A10ROX Posted November 28, 2003 Share Posted November 28, 2003 Any thoughts? Where do I spend my money for best results Looking for a quiet exhaust! Link to comment Share on other sites More sharing options...
Anthony Posted November 28, 2003 Share Posted November 28, 2003 Hi, suggest you have a chat with Ammo. From what I have heard the Raceco can is exellent and I have asked Ammo to see if I can get one fabricated for my SBD primaries Anthony Engine in, oil lines in, now really starting to get nervous Link to comment Share on other sites More sharing options...
greg Posted November 28, 2003 Share Posted November 28, 2003 The Raceco ones do look very, very nice! That's where my next upgrade is. Sig: If it is such a big issue why are the WSCC, Piston Heads, SELOC, BBC, Channel 4 ... not members only? Link to comment Share on other sites More sharing options...
michaelw Posted November 28, 2003 Share Posted November 28, 2003 I have a Raceco on SBD primaries so it can be done although the 2-1 part had to be shortened. I am very pleased with it although I haven't seen the BTB. Michael. Link to comment Share on other sites More sharing options...
Pierre Gillet Posted November 28, 2003 Share Posted November 28, 2003 The Raceco is really fabulous I have one with 4 2 1 a Caterham collector. Pierre Link to comment Share on other sites More sharing options...
Tight fart Posted November 28, 2003 Share Posted November 28, 2003 Raceco L7 club member since 1989 T.F@O.F. A7 RDP Pics here Link to comment Share on other sites More sharing options...
AMMO Posted November 29, 2003 Share Posted November 29, 2003 I agree, get a Raceco 😬 Plus it is a cooler sounding name than BTB. Michael How does the car run with the shortened secion of the 4-2-1? I have been trying to convince four different people with SBD headers to shorten them. This is to enable them to fit the full length Raceco silencers. Will they listen? They are all convinced that something really terrible will happen. They will lose fifty horsepower and the world as we know it will end. What is your experience? Performance? Sound levels? Thanks AMMO Link to comment Share on other sites More sharing options...
michaelw Posted November 29, 2003 Share Posted November 29, 2003 Ammo, yes I am very pleased and although I haven't had the car on a rolling road there doesn't appear to be any noticeable difference in performance in fact it even felt a bit quicker in the mid-range than the previous silencer. Although they are not the most expensive it was a bit more expensive than some others but it is very well made and no heavier than my last carbon silencer and you get what you pay for (mine was a special tapered silencer with a 3" to 2.5" ID). As far as noise in concerned, when I first had the silencer put on I had it tested twice at Goodwood at 4800 and it measured 95db. I have since done 2 trackdays at Goodwood and they insist on 5200 now and my car doesn't like that and coughs and pops etc and it now measures 100db but I am sure this isn't a true representation as the car certainly isn't any noisier. I think this proves how fickle the noise tests actually are although I would welcome any feedback. Michael. Link to comment Share on other sites More sharing options...
A10ROX Posted November 29, 2003 Author Share Posted November 29, 2003 To be safe at 98db drive past on full revs do I need the air box, currently running out of the box Caterham filter? Group winter buy! (new exhaust plus carbon airbox) Looking for a quiet exhaust! Edited by - A10ROX on 29 Nov 2003 10:13:52 Link to comment Share on other sites More sharing options...
Anthony Posted November 29, 2003 Share Posted November 29, 2003 Hi Ammo, as one of the four, I am please to hear of the positive response from Micheal. I really want to fit a Raceco can to reduce noise issues. Ammo, can your supplier run up a set of secondaries to match BTB type - just in case the world ends ? Micheal, can you please let me know what spec your engine is running at and how much you needed to trim off secondaries Best regards Anthony Engine in, oil lines in, now really starting to get nervous Link to comment Share on other sites More sharing options...
AMMO Posted November 29, 2003 Share Posted November 29, 2003 Anthony I have emailed you direct. I still think that cutting down the 2 into 1 section of your headers is the way to go. You need the length of the silencer to get the noise reduction. From what Michael says there seems to be no lack of midrange performance. I can get your 2 into 1 section copied if you want to revert back to your ineffective system. I'm still baffled as why you feel the need to do this. Basically what you have now does not work. It is too noisy to get you onto trackdays. Cut the exhaust, fit a proper silencer and don't look back. That's my opinion. AMMO Link to comment Share on other sites More sharing options...
Julian Thompson Posted November 29, 2003 Share Posted November 29, 2003 I will endorse Raceco too. Fantastic product. Additionally, I had need to call on their customer support when I encountered a slight problem, and I always feel this provides more of a test of a company than the initial trasaction. I am pleased to report that the service was fast, friendly and went well beyond the call of duty. Full marks for every aspect of Raceco. Link to comment Share on other sites More sharing options...
ChrisC Posted November 29, 2003 Share Posted November 29, 2003 Raceco 😬 Chris.... H15 SVN Get it ! Link to comment Share on other sites More sharing options...
michaelw Posted November 29, 2003 Share Posted November 29, 2003 Anthony, my engine is a 2.0 VX built by SBD to "production spec" which I think is 180 BHP plus, running on twin 45 dellortos. I think I lost about 1/3 of the primaries but I am not sure. I went through the same thing when I thought about buying the silencer but as Ammo says if you can't use it on track days it is no use. Michael. Link to comment Share on other sites More sharing options...
AMMO Posted November 30, 2003 Share Posted November 30, 2003 Ah. It's all coming back now. We didn't shorten the 2 into 1 one section at all. We shortened the headers and fitted the full length 2 into 1. This was something to do with the construction of the joins. Michael I need a favour. Can you measure the headers from the cylinder head gasket face to the 4 into 2 section please. That is to where two of the headers join into one not where the 2 into one section actually slides on. My feeling is that this needs to be around 32" (could be as short as 28"). Also the length of the 2 into 1 section please. Do you remember how much header you cut off? Anybody got the dimensions of the stock SBD headers, diameters and lengths? I am sure I have asked for these dimensions before to the reluctant SBD header owners. They must be scared of tape measures as well as hacksaws. 😬 Many thanks AMMO Edited by - AMMO on 30 Nov 2003 09:04:26 Link to comment Share on other sites More sharing options...
Tonycaterham Posted November 30, 2003 Share Posted November 30, 2003 David, Go for Raceco, but the larger 7.25 diameter one to be sure. You've seen mine so you know the quality and workmanship cannot be faulted. As I stated in another post Mike Riley can measure it all up for you. Suggest we discuss at the next meet then you can place your order with Raceco! Tony Edited by - Tony7 on 30 Nov 2003 11:22:09 Link to comment Share on other sites More sharing options...
Anthony Posted December 1, 2003 Share Posted December 1, 2003 Ammo, will measure mine tomorrow ! A Still scared of hacksaw on £1K primaries... Link to comment Share on other sites More sharing options...
AMMO Posted December 1, 2003 Share Posted December 1, 2003 Anthony What gauge are they? Should be 20 gauge / 1 mm approx. or 18 gauge / 1.2 mm. Do you have verniers you can measure this for me please. I was thinking of having some VX headers made in Inconel if there is any interest. Only 0.5 mm wall thickness. Less than half the weight. This way I could sell a complete system that fits. Should be the same sort of money you mention. I will definately make some Inconel ones for my Duratec at some point. AMMO Link to comment Share on other sites More sharing options...
Harry Flatters Posted December 1, 2003 Share Posted December 1, 2003 As one of the gang of four 😬 - I will watch with interest *arrowright*Harry Flatters *arrowright* AKA Steve Mell of Su77on Se7ens and Surrey Joint AO Link to comment Share on other sites More sharing options...
Anthony Posted December 1, 2003 Share Posted December 1, 2003 Harry, when I get mine on the rollers - likely to be Jan/Feb, perhaps we can borrow yours to see what the differences is in terms of output. I am anxious to use car on track, hence possibility of mutilated set of primaries, although I will check secondaries as preference is to cut these down a bit Anthony Engine in, oil lines in, now really starting to get nervous Link to comment Share on other sites More sharing options...
Marius Posted December 1, 2003 Share Posted December 1, 2003 Go on Anthony, get the hacksaw, you know it´s right... 😬 Marius in the queue for a silent Vauxhall race can Link to comment Share on other sites More sharing options...
michaelw Posted December 1, 2003 Share Posted December 1, 2003 Ammo, Anthony, the lengths of my manifold is as follows: 4 - 27" 2 - 12.5" 1 - 7" All these measurements are of the tubes if you see what I mean so as they overlap the total length of the system will be less than the above, but I am not sure what other reference points to use. I hope this tells you how much needs to be cut off Anthony assuming your system is the same length as mine was. As you say Ammo, it was the 2 part that was shortened as the 1 part was too short anyway. I sent the parts to you for shortening Ammo, as the mounting tubes need to be re-welded. Any other questions please let me know. Sorry for the delay in replying but I have been at a Seloc track day today - wet but fantastic fun. Michael. Edited by - michaelw on 1 Dec 2003 20:22:27 Link to comment Share on other sites More sharing options...
Anthony Posted December 2, 2003 Share Posted December 2, 2003 Thanks Micheal, I suspect we have slightly different manifolds. I have discussed with Ammo cutting the secondaries. Here's the plan; 1. I will buy a silencer from Ammo 2. I will cut secondaries to enable silencer to go on 3. I will have car set up on rollers 4. With the help of the "gang of four" I would like to borrow an second set of secondaries and an SBD silencer to do a "back to back" comparison. We can then see if the cunning plan above is sensible or not ! Harry, any chance of borrowing your secondaries and silencer for a brief period ? Thanks to all for your help and for Ammo's patience. I hope this course of action will enable others to support a Raceco can. Regards to all Anthony Engine in, oil lines in, now really starting to get nervous Link to comment Share on other sites More sharing options...
AMMO Posted December 2, 2003 Share Posted December 2, 2003 Thanks Michael. Are the secondaries 12.5" after being shortened? Sorry, Mike did the mods, I didn't see the finished product. The primaries at 27" are OK once you add another couple of inches in the port to reach the valve seat. I have always worked on 28 to 32" (apart from high revving motorcycles where you go down to 25 / 26"). The exhaust dimensions become critical once you start using long duration cams over 300 degrees. Otherwise you do have a bit of flexibility. You should also experiment with the induction system to optimise the engine. Something people don't really do much of. The exhaust and induction should all be viewed as part of the whole system and not viewed as individual components. I usually start with 12" for the induction length from valve head to end of trumpet and 32 " for the primary from valve to collector. You them work from there. If when you go to the dyno you can take some different trumpets or trumpet extensions you might be surprised what you may gain. Chopping the exhaust really isn't a problem in my view. I make recommendation based on what I would do myself if I was in somebody elses's predicament. I never ask anybody to do something I wouldn't do myself. Added to this you now have a silencer which has a reduced outlet you may be getting a stronger returning wave from the end of the silencer which probably didn't have before with the over-large 3" outlet. The engine was probably seeing returning waves from the end of the primaries and secondaries but very little from the end of the silencer. This may have been done intentionally. So no criticism of SBD. Problem is that we have noise restrictions and that problem is the one I have been asked to resolve. The added bonus in your case is that you have a tapered core which is common practice on motorcycles. This helps noise reduction without costing any power. The theory is that as the gas is hotter at the front of the silencer it takes up more volume than when it reaches the end of the pipe where it is cooler. Please keep us informed of any dyno work you eventually do. Thanks. Anthony Excellent plan Edited by - AMMO on 2 Dec 2003 07:06:24 Link to comment Share on other sites More sharing options...
Harry Flatters Posted December 2, 2003 Share Posted December 2, 2003 Anthony, Engine is out at present. When would you want them? How long for? The won't fit in an envelope y'know 😬 *arrowright*Harry Flatters *arrowright* AKA Steve Mell of Su77on Se7ens and Surrey Joint AO Link to comment Share on other sites More sharing options...
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