Newbie - Exhaust Question

martrogers · #1 (**permalink**) 09-09-2006, 08:17 AM

Hello everyone, hello Brett.

I've been so busy figuring how to build my Cobra that I forgot to ask the guys who know.

I reckon I'm about 70% towards registration, about to strip down, get the exhaust sorted and final build.

I've only managed to look at the first 42 pages of the forum

so forgive me if this has been answered. Can anyone advise size and make of mufflers I am likely to need to satisfy the noise ADR (90dB?).

I am (deep breath) running a V6 Alloytek motor - double dark? I will be happy with fake sidepipes and a permanent underslung exhaust.

Also, is it worth going for stainless or is ceramic coating better?

Thanks
mart

boxhead · #2 (**permalink**) 09-09-2006, 04:56 PM

Wow that is a different choice in the engine department, should make for a great around town cruiser.
Did you get the engine from a VZ or Rodeo?

I cant help you with exhaust choices but if you go to any of the more popular exhaust stores they should be able to help considering there are thousands of VZ's out there with your engine.

martrogers · #3 (**permalink**) 09-09-2006, 05:30 PM

Thanks boxhead

I bought a VZ SV6 at the NRMA auctions. I hope to keep the electronic goodies such as stability control and tiptronic, I have the 5 speed auto box.

I also got Brian to put on the IRS from the Commodore.

Needless to say the mufflers from the Commodore are big and many, I assume I can get smaller but higher performance (quieter) ones.

ADR's are a big concern when starting a build these days....

Mart

400TT · #4 (**permalink**) 09-09-2006, 05:33 PM

Wow, another Holden V6 Cobra. Had a Harrison built up here with the earlier V6 Holden engine.

Personally I would go see a few exhaust shops. Just not going to be the experience here. I would expect cat, resonator & good muffler would do the job well.

If you are on a budget, I would just get the exhaust made out of mild steel. Get it painted and it will be fine. A nice upgrade would be to ceramic coat the headers. Little benefit in ceramic coating the rest of the system. Just make sure you put some insulation between cat and floor etc, those cats generate a fair amount of heat. Seen more than a few Cobra's with smoking carpet from cats.

Would love to see some pictures and hear how it progresses.

Shelby400 · #5 (**permalink**) 09-09-2006, 06:12 PM

Hi Martin

Good to see you on the forum. I agree with Craig, theres simply not enough experience on this forum with the use of these motors.
Best to go and talk to the exhaust guys. If they are a quality outfit then they should be able to advise you straight away.

When are we going to see some photo's?

Brett

Aussie Mike · #6 (**permalink**) 09-10-2006, 04:49 AM

Those Holden V6 motors can make a lot of HP if you do the right things to them. A pair of turbos would have you embaresing most of the cobras out there.

I saw a GN Buick V6 Turbo charged powered Cobra in the US a couple of years back ind it was a weapon.

Turbos do a good reasonable job of muffling the exhaust too.

Welcome to the forum Martin.

Cheers

400TT · #7 (**permalink**) 09-10-2006, 07:22 AM

Quote:

Originally Posted by Aussie Mike

Turbos do a good reasonable job of muffling the exhaust too.

Yep, big turbo's do a fantastic job of the muffling the exhaust. Just look at my brother's Harrison and a nice full(noisy) exhaust note when normally aspirated. Fitted turbo charger and the exhaust even at full noise, is just about silent...although you can hear a certain whine and woosh.

So follow Mike's advice, don't go to too much trouble on the exhaust, just fit a couple of big turbo's and you will have no problems with noise test. Isn't that what you were saying Mike.

Aussie Mike · #8 (**permalink**) 09-10-2006, 05:58 PM

Exactly right.

Cheers

BMK · #9 (**permalink**) 09-20-2006, 12:17 AM

Aussie Mike

That turbo V6 Buick Cobra is owned and driven by a fulltime airline jet pilot..

. Must really fly..

Sounds like a great option.

cameron02 · #10 (**permalink**) 09-21-2006, 01:05 AM

If you are running a single system exhaust then the cats plus one big muffler would probably be OK.

If twin system then cats plus small muffler on each side should do it.

Stainless steel looks great. Ceramic coating helps to shield heat but in my opinion does not look as good. Does not matter to me as I dont intend spending that much time under my car.

If you go for ceramic coating then HPC is better quality than JET HOT from the stories I have heard. I got HPC coating which is no probs so far. I even got the mufflers coated.

martrogers · #11 (**permalink**) 09-21-2006, 02:44 AM

Fantastic, thanks Cameron. Presumably muffler performance varies, are there any particular brands I should look at? I dont want to take any chances for rego.

Martin

cameron02 · #12 (**permalink**) 09-22-2006, 02:08 AM

H'mm

, Best ask the experts. ie exhaust place or muffler manufactuer.

If you are only concerned with passing rego then you could put cheap (even 2nd hand) big mufflers on and replace then with small ones after rego.

I'm no expert . A professional would probably tell you that the type of cat converters you use may also effect noise levels.

Rob. Smith · #13 (**permalink**) 09-22-2006, 05:58 AM

I might be a little late but from my own experience....cheap aftermarket mufflers did the job for rego, BUT... my car was wisper quiet but failed the first time because the whistle was too loud ! Go for large diameter pipes after the muffler. despite what the muffler man says.

pezza · #14 (**permalink**) 06-25-2007, 06:56 AM

Quote:

Originally Posted by martrogers

Hello everyone, hello Brett.

I've been so busy figuring how to build my Cobra that I forgot to ask the guys who know.
Martin did you receive the PM and email I sent you last week?

I reckon I'm about 70% towards registration, about to strip down, get the exhaust sorted and final build.

I've only managed to look at the first 42 pages of the forum

so forgive me if this has been answered. Can anyone advise size and make of mufflers I am likely to need to satisfy the noise ADR (90dB?).

I am (deep breath) running a V6 Alloytek motor - double dark? I will be happy with fake sidepipes and a permanent underslung exhaust.

Also, is it worth going for stainless or is ceramic coating better?

Thanks
mart

Martin did you receive the PM and email I sent you ?
Pezza

martrogers · #15 (**permalink**) 06-25-2007, 08:45 PM

Yes, sorry mate, I have now replied to it.

Regards
Martin

jess · #16 (**permalink**) 06-27-2007, 04:13 AM

standard vn comm rear muffler is awesome for keeping things quiet

Asp302 · #17 (**permalink**) 07-04-2007, 07:21 AM

brian made his own set up and it past first go but that is a v8.try tony at tyre power his exhaust man at the shop big dave is great every time my car gets driven i thank the gods for him.ps mine is homebush as well