db of 13b bridgeport motor.

[K1HKS arse]

Can anyone that has either a full or half bridgeported 13b mota running a single turbo measure their exhaust db reading please.(preferably full bridge)

It needs to be below 103db to pass most noise levels for the track,some tracks are 98db!!!!!!!!!
I know it will depend on exhaust make/diameter and silencers so can you also post your exhaust makes and models.

Also what turbo you are running,what sort of lag you get and power levels @ what boost and rpm.


Thanks

[sadgoth]

Does this mean you are planning on staying rotary then Gary?

[K1HKS arse]

This is for a track car mate, not the drag car.

All will be revealed soon!!!!!!!!!!!!;)

[BlitzBoy]

i shall do it for ya this evening but im pretty sure Im well over that DB reading

[K1HKS arse]

Thanks Blitzboy

At 4000rpm and 6000rpm if you can please.

[BlitzBoy]

ahhh just tested mine 98 db static at 1500 rpm idle
110db at 4000 rpm static didnt go to 6K coz of neighbours  (but guessing much more at 6K lol)

3inch down pipe, 3 inch mid pipe no silencer, HKS Hiper 3 inch Back box with 4 inch outlet

[mattmaclennan]

Gregs was 135db at 4000rpm if I remember correctly. There\'s a lot of work to do to loose a  lot of noise. A phenomenal silencer the length of the car might do it??? But hey, if it\'s got to be a bridge, and it\'s got to compete there\'s got to be a way... that\'s racing! Good luck with it Gary, be really interesting to hear how you get on... no pun intended

[20B_boy]

Gregs was 135db at 4000rpm if I remember correctly.

:eek Surely not? I\'m struggling to think how any RX7 could be that high on the db front, db\'s are very unlinear! Loud I can imagine, but thats Concorde taking off loud!

[BlitzBoy]

Yeah Matt what sound meter did you use? I used my mates Pro digital version as used to tune lound sound sytems, and talking to him he said the same as Rich that DBs are very unlinear, and 135 is Jet on afterburner loud :eek

[sadgoth]

I would suggest that Carl\'s 4 rotor at RS II must have been pushing 130dB plus!

Check ou the table 1/3 of the way down the page in this link, gives you an idea of the SPL (sound pressure levels) of various sounds.

http://en.wikipedia.org/wiki/Decibel

dBs are calculated on a logarithmic scale, so as the numbers become greater the difference in SPL between each number increases.

[CraigN]

Ive heard gregs car fcuk me is it loud

has a screamer pipe also sounds like armageddon going past you :D

[royston1xx]

Gregs was 135db at 4000rpm if I remember correctly. There\'s a lot of work to do to loose a  lot of noise. A phenomenal silencer the length of the car might do it??? But hey, if it\'s got to be a bridge, and it\'s got to compete there\'s got to be a way... that\'s racing! Good luck with it Gary, be really interesting to hear how you get on... no pun intended

Close Matt, it was 127db at 4000rpm static at 45 degree angle and 1/2 meter away tested by my works lab grade db meter. It was 106db at idle (1800rpm) May be a little quieter soon though;)