How to make my 69 quiet

[arlen 10]

I just finnished my 69 stang convertible with a 302 that I got in boxes. I have been told by exaust guys that the mufflers I have on it are stock. But this thing is loud and I don't want loud. I don't like the roar on acceleration or the drone at highway speed. And I have put sound deadening throughout the car. I don't care about performance I want Quiet. Are there realy no quiet mufflers out there for this car? No one I have talked to seems to know.

Edited October 15, 2010 by arlen

[DarkBuddha 107]

I'm surprised to hear your exhaust is loud if the mufflers are literally stock, but there are lots of things you can do.

 

- If the exhaust doesn't have a crossover, install an X-pipe, which should tone down the exhaust and help minimize the drone.

 

- Choose a turbo style muffler (not a chambered style) designed for quietness... most of the exhaust companies offer something of the sort. Add a second set of "resonators" to tone it down more if necessary.

 

- Make sure the exhaust terminates in turn downs at valence.

 

- Have the exhaust shop place the mufflers as far back as possible, and keep the pipe size under 2.25", probably 2" would be best for quietness.

 

- If you're running headers, switch to stock type iron exhaust manifolds.

 

- If you're running a "performance" cam, install a smaller grind.

 

- I don't know which sound deadener you installed, but you may want to upgrade to something more effective like BeQuiet, Dynamat, or have the bottom of the car coated with one of the spray on sound deadeners (and I'm not talking about that bedliner spray or undercoating).

 

- And if you're really serious about a quiet exhaust, convert to a stock single exhaust with the stock type manifolds.

 

- And if you're really really serious, convert to a 6 cyl.

 

 

Hope this helps.

[arlen 10]

Thanx for the quick reply. the engine is stock but it does have Hooker headers and no crossover. I am thinking of going with a 6cyl but the 302 runs good and I have trouble justifying changing somthing that is good. How wound a single pipe be any quieter than two? If the muffler is quiet then two should be quiet. The thing is I don't remember the stangs with plane 302s or 289s being this loud when they were new. I realize the headers will add noise to the engine but the real noise is out the pipes and this is what I want to do away with.

[foothilltom 33]

I was going to suggest, "turn up the stereo".

[Angel 24]

How old is your exhaust? Maybe there's a leak somewhere or maybe the fiberglass in the mufflers blew out. If you decide to replace the exhaust, switch to stock manifolds, get an X-pipe, use large turbo mufflers, and run a small pipe all the way to the rear valance. The larger the muffler, the quieter it will be.

Edited October 15, 2010 by Angel

[Trinitys 134]

I'm thinking that ever you said...."mufflers" that it is not a stock set up. A pretty base 302 only had one muffler. Your exhaust guy isn't right.

 

 

this is the set-up you "should" have stock. Anything else is after market and it's gonna be louder, name a after market duel muffler that will fit in your car and not be louder. this whole kit is about $200 from the "stock" manifolds back. Headers will also make the car louder so you may want to remove those Hookers will also add to your louder tone.

[Pakrat 1,043]

First of all welcome to the site Arlen. Trinity is right, Muffler guys don't know everything especially when it comes to the older cars unless they are brand loyal like most of us anyway. Aside from the good advice that's already been given consider if any of the cars you remember back in the day were actually convertibles. Not only is it very difficult to make them quiet with the top down no matter how much sound deadining you use but in my opinion the echoeing sounds seem even worse when the top is up. I don't know why but it seems to trap everything compared to a hard top. It's reason #32 on my list of why I rarely drive with the top up on my 302 vert.

[dlinebar 2]

Congrats on being extra cool like me and Pak and owning a vert! :shifty::shifty:

 

In any case mine does indeed have the original stock exhaust and it is quite and does not drone on the highway, I actually want mine a little LOUDER but only when I step on it. I have had many remarks that it sounds good. It is nice deep and throaty at idle but not loud. So I agree with others you do not have stock setup. Mine did get loud when the doughnut came loose at the manifold but with it all buttoned up it is no way loud.

 

Hope that helps.

Dan

[arlen 10]

Thanx guys but I am sure there are no leaks and I don't even like the rumble at idle. I was hopping to find mufflers that would get rid of all the loud. Even with the top down the loudest thing is out the pipes and to me that aint right. I cant turn the stereo loud enough to overpower the exaust without bleeding ears. I don't want to change the pipes because they are stainless and in great shape. Guess I will just get some stock mufflers ( like two for a single system) and hope for the best if none of you know a brand that is really quiet.

[rangerdoc 22]

I triple what Trinitys said. You don't have a stock system. My stock system with a 302 was single exhaust (which is all that was offered for a 302) and very quiet. Someone at some point added dual exhaust to your car.

 

Since you don't want to get rid of your pipes, then get rid of your headers and use the money to get a couple stock mufflers for your pipe size. That should quiet it down some, but not as much as a the single exhaust system posted by Trinitys.

 

But you could sell your entire exhaust system (with headers), puchase the single exhaust and a pair of used stock manifolds, have someone install it and still probably have money left over.

[relic1864 10]

My 69 is stock with a 302. It has factory manifold and exhaust. It is a single exhaust and my car is very quiet which I also like being it is all stock.

[DarkBuddha 107]

Yeah... I wasn't aware that there was a non-Boss 302 that came with factory dual exhaust in '69-'70, but I didn't think so. I'd find new muffler guys to go to.

 

BTW...

the engine is stock but it does have Hooker headers and no crossover.

That is your biggest problem right now. Headers are a big contributor to having a louder exhaust, and not having a crossover pipe will just make it more pronounced (read up on scavenging and reversion for more info). You can certainly start by choosing quieter style muffler, like a Walker, but I wouldn't pay a premium for stock replacement mufflers. If that doesn't do the job, seriously consider swapping to stock style exhaust manifolds. That should surely do the trick, or at least well enough so that you don't feel the need to swap to a 6 cyl (which is just crazy talk really!).

[Thunder Kiss 13]

The first (and cheapest) thing I would do is get an exhaust shop to fit a crossover pipe. If, after that, you're still not happy have them either change the mufflers, or add an extra hotdog/glasspack muffler to each side.

[MikeStang 247]

Check out the Dynomax Super Turbos...They are a Cheep well made muffler that is pretty darn quiet, the larger case you get the quieter it will be..do the Xover and a set of dynomax mufflers and run it out over the axle and dump the headers and you will be whisper quiet :)

I will take the headers off you hands if you decide to remove them :)

I even have a set of Stock Exhaust manifolds ill give you :P

Mike

[sulphur1 10]

Before you take off the headers try adding a couple of glass packs or 'hot dog' resonators with the cross-over. I found they made a huge difference to get rid of the drone on my earlier warm 289 - 'would also try different mufflers before removing headers.

Cheers

[arlen 10]

I think I will just go with new stock mufflers and see what that does for me. Thanx to all for your input.

[Silverjade 35]

"Thanx to all for your input."

 

I know that was a closing statement, but I need to post again to stress what DarkBuddah said.

 

Having any type of header, especially thin-walled, is going to crate noise not sound.

 

The worst thing I did when I owned my '68 was to put a set of headers on the car.

 

Noise and floorboard heat became unbearable when compared to the stock cast iron units, and that was the only change yjay i had done.

 

You can put on a set of the Pope-mobile's mufflers but I do not think you will be happy as long as the headers are on the car.

 

My 2 cents. JIM