hours ago, Gotama said:

Before I removed the 02 pair system We had to add a bunch of fuel to  get a proper AF. After I remove the pair system We had to take a shit ton of fuel out.

Thumbs up!! You MUST remove the PAIR system prior to tuning because the PAIR  dumps fresh air into the exhaust gases. This causes both onboard O2 sensors and dyno O2 sensors to get an AFR reading that is far leaner than actual.

4 hours ago, Ziffer said:

Well, that's three...only 17 more to go...*sigh*

The minimum order is 15. Actually there are a few others interested in the headers, so possibly 6 or 7 including DivisibleRex, but it’s not official that there is a list or another production run happening.

2 hours ago, Duste said:

Is there a waiting list for the next batch?

There’s not a waiting list at this time, but we’re keeping track of interested parties and if it the numbers keep increasing, there might be the possibility of another batch.

23 hours ago, vfrcapn said:

I have a set of 5th gen headers I don't need, just a couple of pinholes that need welding up. pm me if interested. 

Nice to see VFR guys helping each other out. vfrcapn, you know this, but for others who may not, it’s the 1998-1999 headers that have larger diameter tubes and no catalytic converter. A fair number of VFR owners have replaced stock skinny-tubed catalytic converter headers on 2000-2009 models with success (they work on 6th gen too). The only downside to the 98-99 headers is that they are mild steel, not stainless. 

On 6/22/2021 at 12:19 AM, lplplplp said:

On 6/18/2021 at 12:30 PM, Cogswell said:

 

bit loud just off idle and low RPM, resonating in my helmet a bit but smooths out and much less noticeable after that

Less noticeable after that because the decibels just get further and further behind you as you twist your right wrist - ha!

8 hours ago, ShipFixer said:

Another quick question while I'm thinking about it - which O2 sensor goes in which hole?

The electrical diagram in the service manual shows that from the harness to the natural color O2 sensor connector is cylinders 1-2 (left rear - left front)

From harness to black O2 sensor connector is cylinders 3-4 (right rear - right front)

On 5/29/2021 at 11:54 AM, ShipFixer said:

I am probably going to keep my stock exhaust though

Are your stock cans hollowed out or ‘gutted’ as some describe it? The tubing inside OEM is crazy constrictive - it consists of multiple very small diameter tubes that reverse the direction of the exhaust gases, passing them back and forth inside the OEM cans. If you haven’t cut out all the plumbing inside the OEM cans and replaced it with straight-through perforated tubes (with packing around the perf tubes), there will be too much back pressure to take advantage of the headers’ performance. Below are some photos of what you see when you cut open OEM 6 gen mufflers. Gases come in through a single inlet pipe and are immediately pushed through a perforated metal plate that is perpendicular to gas travel (A giant flow clogger). Then the gases push through  two tubes into the middle chamber, then gases that are too willful to meet Honda engineers’ expectations reverse course through other tubes to circulate at the front of the can, then reverse course again to mix again in the mid chamber with gases that have remained in the middle chamber. Finally it’s all pushed out through the two little exit pipes we are familiar with.

Here’s the screen over the inlet pipe way down at the bottom of the can (after all other midsection crap has been removed):

Here’s the skinny little inlet pipe after removing the screen:

Here are the noodly back and forth tubes in the midsection - now we know why OEM 6 gen mufflers are SO quiet! (Note the perforated sound damping material lining the inner walls of the can):

ShipFixer, I’d suggest running the Delk until you find an open flowing slipon assembly with aesthetics that please you.

Back pressure is never good with quality headers. Some say back pressure is a necessary component of a tuned exhaust, but the way it was described to me is that the column of gas moving through the exhaust system (Specifically after the final merge/collector) needs to have as little obstruction as possible. In a single muffler system, sometimes a longer canister works better, not because of back pressure, but because the column of moving gas spends a longer time moving through a controlled path, which in some cases allows the timing of exhaust pulses in the merges to be optimized. An example of this is my Aprilia RSV4 - another V4 - on which I had dyno runs done back to back, first with a 300mm long Akrapovic can then with a 420mm long Akrapovic. The cans were identical in all dimensions but length, and the bike put out 1.2 more hp and 2.3ft/lbs more torque with slightly richer fueling on the longer muffler. YMMV.

10 hours ago, Cogswell said:

Has anyone with a 6th gen mounted an O2 sensor in the aft bung on one of these headers?

It’s been a couple years, but on the 8 gen test bike, the O2 sensor in the rear bung didn’t seem as tightly spaced as with your installation Cogswell. I like the 270° turn you put in the cable - that seems to allow a decent routing.

Is the bike in the photo your Torocharged 6 gen? That would be  a great candidate for the headers.

18 hours ago, ShipFixer said:

Meanwhile, no luck on the studs and nuts coming apart.

18 hours ago, Gotama said:

I had one stud that was like that up front too

I use a light application of anti-seize on the studs when installing the headers. ‘Light’ meaning just enough to cover the threads, then wipe off as much of the anti-seize as I can with a gloved finger. With this treatment, no nuts have come loose or frozen in place on our three test bikes in the ~ 2 years since we started this project. Granted, 2 years isn’t much compared to the 16-20 years that some header nuts have been subjected to road spray and contaminants, but I was able to easily remove the headers from my 5 gen recently.

2 hours ago, Stray said:

Turns out quite a few people who bought these didn’t fit them and have had changes in circumstances of their own. I’ll pick up one of these and save waiting for the next run. 

Sounds good Stray - glad it’s working out.

8 hours ago, ShipFixer said:

Quitting for the night.  Lining up the front pipes is a serious PITA.  Everything else is in place, waiting to be torqued down.

You are correct about the front two cylinders’ pipes being a pain in the buttocks to fit. It turns out that the original Two Brothers headers we copied were bent...dang. At the time the fixtures were built for 5/6 gen in 2018, the last thing on our minds was cutting up one of the last known ‘magic TBR headers’ in captivity to correct their alignment.

On 5/19/2021 at 6:45 AM, Stray said:

Anyone got one of these headers they want to shift? Ideally the 8th gen version for front-facing rad but I’ll consider any. Based in England and happy to import if it’s not extortionate. 
 

Please PM!

 

Best, 

 

Stray

Hey Stray - glad to see Mr Squiggle might be able to hook you up with a set of headers. You were instrumental early in the process of getting the headers started - I remember you did a lot of work with the importer of Lextek headers, and you and I had a couple good talks during the process. Cheers mate!

6 hours ago, Stray said:

Note how it merges front and rear whilst giving the rear pipes a bit more length. I wonder if those loops interfere with the rider’s feet. 

Cool pipes - the curly-cues on the rear primaries are indeed interesting. I think our headers merge left-front-to-left-rear and right front-to-right-rear like the ones in the photo. It looks like the headers in the photo might be missing the last curves to get the front pipes to meet the cylinders...not sure.

55 minutes ago, interceptor69 said:

Thanks.  I PM'd him.  Do you think you will get better HP and torque numbers from a custom map?  Dumb question-of course you will but how much better I wonder.  Be interested in how much better-please let us know!

PM received and responded. Your question is a good one. Maybe someone who is going to have their bike dyno tuned [Tirso? Other owner of WiLD headers?]  can have a baseline dyno run done with the Attack map before tuning their own custom map? That would be an effective apples-to-apples comparison.

10 hours ago, Madfox said:

If you wear actual riding boots you wont even notice the heat shield is gone. If you're cruising in shorts and flip flops you'll probably feel more heat 

Actually, I left a fair bit of melted heel material from my near-new Dianese Goretex touring boots on the vertical exhaust tube when I took it out for a spin before fitting a heat shield. Right heel started feeling a bit warm in a long sweeping left turn, then got HOT. Cleaning fully baked-on boot heel off the midpipe was no fun.

16 hours ago, ShipFixer said:

I must have missed this, but do we need extension cables for the O2 sensors? 

Just 8 gens need O2 sensor cable extensions as described by Mad Doc in the previous post.

20 hours ago, MadDoc said:

So I've been to 3 different auto parts store in locally (Autozone, O'Reilly, Advanced Autoparts) and I can't find an extension harness for the O2 sensor. I've checked online and seen some, but I'm scared I'll get the one with the wrong adapter. Can someone who has done theirs point me in the right direction?

P.S I have the 8th Gen.

Thanks.

I would send you a link to the exact O2 sensor extension cable I purchased on ebay to extend our 8 gen test bike’s cable, but that seller no longer offers the item. Other sellers do, though, but you’ll have to check the photos carefully and compare connectors with the ebay listing photos. I can tell you that the first cable I purchased was described as for Acura and looked correct at first glance, but had a slightly different connector. The cable that worked was described as being for a Honda Civic, and the photos in the listing showed that the connector was an exact match for the 8 gen harness connector.

4 hours ago, lplplplp said:

While I had it all apart I also build a new Aluminium Center stand.  It weighs in at about 650g starting some weight loss fabrications to come.

That aluminium center stand is an awesome idea! You have mad fabricating skills!

4 hours ago, lplplplp said:

diameter? cause mine arrived with a tube diameter larger than the OEM exhaust??? I had to chop the end off the OEM exhaust and weld it onto the new one, no biggie for me but I wonder how others with 6th gen's went or did mine get missed during fab I wonder?

Yes, the collector exit has a larger diameter than OEM. We decided to keep the dimensions of the original Two Brothers headers because they are a proven performance benchmark. It’s cool that you are welding-proficient, as those of us without welding skills have had to take our midpipes to a local exhaust/muffler shop and have them expanded (swedged?) to fit the new headers. If you have your midpipe expanded, make sure the tech doing the expansion does it in 3-4 small increments so it doesn’t  split at the slots in the clamping area.

13 hours ago, Madfox said:

I'm thinking I'll sell the Rapidbike and get a PCV. I cant justify the cost of the wideband controllers from RB when I'm not getting the full benefit of the Race module on the 5th gen. Turns out Mohawk knows best and i shouldve listened to his advice

Sounds good. Mohawk is definitely a knowledgeable source - he has been invaluable to us throughout the header project. He’s got a very fast, very light 5 gen too...

On 4/21/2021 at 10:31 AM, Madfox said:

Seat of the pants dyno says it's making more power

Looking great Madfox! Are you running a Power Commander or Rapid Bike to get more fuel to the now-better-breathing engine?