Diver944

Has anyone personally heard both the Fabspeed and SFR 3" stainless steel exhaust systems? Which one is quietest?

I'm trying to decide between these two systems to go on to my 3.2 951 with a 3" downpipe off the turbo. The trouble is that we are getting stricter and stricter noise levels for public track days here in the UK so I do not want to end up with a car that keeps getting me black flagged.

I have heard the Fabspeed 3" and 4" systems on cars over here and the 4" is definately WAY too loud but I have not seen a car here in the UK with the SFR system. I notice from the SFR website that they do a 'quiet-flow' rear muffler, has anyone heard this in action and how does it compare to a stock exhaust?

My car is now finished in the bodyshop and will soon be back at Indi Jons workshop so I need to make my decision pretty soon, get rid of that skinny standard exhaust and see what this 3.2 engine will really do

gt37vgt

although they look crap downturned tips have a big effect on quietning the drum . also those ricy mufflers with the choke insert are realy effective

88BlueTSiQuest

Loudness is probably going to have a lot to do with your muffler choice. I have heard people say not to get the SFR due to how loud they are, but I'm also sure that is referring to the cheapest system running the bullet muffler. If they spend a little more on the Quiet flow system, I'd bet it would start sounding more like the Fabspeed and LR w/Magnaflow systems.

Lindsey offers you the option for a pre-muffler on both their 3" and 4" exhausts, that should help quiet things down some. The only issue I see is that they aren't available in stainless, thermal coating is an extra $150.

TurboCab

I have tested avariety of mufflers and I ended with the Aero Turbine resonated
muffler from Aeroexhaust see link.
http://www.aeroexhaust.com/car_muffler_2525xl.html

and resonator:

http://www.aeroexhaust.com/truck_resonator_ar30.html

Essentially what I have are two resonators, one inside the muffler and one outside both 3in. in and 3 in out. The muffler and the resonator are both straigh tube design plus the Aeroexhaust patented "Turbine" design inside the muffler. The car sound level is reduced dramatically. Not at a stock level, but very close. The construction quality is excellent.

Darwantae951

I have the SFR exhaust with Borla XR-1 and on a Turbo car it is not that loud. My wife was actually suprised that it was only minimally louder at idle. Now at WOT going down the highway it's kind of loud, but definitely not obnoxious or annoying. Plus the craftsmanship is outstanding!

-Darwin

Ski

My wife is not a fan of the SFR but I like it, go figure. SFR has a media player file of a car at idle and reving with one of their exhaust systems, test pipe and cat back. I have the bullett muffler with angle cut tip, full polish. At full throttle it sounds great. Loud, no not really. It can be or I could see where it could be considered a bit loud more on partial throttle than any other part of it. I've got a 66 yo neighbor who loves hearing the car coming down the street, just a 30mph cruise.

Diver944

Cheers guys, this is all useful info. I have heard the SFR media player file and it sounds a similar level to the Fabspeed I have heard over here and maybe a bit too loud. I am hoping the SFR Quiet flow would suit my needs and I notice there is an option to have a resonator in the test pipe that I could bolt in and out for tracks with a very low noise limit.

I don't really want to have an extra resonator as that will surely restrict the flow a little, right?

What I'm really hoping for is one of you guys to have heard both styles at a track meet or one of your Pizza runs.

nick_968

Paul

Why dont you look at getting a custom one made to your exact decibel requirements, there is a place called Blue Flame who do OEM stuff for some of the UK car manufacturers and are supposed to be top notch. Will make a full system for around £700 while you wait. You are always going to take a chance on decibel levels based on others experience and videos etc.

FRporscheman

Would it be inconceivable to use 2 "loud" mufflers for more quieting effect?

Spidey944

Don't think that would be much more effective, nor would it fit as well as a muffler and resonator would.

OT: no word on your stolen car yet? That sucks badly, I hope you recover it.

Tom M'Guinn

Well, I have a 3 liter motor with SFR 3" downpipe, 3" test pipe, and factory muffler. The muffler keeps it sounding very much like a normal car. To the casual observer, it sounds essentially stock from the outside. Inside the cabin, the bigger pipe transmits a bit more noise, but not bad by any means. I just put my 2.5" pipe back on today so that Tim can make some adjustments to the 3" pipe. No proof of course, but it does feel a tab faster with the bigger exhaust, and I had about half a psi more boost at the same setting on my Profec.

DrZ1

I have SFR Test pipe and Quiet flow exhaust and am very satisfied, the sound is not much louder then my stock ehaust w/ gutted cat. I had a B&B on a 300zxTT and it was very annoying, esp w/ a droan at 3k rpm. Definatly give this exhaust a very good reccomendation.

Steve

gt37vgt

I've chosen 2 x4" strait through mufflers with ricer removable restricer tip

333pg333

I wonder if there's not a way of determining the db before you have to keep buying and trying these out. Lot of money in the hope that you're not going to set off these loudness meters? How will you know before you go to the track?
On another 'Note', glad to hear that your car is almost ready Paul. Good news!

Diver944

It's quite straightforward actually. The strictest track in the country is just a few miles from me and you have to pass a static noise test of 95db at 3/4 max rpm with a microphone 50cm from the tailpipe at an angle of 45 degrees. Out on track they have several sensors placed 20 metres from the track and the limit on these is 88db for a driveby. I tripped those with induction noise with my old straight pipe from the turbo to the MAF to the air filter :O , but a 90 degree bend sorted that out.

For reference my old standard exhaust measured 84db, then it went up to 89db with a test pipe so I actually have quite a bit of leeway to play with. Most of the other tracks have a static 98db limit and the Grand Prix circuits are 105db, but I'm just trying to play it safe as the only direction that sound limits are going to go is downwards