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

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I think you're cheating. that wheel isn't the stock black 2001 wheel. I bet the extra couple of ounces  you saved with the 3rd gen wheel translate to at LEAST 5 of  horsepowers you found! Mojo = Horsepower. If you'd added a few stickers you might have seen 120.

 

Seriously, It's good to know a normal fan on an average day is plenty to keep these safe on a dyno.  I am convinced there aren't issues with the radiators on the sides with no fairing. Or when moving in clear air, of course. The problem comes with fairings and no ram air coming in from the front as they seem to be optimized for moving air. Even being behind a car that disturbs the airflow will raise my cruising temperatures, it's nuts! I believe Honda engineers tested the whole deal in a wind tunnel and it worked wonderfully, but never  tried making the breeze turbulent.

 

I do wish you'd have been able to see the run. Just because it's deafeningly cool. But even with all the trouble and extra driving you got things done.

 

5 hours ago, Mohawk said:

Regarding a fuel map & why people never generally see the same result with a downloaded map, you need to read this http://www.robsdyno.com/injectors_tuning_massachusetts.html

 

 

Totally, this. Stuff just isn't a simple, static, perfect system. Heck, if it was, you'd never need adjustable starter valves to get per-cylinder flows sync'd at idle as all injectors would have identical flows at all cycle times. But duty cycling can vary. It can vary at different cycle times, too, so wide open might vary differently than 1/4 throttle, which is part of why the highest end race bikes do one per cylinder sensors, even when they're so meticulously maintained. But on the street no two of these will remain the same over the years. Even the spray pattern will eventually vary over time, regardless of how clean the injector is or how matched the flow is when you start out.

 

That said, a downloaded map on a PCIII improved my bike a lot. But there's a substantial difference with the RapidBike, which makes things ridiculously smooth no matter what idiot thing I'm doing with the throttle. It's even MORE better than the PCIII, which was better than stock with my crappy pipes and drippy injector.

 

That said, I get it if someone wants to DL a map and just go. They just dropped $800 on pipes and gaskets and whatever, and if the bike runs good it is good enough for the street.  Plus, I already invested the extra 3 bills on the my tuning bike, so I might be too strong an advocate to justify the expense.

 

5 hours ago, Mohawk said:

 

Remember YMMV.

 

 

Hah. Literally.

 

 

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That's still an amazing price for some dyno runs and a tune. Geez. IIRC, the shop local to me charges $400 to tune including a power commander.

 

When I dynoed my 98' a couple years back, it was making 106.5whp with just a k&n big filter, slip on, and ngk iridium ix plugs. I think it had around 3k miles then, so the dyno test bike is running like new 👍

 

 

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10 hours ago, Mohawk said:

Regarding a fuel map & why people never generally see the same result with a downloaded map, you need to read this http://www.robsdyno.com/injectors_tuning_massachusetts.html

 

Now that is enlightening reading. Thanks for sharing the knowledge-wealth, Mohawk. The Rob's Dyno article mentions RC Engineering's fuel injector selection table, which got me looking further into RC. Now I'm extra happy we used them for our injector service. Once again thanks are due to Duc2V4, this time for bringing RC Engineering Fuel Injection to our project.

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Yeah that was an interesting read especially given the fact that we recently broke an apex seal on our rotary race car due to failure of a nearly 30 year old injector that was serviced, and given a clean bill of health. Not going there again. Fresh injectors with every build now.

 

Of course piston engines like the VFR are more tolerant of lean detonation, but it still gives one pause.

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Also glad to see his reference to Marren Fuel Injection. I sent all 8 of my BMW 540i’s injectors to them when I did my timing chain and guides service. I was extremely happy with the results, and the car purrs like a kitten. So smooth... it’s hard to imagine for a 18 year old car with almost 200,000 miles.

 

Happy injectors are certainly a part of that.

 

 

Sent from my iPhone using Tapatalk

 

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We finished up a second phase of R&D Thursday - dyno testing of the header - prototype #2 - in the photos below at Attack Performance. All this means is that one well researched attempt to improve on header #1 only proved #1 to be better. Production continues w header #1 the original TBR replica as scheduled.

 

I am driving out to Wade’s shop Tuesday to go over proper alignment of the collector exit, taking along 98/99 headers, TBR headers, a center stand, and maybe the fitment bike.

 

Here is header #2:

055BD752-6FF1-4960-A6B1-9720B92079E4.thumb.jpeg.9d5c259282925912a631e9bab7ef2d26.jpegAE1DBC45-A8EB-4979-9CD8-50EE0DBE0BED.thumb.jpeg.72fc957cf5a566ce37abc1b0ba21e6de.jpegFF08B3FB-CA53-4100-B24E-1610EE1AEBB8.thumb.jpeg.591897120da923fd351bcd7239b0199e.jpeg

 

Based on (1) exhaust theory of keeping gas velocity high through the port by maintaining a slightly smaller diameter in the first few inches of the primaries, (2) Wade’s success with this concept on his dwarf car and Razr headers (3) Black Widow and Lextek’s use of this concept,

we had Wade build a second prototype with smaller 35mm od for the first 3.5 inches starting at the exhaust port.

 

The results are clear - header #1 we tested on Saturday Jan 26 is definitely better. This chart shows header #2 down a couple hp and ft/lbs across the entire range, especially in midrange264F88FC-F6E3-4B8F-95D6-466DA36A2A6C.thumb.jpeg.7219097ff09fdb865d8c7f59d6c9d362.jpegA3001160-E6E2-4363-9716-7DAC20C2FCFD.thumb.jpeg.7182a2e5ba47e08ba7d20759d1db9c6e.jpeg

 

 

Note: Dynojet dynos/software correct temperature, humidity, and altitude to a standard density altitude. This means the software corrects to a standard the same way aviation performance calculations are made, ie “Can this aircraft generate enough power and lift to take off from this runway at this weight, altitude, temperature, and humidity?”

Dynojet’s correction calcs are not perfect, and neither is my spelling, but they are better than nothing. Here is an uncorrected  comparison of last Saturday’s run of header #1 against Thursday’s run of header #2:

64EE74CE-6D6D-4A9B-A233-A1A1D4EB6D29.thumb.jpeg.34971c9f171a847a96d99c6714f4ede7.jpeg

 

 

8800AAED-4B1F-4193-9C8B-D37000977039.jpeg

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Great job guys, I didn't realize you all were going to do additional R&D.  Even though it didn't net any real gains, it is good to know that there isn't much left on the table with the original design.  I've done a lot of HVAC pressure/flow analyses and have run into some unexpected situations in real world vs simulation vs fluid dynamics modelling.  Matter of fact, you wouldn't believe how some simple things cause instability and pressure/flow oscillation.  There is a lot that goes into managing interactions between turbulent and laminar flow regions.

 

Just out of curiosity, are the welds/joints in the taper regions smooth inside?  A discontinuous change in diameter (step up or down) will lead to turbulence that disrupts the speed of the central laminar flow region.  Of course exhaust gasses flow in pulses, which contrasts with the relatively steady pressure of HVAC air handling fans, so there may be factors I'm not aware of.

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Just wondering, doesn't matter either way,   are you doing a dyno run with the  finished mandrel bent headers on the 5g / 6g with o2 sensors and RB or PC,

Or just leaving it at that?

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Hmmm, I wonder if anything else can be done to get some more power? Maybe adding h pipes between the primaries, or an h pipe after the 4-2 merge, or maybe a lextek design with tbr diameters? The latter would be a challenge without having one though.

 

 

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MadScientist, your expertise goes right to the crux...at the welds inside the primaries of header #2 there are bits of weld material just barely protruding into the gas path around the internal circumference. I tried to reach in with the Dremel extension and hone down the intrusive weld material, but those bits are tough! They laughed at the high speed grinding tip. Yes, something in header #2 disrupted the combination of factors that make the TBR design so effective.

 

boOZZIE, I'm not sure when/if we'll be able to get a mandrel bent production header onto the dyno - we'd certainly like to do so soon. Wade ordered materials and sent his design specs to his bender vendor, so we'll see how quickly completed production headers get shipped out. I'm going to ask him for a timeline when I see him Tuesday. I hope it's not long before we all get to see a dyno baseline and tuning of a production header. This may be something a customer from the list of persons who have placed deposits gets to first, soon after they receive their headers.

 

At this time it appears the next known dyno baseline/tune on this project will be prototype #1 on VFRD member Hammerdrill's 6th gen, as he is purchasing those headers. Hammerdrill is having an exhaust shop open up the cans of his OEM 6th gen mufflers, gut them, install 1.5" perforated exhaust tubes and pack them. He's keeping the OEM muffler carcasses for their aesthestics. When the mufflers are done, he's going to get his 6th gen to Attack as soon as possible.

 

Note: Prototype #2 is available for purchase at this time.

 

Airisom, Mohawk's curiosity about a crossover header that matches the design of the 6th gen OEM headers but employs TBR tubing sizes and merges does get one pondering...

Sadly, we are not equipped with time or resources [read: dinero] to pursue further prototypes and testing.

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Hey doesn’t matter, you have done a great job to date. Stick with numerono & let the tuning wars commence. Maybe after the first production run, variables may be possible. Kudos to Lance & Wade for making this happen. I’m not sure how many VFR800’s of all types have been sold,  but in the UK alone there are over 5000 still registered for the road of 5th gen variety & as many 6th gen. On my most recent commute, I used to see 4 or 5 distinct 5th gens during the past year, and a few 6th gens. World wide there must be a goodly number of these in the wild, all with mild steel headers that for 5th gens are at least 18 years old & between 5-17 years old for 6th gens. So there is a huge potential market, just need a means to get them known outside VFRD to improve sales. If everyone does their bit & promotes them outside VFRD on their local or national Honda or VFR forums sales should be good, we need a continuous sales stream to keep them in production for a while ! So people do your bit once production units are ready.

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Yeah, Lance, good job keeping this project going. Honestly, there's no reason to spend more on testing, even if you had the cheddar. You know #1 works to buy performance -- pretty much across the entire usable range, not just top end -- and I'm confident the mandrel bent runs will be as good or better. And the header should outlast my bike.

 

It'll still be fun to see if folks get some increases once they get their new headers installed, of course.

 

It's my sincere hope that our guaranteeing enough to cover tooling and development has given Wade a big enough boost  to make post-group-order sets possible. They've done what seemed impossible, so when the final tooling is in place and we've all gotten our pipes, I definitely hope Wade feels rewarded. And, of course, willing to keep making for others who learn of these and don't want to go for the bargain  aftermarkets. There are a few of us, but it's definitely a lot more of a niche market than it was in 1999.

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I can hardly wait for the 8th gen version data to drop, very exciting!

 

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I'm with you SebSpeed.

Can't wait for an 8th Gen version.

It really is only the front headers that need to change.

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Update - there’s not a lot to update. Wednesday I dropped off Prototype #1 at the metal finsher’s to be passivated (acid dipped). They’ll do this first set of headers for $110, and batches of 5 headers for $95 each. I’ll post photos of the treated headers later this week.

 

Production headers are underway, but Wade was sick last week and bowed out of our Tuesday meeting. He’s feeling better (racing motocross sidecars in CA this weekend!) and I’m heading to his shop tomorrow. Objectives for this meeting are:

 

(1) refine our approach to collector exit matching OEM angle/position - relates to having had only TBR and OEM 6th gen headers on hand when making the jig for the prototype. The cat on the 6th gen headers didn’t allow an accurate measurement of the OEM exit angle/position, so I’m taking 98/99 headers to Wade to confirm production units match OEM angle/position (98/99 tubing and merges allow measurement & duplication).

 

(2) examine clearance required between the collector exit pipe and the bottom curve of cylinder #1 primary as relates to the header fitting over the diameter of the right side center stand leg during installation. Clearance at this point on Prototype #2 is enough to just squeeze over the right center stand leg, so the center  stand doesn’t have to be removed to install or remove the headers. Clearance at this point on Prototype #1 isn’t enough to allow the header to pass around the center stand during installation - we had to remove the center stand, thread it through the headers, then mount the center stand with the headers dangling down at the base of the stand like pants around one’s ankles, then mount the headers.

 

 

file

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Thanks for the update. Appreciate the attention to detail you guys are performing. I'm not in a big hurry, and really need center stand compatibility for my '99 commuter/touring bike.

 

 Great job so far!

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When the times comes, I wonder if the 8th Gen headers can be made so removing and reinstalling the center stand isn't an issue where the header bolts won't need to be loosened?

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Lance, you and DucV4 are SMASHING it!

 

Thanks for the effort you’re putting into this. 

 

Stray

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