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Thread: Managing exhaust noise limits - teased from Japfest thread

  1. #161
    S13 + 2bar = 475@wheels bren's Avatar
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    Anyone got a fix for noisy external wastegates other than plumbing it back into the original system?

  2. #162
    Guest nene's Avatar
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    Quote Originally Posted by bren
    Anyone got a fix for noisy external wastegates other than plumbing it back into the original system?
    This may sound like a silly suggestion, but can you not just attach a silencer to it?

  3. #163
    Guest SM's Avatar
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    Thats what I tried to get SX Sam to do the other month - but he plumbed it back in.
    Bren told me he was going to silence his screamer - surely its just an extra exhaust, make it side exit, and as its longer you'll probably have to step up the bore to stop creep (I guess, anybody know? )

  4. #164
    S13 + 2bar = 475@wheels bren's Avatar
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    Quote Originally Posted by nene
    This may sound like a silly suggestion, but can you not just attach a silencer to it?
    Yeah but I wondered if anyone had any experience of it I was going to have to do the research from scratch

  5. #165
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    Id imagine a bit difficult as there wont be the room for it under the car.

  6. #166
    Flamethrower Pablo13's Avatar
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    Quote Originally Posted by ian_t
    Has anybody got any experience of the apexi active tail silencer, they sound too good to be true.

    http://www.apexi-usa.com/product_exh...=217&pageNum=1

    No news on these yet? Anyone got db readings for a ca with this on?
    bstmeetbllk

  7. #167
    Bishop
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    Straightliners will noise test your Cars at Elvington on the 11th of March the noise test is free just pay to get in to the RWUB event £10 if you want to enter the event it is open to cars and bikes just bring a crash helmet and your driving licence Regards Bishop (Straightliners)

  8. #168
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    I find it all well silly personaly, I have a nur spec R and front pipe from apex with some sort of silencer where the cat is, before i went to fit this lot I tought I'd phone my local police department up in Milton Keynes and ask them if they could tell me what my legal limmit is for the ROADS ? After 20 mins of talking to people in the DVLA and with the police, they basicly said, they most certianly dont no of any law, and they deffiantly dont have any equipment for mesureing exhaust loudness, so as far as they no they are currently not enforeceing it. So this crap about noise limmits on the track is just corporate laws placed on them to make life harder for the guy who owns the track, its aload of bullshit I say, and we should just race on the roads, they soon change the limmits then hehe.

  9. #169
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    I have an Apex 3" system from the elbow-back (I have the bung from Apex too). Does anyone know the sort of dB level these produce? Quite worried now I have a track pass for combe at the end of april....

  10. #170
    Guest TrickyK's Avatar
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    Apex 3" full system is 105dB on mine at 4500rpm. 98dB with decat silencer. I havent tried it with a bung though.

  11. #171
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    Interesting reading about the RB25 skyline / resonance issue mentioned on this thread..

    Anyone have any more experiances with the apexi tail silencer?

  12. #172
    Guest Mista Weava's Avatar
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    This is my solution.

    it is a little restricitive - more-so depending on the requirement to use exhaust packing.

    i recorded a 5 decibel loss to get down to 92db static from 97db WITHOUT PACKING.













    the red "X"shows the "X" that i had fitted later on, so i could put exhaust packing behind it to lower the noise as necessary. basically it was two bars welded in this shape to stop the packing blowing out.

    i have not tested the bung with packing yet on a noise meter, but i made provision for its use, in case i got stung at a track; the theory being, that whilst it may be restrictive i would still be getting track time. i can confirm that it lowers the noise level DRAMATICALLY with packing in.





    the bung is stainless and copied from that of a mates inpreza. the bung had to be bespoke as i have a small diameter tail pipe (i hate channel tunnel tail pipes). i got a mate at the local fabricators to knock it out in lunchtime.

    the great thing is being able to remove it in seconds, and also the ability to add and remove packing to tailor the noise level to suit the track.

    crude? maybe.

    cheap? definitely!

    effective?


  13. #173
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    Ive got an Apexi active tail silencer for sale. Reduces noise but not power due to being active.

  14. #174
    Banned Vova's Avatar
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    Don't know how ontopic this is but on the Nürburgring there is also a limit but they never measure it, my open exaust is REALLY loud and they never said anything but I'm not the only one, the M3 CSL's, Caterhams, 911's all roar their ass off and just get to go on.

    So don't bother silencing it if you are going to the Ring

  15. #175
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    Right i've just read thru this whole topic and haven't actually got a FINAL SOLUTION. Can someone tell me what is the best exhaust system that i can buy/create with maximum performance and minimum noise. The tracks I will be goin on allow 95db. Can someone tell me the answer to maintaining 300-350hp and the 95db limit.

  16. #176
    Guest SM's Avatar
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    95 static, or 95 drive by?

    S13 or S14?

    Basically you want big 3" straight through silencers, these usually have to be welded into most aftermarket exhausts, you can buy a silencer installed in a decat pipe for ease of install.

  17. #177
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    S15 actually erm wot is normally louder? static or driveby? So if i went for a 3inch turbo back with Nur Spec and a Jetex 3inch Silencer in the decat region...i'd be good for 95db?

  18. #178
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    I'm running pretty standard S14, Apex'i Induction, Standard Downpipe, CAT, Custom 2 1/2inch centre, HKS Super Dragger Backbox. I hardly notice I've got massive 4.5inch tailpipe. Ticks over with lovely grumble, when I'm driving its not killing my ears. I'm really impressed. Will a Decat make it louder if I don't get the silenced one?

    Cheers guys

  19. #179
    S13 + 2bar = 475@wheels bren's Avatar
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    We are currently testing a prototype Apex S14 track exhaust. The car running it was at Cadwell Park last week and recorded 87Db at 4500rpm. Apparently. Although Im more inclined to think their testing meter was broken!

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