viperbob

OK, I've got the FVD cat bypass with the Fabspeed sport turbo muffler. It now sounds like an exhaust leak at idle, then quiets down as you start revving. Now the biggy. Has anyone tried the cat AND muffler bypass?? Just wondering how loud it would be before I try and pull off my mufflers. <img border="0" alt="[jumper]" title="" src="graemlins/jumper.gif" />

Thanks in advance

TB993tt

viperbob
I tried it - sounded like an inboard engine powerboat but IMHO way too loud, I use Cargraphic mufflers now which are resonance free and just on the limit of what I consider acceptable - maybe I am getting a bit old <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

Anir

Bob,

If memory serves, Greg has removed both the cats and mufflers on his race car - i.e. he has the Fabspeed straight pipes in place of the mufflers.

Granted, it's a NA car, but it is LOUD, no make that really loud.

viperbob

Anir,

In theory, the exhaust flowing through and spinning the turbos will deaden the sound which is not the case with a NA car. As the turbo spins more, it will actually even get quieter. The question is just how much.

TB993TT,

Thanks. I'm getting older, but still want a little more than I've got with just the Fabspeed mufflers. Maybe I'm deaf now from my last project which as a Dodge Viper that had headers. My entire neighborhood was happy when I sold that car...

Q

viperbob

can you make a .wav file for everyone to hear your system ?
how does it compare to my "modified standard" mufflers ?

<a href="http://www.qplanet.org/q/post/STD_driveoff.wav" target="_blank">Standard mufflers</a>
<a href="http://www.qplanet.org/q/post/MOD_driveoff.wav" target="_blank">Modified standard mufflers (effectively muffler bypasses)</a>
<a href="http://www.qplanet.org/q/post/MilieMiglia.wav" target="_blank">Mille Miglia mufflers</a>
<img src="http://www.qplanet.org/images/auto/DSC00742m.jpg" alt=" - " />

911/Q45

A four wheel dyno, now I've got a chubby!

viperbob

Q,

I'll try and take some recordings and post them.

viperbob

Well I tried it and it is even too loud for me. Not by much though. It really does not need the full muffler setup (with the additional weight), but it does need something. There is really no room to add a balance pipe (work great on my 84 911). I also can not find a simple Dynomax Ultraflo muffler that has the inlet and outlet on the same side that could get the DBs down just a touch. As the car speeds up a little, it actully gets a little quieter from the turbos spinning. I'll see if Joe at Fabspeed has any magic he can recommend....

Q

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by 911/Q45:
<strong>A four wheel dyno, now I've got a chubby!</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">LOL
the guy operating the dyno is Dom Rigoli
he is known for building the worlds quickest WRX
He is now sending "quick" motors over to the USA

oh, for the record, the 993 ran 268HP @ 4 wheels
[add 15% to equate it to US figures.
Dyno Dynamics read lower than other brands]

VIPERBOB
oh well
I will do a recording of mine when the cats are removed