ACCELR8

Does a stock WS6 catback flow well enough for a h/c car? Say a car with MTI stage 2 5.3L heads (or AS stage 2 5.3L) and a TR224. Or will the stock catback hurt performance? If so, which catback for better performance, GMMG or Magnaflow?

Just trying to plan for the future.

Thanks,

Jim

black_z

iTrader: (4)

You will definetley be leaving a few HP on the table, as well as sound. Both Magnaflow and GMMG sound very good, the GMMG is pretty spendy though.

ACCELR8

Thanks for the reply!

TruBloodTransAm

iTrader: (24)

get the WS6 exhaust and a cutout

ROLSCH

Mark McPhail of GM told me that the stock cat costs 10 hp on a 400 hp LS1

black_knight

iTrader: (1)

You will definately be losing power with a stock catback.

You will also be missing out on sound bigtime. Go for true duals for the best gains in both.

ACCELR8

I know this is very subjective, but is GMMG really loud on a h/c car with headers and cats? I would like an exhaust that sounds tough, but I don't want it to be obnoxious.

After reading the replies in this post it's apparent that I should get a catback. I'm trying to decide between Mangaflow and GMMG. I'm not concerned about price. I'm only concerned with how loud it is and how well it flows. Sorry, I'm sure this is a common question, but if you have any imput it would be appreciated.

Thanks,

Jim

SouthFL.02.SS

Borla flows very well, even with the full plate on and the exhaust going through the muffler.
For obnoxious moments, you can run open plate. Even better, you can get an electonically controlled butterfly to switch from quiet to loud.

1RawTA

iTrader: (1)

i know someone who is taking this approach with a fully built 383 ci stroker ls1.. he is aware that he is leaving some hp on the table, but he wants somewhat of a sleeper approach, he is just gunna leave hte stock catback for a while then eventually get a better one once everyone figures out what he is packing

Drew98TA

Where might one aquire such a butterfly?

Mike 01WS6

Q-Tec electric cutout in place of the plate.

2KThunder

iTrader: (4)

They are a site sponsor:
http://www.quicktimeperformance.com/QTEC/
Very nice product I might add. Cutouts are good, but you lose time and the cool factor when you need to unbolt the cover, not to mention the plate might be hot and you might not be able to reach it. An electronic cutout fixes all that. You can control it whenever you want from the cockpit. Very James Bondish in a hot rod sort of way.

PunkNPonys

iTrader: (2)

If your still trying to decide out of the magnaflow and GMMG i vote for the GMMG. It sounds awesome. I heard it on a SS down in the valley.

30th TA 0219

Well, Nineball just turned 426 through the stock cat-back on his 02 SS, and I think his Formula had the stock cat back!

SouthFL.02.SS

Yeah, but the stocker's keeping about 15-20 ponies bottled up.

Durien

another vote for the QTP cutout...they are awesome..i run my stock SS exhaust.. and their cutout....my car seems to like it

ACCELR8

I'm actually trying to decide between Magnaflow and GMMG. I'm leaning towards GMMG, but I'm concerned that it will be too loud once I get h/c. I don't mind the car being a little loud, I just don't want it to be obnoxious. As for a cutout, I'm sure they work great, but I'd prefer not to use one.

Thanks,

Jim

pushinfreight

I have had my GMMG exhaust sinece I bought my WS6 in 2001. Yes it is louder than the stock one but it is not real loud until you get to about 3k then you start to hear the sweet music of the motor. I do not have heads and cam yet but if you are going to change to heads and cam keeping it quiet is going to be real hard. Trust me if you get the GMMG exhaust and you are pushing it people will know.

BadAndy

I have LTs, ORY, and a WS6 muffler. The idle is somewhat louder than you would expect from a stock muffler, but WOT is quiet as greased smoke. Nothing is going to be real loud with cats.