Helstrm

Okay since I am going back to NA.. I have a few questions.

1. We don't have any inspections in SC so I plan on deleting the CAT. Will this have any negative effect on performance? I plan on sticking with a 2.5 inch system because I believe going larger on an NA would hurt my low end.

2. What mufflers do you guys use. Keeping in mind that without the cat the car will get louder and I don't want to rattle the windows in my house when I start the car but I do want a good throaty sound if I can get it.

3. Are Bursch Headers a good upgrade?

I have a pipe bender and welding equiptment so I will be making everything myself unless I go back with the stock system.

Chris_924s

Check out S2's SFR exhaust.. it sounds GREAT!!

tifosiman

1. Yes, it may hurt performance on the low end.
2. Stock. It is still throaty, loader than most modern cars.
3. Debatable.

Some people may suggest that you look at the SFR exhaust, but to this day it has not been proven to be a gain in HP or TQ for an 8V N/A motor. While it may show gains for an S2 (which is a completely different animal), it could be detrimental to low end performance on an 8V N/A, and it is definetly loud, probably louder than you would like.

spedracer18

this raises another question i had (sorry if im thread hijacking, perhaps you would like to know too...)

what headers are the best performance for the money:

Bursch headers at around $250
MsDs Headers at around the same
B&B headers at around $800
Dansk headers at ???


as for the cat, removing will increase performance greatly for the little time and effort it requires. im not 100% sure with the 944 but for other cars ive had, the cat is the single most restricitve place in the exhaust. gutting should be well worth your time, if your not too "green"...

as for keeping it at 2.5 inches, it seems like the best idea for a stock or near stock na. increasing even to a 3 in. will signifcantly lower the already low low end torque response.

Helstrm

I have looked at the SFR system but I can do it myself much cheaper. So it looks like the questions remaining are Which header and muffler to use. I will pull the CAT and make a bypass pipe. I can always mount the stock system if they ever start inspections around here.

Serge944

I would not advise Bursch headers on anything but a street car. They are made out of extremely thin steel and resonate a lot. The ones I personally had also arrived with a warped flange. Stock headers are excellent, especially the cast iron ones, which will never crack.

If you want a test pipe, cut the cat portion out and weld in some fence tubing from your local hardware store.

joseph mitro

don't gut the cat. i did and it sounds like crap and smells like ****. place a straight pipe if you do anything.

muffler - i bought an edelbrock off a rennlister. sounds pretty similar to stock, (maybe a bit more throaty at high rpm) but is smaller. i think if i install a straight pipe it will be a little louder.

Helstrm

So there will be no performance increase with the header over the stock system? if that is a fact then I will save my $$$ I don't expect much more performance but a few horses wuld be worth the work.

L8 APEKS

DO NOT gut the cat! Bad idea. If you HAVE to remove it, make a test pipe to match the rest of the exhaust diameter. To offest the noise, add a round muffler in the center section where the cat used to be. With nothing but a rear muffler on an otherwise straight-thru exhaust, the car will be rediculously loud for a daily driver. Use a round muffler as a resonator in the center section, and then an oval at the rear (both straight-thru styles, no chambers/baffles). I'm using Magnaflow's standard aluminized mufflers.

2.5" should be ok, but can anyone verify the stock tubing size? I've heard 2.25" but I'm not certain. Certainly don't go any larger.

On the headers...the Bursch headers don't seem to be very high quality. There's a place in CA that is supposed to make the best header for the 944, but I can't recall the name. They aren't well known (made to order), but I think Jon Milledge sells them on his website. They are pricey though...something like $650.

For what it would cost to do an exhaust and header, keep in mind you're very close to what it would cost to port/mill the head and buy a cam...and you'd get a lot more power there. Probably twice as much. Something to think about. Best of luck!

Helstrm

I would not gut the cat. Too much work involved and makes a big mess. I will fabricate my own exhaust. I found these guys that make a custom header for the 944 http://www.msdsinc.com/exhaust_1.htm $227 for raw steel, They claim an 18hp gain on a well tuned engine.

Enviroteacher924S

I am getting a B&B on my 924S next month (I hope). I have heard it before and I think it sounds SWEET! Have a fanTABulous day - Jaime

Serge944

You will not "improve" the 944 exhaust system without compromise. Period. You can merely change the torque curve to better suit low or high-end rpm. We need to create a vario-exhaust. At low rpm, a flap will close a portion of the flow of a large diamater exhaust pipe.

As for the Bursch. Top gear top tip: Avoid.

L8 APEKS

I've heard the same about the MSDS, but I'm not sure what to believe anymore since everyone is willing to throw down $700 on a part, but no one is willing to throw down $50 to see if it actually made any power on a dyno.

Helstrm

Well I think I will try the MSDS Header. If I don't like it someone will buy it on ebay. I will get my car to a Dyno when it's done. Bet since it will be a complete rebuild I have no idea what HP to expect until I get there. I am not that worried about it right now. I am just building a nice fun car to drive. And cheaper on gas than the Suburban.

944CS

i have a straight pipe in place of the cat with the stock muffler...its not too loud for a daily driver, and i did notice a power gain in the mid range (2800-4800)...i do have a higher compression motor...will let you all know what it does in the upper range as soon as i put on my adjustable cam gear