ShipFixer

My Delkevic mid pipe expanded just fine, no cracks or tearing. The way Delkevic carbon copies things, I suspect the 5th gen mid pipe will be exactly the same pipe as what my 6th gen has.

So my headers almost wrecked someone else's bike last night... 😂 I was following two sport bikes from a left turn lane into an entrance ramp, from 50 yards or so. With the headers and Delkevics, when VTEC kicks in the bike goes from a V-8 rumble to a shrieking V-4 race bike sound. When it switched on one of the riders (clearly now a beginner) did a big, swerving-S panic stop with no idea what was going on... 🤦‍♂️

Throwing some more data points in. I rode mine all the way around San Diego yesterday, including Sunrise Highway, over several hours, and included a stop at @sfdownhill's to show off how his creation is getting used on my bike 😄 So riding between sea level and 5,000 feet, mostly highway speed and 30-60 in twisty highway stuff. It was 78-80 most of the time. I haven't touched the Rapidbike since installing it before the headers and Delkevics, and my bike really needs some injector work plus starter valve sync, etc. just to give you an idea of how it is right now. I'm also only using the stock narrowband sensors. But I still managed 42mpg with saddlebags, which equals what the bike got when new (42 with, 46 without). It hasn't seen quite that good mileage in a while! It also managed to keep temps lower as it wasn't working as hard. At steady speed it was pretty rock solid between 174-180. Performance wise...wow. There is little to no resistance climbing past 6,000 RPM. It's pretty crazy how it wants to run, regardless of gear. There is quite a bit more torque across the rev range, and I'm wondering just how much, along with how it'll go once I've got everything fixed and tuned. This is more due to RapidBike, but there's still no return of the dreaded closed-loop taper/surge behavior. Even though I haven't gone in to reset it or anything, it's adapted to the Delkevics pretty quickly. The "quieter baffle" in the Delkevics also brings down the sound level to just within tolerance for riding. At speed (above 55 or so) the sound disappears behind you so long as you are at cruising RPM. Sitting at idle or low speed it's still pretty loud but doesn't wear me out. What's really interesting is how cars react. They all know I'm there for sure now, and on Sunrise Highway they all either stayed pretty far back or used the next available turnout to let me pass :lol: I still coast in a bit to my driveway and try to get away from home as quickly as possible, but my neighbors tell me they have yet to hear the bike inside their houses. Bike still has some behavior that's attributable to old and dirty fueling, including difficulty starting/restarting sometimes. On my RapidBike auto map there are also a lot more maxed out values than in the other kids. So there are clearly more gains to go here, but the headers are crazy good so far.

Minor update here. Finally got the "quieter" baffles from Delkevic and was in town long enough to install them. They "fit" at an angle and could have been designed better. But...they're in. The bike is a bit quieter and more liveable, but still loud. Kinda wish I'd tried the SS90's instead, as they're capped and another inch (thinking every bit counts). Contemplating getting a couple 13" Delkevics of similar design since they will fit the collector and modding them into 10" sets. Very happy with how the engine is running, just a lot louder than I am used to!

Well, fortunately I did get a switched power extension with the VFRNess I haven’t installed yet (put the R/R in and haven’t felt the urge to prioritize). This is sounding like a bit more work than I was expecting though 🙃

That's awesome! Did you just email Yaman and ask him when he was available? I have not messed with the software too much since initial install. Those baffles are my next priority!

For sure, it's better at speed! 😁 I received the "quieter baffles" but I'm in Virginia for work through most of next week. I'm going to give them a shot and see if it's better.

Well, it's not like I'm totally surprised here... 😄 I have a couple options. Delkevic makes a "quieter" baffle that drops the sound 1-3 dB, or so it says. I can also try their next-shortest increment and buy two 13" tri-oval mufflers from them, but I think they might stick out too far back. My options for rotating the exhaust splitter further forward/up are kind of limited, so it is what it is. Will almost certainly at least go for the quieter baffles, but for now...been too long without the bike!

Only had time for a quick test ride, so it will be a bit before the RapidBike catches on to what's different in the back end here. But...I mostly like it! Only issue I have is the header plus exhaust is louder than I was hoping. On the highway it's not too bad, but at low speed it's way up there. If you get off the bike and stand ten feet back, at idle...quieter than you think. Yet it is loud, so I will be going through a lot of earplugs I'm sure. Performance wise, wow! It's a positive change across the rev range, and once again the higher gears are yet more useable at low RPM with more torque. But there is a dramatic increase above 8K RPM. It's less that I notice the bike is faster/better so much as the RPM's climb a lot more willingly now than they did before. I rarely push the engine that hard, so it surprised me how fast it got near redline without any intent to get there. Definitely want to get the injectors cleaned soon, along with some poking at the RB so I can see how much better I can get. Going without the head shield for now...would need to be trimmed to go back in, it's only a little warmer on my ankle through my Sidis, and I would want to sand and repaint the thing anyway. One install note, for those who haven't done theirs yet. Despite @sfdownhill 's warnings and my double-checking, once everything was torqued my header was in contact with the frame, on the right side near the swingarm pivot. I had to loosen the header nuts, hammer in some wood wedges, and then torque down. I've included a photo below of the area in question, post-test ride when I was verifying I still had space there. Again...I was not in contact all along until after everything else was bolted in so, you may want to check yours! It's a sharp corner that's not obvious unless you really get under the bike to look, or feel in between to check. Second install note/exhaust header trivia. Those extra tall flange nuts I received from Belmetric are very close to the Honda special M6 nuts for the studs, and I used the other Honda part ones that were identical to the VFR part number (which I have not received yet). So if you are still waiting for either part, there are some lifelines out there.

Everything is installed and torqued down, including @SEBSPEED ‘s center stand stop. Cleaning up for a test ride!

All-Honda parts in hand...now to install! 😁 Definitely not touching the injectors until I receive a package with all of the seals...

Should get the Honda M6 flange nuts tomorrow, and finally reassemble this thing. Can't complain anywhere else :lol:

Delkevics arrived. No M6 extra tall flange nuts yet. Argh!

Still waiting on parts. Tried again to separate the nuts from the studs and couldn't. Lame...

Next set of studs came in...they are the right length but have a longer unthreaded section in the middle. Would work, but that first alternate I found is better. Meanwhile...not sure when the special M6 nuts from Honda will come in. I found an alternative though, an M6 extra tall stainless steel flange nut from Bel-Metric. They are in Massachussetts and will ship the next business day, so...it's a race. Delkevics get here Tuesday, frustrating to wait this long! I may yet try to torch the originals off the studs.

So I received the first of my exhaust stud bets today - a different part number listed by Honda as M6x22. It's a dead ringer for the VFR stud, 35mm total length and the unthreaded section is in the same place, with equal threaded lengths on either side. Part number is 92900-060220B. The title on eBay was "QTY 2 NOS HONDA CRANK CYLINDER STUD BOLT 6X22 XR600 GB500 CB400 92900-06022-0B" Of course, now I need the two "special nuts," but those are available in stock at Partzilla and elsewhere anyway.

You are all cutting into my surf and bicycle budget here! :lol:

Well...you guys suck, I ordered the Delkevic 8 inchers...

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

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."

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 🙃