odurandina

well, i know some cities in the desert southwest like Albuquerque and Phoenix, they have horrible air stagnation and smog. in Massachusetts we don't have any such problems and as such, we have no visual exhaust inspection or smog check after 15 years. i hope things stay that way. i can go to the most **** inspection center w/ no worries.


just wish to add one more thing. "the variocam is a huge 4 cylinder engine that breathes very large volumes of air by 4 cylinder engine standards; so why do none of the exhuasts on youtube allow the 3.0 litre engine to sound like a 3.0 litre engine ? furthermore, all the 968 catback systems desperately need resonators. watch the videos. they sound i bit less 'ricey' than Honda's but they all still sound like crapola.... if you're running an old cat (or any cat), stock or aftermarket exhaust, they all sound basically the same; like pee-shooter fart cans with about 2 point nuthin' litres of displacement. why ?

i believe it's mostly due to; 'once the variocam kicks on, you've got a mild race engine.' and after that point there's no benefit to having a catalytic converter in the circuit.



stand next to this car at idle, and just give it a little gas.... it sounds more like 4.0 litres. rev it up to 4,500 and then let off the gas and it makes a lovely, low-frequency crackle... then rev it toward the limiter. heaven.


Carl (928 forums) drove it last summer. at that time it was loud but the exotic sound was still there.




this experience has taught me something about what a normally aspirated 4 cylinder can do as far as the exhaust note. but, the four cylinder architecture is the limiting factor... in the end, flat 6's w/ turbos, v8's, v10's and v12's all sound better... but this combo makes way better sound than other exhausts, and costs much less to put on the car. i would recommend my setup starting with at least an 18" X 9" Magnaflow stainless steel glasspack... and don't forget to run a heavy guage pipe and use all three mounting points.




.

sTyleR

This should give you an idea. Setup is alike, aside from the car being a 2.5L 924S rather than a 3.0L 968. Cat removed, SLP hollow resonator added, and muffler replaced with a Borla XR1 (rather than a Hooker or Magnaflow here). Cut to 1:56 for the exhaust sound clip. How close is this to yours, Allan?

haydenlewis

Lets see some pictures of underneath the car and a video of how it sounds.

odurandina

liking that video a lot !! i can see you're very happy with the result. frankly so are we !! as i promised in my op, your cloned system is sounding fantaastic...similar to my car in a smaller engine package... unfortunately, to do a good comparsion i'll need help from someone with a good recording device or get one myself.... my video is sort of crapola due to the lousy microphone and recording platform... on the video below, i had the microphone and laptop sitting on the passenger seat..... it's best to use a good pair of headphones or a good sound system with plenty of gain and decent subwoofer to hear the full volume range between idle and wide open throttle....








btw, you're not the only one.... a guy with a 3.0 has also done a similar setup.





now i gotta go do a top speed run with a proper digital recorder.

od.



'

odurandina

not surprised to hear that, due to the fact that you were running a very short system after the breakage.... keep in mind, i'm obviously getting the proper scavaging from

1. running the right size pipe,

2. nothing to block exhaust flow (completely open system)....

3. running all the way to the back (the gasses exiting at the rear are making a lot of vaccuum/scavaging).... you can see it on a cold day at idle. the gas shoots back about 25 feet as it slowly begins to arc upwards....

in all, the combination of running the better exhaust, and larger, proper 25.6" rear tire.... and since completing the new front valance, the car no longer needs 7~8 miles of straight to get up to top speed... now, it races to 140 in 5th really quick and on to the redline (163 mph) in 6th quickly. remember that the factory spec was 156 mph, so with getting a good deal past that, i'm so happy with this car, almost sad to see such a good running setup go.

mytrplseven

Stebro came up a couple of times on this post. Back when I bought a Datsun 240z in 1971, I put a Stebro system on it. Quality was top-notch and the sound was awesome. Agreed, it was a 6 cylinder car so the sound vs a 4 cylinder doesn't wash here, but I loved it. The California cops, however, didn't share my enthusiasm for the sound it made going through the concrete canyons of downtown San Francisco. I'd love to hear one on a 944 today.

rgs944

Nice video and nice car Tyler.

F40LM

I took the plunge and ordered the SLP resonator and the magnaflow muffler. The muffler is HUGE and I decided to try out a smaller IMCO muffler instead. Have only driven it say 20 min so far but I have to admit....I am really impressed with the sound, the SLP resonator does really make a difference. I plan to do about 2 1/2 hours in the car tomorrow in mixed driving and will further report impressions if there is interest.

Michael

odurandina

cool,
so, now that you've had a chance to drive it a bit longer, what do you think ?

Butters944

Bumpin' a good thread...

I took a look under my car at the exhaust tonight...

Looks like the only place to fit the SLP resonator in the stock pipes is right here in the angled section after the cat before it straightens for the muffler.


Measured the length of the straight section, it's like 2" too short to fit the SLP resonator

Looks like the only way to go, since I want a cat/resonator/muffler system, will be to do custom pipe work

It can't be too hard, can it..? Pipes are cheap and I have friends with a welder... Can't afford a shop lol I might have a welding learning experience this winter.

Chunkerz

That guy has a HUGE nose. I like the fake flame they added when the guy shifted during the exhaust sound clip.

Dino V

Stop giving me winter project ideas LOL!

Butters944

I think that guy is sTyleR...

Dougs951

Put it in the cat position.

mfyoung1086

Don't get stainless then, I doubt any of your friends have a TIG welder... and if they do I need to be their friend

Also butters cutting your cat off is not illegal as long as you'll pass emissions, this is kinda a case of you won't get caught once its done, but you'll have to put it back on when you need to go through emissions again

Also did the OP seriously refer to variocam kicking in as turning the engine into a mild racing engine? I'm gonna tell that to the honda guys with vtec (btw most modern race cars dooo have cats on them.....) glad you like your exhaust system....

Personally my fav. mufflers are Borla. Had a 944 in the shop I worked at back in HS that replace the muffler and cat with two Borla (i think the were XR1's but its not like I have the catalog memorized) anyways that sound nice, we also had a very golfs, and even a passat TDI with Borla systems on them, and they all sounded great!

lastly a couple points

Exhaust flow is good for turbo's (since they can support them via higher exhaust velocity), but exhaust velocity is best for N/A. You want to chose the dia. pipe for the best velocity, 2.25-2.5 would be idle for a 2.5 butters

to the OP if you put larger tires on the car, hav you compesated the speedo for this? cuz otherwise that 163 you're getting def isn't 163 mph.... unless you're taking your readings via GPS