Car exhaust and SPL meter? Car Guys

Discussion in 'After Hours Lounge (Off Topic)' started by David Preston, Aug 24, 2003.

  1. David Preston

    David Preston Supporting Actor

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    I was wondering if it is possible to measure how loud your car exhaust is with your SPL meter? What setting would you set it on? Would it be 120? IF so how loud is your car at half redline and close to redline.
     
  2. Jay H

    Jay H Producer

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    Well, if your SPL doesn't melt and the needle is pegged, turn it to a higher range if your SPL has it. 120db sounds like a good place to start though and 120db is quite loud!

    Get a fix-it ticket from the cops? [​IMG]

    Jay
     
  3. Todd Hochard

    Todd Hochard Cinematographer

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    Sure, just turn it on and measure. Try from 3 meters or so directly behind the car.

    However, the exhaust will be substantially louder under load (i.e. full throttle moving the car forward) than with you just revving it in the driveway. So, it may be tough to get a true highest-level reading.

    Get a ticket?[​IMG] On your Z, if you're running anything much beyond stock and/or with no cat (shame shame[​IMG] ), it's going to be too loud to be technically legal. SLP Loudmouth, Flowmaster 40s, Borla's bypass- all too loud past part throttle.

    My car is technically too loud (dual 2.5" with Flowmaster 40 series), but I'm careful not to make noise where people don't want to hear it. I've never been bothered by the police (or any of my neighbors for that matter) in 12 years of owning it.

    Todd
     
  4. NicholasL

    NicholasL Second Unit

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    Not to mention removing the catalytic converter is illegal. i guess just don't gun it when a cop is next to you. Flowmasters are probably one of the loudest brands of exhausts there are...over Gibson (which I have) and Magnaflow (which I think sounds like an empty fart can). I just hate the little stupid fixed up wannabe race cars with louder than hell exhausts yet the driver punches all that motor, making heads turn, he's bobbing his head up and down to his stupid little stock audio system, and the car still ain't going nowhere. WEAK.
     
  5. Seth_L

    Seth_L Screenwriter

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    Get the car on a dyno and measure the volume from behind with a SPL meter.
     
  6. David Preston

    David Preston Supporting Actor

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    I'll try to measure tomorrow and see what it registers.
     
  7. NicholasL

    NicholasL Second Unit

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    Any results?
     
  8. David Preston

    David Preston Supporting Actor

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    I didn't have a second to spare yesterday. I was so busy and I was gonna do it before work but was rushing out the door cause I almost overslept. I'll get it done asap. Hopefully someone else will do their's also. Can't do it now everyone is sleeping. I live next to a cool Cop but I don't think he would like to be waken up this time of the morning by me reving my car to see how loud it is[​IMG] . He actually loves the ways my car sounds and it is loud.
     
  9. David Preston

    David Preston Supporting Actor

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    I went out to my car to see what it registers at idle. It's at 90-91 when I'm standing to the side of it and 100 when I set the SPL meter on the ground next to it. I'll do some louder test when I can. How loud is to loud?
     
  10. NicholasL

    NicholasL Second Unit

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    Well I hit about 155 dB at a car audio competition sound off recently with my sound system. Dual aluminum 15's with 1000 watts per. Is that too loud?
     
  11. David Preston

    David Preston Supporting Actor

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    My SPL meter only goes to 120 so it will probably max out when reving it up. Nicholas do you have a SPL meter? I know your Explorer had to be loud. You ever catch any air it when off roading? Those would be some awesome pics.
     
  12. Todd Hochard

    Todd Hochard Cinematographer

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    Distance from the pipe matters. I found this for Cali-
     
  13. David Preston

    David Preston Supporting Actor

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    Todd thanks for the info. I'm pretty respectful when I come in the neighborhood at sleeping hours. My nextdoor neighbor is a Cop so if it don't bother him and his children right next door then I think I'm good to go. I coast in from about a quarter mile away so I don't make to much noise. By the way what year Z do you own and how much HP does it have. I had mine dynoed a few years ago before I did many mods and it was a little over 300. I have done a few mods since then to boost it a little but nothing crazy like nitrous or SC. I'm trying to get 400hp I'm not to far away.
     
  14. NicholasL

    NicholasL Second Unit

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    I don't have an SPL meter but during competitions I usually borrow a friend's, or if they provide one, a SPL mic. And yes, I've caught air a few times (very scary), and when I realized my truck was strong enough to take the brunt of the landing, I started flying over speed bumps and big dips around town.

    I totally agree with the loud driving through quiet neighborhoods thing. Who the hell they trying to impress? What the hell they tryin to prove? 4 years ago, before college, I lived in Hawaii. There, alot of people don't have loud cars, but many, and I do mean MANY have loud ass mopeds. The kind that sound like mosquito buzzing through a loudspeaker. They would RIP through the silence at 1am every damn day. I hated them so much. Me and my brother did a stake out one night with our laser sight air guns with CO2 canisters. Pegged a few of them REAL GOOD. Oh yes, it was fun...
     
  15. Todd Hochard

    Todd Hochard Cinematographer

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    David,

    Mine's a 1980- old school disco style, baby![​IMG] I've had the car 12.5 years now, so I'm really attached to it. My wife will probably bury me in it.[​IMG]
    I'm probably putting around 300hp to the wheels, but I've not dynoed it ever. That's a best estimate, based on weight and trap speeds in the 1/4. I've done many things to the engine, but it's still a docile, stock-like motor when cruising. I put a 6-speed in years ago ('95). I'm getting funds together for a better motor (stroker, fuel injected). The process is slow, as I'm busy, and I do all my own work (except machining, of course).
    I love those LS1 motors- the best small block Chevy ever. I've considered fitting one of those into my car.

    Check my website- the details are there.

    Todd
     

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