mdsarch

I see a lot of people replace the primary muffler on our cars with a cup pipe and then add a g or J pipe as well for performance reasons (and weight as well). Wouldn't it be better to just replace the primary and secondary mufflers with a performance exhaust, like a Fabspeed unit?

crg53

I had a Fabspeed RSR system on my car, but returned it due to poor fitment and an unbearable DRONE in the RPM range you use the most. Don't waist your money. Many people are selling their Fabspeed exhausts for the same reason.
If you want an exhaust upgrade, do cat bypass, primary bypass (cup pipe) or do cat bypass, secondary bypass with a J or G pipe. Please do not do both muffler bypass, way....... too loud.

Vandit

Yup, it's cup pipe OR g-pipe, not both.

Steve Weiner-Rennsport Systems

Based on extensive dyno testing, my suggestion would be a cat bypass and the G-pipe (secondary muffler bypass). Nice sound, no drone, and good power.

Be certain to install custom software for this configuration.

540964

What chip(software) do you recommend for cat bypass, cup pipe and OE final muffler?

mdsarch

Good to know, thanks. Also, can I do the improvements one at a time or best done all at once?

Trj

OK what is a "g" pipe

Mixter

I'm just running a cup pipe (primary bypass) only, no cat bypass or G-pipe. Do I need custom software?

Steve Weiner-Rennsport Systems

Right there,...

Steve Weiner-Rennsport Systems

I would recommend checking your car's AFR's on a chassis dyno to see if you are too lean in the mid-range & upper end. In most cases, these engines are with that modification and need a good chip to correct that.

Trj

Just noticed this was on 964 forum....

garrett1021

I have both primary and secondary removed.

Totally awesome.

I LOVE IT.

if your not afraid of some noise, I would absolutely recommend it

For reference I have a RUF primary bypass and a custom fabbed G pipe

mdsarch

Thanks Steve, looks like this is the way I will go. Based on your dyno tests with the above configuration, what hp/torque results did you get (including new chip)?

Steve Weiner-Rennsport Systems

Hi Mark,

There are simply too many variables at work to offer results that have context for your engine.

Octane, airbox box mods, engine condition, cam timing are just a few that affect the final figures.

We did see several that made between 265 BHP & 275 BHP with good gas.

jfl503

anyone have the schnell bypass? based on comments above, I'm thinking the piece by fabspeed is not worth the extra dough...?

anyone have an used bypass for sale?