aussiechris Posted July 3, 2015 Report Share Posted July 3, 2015 Hi folks, My local dealer (just 900km away) has a good price on the S3 titanium header pipe for the 4RT. But there appears to be little information available so I have a few questions for anyone who has actually fitted one. 1. Does anyone know what diameter they are? The original pipe measures 25.4mm OD. 2. Does the original heat shield fit this pipe? 3. Assuming the pipe is a larger diameter, how does it fit into the existing muffler? The original fibre sealing ring would be too small so how does one seal this joint? 4. The original pipe has a slight bend before entering the muffler, the S3 pipe appears to be straight. Do they fit properly? Do they hang further out? 5. Are they any good - performance, sound? Many thanks, Chris Brisbane Australia. Quote Link to comment Share on other sites More sharing options...
stkman Posted July 3, 2015 Report Share Posted July 3, 2015 (edited) Hi folks, My local dealer (just 900km away) has a good price on the S3 titanium header pipe for the 4RT. But there appears to be little information available so I have a few questions for anyone who has actually fitted one. 1. Does anyone know what diameter they are? The original pipe measures 25.4mm OD. 2. Does the original heat shield fit this pipe? 3. Assuming the pipe is a larger diameter, how does it fit into the existing muffler? The original fibre sealing ring would be too small so how does one seal this joint? 4. The original pipe has a slight bend before entering the muffler, the S3 pipe appears to be straight. Do they fit properly? Do they hang further out? 5. Are they any good - performance, sound? Many thanks, Chris Brisbane Australia. Hi Chris, I fitted one to a 2015 Repsol a few months ago. 1. I seem to recall I measured it at 27mm external. Forgot to check wall thickness but larger bore for sure. 2. Heat shield almost fits ... a minute with a small file and it went on just fine. Looks OK. 3. Comes with a thinner seal. No issues fitting into the original silencer. If the dealer (?Tarp) doesn't send the seal, send the pipe back. I bought direct from S3 and definitely comes with a new seal. 4. I wondered about the straight pipe but the fit was good. Tried to fit without removing the silencer. Not easy so removed the silencer, put the header on without tightening things up, refitted the silencer and then tightened everything up. 5. Starting turning blue within an hour. I like the look. Needed to increase the idle speed. Seems smoother off idle. Sounds similar - maybe a slight bit deeper. Am happy with it. Let me know if you want a photo and I can post one, Andrew Edited July 3, 2015 by stkman Quote Link to comment Share on other sites More sharing options...
aussiechris Posted July 3, 2015 Author Report Share Posted July 3, 2015 Thanks Andrew, That's exactly the info I was after. I think I'll go ahead and buy one. I'm actually buying from my Gas Gas dealer! Again, thanks. Chris. Quote Link to comment Share on other sites More sharing options...
aussiechris Posted July 12, 2015 Author Report Share Posted July 12, 2015 Just by way of an update... I bought the S3 pipe. Overall I'm pretty happy with it. It fits perfectly and is very compact and tight into the bike. And it weighs 158 grams less than the original pipe and seal. The big problem for me is the mountings for the heat shield. The hole spacing is perfect but the mounts are too big and too far off the pipe. As you can see in the photos, the mounts are rectangular instead of square and the rounded shape of the heat shield won't sit down on them. I had to bend the front one to get it to fit but that exacerbated the second problem in that the mounts are too high (to far off the pipe) meaning the heat shield hangs out to the right more than it should. That's a pity because the pipe itself is so compact. S3 could have saved precious titanium and weight by making the mounts the same as stock. Performance wise, the bike does feel smoother (and slightly quieter for some reason). But no more power. At 28mm OD, the S3 pipe is 3mm bigger than stock and looks right on the bike (other than the heat shield problem). 1 Quote Link to comment Share on other sites More sharing options...
crazybond700 Posted July 14, 2015 Report Share Posted July 14, 2015 (edited) The solution could be to take it to a welder and let it replace the bracket, but not really what you want when you buy a new part. I would contact estres with the pictures, they could learn something from it, and they might have advise or a future discount or something for you Only adapting the product yourself makes it difficult to send it back. It does look sweeet. Edited July 14, 2015 by crazybond700 Quote Link to comment Share on other sites More sharing options...
guys Posted July 14, 2015 Report Share Posted July 14, 2015 The shield on my Mitani titanium pipe has the same problem, it stands to far of the pipe Quote Link to comment Share on other sites More sharing options...
aussiechris Posted July 17, 2015 Author Report Share Posted July 17, 2015 Thanks Guys, for taking the trouble to show your Mitani pipe. Don't feel too bad - mine is a lot worse. I can TIG weld ok, so I need to visit the local welding shop to see if I can buy a single stick of titanium TIG wire and I'll fix it. But right now I don't feel like taking the pipe off again. Such a pity S3 couldn't be bothered to check their products a bit more closely. The pipe itself fits great. 1 Quote Link to comment Share on other sites More sharing options...
crazybond700 Posted July 19, 2015 Report Share Posted July 19, 2015 Not the preties way, but grind of the front bracket and use a clamp> Quote Link to comment Share on other sites More sharing options...
guys Posted August 16, 2015 Report Share Posted August 16, 2015 (edited) The shield on my Mitani titanium pipe has the same problem, it stands to far of the pipe Do you have the full mitani system? Do you have a pic of how the rear and front join? The standard pipe to the mitani rear doesn't slot over as far as the standard set up. Also what size mitani pipe is that? A 26mm or 27mm, do you know what the difference is between buying either? Regards Montesa uitlaat 001.JPG Yes, I have a full Mitani system. On my previous 2008 4RT I had a 25.4mm Mitani front pipe which fitted perfectly in the Mitani rear exhaust. I sold this bike last year so can't take a picture of the joint. On my 2015 4RT I mounted the rear Mitani exhaust of my previous bike and I bought a 27mm Mitani front pipe. Because the connection part of the rear exhaust also has a 27mm outer diameter, I made a stainless steel split sleeve that goes over both pipes, which is held in place with a stainless steel exhaust clamp. I was assured by Josep Banyeres that a 26mm is more than enough for a 4RT, even with a 280cc kit, but I bought the 27mm because of the matching outer diameters. But I'm not sure that a 26mm front pipe will fit in the Mitani rear exhaust because that is made for the standard 25.4mm front pipe. I can't say this for sure though because it might have a reduced diameter at the joining part.. Edited August 16, 2015 by guys Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted August 16, 2015 Report Share Posted August 16, 2015 Wouldn't it be a lot better just to make a new heat shield? The original, in my opinion, looks a bit tacky even on the standard pipe. A titanium pipe surely warrants something a bit more special. Quote Link to comment Share on other sites More sharing options...
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