Notices
996 GT2/GT3 Forum 1999-2005

Muffler Bypass db levels?

Thread Tools
 
Search this Thread
 
Old 08-10-2008 | 05:00 AM
  #1  
Carnerd's Avatar
Carnerd
Thread Starter
Three Wheelin'
 
Joined: Apr 2006
Posts: 1,816
Likes: 1
From: Bay Area
Default Muffler Bypass db levels?

Does anyone know what the db levels for muffler bypass pipes are? I had an older Cup style system installed and its close to as loud as mbp pipes. Just making sure i can pass sound at TH. TIA!
Old 08-10-2008 | 05:13 AM
  #2  
ex10psi's Avatar
ex10psi
Racer
 
Joined: Jul 2004
Posts: 482
Likes: 0
From: WA state
Default

mine registered 105 db about 15 ft off the main straight wall at PIR (portland raceways), i believe it was WOT about 6-7k rpm
Old 08-10-2008 | 05:21 AM
  #3  
mooty's Avatar
mooty
GT3 player par excellence
Lifetime Rennlist
Member
 
Joined: Apr 2002
Posts: 43,569
Likes: 5,905
From: san francisco
Default

not sure about cup car exhaust, but fabspeed bypass will pass sound at TH.
i believe stock cup car exhaust will pass as well.
RSR will not.
Old 08-10-2008 | 07:12 AM
  #4  
Dale Gribble's Avatar
Dale Gribble
Pocket Sand
Rennlist Member
 
Joined: Jul 2004
Posts: 7,648
Likes: 1
From: Ask Rusty Shackleford.
Default

102dB at 4000RPM measured with a handheld at the track about 20 or so feet away
Old 08-10-2008 | 02:55 PM
  #5  
fhp911's Avatar
fhp911
Rennlist Member
 
Joined: Jan 2007
Posts: 1,127
Likes: 106
From: Metuchen NJ
Default

Loud is fun, but do you get more power with these bypass devices? Real, measured gains?
Old 08-10-2008 | 03:47 PM
  #6  
GT3 Chuck's Avatar
GT3 Chuck
Rennlist Member
 
Joined: Jul 2005
Posts: 972
Likes: 1
From: Fresno, Ca
Default

a little more top end hp at the expense of a little low end torque...pretty small difference....
Old 08-10-2008 | 07:42 PM
  #7  
Carnerd's Avatar
Carnerd
Thread Starter
Three Wheelin'
 
Joined: Apr 2006
Posts: 1,816
Likes: 1
From: Bay Area
Default

Originally Posted by mooty
not sure about cup car exhaust, but fabspeed bypass will pass sound at TH.
i believe stock cup car exhaust will pass as well.
RSR will not.
Good to know. I read that the db at TH is only 103 but i take your word for it.

Originally Posted by GT3 Chuck
a little more top end hp at the expense of a little low end torque...pretty small difference....
Ya, nothing too noticeable except for the glorious sound!
Old 08-10-2008 | 08:23 PM
  #8  
RJFabCab's Avatar
RJFabCab
Addict
Rennlist Member

 
Joined: Nov 2003
Posts: 1,820
Likes: 12
From: NC - One headlight capital of the world
Default

Originally Posted by fhp911
Loud is fun, but do you get more power with these bypass devices? Real, measured gains?
Ditto the other comments... and don't forget that you get to LOSE the weight of the cans in the back!
Old 08-10-2008 | 10:32 PM
  #9  
GT3 Chuck's Avatar
GT3 Chuck
Rennlist Member
 
Joined: Jul 2005
Posts: 972
Likes: 1
From: Fresno, Ca
Default

+1 the 50lbs you lose by removing the mufflers from where you need the weight the least is the biggest benefit
Old 08-11-2008 | 01:36 PM
  #10  
XLR8N-FAN's Avatar
XLR8N-FAN
Instructor
 
Joined: Mar 2008
Posts: 146
Likes: 0
From: SoCal
Default

How much louder is the muffler bypass than the PSE? I have the PSE with one muffler doing a rattle. Has anyone gotten a muffler fixed? Does anyone have a sport exhaust to sell? Thanks Chuck, I guess I should wake up before posting.

Last edited by XLR8N-FAN; 08-11-2008 at 03:19 PM. Reason: Posted wrong question.
Old 08-11-2008 | 02:23 PM
  #11  
GT3 Chuck's Avatar
GT3 Chuck
Rennlist Member
 
Joined: Jul 2005
Posts: 972
Likes: 1
From: Fresno, Ca
Default

what check engine light...been running bypass pipes for 3 years (with mufflers back on for Laguna Seca) with no cel issues...the cel issues I have heard about result from cat bypass not muffler bypass...

check this thread...

https://rennlist.com/forums/996-gt2-gt3-forum/395949-no-cats-and-fooling-obd-ii.html)
Old 08-13-2008 | 09:14 PM
  #12  
va122's Avatar
va122
Drifting
 
Joined: Jul 2006
Posts: 3,065
Likes: 2
From: On Rennlist avoiding work
Default

Martin, call me i have one modified oem muffler in storage, I can't remember if it's left or right though, I think right.

I also have a set of GHL mufflers if you're interested

Oh, MBPs read 108 db at 15ft

My CG i think is 98, i have the full R system which according to Fabryce (if you get a straight answer) is very similar to the cup system that was on their 996s...
Old 08-13-2008 | 10:17 PM
  #13  
Carnerd's Avatar
Carnerd
Thread Starter
Three Wheelin'
 
Joined: Apr 2006
Posts: 1,816
Likes: 1
From: Bay Area
Default

Originally Posted by va122
My CG i think is 98, i have the full R system which according to Fabryce (if you get a straight answer) is very similar to the cup system that was on their 996s...
Do you have any sound clips? Is this the system that incorporates the center section cross over?
Old 08-14-2008 | 03:09 PM
  #14  
va122's Avatar
va122
Drifting
 
Joined: Jul 2006
Posts: 3,065
Likes: 2
From: On Rennlist avoiding work
Default

No clips, go to cargraphics website I think there's one.

Yes it crosses over, it's great, gobs of torque! I love the mbp sound, but the loss of torque bothered me.

Funny, guys on harleys couldn't get over my car being louder. I have a harley, and it's no where near as loud as mbps
Old 08-14-2008 | 09:06 PM
  #15  
Carnerd's Avatar
Carnerd
Thread Starter
Three Wheelin'
 
Joined: Apr 2006
Posts: 1,816
Likes: 1
From: Bay Area
Default

[QUOTE=va122;5703748]No clips, go to cargraphics website I think there's one.

I checked, i think its their non R system though

Originally Posted by va122
Yes it crosses over, it's great, gobs of torque! I love the mbp sound, but the loss of torque bothered me.

Funny, guys on harleys couldn't get over my car being louder. I have a harley, and it's no where near as loud as mbps
Really? I thought with the cross over the sound would be more mechanical? I agree, love the loudness of mbp but didnt want the loss of torque either. GMG's Cup bullet system was exactly what i was looking for. Muffler bypass pipe loud, slightly more refined, but no loss in torque for a lot less than a full system.



All times are GMT -3. The time now is 11:36 PM.