Homer Posted May 9, 2010 Share Posted May 9, 2010 (edited) [table=head;sort=7]Exhaust model|2nd cat/decat|1st cat/decat|engine spec|Member name|dB reading idle|dB reading 4rpm Boostlogic 4in (+2nd silencer)|4in decat|4in DP|BW 88/75 single|Steve|95.0|115.3 Motoria 3in|decat|decat|TT|brettjones|93.5|104.0 Nur Spec R|decat|decat|TT|supra_steve|85.0|102.0 RSR - Envy copy|decat|decat|TT|danhicks22|86.9|101.5 TBC - 5zigen?|decat|decat|TT|Pete_TT|97.2|108.5 Whifbitz twin box 3.5in|decat|decat|TT|jaymdee|81.2|102.0 Nur Spec RX|decat|cat|TT|Branners|69.1|85.2 HKS Ti 4in|3in decat|3in DP|T61 Single|Supramatt|88.7|105.6 Whifbitz twin box 4in|4in decat|4in DP|T74 single|JamieP|96.2|106.5 Stock|cat|decat|TT|GJD|62.6|81.4 Whifbitz single box 2.5in|cat|cat|NA|Fitz|76.4|88.0 Whifbitz single box 2.5in|cat|cat|NA|scottc998|78.8|92.5 Whifbitz single box 3.5in|3in decat|3in DP|T60-1 Single|Heckler|99.0|109.0 Boostlogic 4in|3in decat|3in DP|T67 single|Homer|96.3|121.6 Whifbitz Twin box 3in|3in decat|3in DP|BW 88/75 single|Gaz6002|84.2|90.8 [/table] All readings taken at 50cm from the exhaust at 45 degrees right of the exit angle Edited May 15, 2010 by Steve (see edit history) Quote Link to comment Share on other sites More sharing options...
Steve Posted May 9, 2010 Share Posted May 9, 2010 What do I win? Quote Link to comment Share on other sites More sharing options...
JamieP Posted May 9, 2010 Share Posted May 9, 2010 (edited) Lol, that was a waste of money buying the whifbitz 4" twin box, its louder than my old HKS ti thats now on supramatts car:) Also the whifbitz twin box 3" is louder than the single box? maybe i should cut a box of of mine to quieten it down a bit? Edited May 9, 2010 by JamieP (see edit history) Quote Link to comment Share on other sites More sharing options...
jevansio Posted May 9, 2010 Share Posted May 9, 2010 What do I win? Lol I was looking at that end of the chart being the winner too Do you think the Whifbitz 4" would be quieter than the HKS Ti on a like for like comparison? Quote Link to comment Share on other sites More sharing options...
Homer Posted May 9, 2010 Author Share Posted May 9, 2010 Lol, that was a waste of money buying the whifbitz 4" twin box, its louder than my old HKS ti thats now on supramatts car:) Also the whifbitz twin box 3" is louder than the single box? maybe i should cut a box of of mine to quieten it down a bit? Yeah, it was a bit odd, I did 4 readings on your car (that's why it took a while) as I was expecting it to be quieter. Got to admit after standing behind a lot of cars today your one did sound one of the noisier ones. However, it's my understanding that new exhaust takes some time to build up some soot (or whatever it is) on the surfaces which helps quiet things down. The two identical NA's with the single box system show this, one system has been on a while, the other was fairly new and was noticably louder. The two single box systems were NA's and had cats in, so probably not that comparible to the TT or single with no cats. Will bring the meter to Japfest to get some more results Quote Link to comment Share on other sites More sharing options...
supra matt Posted May 9, 2010 Share Posted May 9, 2010 Lol, that was a waste of money buying the whifbitz 4" twin box, its louder than my old HKS ti thats now on supramatts car:) Also the whifbitz twin box 3" is louder than the single box? maybe i should cut a box of of mine to quieten it down a bit? Ya that seems a bit loud on idle for a twin box mate though you wonted to do more track days to ! Also thanks To Homer for sorting this nice to see the difference in the exhaust db and non seem to be track friendly lol . Quote Link to comment Share on other sites More sharing options...
jevansio Posted May 9, 2010 Share Posted May 9, 2010 Jamies also has 4" dp/mp & a larger turbine housing which will increase the noise, how much I don't know Quote Link to comment Share on other sites More sharing options...
Homer Posted May 9, 2010 Author Share Posted May 9, 2010 What do I win? "Neighbour from Hell" status Quote Link to comment Share on other sites More sharing options...
johnny g Posted May 9, 2010 Share Posted May 9, 2010 How did you measure it, and what with? I'll see if I can get the Tanabe Medallion measured to add in Quote Link to comment Share on other sites More sharing options...
Homer Posted May 9, 2010 Author Share Posted May 9, 2010 How did you measure it, and what with? I'll see if I can get the Tanabe Medallion measured to add in 50cm from the exhaust at 45 degrees right of the exit angle (will add that to the first post) Quote Link to comment Share on other sites More sharing options...
heckler Posted May 9, 2010 Share Posted May 9, 2010 can you add mine... whifbitz 3.5" single box, 3" double decat, T60-1 on cast manifold, 99dB on idle, 109 Idle 4k (approx) Quote Link to comment Share on other sites More sharing options...
Homer Posted May 9, 2010 Author Share Posted May 9, 2010 can you add mine... whifbitz 3.5" single box, 3" double decat, T60-1 on cast manifold, 99dB on idle, 109 Idle 4k (approx) Thanks Si, will add it now Quote Link to comment Share on other sites More sharing options...
imi Posted May 9, 2010 Share Posted May 9, 2010 Great Thread Darryl; shame not to see a single "single" supra quieter than 100db at 4K Lets see whether Paul from Whifbitz can comment and see whether there is something that can be done. Quote Link to comment Share on other sites More sharing options...
Jazzy Posted May 9, 2010 Share Posted May 9, 2010 Seems to show that once both cats are out you've no chance on getting on most UK tracks. Quote Link to comment Share on other sites More sharing options...
Kirk Posted May 9, 2010 Share Posted May 9, 2010 even with a 2nd silencer box added to the boost logic its still the loudest Quote Link to comment Share on other sites More sharing options...
Homer Posted May 9, 2010 Author Share Posted May 9, 2010 Seems to show that once both cats are out you've no chance on getting on most UK tracks. With the measure 105db would meet *most* track day requirements even with a 2nd silencer box added to the boost logic its still the loudest Just added my old ones with the BL original, Wez's (really) old exhaust was pretty much the same level too, but never found out the spec. (Wez?) Quote Link to comment Share on other sites More sharing options...
Wez Posted May 9, 2010 Share Posted May 9, 2010 Nice work Daryl, as you already know I forgot the bleeding sun visors, I will get them over to you this week Quote Link to comment Share on other sites More sharing options...
Jazzy Posted May 9, 2010 Share Posted May 9, 2010 I thought most tracks ran between 98 and 100db, with only some 'special' days allowing the higher 105db level? Quote Link to comment Share on other sites More sharing options...
Abz Posted May 9, 2010 Share Posted May 9, 2010 Damn, forgot to get mine tested! Really wanted to know what exhaust it was as well. My apologises for talking through one of your tests Quote Link to comment Share on other sites More sharing options...
GJD Posted May 10, 2010 Share Posted May 10, 2010 What do I win? I thought I won Thanks for putting this list together Homer. Quote Link to comment Share on other sites More sharing options...
GJD Posted May 10, 2010 Share Posted May 10, 2010 My apologises for talking through one of your tests Nearly cost me my place at the top of the list Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted May 10, 2010 Share Posted May 10, 2010 Interesting stuff. Sound testing is quite a difficult one. You've got a few variations to consider like quality of the sound tester, what revs you do the test at, if its windy, how far away and which angle from the exhaust, etc. We normally test them between 4500-5000rpm approx, and they should get quieter the higher the revs. Try testing one of them again at 5000rpm instead of 4000rpm and see what happens. Steve L's 3" twin box system on his single turbo 3" dp/mp was tested at Oulton Park with a calibrated sound tester, 4500rpm and registered 100db in the garage which normally makes them louder. And the same exhaust on jaymdee car is 2db louder with I presume 2.5" decat pipes and stock turbo which will make it quieter. The difference between 3" and 4" will be quite a lot, I reckon 5db difference and I'm pretty sure I guessed it would be about 106db Jamie? Only way to quieten it down further would be either another silencer in the midpipe or bigger silencers on the back. My own car used to run a 4" with 3 silencers and that was down to 93db, I now run 3.5" with 2 smaller silencers and its now 94db. Hope that helps a bit. Quote Link to comment Share on other sites More sharing options...
imi Posted May 10, 2010 Share Posted May 10, 2010 Interesting stuff, something to bear in mind for the next test. Quote Link to comment Share on other sites More sharing options...
dandan Posted May 12, 2010 Share Posted May 12, 2010 I'll double check mine again at the weekend but if I remember rightly, at idle it is around 62-66dB; that's with a 4" DP and MP. I'll get a 4000rpm and 5000rpm number as well. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted May 12, 2010 Share Posted May 12, 2010 I'd like you to test mine at the weekend Darryl I've got my own noise tester, but it's always better to have others to compare the results with. I could bring mine too if it helps but that might be overkill lol Quote Link to comment Share on other sites More sharing options...
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