SYMES1515

Hi everyone,

Without laboring the point any further I just want a straight answer to this question.

If I am to get a tune and some K&N filters and dont want to shell out for a full exhaust system or have an extremely noisy car, what section of the exhaust would, on its own, liberate the most power without making the car ridiculously noisy?

ie. X pipe, mid pipe, headers, mufflers

I want to keep the resonators for obvious reasons but might entertain the removal of at least one set of cats. Additionally I do not want any cutting and welding, the solution must be bolt on.

with all the knowledge on this forum I hope someone can help.
PS. I live in Australia

propain

Do you guys have cats installed in Australia?

harrower

Headers for sure

RM-6302

Headers FTW.
Short to keep both sets of cats.
Long to take out the primary cats

SYMES1515

Yes we have cats in Australia.

I am aware that headers provide massive gains but please bare in mind the importance of not making the car too noisy.

any other suggestions based on the above requirements, or can anyone shed light on headers not in fact making the car too much louder, or there effect/lack of effect when coupled with the stock exhaust.

alqamzi

MHP catted headers. They are bolton.

SYMES1515

That would be an option if our cars were LHD but we are RHD here in Australia.

superlubricity

Long Tube Headers are not the answer unless you want ridiculously loud. Even with cats it is insane at cold start and WOT. I've heard both configurations in person and it is not for the faint of heart. This is the current state.

I'm still going with Long Tube Headers myself but like you I'm seeking a quiet bolt-in/bolt-out solution. I'm going to try something new to see if it is possible to have the best of both worlds. Hopefully in few weeks we'll know if it is possible.

SYMES1515

Plus you honestly expect me to believe that this is not "noisy" as I'm trying to avoid.

http://www.youtube.com/watch?v=fLDdqxhc_Tc

Sincity

Will it be similar to bhamg's MBH setup?

SYMES1515

Can someone correct me if I'm wrong with the below assumptions about the stock exhaust system.

1. The headers are plain log manifolds which join directly with the Mid Pipe and have no cats?
2. The mid pipe has one set of cats and links the Log manifold to the X pipe section or equivalent?
3. The X pipe section (or equivalent) has a resonator and a set of cats and this joins the Mid pipe to the Mufflers?
4. The mufflers

superlubricity

See above and use this diagram:

SYMES1515

So essentially besides the headers which would be too loud, what would be the next most beneficial change to make to the exhaust system, without going completely catless or making it too noisy, eg deleting the resonator?

if you could refer to the diagram above to explain that would help a lot.

thanks in advance

RNS-11Z

Do the tune, delete 2nd cats, fit x pipe. Thats what i would do.


h.

Even Money

One of the neighbors at the bottom of my street notices my car passing each day.....from the sound only. He thinks its pretty cool....wait till he hears the catless LTs.

Super is right, it's the cold starts and WOT that'll garner attention...Otherwise, it's not that bad.

Brian GT PRO

My vote is for a Single X or Double XX, but I'm biased

C63newdude

Are you serious?. The cats are probably installed by any car manufacturer worldwide regardless of the location. I don't think that there are any cars without cats being built any where in the world.

malooamg

hello fellow aussie <im in perth ,have done tune and air box mod only on my c63 and have run a 11.61 down the 1/4 mile @120.3mph.the company i used for the mods was modern horse power ,highly recomend them .the most gain to be had on the c63 is in the headers and centre section, leaving the standard rear mufflers keeps the noise and droning to a level you would expect from a merc.

bhamg

S - My MBH system utilizes a very restrictive swappable aftermarket CA-legal primary cat and OE exhaust components downstream of that. I just might have the quietest LTH installation out there. The system makes a great sound but under moderate+T to WOT conditions it'll attract a lot of attention. Where it is a PITA is that even when you conduct a normal pass in city traffic there will be no way to keep the db level down. I've had LEO's follow me for that reason while I've been driving (IMO) totally normally. Frankly I did expect the system we designed to be a littler quieter overall...LTH's deliver the power but they are not for the faint of heart,