Tone Down Exhaust

[DECIM8]

Step one - Admit you have a problem.

Ok. I have a loud exhaust - 3.5 catback is not helping - Yes it has a mid muffler and rated a 93Db

Step two - Options

Apexi Active Tail Silencer - This works by a spring and seal which is pushed out via exhaust pressure, it fits into the exhaust like a normal cannon silencer and is dynoed at 16% all over power loss, which is acceptable for street use. It dropped sound overall by about 20% (no idea in db ratings)

Pros - Fairly cheap $200 in comparison to other options, Easy to remove.

Cons - Pain in the ass to actually be bothered removing, Abit of a eyesore, noticable to the police, noticable loss to HP/KW

Varex Exhaust cannon - Adjustable butteryfly valve which recirculates air through an external muffler to minimise sound, Sound drop is huge. I was hoping to weld it in after the cat as my catback is a N1 Mega Kakimoto with a very unique sound. What do people think about this possable?

Pros - Easy to work, Best at silencing.

Cons - Has to replace my current cannon which I wish to prevent, If replaces cannon you can see the butterfly, Exhaust size to large for biggest avaliable inlet they currently make, Will look tiny next to the 4.5" outlet cannon I have now.

Apexi Flange fitted Exhaust control valve - Worked via a manual wire which fires a butterfly valve to fully close, this would be pre drilled with 10mm holes to minimise airflow backup yet muffel sound (small holes is how a silencer works)

Pros - Easy to fit, Unsightly, Decent silencing, From what ive seen may be able to be hooked up to a motor/cog setup.

Cons - Controlled via big clunky cable and setup, may not be easy to trigger

Bigger, better mid muffler/hotdog - Currently the hotdog I have takes up almost the whole cat back its about 1m long so another hotdog would have to be revamped.

Pros - Cheapest.. Easier?

Cons - Chop up my nice SS system and will weld in some ugly mild steel crap.

So.. You've got the info, what do you feel is the best option? Do you think some of the ideas can be done and be sucessful>?

[andygtr93]

It all depends on how much you want to spend... If you're a tightass like me, you'll go the cheapest way which will still leave you will the same power figures

It's all physics. Sound travels as a block, if you break up the block, you quieten the sound. When I was at apprentice training, a guy in my class had a silvia and the exhaust was too loud. All we did was drill 4 holes near the end of the exhaust tip and placed really long split pins so they formed an X across the exhaust tip...

without a dB meter we don't know exact numbers, however the exhaust note was obviously quieter and there was no performance loss whatsoever

If you don't wanna start replacing exhaust components, this is a much easier and cheaper alternative...

[DECIM8]

Could do that too, would prefer to do it as a flange in the exhaust however. Sounds like a good idea but not too keen to drill holes in the exhaust.

Will try with a single pin though. Thanks!

[DECIM8]

anyone else?

[joeyjoejoejuniorshabadoo]

cheapest = clutch in around cops

[R31Nismoid]

1. Hotdog = useless. Countless people have tried them and they dont do shit.

Just get TWO decent sized mufflers, and thats all you'll need.

You'll still have that niec RB note, without that attention drawing drone and noise about town

93dB is not a loud exhaust by the way

[Dahtone Racing]

Hey Nathaniel

prsonally i would go for a Varex muffler, i was going to use one on my car but never got round to doing it

i will be using one on the WRX though

but in your case because you dont wanna butcher up your current exhaust

i would go for something like the apexi style valve

simply because

1. it works

2. you dont have to cut anything

3. im pretty sure you can find and electronic version

[godzl1975]

cheapest = clutch in around cops

lol..that works but not when they have pulled you over

here is a site of a place in ingleburn that only sells the mufflers...thats what i will be doing to...chopping up SS kakimoto canon

http://www.smb.net.au

[DECIM8]

Thanks guys.

Clutch in is what im current doing, Idle is still loud and Ill be gone if I get RBT'd

Resonators and Hotdogs - Same things?

93db is the rating, due to its age I doubt its close any more.

The Varex is good but they dont make a 3.5 entry which will be a bottle neck with power. Im thinking Apexi device thanks Anth.

Thanks for the help.

Mufflers to much sound loss.. I think I just want to much - Dont we all

Edited August 24, 2008 by DECIM8

[gotRICE?]

The Apexi sounds good. You dont need to cut up a flash exhaust system and is easy to open up when you want. (also simple to remove)

I find that in my 33 (3" turbo-back, split dump/front, HKS Silent Power) is louder at idle, so keping the revs constant around 3200rpm its silent.

Its a funny one, i dont know about others with the same exhaust, but the higher the revs the quieter it gets.

[SLY-25T]

hey Nath

dunno y you would wanna change the exhaust. sounds great how it is! but i dunno if this will help with your pipe sizing but check this exhaust out

http://xforce.com.au/cars/view_car/29

hope you find wat u want m8.

Jaye

[R31Nismoid]

The Varex is good but they dont make a 3.5 entry which will be a bottle neck with power. Im thinking Apexi device thanks Anth.

Not if your making less than 300rwkw. It wont be a bottle neck at all.

[SLY-25T]

must read whole thread b4 i reply. lol.

sorry

[DECIM8]

Thanks for the replys again. Apexi device it is - Will remove it in tuning as ive heard it causes issues.

Cheers

Nathaniel