The 'Maverick' Classic Porsche Forum and Classic Porsche Club for Porsche 356, Aircooled Porsche 911, Porsche 912, Porsche 914 & Porsche Replicas. 'We join for the cars but stay for the people'
I keep seeing 911's with 2 small rocket launchers coming out of the muffler box under the rear numberplate. They seem to be blocked off with a lockable cap. What are they and what do they do?
What are the options for exhaust systems for early 911s and there relative merits? Sorry to be technical
regards
Mike
former owner, still hoping to be reunited with my STOLEN 1972 911T/E 2.4 . Keep looking guys
No Hydrocarbons were hurt in the sending of this mail. Thanks
This one came from Autofarm, but I know Barry and others have made their own. Uncap the centres and the sound is glorious, but too much for towns and villages.
Transend sells a twin pipe without a side exit, haven't fitted it yet so can't vouch for it, supposedly good sound, deep noise, galvanised steel,
Pelican sells Bursch exhausts, they have side exit but smaller actual muffler box, appare ntly they sound fantastic
Thats the suckers They look wonderful, is it a case of only unpluggin them on track days etc? what kind of DB's do they give out since i'd be concerned at tracks like Castle Coombe (100BD static limit )
Is it a completely new exhaust system? how does it work? hmmmm, whats that sound......kerrrching!! oh no, more cash gone
regards
Mike
former owner, still hoping to be reunited with my STOLEN 1972 911T/E 2.4 . Keep looking guys
No Hydrocarbons were hurt in the sending of this mail. Thanks
The one that I modified was a bit loud for road use: the whole car used to resonate at around 3000 revs, just as you were going through towns. In the end I made a couple of simple baffles for the twin pipes.
They were just a couple of lengths of pipe that were a good fit in the tailpipes. At the silencer end I ran four (90 degree spaced) cuts about one ince long up the length of the pipe. I then folded these 'flaps' in slightly to disrupt the gas flow. It was then possible to keep tweaking the amount of 'fold' until the sound was a nice balance between tuneful and socially acceptable.
I had chrome exhaust trims on mine which hid the fact there were inserts there. Obviously the gas-flow was compromised slightly, but frankly you are more likely to be putting the triple outlet type box on for looks and noise, rather than outrght performance. I would suspect that a good quality standard box would flow just as well.
DDK Member1243 07741 273865. Home of the RY Austin 7 Trophy's and Austin Single Seat Racers
Forgot to say, I just modified a standard box, which I believe is all Autofarm do (?), therefore the 'new' backbox can go directly onto the existing heat exchangers.
I'm sure there are a number of other options, but I supose a lot is going to come down to what you are looking for: sound, looks, performance, standard appearance etc etc.
It'd make a good sticky article if someone had a good handle of all of the 911 exhaust options right through from a budget, mild steel system, right up to a stonking, top of the range, ultra performance stainless solution .
DDK Member1243 07741 273865. Home of the RY Austin 7 Trophy's and Austin Single Seat Racers
Hi Andy, whats the 911R system made of, and how will you refinish it?
cheers, Mike.
previously..
1994 968 Club Sport Riviera Blue
1994 993 C2 Carrera Riviera Blue
1972 911S to Martini RSR Prototype Spec
1973 911E to RS Lightweight Specification
1981 924 Carrera GT ex Mexborough car
3.2 Carrera Sport x2
106.7dB at 4500 revs and Gawd knows what at 7300 revs
Quite intoxicating for a while, but tiring after a couple of hours. I carry ear defenders to wear for the last hour on the way home to regain some sanity!!
I have no idea of the dB level, but as Barry says its too loud with the caps off except for open roads, so probably to much for a trackday. With the caps on the noise level was normal I would say. The rest of the system was SSI which is a little louder tahn standard anyway. Steve Wright may know the dB level as he has an Autofarm triple on his 2.2S before he modded it, and I thing he used it on track days.
.
