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New 5th/6th/8th gen performance header now in production in USA


sfdownhill

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Well...one thing, the bolts are still seized on two studs.  I have them off the bike and soaking now while I play PUBG 😁

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12 hours ago, Gotama said:

Sheesh I just physically moved the front pipes in place by hand 

fit perfectly 

no fancy tools needed except muscle 

The wood shims and hammer were the only tools required to make up for the front end misalignment.  I think I could get them in place without them but it was a lot easier that way.  I'd assume all of these experiences will be a little different, but I got the right one in first, then the shims pushed the left one out a bit where i could get it more forward and between the stud holes, then when i took the shims out it was pretty easy to line up the last centimeter or so of movement in the left one.

 

If it were a bit harder for me and I didnt have the shims, I would consider removing the front wheel and fender so I could really get in and pull it a part and line them up by hand.

 

Meanwhile, no luck on the studs and nuts coming apart.  I may try a torch if I can find one, but meanwhile, if you haven't installed yet and you have an older bike like mine, you may want to order a few of the studs and nuts for the front cylinder ports just in case.

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32 minutes ago, ShipFixer said:

The wood shims and hammer were the only tools required to make up for the front end misalignment.  I think I could get them in place without them but it was a lot easier that way.  I'd assume all of these experiences will be a little different, but I got the right one in first, then the shims pushed the left one out a bit where i could get it more forward and between the stud holes, then when i took the shims out it was pretty easy to line up the last centimeter or so of movement in the left one.

 

If it were a bit harder for me and I didnt have the shims, I would consider removing the front wheel and fender so I could really get in and pull it a part and line them up by hand.

 

Meanwhile, no luck on the studs and nuts coming apart.  I may try a torch if I can find one, but meanwhile, if you haven't installed yet and you have an older bike like mine, you may want to order a few of the studs and nuts for the front cylinder ports just in case.

I had one stud that was like that up front too 

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I've pulled several VFR exhaust studs using the "seized nut removal method".  I've found that to be a good time to replace the studs with stainless versions.  Something like these:

 

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(£20 on eBay UK)

 

But not like these:

 

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I seem to recall reading somewhere that the un-threaded portion in the middle is necessary in order to attain the benefit of using a stud, rather than a screw, in a fastening application.  However, that OEM Honda VFR750 studs are made with the gap is enough for me:

 

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Unfortunately, I've never seen any stainless flange nuts in the OEM length, but someone might make them. 

 

Ciao,

 

JZH

 

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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.

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Has anyone with a 6th gen mounted an O2 sensor in the aft bung on one of these headers?   With the Bosch sensor I have on the My Tuning Bike module, the wire is coming up right between the chain and the triangle plate for the shock, both moving parts.  The particular concern is contact with the chain though obviously both matter.  If you have done this, how have you routed / secured the wire?  

 

Thanks for any ideas.

 

 

20210527_210649.jpg

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I haven't.

and have not thought about trying an OE o2 sensor, but now you have given me an idea 🤯 . Will there be enough length in the wires?    I'll try 2moro. 

 

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Wire length is a challenge.  There are a couple of ways to extend the wiring,  have been looking at those.  There are pre made wires with connectors on ebay.  The other is to follow Bosch's recommendation and use Posi-Locks. Bosch says specifically not to solder wires.  

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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.

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There isn't enough length in the oe wire but with a rough measurement I'd say it would be about 1/2" space to the chain. Yikes. 

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12 hours ago, Mohawk said:

I ended up with a similar pig tail for my MTB wideband O2 sensor too ! 👍

 

It looks like a zip tie around it to hold it is about the best that can be done.  I also have Sebastisn's center stand stop, so that provides an added structure to retain the wire.

 

How is it holding up for you? 

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Waiting to see how it works out for you guys before I shift to a wideband on mine 😂

 

Do they make sensors with right angle connectors by any chance?  Gonna go look...

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18 minutes ago, ShipFixer said:

Waiting to see how it works out for you guys before I shift to a wideband on mine 😂

 

Do they make sensors with right angle connectors by any chance?  Gonna go look...

First ride with it coming up later in the week.  Will let you know. Just got the MTB synched up with Racing module. Got on the phone with Yaman this a.m. who remoted in to the sytem for an initial checkup and to make base settings - got a clean bill of health.  He sets it up with a leaner AFR target below about 8,000 rpm  for mileage - IIRC 13.5.  For rpm beyond that the target goes to a richer mixture to optimize power.  The MTB will hit those targets even at higher elevations and then readjust back at sea level. Try that with a P.C. . . .   Now just other reassembly from other maintenance and she'll be good to go. 

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2 hours ago, Cogswell said:

First ride with it coming up later in the week.  Will let you know. Just got the MTB synched up with Racing module. Got on the phone with Yaman this a.m. who remoted in to the sytem for an initial checkup and to make base settings - got a clean bill of health.  He sets it up with a leaner AFR target below about 8,000 rpm  for mileage - IIRC 13.5.  For rpm beyond that the target goes to a richer mixture to optimize power.  The MTB will hit those targets even at higher elevations and then readjust back at sea level. Try that with a P.C. . . .   Now just other reassembly from other maintenance and she'll be good to go. 

Well, I am hoping to hear that it is in fact better, but I kind of expect that?  I'm more interested in hearing that your chain did not eat the sensor cable :lol:

 

While I'm on an indefinite wait for exhaust studs (I have one on my desk right now with calipers, to see if I can find some generic alternative in the US...argh) I'm thinking of sending my injectors out to be cleaned, or flush them myself.  At that point you and I should be about even-stevens for mods right?  I am probably going to keep my stock exhaust though, I don't like the looks of the Delkevics enough to reeeeaaally want to do it, and I think the advantage of the headers is going to dwarf any gains from the cans anyway.

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Here's a the lower rev portion of the map showing fuel trims.  There are also ignition timing changes made on the Ignition tab.  Note  the largest fuel changes are made right around 6,700 rpm between 20% and 80% throttle - where riders have issues with the 'transition'.  The ignition function Power Commander cannot do.  PC does not tap in to the ignition pulse generator as RB does and thus there's no way for it to adjust what's happening.   This is much closer to what a dyno tuner would do on a car, adjust both timing and fuel delivery vs. only the latter. Should be interesting to see how this thing evolves as it's ridden. 

 

 

Capture.JPG

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I'd have to go back and look to be sure, but among other reasons I want to clean my injectors like starting issues, I think my self-tune map has a lot more +8's than yours, and that's with the stock exhaust. Great once it's running of course.

 

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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):

C6CDDDCC-7AE1-4FB4-ABA3-5C743FC54382.thumb.jpeg.2bd0558363e722c83aa20f1f5e209075.jpeg


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

6C4831AC-FD2C-482F-B4F2-1495CBC885A7.thumb.jpeg.737ec9561dff892e33508d9c3ad2d768.jpeg


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):

3E4B6CD1-3D92-459C-B6AC-93E21C1A7F0B.thumb.jpeg.18cb860fe1bf5bc19052b59fb411d079.jpeg

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.

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Weeeelllll I guess I could go Delkevic, but I don't want crazy loud.  I'm in a quiet HOA and I'm the newest resident 😂  I think the 8" are supposed to be fairly quiet with the baffles?  But I also think way back in the early days of VFRD it was quantitatively  determined the stock cans arent that restrictive?

 

Searching the older posts gets tedious, but I seem to recall the cut-up cans didn't affect output much but did get louder.

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And the weight savings on changing out the stock mufflers will be significant. So much so you'll need to adjust your suspension 

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2 hours ago, Gotama said:

All these attempts to achieve what is simple 

stock cans are crap lol plain and simple 

R1 cans from corresponding years can and will work beautifully .

 

Simple is for the money I've now put into rehabbing my repurchased 6th gen I could've gotten a new or like new 8th gen 🙃

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Still waiting for the exhaust studs.  I've ordered a few "looks like" things from eBay, we'll see what gets here first.

 

Meanwhile...I e-mailed Delkevic to ask about the SS70 vs. Mini 8.  The short answer is "LOL they're both loud." 

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