mufflers and noise

Ant · #1 (**permalink**) 06-02-2003, 05:15 AM

I am interested to know what others use for mufflers with sidepipes and under the car, I am almost 100% sure that my system will be under the car, brands we have here is Flowmaster and Supertrapp mufflers, I think they will probably restrict noise to about 90dba, which is crap!

There is a major problem here with "Hoons" and they are doing skids killing themselves and have caused the Government which is about to pass leglislation restricting noise, but its not all bad as your car has to run what it was built with so that gives the Cobra scope, but if you own a modified Honda with a 6" stainless straight through muffler, it will get the get off road card.

CowtownCobra · #2 (**permalink**) 06-02-2003, 07:22 AM

Most side pipes here are (lightly) packed with glass, the old "glass packs". Supertrapp makes a lot of racing units for sprint cars and midgets, so they must flow well.

A "Hoon?"

I would be very interested in how that word came to be.

walt347 · #3 (**permalink**) 06-02-2003, 08:30 AM

A J., 90dba is not that bad, belive me. I had to restrict noise to 82dba (at 3'400 rpm, 2nd gear, 7 meters distance to the car) and the sound of the sidepipes is still very attractive.

Walter

Mike I · #4 (**permalink**) 06-02-2003, 10:05 AM

A.J.,
I have flowmasters and under car exhaust. Very quiet at idle with the Weber induction system, but sounds very good on acceleration and at cruising speed, without being obnoxious (or illegal!). Not a bad compromise. And also, no snake-bite.....

Mike

750hp · #5 (**permalink**) 06-02-2003, 05:28 PM

My last Cobra had an undercar exhaust, and I used 4 DynoMax Race Magnums. These are very slim, so ground clearance is not compromised. I put two half way along the car, and two just before the end of the system. Having a Jag IRS meant that the pipes could go under the diff, and fairly close to it, so it still flowed well and had reasonable ground clearance.

If we're caught spinning the tyres in Qld, we can have the car impounded for 48 hours, but I've heard it's even worse in UnZud.

Good luck!

Ant · #6 (**permalink**) 06-04-2003, 11:20 PM

Yep things are getting bad here, but its mainly over zealous cops, picking on the road racers!

As I am going under car there is heaps of length, but only allows for 8.5" width and 4" depth and the muffler would be flush with chassis rails at that.

There is an outfit which is going to build an engine for me, they make a racing muffler that has a 700bhp, 8000 rpm chev engine under 95dba, the guy is a guru he builds most of the Fords here for speedway etc and he is booked virtually for a year, the claim is no power loss.

It just makes the car enthusiast more determined to do what we can get away with, why have an a**holes behind desks spoiling my enjoyment, especially when they hate cars themselves.

I wrote a letter to the LTSA (Land transport) giving my point of view, as this young fellow, (wifes, bosses, son) was doing 80kph in a 50kph area and his friend was following him from a good distance, result car impounded and parents incensed and fighting charge of road racing with a good lawyer, the police should've giving him a speeding ticket only.

Well I suppose all I can hope for is the police car biff a rod and it hits the cop between the eyes.

trularin · #7 (**permalink**) 06-05-2003, 05:32 AM

Here is a small suggestion.

Small heat shields between the mufflers and the chassie/body.

It helps.

BTW, "Hoon?"

Ant · #8 (**permalink**) 06-05-2003, 10:06 PM

trularin, A "hoon" is the person that is doing the hooning, which is skids, dangerous driving, out of the ordinary, and road racing in the public eye, as I dont mind a bit of racing myself on the open road.

Mike, what series Flowmaster do you run like 40, 50 or whatever?

Mike I · #9 (**permalink**) 06-05-2003, 10:40 PM

AJ, I'm running 40 series flowmasters on my car, I think they are part #42441.

Mike

Ant · #10 (**permalink**) 06-06-2003, 03:49 AM

Thanks Mike,

Do they make a tinny sound, I rang the guy who sells them in Auckland, he reckons they sound tinny, and didn't want to go there, he may have heard a peice of crap with them on?

Mike I · #11 (**permalink**) 06-06-2003, 08:47 AM

AJ,
I've never heard any car with flowmasters sound tinny. They have a deep, powerful sound to them and don't seem to hinder performance at all. I would think that if you match the correct mufflers to your engine's power level, you'll be happy with them.

Mike

Chuck Nickloy · #12 (**permalink**) 06-06-2003, 03:12 PM

I am using the Hooker aero max (spell?) for under car exhaust.
Great sound and no loss from restriction!!
Have them under an old 65 chev malibu with a 406 small block.

Here is a link

http://shop.store.yahoo.com/gofast/maxflowmuf.html

Good Luck
Chuck

BB427 · #13 (**permalink**) 06-06-2003, 04:01 PM

Put a chevy motor in it.

That way the only muffler noise you will hear is from the rollback it's on.

ac andy · #14 (**permalink**) 06-08-2003, 06:31 AM

750hp, i am still very interested in how you are keeping your car quiet. My excuse will be that i will pretend i am deaf and didnt know it was that loud!

Andy.

750hp · #15 (**permalink**) 06-08-2003, 07:06 PM

C'mon Andy - you're stressing me out now! It's not that loud....

Is it?

ac andy · #16 (**permalink**) 06-09-2003, 04:10 AM

Have you got it running now? I think I can hear it! Ha Ha.

Andy.

Seriously, I think it just sounded super loud coz we were in your garage. Im sure when you are driving it, it wont be so loud out in the open. Have you got it registered yet?

750hp · #17 (**permalink**) 06-09-2003, 04:24 AM

I think it was the garage also, but I have to admit that it sounded pretty loud when I drove it onto the trailer. Our local Cobra get together is early on a Sunday morning - probably the only time of the week when neighbours are trying to sleep in....

IT'S REGISTERED!!!!

I'm just waiting for a couple of things before I drive it around too much. Only little things like fuel filler, headlight rims, some small exhaust work etc. Nearly there!

ac andy · #18 (**permalink**) 06-09-2003, 04:29 AM

I wont ask about rego (secret mens business), but thats great. My rego plans have nearly come to fruition as well. I am sure i can hear your car right now!

Andy.

750hp · #19 (**permalink**) 06-09-2003, 04:55 AM

No smoke and mirrors, I put all my drivetrain into a 1991 RMC Cobra, and as it's already been registered in Queensland previously, the car didn't need to be Engineered. It was simply a matter of ensuring that the car met a Roadworthy Inspection, and was then inspected by Dept Transport. Job's done!

You might hear my car in about 12 hours time

Craig

decobraman · #20 (**permalink**) 06-09-2003, 11:45 AM

Well, our Cobra has a thin walled, titanium side exit exhaust. Loud as hell, very good sound. However, I don't have to worry about emissions, since I'm a mechanic.