The most difficult question

LP944 · 11-03-2009, 10:42 PM

As Ive been looking for parts for my 83' NA, aparently the most difficult decision to make for a 944 is the exhaust muffler. Ive heard many opinions from people and still cannot make up my mind. What is the best muffler for the money and the most widely accepted muffler by the 944 community. Especially important, which ones do not sound ricey, last thing I want is to sound like an annoying Honda with a coffee can on the back. Please have direct answers, discussions only if you absolutely need to start one, since thats the main problem with threads on mufflers...
Important: For an NA, which is wiser, normal or high flow cat.

M758 · 11-04-2009, 11:31 AM

I have been racing with my 944 spec using a test pipe (no cat at all) and stock muffler. It works well and make strong power vs the other cars in my class. I don't believe you will gain noticable power going away from a stock muffler. You can however gain power by going to a test pipe. Of course this really only usefull for track cars. High flow cats will not gain power unless stock is clogged.

aj986s · 11-04-2009, 11:39 AM

X2 on the test pipe vs the cat. I have a street 944 using test pipe and stock muffler. Has a unique raspy note, that gets lots of compliments. A good muffler shop can make a test pipe with flanges corresponding to cat if need to remove periodically for emissions testing.

My SP2 944 racer has a straight custom fab'd exhaust pipe into a small Flowmaster muffler (a bit lighter than OEM). Too loud for street, but has a throatier sound than the street car.

ernie9468 · 11-04-2009, 12:08 PM

I'll go with Tony & Joe ,muffler should be complement with a nice oval exhaust tip polish s/s if possible not to big 4 to 41/2" is just rigth for an 83 na.

StoogeMoe · 11-04-2009, 06:52 PM

What do you do about the O2 sensor with a test pipe? Get a bung welded in for it?

LP944 · 11-04-2009, 08:45 PM

Quote:

Originally Posted by M758

I have been racing with my 944 spec using a test pipe (no cat at all) and stock muffler. It works well and make strong power vs the other cars in my class. I don't believe you will gain noticable power going away from a stock muffler. You can however gain power by going to a test pipe. Of course this really only usefull for track cars. High flow cats will not gain power unless stock is clogged.

But doesnt the powerband shift to higher RPMs when you remove the cat? Is the power noticable or barely. I thought it was better to have low/mid powerband on street cars.

ernie9468 · 11-04-2009, 09:35 PM

On the 83 na the oxygene sensor is not plug in into the cat, so all you do is replace the cat with a test pipe.the oxygene sensor stay excatly where it is in the exhaust pipe.

odurandina · 11-04-2009, 10:27 PM

go look at my exhaust thread on the 968 forums "improved exhaust for better HP gain w/ SUPERCHARGER," on the 968 forum. read it. I got a 10 mph gain on my top end -- and that is before adding the supercharger. You can't go wrong.

LP944 · 11-05-2009, 12:30 AM

Quote:

Originally Posted by odurandina

go look at my exhaust thread on the 968 forums "improved exhaust for better HP gain w/ SUPERCHARGER," on the 968 forum. read it. I got a 10 mph gain on my top end -- and that is before adding the supercharger. You can't go wrong.

But I thought those engines were a bit different then the 2.5 in my 944?

ford_jj · 11-05-2009, 12:38 AM

Quote:

Originally Posted by LP944

But I thought those engines were a bit different then the 2.5 in my 944?

I aslo think that.

ernie9468 · 11-05-2009, 12:01 PM

They sure are and what Odurandina is talking about cost a lot more $$$ then a simple test pipe.

M758 · 11-05-2009, 01:12 PM

Quote:

Originally Posted by LP944

But doesnt the powerband shift to higher RPMs when you remove the cat? Is the power noticable or barely. I thought it was better to have low/mid powerband on street cars.

Maybe it does. However that is perfect for my race car. My car run s 3600 rpm to 6200 RPM all the time. Even on pace laps I never seem to run it under 3k A test pipe is not legal on street driven car anyway.

V2Rocket_aka944 · 11-05-2009, 03:16 PM

Quote:

Originally Posted by StoogeMoe

What do you do about the O2 sensor with a test pipe? Get a bung welded in for it?

the o2 sensor goes a few feet before the cat. its in the 2-1 Y-pipe coming off the headers.

luftpirate · 11-05-2009, 08:59 PM

Quote:

Originally Posted by M758

Maybe it does. However that is perfect for my race car. My car run s 3600 rpm to 6200 RPM all the time. Even on pace laps I never seem to run it under 3k A test pipe is not legal on street driven car anyway.

Removing a cat is not going to shift the power band, its just going to improve exhaust flow which will see some power gains.
The main reason a lot of people see "gains" with a test pipe is because the cat they were using before hand was clogged after 150k. A properly working high-flow cat is not going to hinder flow to the point to make a significant difference between itself and a test pipe in an N/A application. So really what it comes down to is whether or not you like the raspy sound that comes from a test pipe or whether you prefer the more stock throaty tone which comes from the cat. acting as a resonator.

odurandina · 11-05-2009, 10:34 PM

I did not mention the downsizing part for n/a 944 from the heavier breathing 968, because I thought that would be implicit in the discussion.

Removing the cat will not shift the powerband up, but running a wider pipe will... and the fine line for my type of exhaust running in your car is about 2-1/4 inch pipe... running any wider is highly likely to reduce your low end power.

so, run 2-1/4 inch pipe. Not easy to find. It made me want to drive my car 10 times more than I did previously. Every Porsche and non Porsche driver is addicted to my exhaust... Way too stout for a production car, but not too loud for boulevard crusing.

11-03-2009, 10:42 PM	#1
LP944 User Join Date: Jan 2009 Location: Lake Placid, FL Posts: 77	The most difficult question As Ive been looking for parts for my 83' NA, aparently the most difficult decision to make for a 944 is the exhaust muffler. Ive heard many opinions from people and still cannot make up my mind. What is the best muffler for the money and the most widely accepted muffler by the 944 community. Especially important, which ones do not sound ricey, last thing I want is to sound like an annoying Honda with a coffee can on the back. Please have direct answers, discussions only if you absolutely need to start one, since thats the main problem with threads on mufflers... Important: For an NA, which is wiser, normal or high flow cat.

11-04-2009, 11:31 AM	#2
M758 Addict Rennlist Member Join Date: Aug 2002 Location: Phoenix, Az Posts: 12,432	I have been racing with my 944 spec using a test pipe (no cat at all) and stock muffler. It works well and make strong power vs the other cars in my class. I don't believe you will gain noticable power going away from a stock muffler. You can however gain power by going to a test pipe. Of course this really only usefull for track cars. High flow cats will not gain power unless stock is clogged. __________________ Joe P. 88 944 Turbo S - 100% Stock ++++++++ 84 - 944 Spec #94 Red/White Arizona Region 944Spec Director - Az 944 Spec Champion 02/03, 2006 - 2nd Az Region 944 Spec 2003,2004,2008 4th - 2009 NASA Nationals - Fastest 944 spec lap at Miller Nationals - 2.19.282 (Sat Warm-up)

11-04-2009, 11:39 AM	#3
aj986s Addict Rennlist Member Join Date: Mar 2006 Location: Damascus, MD Posts: 191	X2 on the test pipe vs the cat. I have a street 944 using test pipe and stock muffler. Has a unique raspy note, that gets lots of compliments. A good muffler shop can make a test pipe with flanges corresponding to cat if need to remove periodically for emissions testing. My SP2 944 racer has a straight custom fab'd exhaust pipe into a small Flowmaster muffler (a bit lighter than OEM). Too loud for street, but has a throatier sound than the street car. __________________ Tony P. '89 944S2 '84 944 SP2 Racer '85.5 944 (my son's bribe...) '00 Boxster S (wife's DD) ...and other assorted vehicles as needed.

11-04-2009, 06:52 PM	#5
StoogeMoe Addict Rennlist Member Join Date: May 2004 Location: Poconos PA Posts: 986	What do you do about the O2 sensor with a test pipe? Get a bung welded in for it? __________________ 1986 944 NA Guards Red all original 92K mi. - minty 1983 944 NA Platinum Metallic w/LSD 48K mi. on rebuild, 181k total - the track monster 1984 911 Carrera Coupe (gone, but not forgotten) "If you're not living on the edge, you're not living."

11-04-2009, 09:35 PM	#7
ernie9468 Addict Rennlist Member Join Date: Jul 2009 Location: caraquet, new-brunswick, canada Posts: 116	On the 83 na the oxygene sensor is not plug in into the cat, so all you do is replace the cat with a test pipe.the oxygene sensor stay excatly where it is in the exhaust pipe. __________________ - Ernie Cars: 1983 944 n/a show room sold 1993 968 (mods: Bilstein ajustable front strut inserts, bilstein sport rear, 17" C2 Road Contact FALKEN 452's)

11-04-2009, 10:27 PM	#8
odurandina Addict Rennlist Member Join Date: Oct 2009 Location: Dover, Massachusetts Posts: 264	go look at my exhaust thread on the 968 forums "improved exhaust for better HP gain w/ SUPERCHARGER," on the 968 forum. read it. I got a 10 mph gain on my top end -- and that is before adding the supercharger. You can't go wrong.

11-05-2009, 12:01 PM	#11
ernie9468 Addict Rennlist Member Join Date: Jul 2009 Location: caraquet, new-brunswick, canada Posts: 116	They sure are and what Odurandina is talking about cost a lot more $$$ then a simple test pipe. __________________ - Ernie Cars: 1983 944 n/a show room sold 1993 968 (mods: Bilstein ajustable front strut inserts, bilstein sport rear, 17" C2 Road Contact FALKEN 452's)

11-05-2009, 10:34 PM	#15
odurandina Addict Rennlist Member Join Date: Oct 2009 Location: Dover, Massachusetts Posts: 264	I did not mention the downsizing part for n/a 944 from the heavier breathing 968, because I thought that would be implicit in the discussion. Removing the cat will not shift the powerband up, but running a wider pipe will... and the fine line for my type of exhaust running in your car is about 2-1/4 inch pipe... running any wider is highly likely to reduce your low end power. so, run 2-1/4 inch pipe. Not easy to find. It made me want to drive my car 10 times more than I did previously. Every Porsche and non Porsche driver is addicted to my exhaust... Way too stout for a production car, but not too loud for boulevard crusing.