thejean must be a math major... or really hardcore on stats Thanks for the info! But I still wonder if it's a good idea to remove now... anyone know how much louder it is? Like unbearably loud?

 

Hey i have a Dual Vent Blow Off Valve, i was wondering if taking out my silencer would make it a little louder since half of it is venting back into the intake system..

 

haha. Nope, not a math major. I'm an engineer who designs water and wastewater treatment plants. But, as part of my masters I did have to do an graduate level applied regression analysis course. Not fun. Not fun at all.

Anyway, glad to hear this data will be of some help. FWIW, I have the hacked silencer with the hole left venting to the fenderwell. That way, if the air is colder in the fender, I can access it. This would also help to reduce pressure loss in the intake tract since the suction piping is effectively shorter. Plus, I likely still get some of the slight "ram air" effect that stock scoop gives by allowing the whole fenderwell to be "pressurized" by the scoop.

An added advantage, if by chance any rain did get in the intake (we get a lot of rain up here in Nova Scotia), then the hole where the stock scoop is could vent that water downwards. My thoughts is that in the stock setup, the incoming air goes down into the silencer, which is shaped to project the air flow back up towards the air box. My feeling is that Subaru put the scoop there for a reason and I like the idea of keeping it in the equation as a minimum.

I guess I was trying to get the best of all worlds. Unfortunately, there's always a trade-off isn't there?

JC

 

I left my silencer in place

 

How about leaving the snorkel that feeds air in from the front. Gut the silencer, and making sure you seal the airbox between the airbox and fenderwell. And don't forget the K&N filter!

-scu

 

hacked mine too! i haven't really looked around but i'm sure they aren't that hard to get a hold of....

 

hahahaha
Thats exactly the look I had on my face for 99% of that course.
jc

 

Would this mod effect the warranty in any way? Like if they see it modded, they would reject service to my car?

 

Probably. So slap it back on when/if you go into your dealership

 

kinda revivin the thread.... but i just did the silencer removal and i DID get a CEL. But i reset the ECU and it went away. Did that by disconnecting the battery for a minute and reconnecting it. Great first mod

 

Good reminder for people to reset their ECU when this or nearly any other mod is done. Thank you

 

Well... I did this mod about a month ago. Just wanted to add my impressions.

First try: Took out silencer. Could hear turbo spool much better. Ran it for about a week. Felt slower than usual on the "butt dyno". Felt like I had less torque. RPM revved slower and turbo seemed to spool slower. (When I say "spooled slower"... I don't mean like significantly, maybe like by a few hundred RPM's)

Second try: Added GP Moto Delete Elbow. Felt slow still. And lost most of the spooling sound now. Almost sounded like stock again. Turbo still spooled slower. Checked cables/hoses. Got pissed off.

Third try: Put silencer back in. Tossed GP Moto Delete Elbow onto junk parts box (waste of $40). Runs like normal now. Turbo spool is back to normal. Torque is back to normal.


All this was done on a stock 2004 WRX with ECU being reset. I could just be all psychological. Others I've talked to have had the same problem. Some people don't have any problems. Logically you shouldn't have any problems with it, but I guess some of us just have bad luck.

So, this being said... Anyone want to buy my used but pretty much BRAND NEW GP Moto Delete Elbow? $30 free shipping :-P