Dr.G

iTrader: (1)

I've got the exhaust setup on order, was wondering if I should add a high flow cat converter or stick with a regular stock replacement? what's the good and bad with a hi-flow cat? With a high flow cat, will I have to worry about passing emission tests?

lex400sc

I would get a performance cat. I don't know about the smog laws in Georgia, but I'd imagine they are substantially lower than those of California. They do make perofrmance cats that are 50-state smog legal, but my muffler guy keeps telling me it won't pass the visual check here.

Here's what I'd do... Buy two single cats, cut your exhaust pipes at the first y-pipe, plumb in your own 2.5-inch dual pipes, make them as straight as possible (running inside the suspension pillars), weld the inline cats, and weld on your Greddy mufflers. Your exhaust will sound very meaty and aggressive. You'll love it.

The problem with some cats is that they are so open that they don't warm up quick enough or at all and you get condensation build up and ultimately RUST in your pipes. The advantages of a good performance cat is of course less back pressure and less sound dampening.

Dr.G

iTrader: (1)

I understand your suggestion, but with the Greddy MX, this is a complete cat-back system- so getting a custom piping job done isn't necessary correct?

lex400sc

From my understanding the Greddy MX is a muffler with a short mandrel-bent pipe and flange that lines up with the stock resonators. You'll still have the the stock "spaghetti" piping with 2-inch pipes and redundant bends. Not to mention it's still a single exaust system with four mufflers and three cats. You can try out the Greddys stand-alone since they are very simple bolt-ons and see how you like them, but I'll tell you now: your exhaust can sound much more aggressive with dual 2.5-inch straight pipes and dual performance cats. Replumbing your entire exhaust system will only cost you about $100 total in parts and labor (plus the cost of new cats and mufflers).

Soarer_25GTT

The GReddy MX is only resonator back? I went into a speedshop here is Sydney, and the guy told me that it was a full cat. back system. Mind you, I've got a Soarer 2.5GT so I'm not sure if he was talking about the MX muffler for both the SoarerTT and SC4, but I was pretty sure that he said it was a cat. back system.

There is also another alternative, the A'PEXi Super Megaphone. This exhaust would look REAL nice on any Soarer/SC...


I was reading an article on Auto Speed (they were testing a Soarer 4.0GT-L, similar to the US SC4) that the Soarer's exhaust system was restrictive, so I would get the whole thing redone if possible. Peter Scott has done much research on exhausts for the V8 Soarer... give this site a look for more information. I would get a new cat converter as well for maximum flow, but I'm trying to get a system that is not too loud (i.e. nice mellow 6-cylinder sound on idle and normal cruising, but a more "serious" tone when the throttle is open)... any suggestions?

lex400sc

I don't know for sure, but back when I was shopping for mufflers, I remember running into a picture of the Greddy MX muffler with a short inlet pipe, definitely not long enough to reach the cat. Remember you have about 5 feet of piping to reach the cat from the rear muffler. I'm looking into some performance cats that are CA-smog legal. Any idea on where I would go to find out if a cat is legal on my car? Those Apexi mufflers looks good, very OEMish. I would tuck them into the bumper a bit more though.


Here's one of Pete's exhaust pages...
http://www.users.bigpond.com/pgscott...asurements.htm

Dr.G

iTrader: (1)

Yeah, the Greddy MX exhaust system that I'm speaking of is the entire catback system, not just the mufflers...with that being said, would installing aftermarket hi-flow cats be a good idea or should I stay with OEM? Another option that seems to be popular is getting an entire custom piping job done along with either Magnaflows or Apexi N1 mufflers. If given the choice between a custom job and the Greddy MX system, which would you guys recommend? Grant it, I'll only be paying ~$575 for a new Greddy MX system. Bottomline, I'm wanting an agressive sound but nothing obnoxious...If anyone has the Greddy MX setup or something similar on their sc300, please give me some feedback..

lex400sc

Well I haven't heard the Greddy MX in person so I can't give you a fair comparison, but my exhaust setup cost about $400 total for the piping, hangers, mufflers, and labor. It sounds great on my car, but it may sound totally different on the SC300.

wolfy187

its cat- back. i have the setup. its subtle. my wastegate does all the talking for it.

it has its own resonator replacement. when i just had the exhaust, I've never heard it outside of my car. but everyone says they can tell teh difference. I recommend you get it. it looks clean and i've had no real problems with it.

you can't beat 50 state legal too

Arthur

Dr.G

iTrader: (1)

I'm convinced to go with the Greddy MX setup, now the only other dilemma I have is whether or not to add in hi-flow cats? Would this addition be worth the money spent in terms of complimenting the Greddy system for added performance? I already have the cold air intake...Anybody?