RevGTO

iTrader: (12)

Would it make sense to install a new y-pipe from the cats back with a GMMG? I'm not planning on headers anytime soon. I have a friend with a shop who bends good pipes and the price would be good. I'd be willing to spend the money if it'd help the flow - the crimped stock pipe looks like it flows like ***.

JamRWS6

Unless it is dirt cheap it's not worth it. That pipe doesn't flow as bad as you think it does because it is also wider.....plus it doesn't bang.

4mula

waste of money doing a y pipe.

RevGTO

iTrader: (12)

Thanks, guys. I have no motivation to spend money on useless mods.

2_wacko

iTrader: (2)

Just get the GMMG put on.

Dawg One

I did this backwards.
I ripped off the crimped, flat Y-pipe on my Firehawk two years ago and replaced it with the SLP larger diameter Y-Pipe. Made a 5 RWHP gain. Sounded better, pulled ever so slightly better. It's not a dramatic difference, by any means.
Put the GMMG Chambered Exhaust on this past January and my Hawk Rawks!!!

monyhunter

Dawg One, have you dyno'd the difference after the GMMG? and what exhaust/catback did you have when you first replaced the Y with the SLP Y? I'm wondering how much sound difference just the SLP Y will make with my Dual/Dual.

Dawg One

I haven't had the chance to yet. I had the factory SLP Dual/Dual when I replaced the Y-Pipe. This is considered one of the free-est flowing catbacks on the market, but it was too quiet for me. The sound difference will be minimal. The GMMG really wakes the car up.

Z-286speed

Have you already installed the GMMG or bought it??? If not, get some LT headers and true duals!!!

Catskynr

When I bought my GMMG a few years back, I ask GMMG engineers this exact same question. What I was told by THEM was a Y-Pipe (with stock manifolds) made absolutely no difference on the Dyno and was a waste of perfectly good money. Hence why the Blackbird still utilized the stock Y-pipe.