r300chris Posted May 5, 2018 Author Share Posted May 5, 2018 Simon, I’ve heard of the acustafil, material, but I though I better use Raceco stuff for best noise reduction, but it’s possible that acoustafil is better, another option to try.the picture of the exhaust is exactly what I saw at brands, thanks for posting itChris Link to comment Share on other sites More sharing options...
r300chris Posted May 5, 2018 Author Share Posted May 5, 2018 Further information, I found on re reading the build info I got with the car, as the car is not a standard R500 but built with CSR rear end, by owain Davies it mentions standard CPT 500 engine, with cosworth roller barrels and a higher compression ratio of 12:1, engine built by Mick Attree.dont know if any of the above will make a difference on noise ?Chris Link to comment Share on other sites More sharing options...
Leadership Team Shortshift Posted May 5, 2018 Leadership Team Share Posted May 5, 2018 ChrisYour spec differences could be significant here... Funnily enough, Mick was at Brands on Thursday. Why not reach out to him and ask his advice - I am not certain but think he is still on BC but, in any case, he is on FB and contactable through several of the Caterham groups there.Out of interest, do you have any performance figures or plots for your engine? It would be interesting to compare to a standard R500 Duratec.James Link to comment Share on other sites More sharing options...
r300chris Posted May 5, 2018 Author Share Posted May 5, 2018 Hi James, thats a shame re not having chance to chat to Mick about the car, but I’ll try and contact him as you suggest.unfortunately I don’t have any performance data on the carchris Link to comment Share on other sites More sharing options...
elie boone Posted May 6, 2018 Share Posted May 6, 2018 R300C, my can is made by a guy that normally only does silencers for motorbikes, he made it from scratch. It's something he does if noise could be problematic. it's made from the same perforated inner tube. Link to comment Share on other sites More sharing options...
r300chris Posted May 6, 2018 Author Share Posted May 6, 2018 Ellie, do you mean the whole can or the small additional piece you talked about in a previous post ? Link to comment Share on other sites More sharing options...
SKC Posted May 6, 2018 Share Posted May 6, 2018 Hi All,We rebuilt an R500D engine a couple of years ago that swallowed one of the air intake trumpet screws.The cylinder head was salvaged and we did do some work on this. The engine was fitted with the Caterham trackday airbox and a cone airfilter. I have no idea what the noise levels were with this but the car gave 259bhp and 175ftlbs of torque which I believe is good for an R500D, especially with one of these airboxes. I would expect the airbox to give a bit of a reduction in performance as it's drawing warm air in from above the bellhousing and gearbox. Also if feeds air from the cylinder four end of the box which means cylinder one my be starved a bit of air but if it gets you through a noise test then this is a solution.If any of you are concerned about reduced performance with fitting the airbox, back to back them on a good rolling road first, you might be surprised to fine what you haven't got to start with.RegardsSKC Link to comment Share on other sites More sharing options...
elie boone Posted May 7, 2018 Share Posted May 7, 2018 The small piece of domed perforated tube is about 2" long and inserted into the perforated inner tube in fact at the very end of the perforated tube Link to comment Share on other sites More sharing options...
r300chris Posted May 7, 2018 Author Share Posted May 7, 2018 Elie, I take it it’s fitted at the outlet end ? Link to comment Share on other sites More sharing options...
dave_h34 Posted May 8, 2018 Share Posted May 8, 2018 I repacked my Raceco with Acoustafil this winter and it appears to have made little difference, despite the clear loss of the previous wadding! 100dB at Rockingham (static). More importantly I have a brand new Caterham carbon trackday airbox with K&N cone filter in the cupboard doing nothing. Would be happy to sell it but really would like to recover a lump of the ill-fated outlay if possible! Link to comment Share on other sites More sharing options...
elie boone Posted May 8, 2018 Share Posted May 8, 2018 Yes it is. Link to comment Share on other sites More sharing options...
Area Representative gileshudson Posted May 8, 2018 Area Representative Share Posted May 8, 2018 For those interested in seeing and learning more about the extra bolt-on/bolt-off silencer talked about the very start of this thread, you can see more about it on McMillan Motorsport's news page on FB: https://www.facebook.com/permalink.php?story_fbid=1821222317945207&id=221277681273020 Apparently less than 5 mins to fit... on a cold exhaust... and takes you below Brands' GP circuit nose levels? Link to comment Share on other sites More sharing options...
Leadership Team Shortshift Posted May 8, 2018 Leadership Team Share Posted May 8, 2018 Replying to Dave at #36Isn't that the airbox that Chris was looking for at the very start of this thread? You may have a willing buyer...James Link to comment Share on other sites More sharing options...
Leadership Team Shortshift Posted May 8, 2018 Leadership Team Share Posted May 8, 2018 Interesting Giles, and I guess it does the job.But... fuggly or what??James Link to comment Share on other sites More sharing options...
r300chris Posted May 8, 2018 Author Share Posted May 8, 2018 I’m in process of ordering the extra exhaust, from McMillan motor sport and have sent a pm to Dave post 36chris Link to comment Share on other sites More sharing options...
Area Representative gileshudson Posted May 8, 2018 Area Representative Share Posted May 8, 2018 Yes, very fugly James :) Link to comment Share on other sites More sharing options...
dave_h34 Posted May 8, 2018 Share Posted May 8, 2018 That's sooooo ugly it appeals to me!!!! :-) Heading to PM now... Link to comment Share on other sites More sharing options...
tomwood Posted August 7, 2018 Share Posted August 7, 2018 I thought I would resurrect this thread as a previous poster. Since my last messages on this, I have managed to source (thanks James) a carbon Track day air filter and am also now in possession of a new 750mm Raceco silencer which came pre-packed with filling.Recap on car config = R400d, RBTB's, Raceco 750mm exhaust + Decat pipeI was at Silverstone yesterday which thankfully had barely any noise restrictions so it was a nice chance to try out the various configurations without fear of getting black flagged. Unfortunately they weren't bothering to do any static tests so was unable to get a reading for this.For those that know the circuit, the configuration is such that as you round the last corner coming onto the pit straight you are at full throttle and conveniently my passengerfor the day was able to stand right at the point at which I was hitting max revs in 3rd and looking to change into 4th. We took the opportunity to do some basic measurements using an app on his phone and whilst hardly scientific, it gives some basic evidence as to the effectiveness of the track day air box versus the open air filter it replaces.He was standing on the pit wall, probably about 20m distance from where I was passing him. Admittedly the wall itself probably means the sound is reflected off the wall somewhat so the reading may be slightly higher than would be detected by a typical noise meter. We also have to consider the accuracy of his iPhone App which I suspect may have been over-reading by a few DB but nonetheless, some info below.Here are the results and also my perceptions from within the car on what was an extremely hot day (30 degrees Celsius and bright sunshine): Track day airbox was a little quieter (about 1db) as measured on his phone. 103DB drive-by recorded with open filter, 102BD recorded with Track Day Air box The tone of the exhaust note is a little more aggressive with the open filter in place but marginally so. Whilst the tone is somewhat different and noticeable from within the car, noise levels do feel very similar which seems to back-up the data as taken on the phone In terms of performance I was unable to detect any discernable reduction in performance after I switched from the open filter to the track day one. Bearing in mind that it was about as hot as it's likely to get here in the UK I think that bodes well for the track day air box. My suspicion is that there is considerable air movement within the engine bay when you are traveling at speed which probably negates some of the concerns in terms of this configuration sucking in hotter air from inside the engine bay in comparison to ambient air temps but that's just a guess on my part. I would be very interested to see a dyno plot comparison of the 2. The performance hit could well be there and I was simply unable to notice out on trackTom Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 7, 2018 Member Share Posted August 7, 2018 Great write-up.'Phone apps can perform very well: what hardware and software were you using, please?Jonathan Link to comment Share on other sites More sharing options...
tomwood Posted August 7, 2018 Share Posted August 7, 2018 iPhone 7 with an app called ‘Soundcheck’ Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted August 7, 2018 Member Share Posted August 7, 2018 Thanks.This is what I found in 2016.Jonathan Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now