Ade 517 Report post Posted August 8, 2016 Some of you may be aware that I am getting tired of my Cat Back exhaust. I think it sounds fantastic and one of the best sounding on the market, but the old man inside me finds it a tad loud. Current Exhaust is the Cosworth 3" cat back. It measures 92dB using the 1meter/45degree test, so not exactly loud but I find it undesirable on longer journeys. This is not the crazy loud full Cosworth exhaust some of you would have heard at the open day - this is just the cat back. My aim is very little noticeable noise on the motorway. I dont mind a little rumble, but with the current setup small amounts of throttle and it gets loud/boomy at 3k rpms so its okay when cruising on the flat but any hint of throttle to overtake or go uphill and it gets boomy. Its a subjective thing, and many don't consider this to be "loud" but I do and have decided it is time to swap it out for old man mode exhaust. Current list of alternatives are: Invidia Q300 - very quiet and popular with people that swap the manifold out. You tube videos vary. Some it sounds quite loud and other it sounds almost stock. Miltek resonated - You tube videos make this sound louder than the Q300 with a more bassy tone. Bliz Nur Sec C-TI - very quiet but small bore and chamber type back box makes it as restrictive as the stock back box. Ear plugs - Cheap and effective but then I wouldn't be able to hear passenger talking to me. Custom - could ask H&S to make me a massive straight through back box and fit a large silencer in the mid pipe. Might be expensive but also might be able to retain the "3 piping. Does anyone else have any real world experience and possible alternatives? Budget up to £1k Share this post Link to post Share on other sites
long-gone 152 Report post Posted August 8, 2016 Have you considered the 2.1/2" AVO TurboWorld cat-back? 1 Ade reacted to this Share this post Link to post Share on other sites
Paul 442 Report post Posted August 8, 2016 The Q300 is quiet. No 2 ways about it. Even with a catless manifold and just an HFC in the middle it's burbly and pops and bangs but it's never obnoxious. If you want something with literally zero drone, no cruising noise whatsoever and just a nice tone, then it's probably good (for an old man anyway). 1 Ade reacted to this Share this post Link to post Share on other sites
Steeps 294 Report post Posted August 8, 2016 You're 4dB louder due to having the supercharger, I recommend ditching that and selling it on cheap to another 1.1 owner I'm looking into possibly adding some soundproofing around the back seats/boot as the car is great when the boot is full, but with an empty load it does feel loud. Off throttle on a cool down lap on track has a really bad drone! 1 Ade reacted to this Share this post Link to post Share on other sites
smudge 1020 Report post Posted August 8, 2016 I had the Q300 with a catless UEL manifold and just a HFC and it was far too quiet for my liking - probably perfect for you! 1 Ade reacted to this Share this post Link to post Share on other sites
Ade 517 Report post Posted August 8, 2016 I had the Q300 with a catless UEL manifold and just a HFC and it was far too quiet for my liking - probably perfect for you! Have you ever heard a Cosworth cat back to compare? When I first installed the cossy supercharger before the cat back I thought the stock exhaust was not too quiet! Just needed a bit more rumble on full chat I'd say. Sent from my SM-G935F using Tapatalk Share this post Link to post Share on other sites
Ade 517 Report post Posted August 8, 2016 Have you considered the 2.1/2" AVO TurboWorld cat-back? I was under the impression the avo exhausts were quite loud? Sent from my SM-G935F using Tapatalk Share this post Link to post Share on other sites
Ade 517 Report post Posted August 8, 2016 The Q300 is quiet. No 2 ways about it. Even with a catless manifold and just an HFC in the middle it's burbly and pops and bangs but it's never obnoxious. If you want something with literally zero drone, no cruising noise whatsoever and just a nice tone, then it's probably good (for an old man anyway). Sounds spot on. I want some nice noise when going through the gears and then a nice background rumble when using partial throttle on the motorway. Sent from my SM-G935F using Tapatalk Share this post Link to post Share on other sites
Ade 517 Report post Posted August 8, 2016 You're 4dB louder due to having the supercharger, I recommend ditching that and selling it on cheap to another 1.1 owner I'm looking into possibly adding some soundproofing around the back seats/boot as the car is great when the boot is full, but with an empty load it does feel loud. Off throttle on a cool down lap on track has a really bad drone! I tried filling the boot. I hardly noticed any difference, mainly track day tools though so foam might be better. Sent from my SM-G935F using Tapatalk Share this post Link to post Share on other sites
Ade 517 Report post Posted August 8, 2016 Is the hks legamax an option? Sent from my SM-G935F using Tapatalk Share this post Link to post Share on other sites
Paul 442 Report post Posted August 8, 2016 8 minutes ago, Ade said: Sounds spot on. I want some nice noise when going through the gears and then a nice background rumble when using partial throttle on the motorway. Sent from my SM-G935F using Tapatalk Sounds like it's right for you then. Share this post Link to post Share on other sites
Steeps 294 Report post Posted August 8, 2016 A kingsize duvet packed against the parcel shelf/back seat held in with a suitcase makes a huge difference to the amount of noise transmitted. Very comfortable. 1 Ade reacted to this Share this post Link to post Share on other sites
Rich196 103 Report post Posted August 8, 2016 Can you not just get another silencer put in the mid pipe? Share this post Link to post Share on other sites
Ade 517 Report post Posted August 8, 2016 Can you not just get another silencer put in the mid pipe? I don't think there is space. Sent from my SM-G935F using Tapatalk Share this post Link to post Share on other sites
Rich 378 Report post Posted August 8, 2016 I had a similar problem and swapped the resonated midpipe into my Milltek catback. Really cuts the drone down a lot, but it's still a fair bit louder than stock, and much bassier. Had I realised you were looking to swap you could have come for a ride at Blyton to hear it. Share this post Link to post Share on other sites
will300 812 Report post Posted August 8, 2016 Are you concerned about staying 3" @Ade? Bare in mind the Q300 & Blitz are only 2.36" (60mm) systems. Share this post Link to post Share on other sites
Ade 517 Report post Posted August 9, 2016 10 hours ago, will300 said: Are you concerned about staying 3" @Ade? Bare in mind the Q300 & Blitz are only 2.36" (60mm) systems. The Q300 is 2.5" (63mm) outside diameter like most other exhausts I think. For some reason Invidia liek to quote the internal diameter which is 2.36" - the Q300 knockoffs however are 2.36" O.D and 2.25" I.D. I've been listening to soundclips. It appears that the Q300 get raspy when paired with a UEL manifold But the Miltek Resonated seems a bit better? or is it just the microphone being used playing tricks. The Q300 certainly has the biggest back box of the lot, so if it is packed well with good quality materials, it should work well to suppress noise. Share this post Link to post Share on other sites
S18 RSG 429 Report post Posted August 9, 2016 I think your best bet is to go custom unless you find EXACTLY what you want in the aftermarket. The place I had my exhaust made charged me £450 for a 2.5inch catback, designed to my exact requirements of sound and volume. I would guess a 3inch might run you a little more than that. In terms of volume, I know hundreds of people who've had exhausts made by Charlie, and lots who have asked for quiet exhausts. A lot of the time they're barely louder than stock. The only downside I suppose, would be that he's based in Cardiff, which is quite a trek. Couldn't recommend him enough though. There are examples of the sound differences on his website, as well as lots of testomonials around the web, and a gallery showing his work (a few of my past cars are in the gallery). His website: http://www.pro-speedexhausts.com/ Share this post Link to post Share on other sites
Ade 517 Report post Posted August 9, 2016 @Rich @Lauren and anyone else. Do you know the diameter of the pipes coming out of the back box on the Milltek system? Share this post Link to post Share on other sites
Rich 378 Report post Posted August 9, 2016 The pipes running to the tips? I believe they are 2.5" - I had to replace one of the clamps on mine and a 63-68 mm just fits. Share this post Link to post Share on other sites
Ade 517 Report post Posted August 9, 2016 22 minutes ago, Rich said: The pipes running to the tips? I believe they are 2.5" - I had to replace one of the clamps on mine and a 63-68 mm just fits. Spot on thanks. New thinking (out loud) is to get a massive OEM sized box welded in place of the current twin canisters. Lager volume box should reduce the noise significantly while keeping the 3" diameter. Share this post Link to post Share on other sites
KevinA 695 Report post Posted August 9, 2016 5 hours ago, Ade said: @Rich @Lauren and anyone else. Do you know the diameter of the pipes coming out of the back box on the Milltek system? I have a new Miltek at home, can measure it later for you. 1 Ade reacted to this Share this post Link to post Share on other sites
smudge 1020 Report post Posted August 9, 2016 I never had any rasp with my UEL and Q300 setup @Ade Few of videos of mine: 2 willclarke and Ade reacted to this Share this post Link to post Share on other sites
Ade 517 Report post Posted August 10, 2016 @smudge how much power were you making with the sprintex and that ^^ exhaust setup? Share this post Link to post Share on other sites
TTR 509 Report post Posted August 10, 2016 @CGR Automotive sorted me out with mine, went the custom route like S18 did. I did briefly discuss with them about 3" when I had mine made, but I went for 2.5" in the end. They're based up in Doncaster, not sure if that's too far from you. Share this post Link to post Share on other sites
