<div dir="ltr">Here in the UK noise has become a bigger issue over the last decade + (that I've been a scrutineer (tech official)). A turned down pipe outlet or a turned outside track rather than inside track doesn't fool us. Nor does under declaring the rpm limit for testing, or rigging the tacho to under read rpm. Several tracks have sophisticated sound metering equipment that not only identified a noisy car but takes a photo of it (while racing on the track) with the decibel reading imposed on the photo. Some even automatically send that data to the local council/authority.<div><br></div><div>However, noisy cars don't necessarily make more power. Yes, there is a weight penalty on having an exhaust silencer fitted but any good quality silencer on a racing A-series engine won't rob power. If you're interested in exhaust add-on parts, like the Super trap product - read what David Vizard has to say about them. In recent years they have become increasingly scarce in UK motorsport, and that's not just because they often parted company with the exhaust system pipe.</div><div><br></div><div>UK Noise limits vary but 98 to 103, and occasionally 105 are typical.</div><div><br></div><div>Regards</div><div><br></div><div><br></div><div>Daniel</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jun 28, 2018 at 3:23 AM, <a href="mailto:crusaderchuck55@aol.com">crusaderchuck55@aol.com</a> via Spridgets <span dir="ltr"><<a href="mailto:spridgets@autox.team.net" target="_blank">spridgets@autox.team.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div style="font-size:10pt"><p dir="ltr" style="margin-top:0;margin-bottom:0">Considering I'm better known for racing my 1960 saab 93F , I'm very aware of decibels. Kinda explains why I have my own meter? LOL!</p><p dir="ltr" style="margin-top:0;margin-bottom:0">We encountered ( a number of years ago) a huge amount of prejudice towards the saab and rotary powered RX7's with the Pennsylvania hillclimb association. After a few events the individuals objecting to our alleged offensive noise .....backed off significantly! Why you ask?? It was determined the MAC's, MGB's and spridgets were producing high enough levels that they should have been protested , not our saab nor the mazdas. Rotarys & 2 strokes have piercing high pitches, but not near the SCCA maximum allowed Db limits. And I'm aware of troubling road and lime rock with restrictions. I did add a turn down to attempt to be kind to our starting line workers at hillclimbs but it had no bearing on our Db readings. Chuck</p><p dir="ltr" style="margin-top:0;margin-bottom:0"><br></p><div id="m_1424008077760866137SignatureBox" dir="ltr" style="margin-top:0;margin-bottom:0">Sent from my LG Mobile</div></div>
<div style="font-size:10pt"><div id="m_1424008077760866137LGEmailHeader" dir="ltr" style="margin-top:0;margin-bottom:0"><p dir="ltr" style="margin-top:0;margin-bottom:0"><br></p><p dir="ltr" style="margin-top:0;margin-bottom:0">------ Original message------</p><p dir="ltr" style="margin-top:0;margin-bottom:0"><b>From: </b>Bob Spruck<u></u><u></u></p><p dir="ltr" style="margin-top:0;margin-bottom:0"><b>Date: </b>Wed, Jun 27, 2018 9:21 PM</p><p dir="ltr" style="margin-top:0;margin-bottom:0"><b>To: </b><a href="mailto:spridgets@autox.team.net" target="_blank">spridgets@autox.team.net</a><a href="mailto:;crusaderchuck55@aol.com" target="_blank">;<wbr>crusaderchuck55@aol.com</a>;</p><p dir="ltr" style="margin-top:0;margin-bottom:0"><b>Subject:</b>Re: [Spridgets] 1275 with headers exhaust?</p><p dir="ltr" style="margin-top:0;margin-bottom:0"><br></p></div> <p dir="ltr"><font size="+1"><font face="Arial">FYI - One thing to consider is noise limits at the tracks you plan to race at. I race at Road Atlanta which has none but the limit at Roebling Road is 104 decibels for vintage cars. I am also a Tech Inspector for VDCA and warn new drivers of the consequences of too loud exhaust. They send you home! Most drivers have designed a swiveling, down-turned tailpipe extension that can be pointed away from the meter at the sound station. Some drivers have had to install a muffler (what heresy!). A friend in a Turner had to back off at a point about 1/3 down the front straight, where the sound meter was. Really impacted his racing and happiness (and safety). The neighborhood monitors impose LARGE fines to the track for those over the limit.</font></font></p> <p dir="ltr"><font size="+1"><font face="Arial">Just sayin'.</font></font></p> <p dir="ltr"><font size="+1"><font face="Arial">Bob Spruck</font></font><br> </p> <br> <div class="m_1424008077760866137moz-cite-prefix" dir="ltr">On 6/27/2018 6:00 PM, Rick Fisk via Spridgets wrote:<br> </div> <blockquote type="cite"> <div dir="ltr">This was on my car when I bought it a few months ago. No pipe at all under the car!</div> <div id="m_1424008077760866137AppleMailSignature" dir="ltr"><br> </div> <div id="m_1424008077760866137AppleMailSignature" dir="ltr"><img src="cid:15968@M724060636U30645047" alt="image1.JPG" id="m_142400807776086613754E4D6A4-0335-4AAA-9302-E7B7A5F472A0"><br> <br> Sent from my keyboard</div> <div dir="ltr"><br> On Jun 27, 2018, at 4:10 PM, <a href="mailto:crusaderchuck55@aol.com" target="_blank">crusaderchuck55@aol.com</a> via Spridgets <<a href="mailto:spridgets@autox.team.net" target="_blank">spridgets@autox.team.net</a>> wrote:<br> <br> </div> <blockquote type="cite"> <div dir="ltr"> <div style="font-size:10pt" dir="ltr"> <p dir="ltr" style="margin-top:0;margin-bottom:0">Here's a question! Ignore what size header collector..ok? Ignore the fact all available mufflers only come in a certain size!</p> <p dir="ltr" style="margin-top:0;margin-bottom:0">What diameter pipe would you run from front to back and why. I'm building an exhaust for Frank's race car project. I'm making an oval pipe for front to rear ( or possibly a side pipe! A custom made side exit header is coming my way and might end up on the car!). I've heard a lot of 1&3/4", 1&7/8" and 2" suggestions. Ok what's going to work for a tad of back pressure and outright breathing if I create a chambered pipe ( like corvette 1960's had) . I can fabricate any specific area in an oval as far as the end area equaling a round pipe.</p> <p dir="ltr" style="margin-top:0;margin-bottom:0">So, what are the collective thoughts?</p> <p dir="ltr" style="margin-top:0;margin-bottom:0">Share away!</p> <p dir="ltr" style="margin-top:0;margin-bottom:0">I'm not putting a round pipe under this car! Also I'm not going through the tunnel. Also for those of you who have had dyno time, the length is important to dial in max torque at a specific RPM range. </p> <p dir="ltr" style="margin-top:0;margin-bottom:0">So? What cha think?</p> <p dir="ltr" style="margin-top:0;margin-bottom:0">Chuck</p> <p dir="ltr" style="margin-top:0;margin-bottom:0">Flogging away on Frank's race car!!</p> <div id="m_1424008077760866137SignatureBox" dir="ltr" style="margin-top:0;margin-bottom:0">Sent from my LG Mobile</div> </div> </div> </blockquote> <blockquote type="cite"> <div dir="ltr"><span>------------------------</span><br> <span></span><br> <span><a href="mailto:spridgets@autox.team.net" target="_blank">spridgets@autox.team.net</a></span><br> <span></span><br> <span>Donate: <a href="http://www.team.net/donate.html" target="_blank">http://www.team.net/donate.<wbr>html</a></span><br> <span>Suggested annual donation: $12.75</span><br> <span></span><br> <span>Archive: <a href="http://www.team.net/pipermail/spridgets" target="_blank">http://www.team.net/pipermail/<wbr>spridgets</a></span><br> <span></span><br> <span>Unsubscribe/Manage: <u></u>http<a href="mailto:://autox.team.net/mailman/options/spridgets/refisk@chartermi.net" target="_blank">://autox.team.net/mailman/<wbr>options/spridgets/refisk@<wbr>chartermi.net</a><u></u></span><br> </div> </blockquote> <br> <fieldset class="m_1424008077760866137mimeAttachmentHeader"></fieldset> <br> <pre>------------------------<a class="m_1424008077760866137moz-txt-link-abbreviated" href="mailto:spridgets@autox.team.net" target="_blank">spridg<wbr>ets@autox.team.net</a>Donate: <a class="m_1424008077760866137moz-txt-link-freetext" href="http://www.team.net/donate.html" target="_blank">http://www.team.net/donate.<wbr>html</a>Suggested annual donation: $12.75Archive: <a class="m_1424008077760866137moz-txt-link-freetext" href="http://www.team.net/pipermail/spridgets" target="_blank">http://www.team.net/pipermail/<wbr>spridgets</a>Unsubscribe/Manage: <a class="m_1424008077760866137moz-txt-link-freetext" href="http://autox.team.net/mailman/options/spridgets/raspruck@gmail.com" target="_blank">http://autox.team.net/mailman/<wbr>options/spridgets/raspruck@<wbr>gmail.com</a></pre> </blockquote> <br> </div></div><br>------------------------<br>
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