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Post by wannabe on May 9, 2019 18:30:51 GMT
Regarding the AK system. I remember seeing a Nutz thread a while back about the system that mentioned dyno testing during the development. Are there any graphs or anything knocking around on the web that show this? I have looked but couldn't find any. I remember that claim also. I never did a back-to-back dyno check with mine as the previous exhaust had the tailpipe fall off so it was too late at that point to test power with it! IIRC the rear canoe dyno felt it made a difference, lol. Either way, I much prefer its 'voice' to the other options I've seen on the internetz videos - it has real character that changes across the rev range, rather than being one note that gets louder, and it also basically goes silent as soon as you back off, so you can pass that police car or grumpy-looking pedestrians/homeowners much more quietly
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Post by Zed. on May 9, 2019 23:14:06 GMT
I 'fixed' the cobalt on my car went from horrible loud to being able to hear the induction by 'fixed' I removed the stupid tailpipe & replaced it with plain pipe (hacksaw & tig to the rescue ) Rich. Any pics? Having trouble visualising this or understanding how it might make a difference. Cobalts do mellow out considerable with some use. After a couple of months the worst drone was gone. Then its ok for a year or two as the packing slowly burns away. Then its back to droning. just replaced the sily tailpipe with plain straight pipe removed the tailpipe is 59mm id from the backbox to75mm id inside the tailpipe and thats inside the outer 'shroud'. the size increase acts like a 'megaphone' and the outer can help amplify - something I do not think is needed I had some 2 1/2" id steel pipe so welded that in place - sorry no photo's as it's under the car (okey, I know its a schyte 'dissimilar' weld of Cobalt's Chineeseium stainless & mild steel with argoshield light 'shield' gas but it's just a tailpipe extension to get exhaust gasses outside the rear bumper ) Rich. (bodger)
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Post by JamesMk3 on May 11, 2019 12:05:57 GMT
You mentioned the quality of the Cobalt material. I've had a Cobalt back box on my Mk3 for a few years now. As it's aged it has become apparent that they seem to have used non stainless/mild steel filler on most of the welds. I think I'm going to be on the lookout for a replacement this year.
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Post by carl4x4 on Jun 5, 2019 20:59:43 GMT
Update: had the cat-back exhaust made, really nice craftsmanship. It started out sounding great, quiet when off the throttle but a nice bark when you accelerate. However after this had bedded in it started sounding quite loud all the time, certainly not what I was after, The guys at Infinity mentioned that my silenced cat bi-pass didn't appear to be doing much and wouldn't be doing much. So after a few hundred miles I have replaced the silenced cat bi-pass with a new Catalytic Converter. This has quietened the noise down noticeably, it's still a little louder than I wanted but I'm going to give it a few hundred miles to get used to.
One question if anyone can answer, does the size or shape of the tailpipe really make that much difference to the sound?
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Post by wannabe on Jun 29, 2019 22:15:14 GMT
One question if anyone can answer, does the size or shape of the tailpipe really make that much difference to the sound? I think it must do, because the shape of a piece of metal must affect the sound coming out of it, in the same way that the brass section in an orchestra sounds different depending on the instrument. I have no evidence for this, of course but I'm sure there is a geek on the internet who does! lol
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Post by V6 on Aug 9, 2019 17:43:38 GMT
A mate just sent me this. Inspiration... Tasteful. Worse than the Golf R mods
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Post by Zed. on Aug 9, 2019 17:50:29 GMT
A mate just sent me this. Inspiration... Tasteful. Worse than the Golf R mods note the 'pea-shooter' sized exhaust pipeing inside those dustbins also, if you look on the DVLA's mot history, it's had advisories for exhaust noise Chav-tastic. Rich.
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