kiwi 911

OMG.......existing threads and you tube clips are doing my head in.........

The brief is simple, I want an exhaust solution to assist with making the engine rev freer / better, that is close to stock sound (i.e. quiet)

The V8-ish gurgle sound is very cool, but not for me........

I don't have smog laws in NZ, so want to look at de-cating and running a standard muffler.

I do like the sound of RSR mufflers, but understand this is acoustically cosmetic only, and will not actually make the car revv better or go faster.

What is the quietest de-catted solution that doesn't pop and gurgle......??

Your help (and sound clips if poss) would be appreciated please.

Thanks in advance........

rsabeebe

de-cat and quiet? maybe add a resonator in place of the cat? add to that the quietest, free-flowing mufflers you can find.

OverBoosted28

You can gut the cats and then clean out the mufflers. It is not near as loud as my bypass pipes. Smooth slight rumble at the most.

vincer77

Cleaning out mufflers is essentially what RSR does.

RSR with cat bypass sounds pretty good. I think that Fisters sound best, and have a better flowpath than RSR.

The cat bypass will help with performance.

mgianzero

If you know of a good welder, have them weld a bypass pipe (simply a pipe connection outside of mufflers) and large enough (same diameter as inflow/outflow pipes) it will sound very throaty with no gurgles. Mine sounds a little more aggressive than a Fister II and doesn't require anyone to open the cans.

OverBoosted28

These are the by-pass pipes I made. But I didn't think you wanted it much louder.

steve porter

I have a set of cat bypass pipes that I will sell for what they cost $500.00 ausi dollars ,but with std mufflers they are about as loud as fister stage 3 give or take a few db

kiwi 911

Nice car Steve - identical in year and spec to mine.

Are you able to take a sound clip of them??

steve porter

They aren`t on the car any more, I have fister 3s on now as I was worried about getting busted without cats. it did sound good though

cdmdriver

Ok,
All I can do, is tell you my preference, based on my experience.
First I had the stock exhaust and stock catalytic converter.
Second, I have installed the Fabspeed sport cats and Cat bypass pipes, with stock exhaust.
Third, I have installed Fister stage II exhaust with stock catalytic converter.
Fourth, I have install both the Fabspeed Cat bypass, and sportcats with the Fister exhaust.
My opinion.
First, stock cats with stock exhaust. - If I can hear the engine noise over the exhaust, something is wrong.
Second, Fabspeed sport cats with stock exhaust. - Not bad, the exhaust note is louder(better), lower end torque is a tiny bit less, but the upper end is opened up quite a bit.
Third, The Fister stage II exhaust with the stock cats is actually quite close to the Fabspeed sportcats with the stock exhaust. The exhaust note can be kept under control with lower throttle inputs, but the volume can be increased substantially with WOT. No interior drone, just a very nice exhaust note. MY favorite.
Fourth, The sound with the sportcats and Fister II exhaust was much louder than I thought it was going to be. I can not imagine having the stage III with combined with the Sportcats, it would be way too loud. In fact, I was warned about the noise level with the Stage II exhaust and the sportcat combination, from NBPD. Additionally, replace the sport cats with the bypass pipes and you take the noise level up another notch and add in the exhaust smell.
I hope this helps

MielsOnWheels

I'm happy with MS mufflers and FD 200 Cell Sport Cat...raspy but not over the top