VZ V6 Exec Sports exhaust sounds TERRIBLE Pls Help

[DeathVZaudiO]

Hey guys,
So basically im after some advice or direction on what i can do. Heres the story.

I went and lashed out on my standard 3.6litre VZ exec with a full 2 1/2" Dual stainless sports exhaust.
Pacemaker Extractors, HighFlow stainless 2 1/2" Cats, Mach1 Dual stainless 2 1/2" system with individual intermediate mufflers and a shared rear muffler with dual 2 1/2" tips at the end.

By rights this system should be insane.
Not the case.
When the car is under any kind of high revving load 3000+rpm it all of a sudden magically sounds like a rotary with this crazy vibraty/buzzy sound instead of a nice clean note (cant say roar cause its no v8). Also the volume is quite excessive and if i take off within 500m of a cop im gonna be pulled, booked, fined and sent directly to the EPA. But in saying this the system also provides no drone and it sounds magic cruising along the freeway doing 100 on cruise, it sounds pretty average however driving in traffic doing about 80. Would a Mace CAI solve this?? Im not gonna see that for another 2 weeks though, gotta save the coin.

Mr exhaust man says that he wants to remove the high flow stainless cats (i think not) and this will solve the problem. I want this badboy to flow. I said there has to be another way...... Is there??????

So what advice can you guys offer me that i can relay to this dude so i can still have the mean system in place with removing some of the goodies. Mufflers or something.

Im not worried if the volume wont drop if it comes to it, i can control my right foot and have had many an insane exhaust on my cars. Just the buzz is sooooo bad.

Thanks heaps in advance guys. Im dropping the car in to him next Monday so i would like to offer some advice from people who may know what the problem could be.

JOSHA!!

[torana355]

What you need are some high quality resonators. The bigger the better!!

[DeathVZaudiO]

I just got an sms from a mate saying that i should be rid of the 2nd part of the dual system after the intermediate mufflers and go single 3" for the rest, does this sound right??

Resonators you say, cool cool.

[torana355]

Well intermediate mufflers and resonators are basically the same thing but whatever you have in there needs to be bigger/more effective at cutting out the sound.

[DeathVZaudiO]

Well intermediate mufflers and resonators are basically the same thing but whatever you have in there needs to be bigger/more effective at cutting out the sound.

Ok cool, thanx man.

[Escape-The-Fate]

drop the dual set up and go back to a single 2 and half inch..either that or go to a 2 1/4 dual set up..any alloytec engine sounds pretty bad with a big system..and you will never get them to sound like an ecotec..every vz i've heard with a zaust sounded like a wet fart or a screaming kid..

[Not_An_Abba_Fan]

As I stated in the other thread, you need to fit a couple of hot dogs just after the cats. If you can, move the cats forward a bit too. The original system has resonators there to take that sound away.

IMO, twin 2 1/2" is a bit big for the 175, but if you fit an X pipe in the system just after the flanges where the system bolts up to the cats, then you will gain some bottom end and lose a bit of that shit sound too.

[jaisvz]

I just got an sms from a mate saying that i should be rid of the 2nd part of the dual system after the intermediate mufflers and go single 3" for the rest, does this sound right??

Resonators you say, cool cool.

this is what i have and it sounds great.

[DeathVZaudiO]

GOLD guys, thanks for the input thus far.

[impulsive]

i would also lose the twin system, i have after cats a single 2.5

[Fishman88]

I would copy the original catback system except use a Sureflo x-pipe and use hi flow quality mufflers. This is wat im gona do soon. Theres a clip of monaro327 SV6 on youtube with redback mufflers sounds good n nice deep note not tinny. Hope that helps you!! cheers!

[DeathVZaudiO]

Hahaha, im gonna smash this guy with info on Monday and he is gonna hate it. Top stuff. Thankyou guys. I just have my fingers crossed for a good outcome.

[svsex]

Hahaha, im gonna smash this guy with info on Monday and he is gonna hate it. Top stuff. Thankyou guys. I just have my fingers crossed for a good outcome.

haha good one, well i no im the millionth person to say so, but the single system is the way to go i got a 2 1/2 inch, sounds pretty sweet and burbles down gears,

the alloytec never liked the twin systems, because they like the back pressure? well anyways i gota say the ecotecs do sounds real nice compared to the vz's. but ive heard a few nice vz around maybe with more products coming out and better desiged systems, it might change

[Not_An_Abba_Fan]

It's actually the opposite, alloytecs don't like back pressure, in fact no engine likes back pressure. Back pressure in an exhaust is a bad thing.

Going twin until after the mufflers is better as you are keeping exhaust velocity to a maximum. Going into a single after that will kill the drone but not sacrifice flow.

Some people like the sound of a single on the alloytec, but they do drone, if you can put up with it then go for it.

[torana355]

It's actually the opposite, alloytecs don't like back pressure, in fact no engine likes back pressure. Back pressure in an exhaust is a bad thing.

Going twin until after the mufflers is better as you are keeping exhaust velocity to a maximum. Going into a single after that will kill the drone but not sacrifice flow.

.

Exactly, no engines like back pressure. People get back pressure confused with exhaust velocity and pulsing.

[DeathVZaudiO]

Would my intake system make much of an impact on my exhaust note? What im getting at is should i get my CAI before i take this badboy in to be fixed on Monday or not??

[Not_An_Abba_Fan]

Yes it will make a difference to the note, more noticeably the induction noise, but you can tell the difference with the exhaust too. It won't make any difference to the crappy note though.

[Daz750]

I've only just started playing with the Commodores, but a 2 1/2" with a good muffler and Cat sounds great and flows well......

[bigdaddycool]

Note of Interest: VZ Exec Alloytechs sound horrid due to the cam settings........ if u ever changed it to like a VE Omega tune....... the sound would change as their cams are tighter (not as much air).

-- An idea, I had a similar problem when I kitted my car out........... either change the whole cat back to a single 2.5" ....... or u could try "adding" two resonators (one for each line) directly after the cats which will change the note........

AND OR......... have them add a H-Pipe which will also change the note.

I have all of the above. Mines virtually quiet, but has a real unique sound on take off...... My sound changes everytime I change my tune

[GTP 85]

I don't have personal experience to put forth a proper suggestion, but i do have a few comments about it.

There's a particular VE that boots around Adelaide that i always see... well hear lol. First time... i was at the petrol bowser filling up and could hear a lancer gearing down and hammering out of the corner. as it zipped by i swung round to see a mustardy green VE!!!! no lancers in sight! i could have sworn it was a lancer as my bro owned a riced out one. I couldn't believe it.

Anyhow back on topic. First thing that came to mind after reading the OP was... Isn't twin 2.5 WAY oversize for such a small capacity engine?? I have messed around with 4 different setups on my heavily worked ecotec and the best for allround performance and sound was twin 2-1/4, with twin intermidiate mufflers and rear hotdogs. I never ever considered twin 2.5 as i felt i didn't have enough HP to need it. and mine makes 250rwhp

ALSO... to DeathVZaudiO a mate of mine has a very similar setup to yours, except in 2-1/4 on his VY (ecotec) and it makes exactly the same noise you describe. it may just be the pipe resonance? Not just an alloytec issue? IMHO i think the hiflo cats have a lot to do with the crap note, but thats just me..

Sorry for the novel..

Don't flame me ppl. Just conveying my thoughts.

[Commydoor]

how long has the system been on?...the one i had fitted to my SS took weeks and weeks to get the soot buildup inside the pipes to tone it down to a nice crisp howly bark...my advice is wait till you throw the CAI on which if thats a few weeks will give it time to get that buildup on it then if its still the same take it back...and run some 98 in it for a while, while your at it, with the CAI will run a tad smoother...

[DeathVZaudiO]

Yes it will make a difference to the note, more noticeably the induction noise, but you can tell the difference with the exhaust too. It won't make any difference to the crappy note though.

Ahh cool, what i was getting at was should i do this before he rejigs the zorst to avoid a disaster to the note if i change it after.

[DeathVZaudiO]

I don't have personal experience to put forth a proper suggestion, but i do have a few comments about it.

Sorry for the novel..

Don't flame me ppl. Just conveying my thoughts.

Thanks mate, no stress about the novel, input is what im after, much appreciated.

[DeathVZaudiO]

Note of Interest: VZ Exec Alloytechs sound horrid due to the cam settings........ if u ever changed it to like a VE Omega tune....... the sound would change as their cams are tighter (not as much air).

-- An idea, I had a similar problem when I kitted my car out........... either change the whole cat back to a single 2.5" ....... or u could try "adding" two resonators (one for each line) directly after the cats which will change the note........

AND OR......... have them add a H-Pipe which will also change the note.

I have all of the above. Mines virtually quiet, but has a real unique sound on take off...... My sound changes everytime I change my tune

Awesome, another avenue, Thanks man.

[Not_An_Abba_Fan]

Ahh cool, what i was getting at was should i do this before he rejigs the zorst to avoid a disaster to the note if i change it after.

No harm in doing it first, that way if you do it after and you're not happy, you will have no comeback to the exhaust place.