Gav
|
| posted on 23/3/09 at 10:45 PM |
|
|
Lowering the noise...
At SVA i got 103.2 DB, quite loud then 
With a CAT and big exhuast fitted i reckon it must be the induction noise thats the majority of it.
Right now i have just some pipercross filters fitted, i do have the original airbox but it wont fit under the bonnet, i dont really want to hack a
hole in the bonnet to fit the airbox and i dont really wont to butcher the airbox to fit under.
Any ideas?
|
|
|
|
|
omega0684
|
| posted on 23/3/09 at 10:54 PM |
|
|
can you make an air box that will fit under the bonnet and then duct an intake into the nose?
|
|
|
twybrow
|
| posted on 23/3/09 at 11:21 PM |
|
|
I tested mine this evening with a meter borrowed from work (uncalibrated, but the guy I borrowed it off said it never wanders my more than 1 db or 2
from calibration).
I was getting ~102.5db. Tonight I have stuck camping mattress to the underside of the bonnet, and tomorrow, I will be sticking self adhesive foam
behind any bit of panel that looks like it might vibrate. My only other thought was some sort of restrictor/defelctor welded into the tail pipe... Any
other bright ideas how I can drop a db or 2!?
My last resort would be to tweak my gauges, but I'd rather get an honest pass!
|
|
|
iiyama
|
| posted on 24/3/09 at 07:13 AM |
|
|
Got 103.5 at SVA last Tuesday. Have stuck some car HiFi sound deadning material to the floor under the seats, on both sides of the engine bay and in
the boot area. Have also bought one of these:-
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=250391607443
And will have a play around to see what, if anything, has changed!
If its broke, fix it. If it aint broke, take it apart and find out how it works!
|
|
|
smart51
|
| posted on 24/3/09 at 07:21 AM |
|
|
Induction noise is generally only a problem when the throttle is open. At a fast idle, it is barely open.
Do you have a noise meter? Can you borrow one? A cheap maplin one will do. Measure the noise on the exhaust side of the car then the non exhaust
side. That will give you an idea of whether the exhaust noise is louder than the "ambient noise" from the engine. Measure the noise
from the inlet ports then from the other side of the engine at the same distance. That will tell you whether the induction roar is a problem or not.
|
|
|
Richard Quinn
|
| posted on 24/3/09 at 07:39 AM |
|
|
quote:
Originally posted by iiyama
Got 103.5 at SVA last Tuesday. Have stuck some car HiFi sound deadning material to the floor under the seats, on both sides of the engine bay and in
the boot area. Have also bought one of these:-
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=250391607443
And will have a play around to see what, if anything, has changed!
Do these have to go in the tail pipe or can they go in the system before
the can? Just trying to work out whether I could fit one if necessary.
|
|
|
nitram38
|
| posted on 24/3/09 at 08:12 AM |
|
|
The problem with those punched baffles is if you are taking them to sva. The emmissions probe cannot fit inside some.
I bought this and it knocked mine down from 102db to 100db and
according to my AFR, it stayed the same.
|
|
|
iiyama
|
| posted on 24/3/09 at 08:50 AM |
|
|
Ill let you know later as it should be here today......
If its broke, fix it. If it aint broke, take it apart and find out how it works!
|
|
|
easisatman
|
| posted on 24/3/09 at 09:21 AM |
|
|
I had a lot of db's with my r1 Striker, also a lot of popping back on affterrun . it has a 6 inch re packable silencer with springs only to hold
it on!! so I used some High temp silicone around the joint with manifold-worked a treat, Much quieter- untill I did a few miles and the silicone
failed (only rated to 300 degs) so went and bought some exhaust paste - withstands much higher temp!, again ok for 5 mins till it all broke off!!
and fell out. So just looking to get a stainless clamp to hold it together with the paste,
|
|
|
twybrow
|
| posted on 24/3/09 at 09:35 AM |
|
|
What sort of diameter is the emissions probe? How far in does it have to go?
I was thinking of welding a large washer on the inside of my tailpipe - do you think this would make much difference?
|
|
|
iiyama
|
| posted on 24/3/09 at 12:39 PM |
|
|
Its about 4-5mm in dia and they shove it in about 3-400 mm.
If its broke, fix it. If it aint broke, take it apart and find out how it works!
|
|
|
twybrow
|
| posted on 24/3/09 at 01:23 PM |
|
|
Fantastic, I might try an experiment tonight then with a large washer(s) welded into the outlet. It will screw the power delivery, but I'm not
driving it very far....!
|
|
|
nitram38
|
| posted on 24/3/09 at 06:53 PM |
|
|
quote:
Originally posted by twybrow
Fantastic, I might try an experiment tonight then with a large washer(s) welded into the outlet. It will screw the power delivery, but I'm not
driving it very far....!
It might also change your emissions so recheck again afterwards
|
|
|
