Member Contributer apexandy Posted April 28, 2015 Member Contributer Share Posted April 28, 2015 Looking forward to seeing your exhaust mods. I have thought about doing something similar with rc30 headers for my 4th gen. What are your thoughts on merging cylinders 2&4 and 1&3? I have very limited knowledge with header design but can find little information about this. Keep up the great work, I always enjoy keeping tabs on your project. Link to comment Share on other sites More sharing options...
Member Contributer HighSideNZ Posted April 28, 2015 Member Contributer Share Posted April 28, 2015 The merge situation is a bit of a can of worms. With the firing order of the 5th/6th Gens (180 deg crank) being what it is at 1-3-2-4 and the 360 deg crank RC30/45 being 1-4-3-2 I've always thought that merging 1-2 and 3-4 was the right way to go. Then I looked at an Akropovic Racing system for the Aprilia RSV4. There firing order is the same as the 180 deg crank at 1-3-2-4, albeit the V angle is different at 63 compared to 90 for us. But, they merge 1-3 and 2-4, so both rear pipes together and both front pipes together. They also have a 180 deg crank. So, if it is good enough for Aprilia/Akropovic, then I'm OK with it as well. Phil Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted April 28, 2015 Share Posted April 28, 2015 Nope no gaskets or sealants, if you spend enough time lining it up and slowly and evenly torquing it down, you can get it to seal up with no leaks. Also the new eighth gen vfr800 comes from the factory with a header that merges the from two primaries and the rear two primaries, so I'm sure its fine. Link to comment Share on other sites More sharing options...
Member Contributer HighSideNZ Posted April 28, 2015 Member Contributer Share Posted April 28, 2015 Thanks CRRC46 That is interesting about the Gen 8 headers. Link to comment Share on other sites More sharing options...
Member Contributer gig Posted April 28, 2015 Member Contributer Share Posted April 28, 2015 FREE SHIPPING http://www.ebay.com/itm/like/190691213429?lpid=82&chn=ps I used these 41MM gaskets with twobros headers, fit with no interferance. Link to comment Share on other sites More sharing options...
Member Contributer apexandy Posted April 28, 2015 Member Contributer Share Posted April 28, 2015 I also noticed I think the ducati motogp bike merges the front primaries and rear primaries together. I believe that bike is a 180* crank based on it's sound. Link to comment Share on other sites More sharing options...
Alhazred Posted April 28, 2015 Share Posted April 28, 2015 I have two TBR full systems for my 4th gen,one that has cylinders 2&4/1&3 paired and the other has 2&1/4&3. There really isn't a significant difference seat of the pants wise,maybe a bit extra midrange with 2&4/1&3 together,it's really hard to tell. The main difference is the sound,with 2&1/4&3 it has that classic VFR nascar sound but with 2&4/1&3 it sound almost like an Impreza wrx to me. Link to comment Share on other sites More sharing options...
Member Contributer apexandy Posted April 28, 2015 Member Contributer Share Posted April 28, 2015 That was gonna be my next question... Sound difference. Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted April 28, 2015 Share Posted April 28, 2015 I have two TBR full systems for my 4th gen,one that has cylinders 2&4/1&3 paired and the other has 2&1/4&3. There really isn't a significant difference seat of the pants wise,maybe a bit extra midrange with 2&4/1&3 together,it's really hard to tell. The main difference is the sound,with 2&1/4&3 it has that classic VFR nascar sound but with 2&4/1&3 it sound almost like an Impreza wrx to me.Videos please!!! :) Link to comment Share on other sites More sharing options...
Alhazred Posted April 29, 2015 Share Posted April 29, 2015 I would like to but unfortunately I don't have anything to capture video or sound with. Link to comment Share on other sites More sharing options...
Member Contributer Rush2112 Posted April 29, 2015 Member Contributer Share Posted April 29, 2015 I have two TBR full systems for my 4th gen,one that has cylinders 2&4/1&3 paired and the other has 2&1/4&3. There really isn't a significant difference seat of the pants wise,maybe a bit extra midrange with 2&4/1&3 together,it's really hard to tell. The main difference is the sound,with 2&1/4&3 it has that classic VFR nascar sound but with 2&4/1&3 it sound almost like an Impreza wrx to me. That is odd that TBR made two different exhaust merging pairings for the same bike... Is one a left exit and the other a right exit exhaust? Link to comment Share on other sites More sharing options...
Alhazred Posted April 29, 2015 Share Posted April 29, 2015 I have two TBR full systems for my 4th gen,one that has cylinders 2&4/1&3 paired and the other has 2&1/4&3. There really isn't a significant difference seat of the pants wise,maybe a bit extra midrange with 2&4/1&3 together,it's really hard to tell. The main difference is the sound,with 2&1/4&3 it has that classic VFR nascar sound but with 2&4/1&3 it sound almost like an Impreza wrx to me. That is odd that TBR made two different exhaust merging pairings for the same bike... Is one a left exit and the other a right exit exhaust? Yeah one is left exit and one is right. Link to comment Share on other sites More sharing options...
Member Contributer MadScientist Posted April 30, 2015 Member Contributer Share Posted April 30, 2015 I really don't like you people. My VFR makes more than enough power for me but I feel strangely compelled to buy another engine, buy a 6th gen throttle body assembly, have cams ground, and up the displacement to 825. Modification is like some form of peer pressure combined with mental illness. 781ccs is big enough, 781css is big enough, .... Nice work to everyone in this thread though, even if I avoid it just so don't I have to upgrade my engine. Now where is mohawk's thread on carbon wheels.... Link to comment Share on other sites More sharing options...
Member Contributer MBrane Posted April 30, 2015 Member Contributer Share Posted April 30, 2015 I really don't like you people. My VFR makes more than enough power for me but I feel strangely compelled to buy another engine, buy a 6th gen throttle body assembly, have cams ground, and up the displacement to 825. Modification is like some form of peer pressure combined with mental illness. 781ccs is big enough, 781css is big enough, .... Nice work to everyone in this thread though, even if I avoid it just so don't I have to upgrade my engine. Now where is mohawk's thread on carbon wheels.... This is why you need at least 2 of every VFR you like. One to ride, and one to mod. Successful mods are then transferred to the riding bike. It's only time, and money. Link to comment Share on other sites More sharing options...
Member Contributer KevCarver Posted April 30, 2015 Member Contributer Share Posted April 30, 2015 ^^^ Link to comment Share on other sites More sharing options...
Member Contributer HighSideNZ Posted May 1, 2015 Member Contributer Share Posted May 1, 2015 MadScientist I do like your comment! Yes, it becomes a disease and addiction. But it is soooo much fun!! Just don't tell my wife. LOL Link to comment Share on other sites More sharing options...
Member Contributer adeyren Posted May 1, 2015 Member Contributer Share Posted May 1, 2015 You must have a verrrrry understanding wife. I did too until my passion for racing Range Rovers took over. Wife now gone, replaced by bikes! Link to comment Share on other sites More sharing options...
Member Contributer HighSideNZ Posted May 1, 2015 Member Contributer Share Posted May 1, 2015 I take it you don't get half the grief you did before then!! Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted May 1, 2015 Member Contributer Share Posted May 1, 2015 You must have a verrrrry understanding wife. I did too until my passion for racing Range Rovers took over. Wife now gone, replaced by bikes! I am sure your happier now !! Link to comment Share on other sites More sharing options...
Member Contributer adeyren Posted May 1, 2015 Member Contributer Share Posted May 1, 2015 Much happier now thank you. My ex wouldn't have let me have an engine on my lounge table (workbench). Well i am gonna have one soon!! Link to comment Share on other sites More sharing options...
vfrtoy Posted May 5, 2015 Share Posted May 5, 2015 Hello HighSide, I admire your hard work and follow this thread for your updates. As for exhaust, I understand you want to go titanium, that is why you are welding it all yourself. Or is it for tight fitting slip-on connection of all the elements together? If you would like to try stainless, you could probably get stainless steel cat-less downpipes for 98-2000 model. I installed these to my gen6 bike (standard gen6 engine) and they fitted as a glove. Two things that were missing was support screw bracket (originally welded to the CAT) and centre stand stopper. These you could easily weld yourself. Would this work for you? I got mine brand new, but incomplete without rear cylinder links for 60-70 odd quid from flee bay in the UK. I only needed to match rear links to them and got me a while to get proper seal between the rear elements and main down pipes (standard seals + slip-on springs with welded hooks holding things together did the trick). I also had to weld bungs for o2 sensor for my auto tune module. I look forward to see your dyno results once you finish! All the best, Mate! Pipes made for the RC45 will probably not fit a Gen 6 as the rear cam chain tensioner sticks out and interferes with the pipe from cyl 3 I'm OK with this as I'm using the Gen5 engine in the Gen 6 frame. So be careful if you go this route. Also, the front cross over radiator hose at the bottom of the rads goes behind the standard pipes. Most RC45 pipes hug the front of the engine more closely and the hose will not pass behind them. I'm going to run the host in front of the headers so there is another mod needed to make this work. Not a straight forward conversion. I'm buying pre bent bends etc. to do the secondary pipes and will cut them to suit and then weld them up. Most tube benders do not use mandels and so the inside of the bends crushes. There are a couple of good companies in the US that sell good quality mandel bent tubing in lots of varying angles and diameters so I'll be buying an assortment and working from those. Dependant upon my TIG skills, haven't done much for a fair few years, I might just tack it all together and then get it professionally welded. Want to make a good job of it overall. The pipes on ebay mentioned above are in Ti hence the price. don't want to go that exotic, and anyway they are a left exit twin system. EG: 2 x 2 in to 1 I'm sticking with the trusty old 4 into 2 into 1 Tri-Y pipes. Link to comment Share on other sites More sharing options...
CandyRedRC46 Posted May 5, 2015 Share Posted May 5, 2015 98/99 headers, motad, delkivic, Sandy's etc are not performance headers. Negligible performance benefit besides weight reduction. Link to comment Share on other sites More sharing options...
Member Contributer HighSideNZ Posted May 6, 2015 Member Contributer Share Posted May 6, 2015 Hi all No I'm not going Ti, just plain old 304 SS. Too hard welding Ti and I'm too old to learn. I agree with CRRC46, the pipes available on market now for the VFR are really just replacements for the standard pipes. The Delkevic probably are better than the Motad but the quality is still pretty ordinary. CRRC46, here is a question for you. How far down the headers did you place the bungs for your Wideband O2 sensors? I'm thinking I may as well incorporate a set in the headers I'm building seeing that I'm welding the rest of the shooting match up anyway. I've got bungs, just need to know where to put them! My bends etc., from Burns Stainless in the US hit the country today so hopefully they won't get held up in Customs and I'll have some bits to play with for the weekend. Cheers Phil Link to comment Share on other sites More sharing options...
vfrtoy Posted May 7, 2015 Share Posted May 7, 2015 You are probably right, guys. My only goal with those was to get rid of the cat. Lame question: what are the differences between standard cat-less headers and performance headers and how much can you gain by going performance? All the best! Link to comment Share on other sites More sharing options...
Member Contributer Rush2112 Posted May 8, 2015 Member Contributer Share Posted May 8, 2015 You are probably right, guys. My only goal with those was to get rid of the cat. Lame question: what are the differences between standard cat-less headers and performance headers and how much can you gain by going performance? All the best! Performance headers have proper primary diameters with equal lengths with better flow characteristics... switching from a stock cat-with headers to stock cat-less headers already improved your performance by eliminating the restriction of the cat and improved exhaust gas flow by switching to larger diameter primaries... providing you switched your rear downpipes with '98 - '99 downpipes and didn't keep your Vtec or '00 - '01 downpipes that have a smaller internal diameter (ID) than the older 98 - 99 headers. Current available after market headers may be lighter but their tubing ID's are no better than stock cat-less headers. We are trying to get a group buy together to purchase true performance headers for our VFR800s based on the RC45 exhaust header dimensions. Link to comment Share on other sites More sharing options...
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