Quieting an FJ40 exhaust?

[Azrocks]

I have a 79 FJ40 with a SBC engine with headers and flowmasters. I just put in a new crate motor about a year ago and the exhaust was a PO special.

I'm not looking to take my vehicle to the drag strip anytime soon and there is no relation between the loudness of my exhaust and my ego, sooooooo.......

What would you recommend for a muffler to make this thing quieter in the exhaust department? I'm sure I've got a good "performance" system but really don't need that as much as a few less db's.

I guess my next question is has anybody gone from a noisy muffler to a quieter muffler in an FJ40 w/SBC and how much of a difference did it make?

Thanks!

 

[Grim Reaper]

Actually your problem is two fold. The FJ40 has minimal sound deadening material. Adding something as simple as a big rubber backed commercial door mat will go a long way to taking some of the Db out of the truck. Costco or Sam's usually has 3'x5' mats for $30 or so.

SBC come in Cadillacs so yes it can be quited.

If you have headers then some header wrap will help knock down some of the noise. The down side is they will rot out the headers faster especially if you get in the watter often. Its a trade off. It also lowers under hood temps. Advance Auto parts and Pepboys usually has it on the shelf.

As for the muffler it is just a matter of how quite you want to go. Go junkyard some mufflers off a Cadillac of you want it real quite and out a couple shields off the floor above the muffler the help knock down heat and sound. There is also a recent post about sound deadening materials that is worth the read. Look for it. I think it is in General.

 

[Azrocks]

Actually your problem is two fold. The FJ40 has minimal sound deadening material. Adding something as simple as a big rubber backed commercial door mat will go a long way to taking some of the Db out of the truck. Costco or Sam's usually has 3'x5' mats for $30 or so.

SBC come in Cadillacs so yes it can be quited.

If you have headers then some header wrap will help knock down some of the noise. The down side is they will rot out the headers faster especially if you get in the watter often. Its a trade off. It also lowers under hood temps. Advance Auto parts and Pepboys usually has it on the shelf.

As for the muffler it is just a matter of how quite you want to go. Go junkyard some mufflers off a Cadillac of you want it real quite and out a couple shields off the floor above the muffler the help knock down heat and sound. There is also a recent post about sound deadening materials that is worth the read. Look for it. I think it is in General.

I hear you (pun inteded). I understand it's just a noisy vehicle plain and simple and will always be that way to some extent. I like your suggestions. I'm going to wrap the headers for sure. I don't have to worry too much about rust where I live. I'll check out the mats. I have a thick mat in the back area but need some in the front firewall and floor area for sure. I still need to chase down all the firewall holes that are letting in noise and heat as well.

The flowmasters are amazingly loud. Then to add to the misery they resonates like crazy just off idle which is were I'm at a lot when driving in the backcountry.

 

[Grim Reaper]

I
The flowmasters are amazingly loud. Then to add to the misery they resonates like crazy just off idle which is were I'm at a lot when driving in the backcountry.

Ohhh the worst mistake I ever made on my first K5 was the flowmasters. It was fun to make a little noise and it was really fun at stop lights when the punk next to you had the mobile Boom box cranked up. It was Miserable on the hwy. Just droaned horribly. I did a lot of sound proofing but it just couldn't get rid of it. The Cats being put back on helped.

I have Sonic Turbo's on on My 70 LeMans and they are not so bad but I would never put them on a SUV (large box). I just went with regular passenger car $30 replacements on my second K5 and it was not bad at all.

The reason I pointed you at the junk yard late model Caddie mufflers is they are usually stainless on the new ones and they flow pretty good while being quite. To buy them new would be pretty pricey but probably get them for $20 at a Yard. I plan to run a pair of them on my 454 Suburban.

 

[Azrocks]

The reason I pointed you at the junk yard late model Caddie mufflers is they are usually stainless on the new ones and they flow pretty good while being quite. To buy them new would be pretty pricey but probably get them for $20 at a Yard. I plan to run a pair of them on my 454 Suburban.

Thanks for the additional info. That would be great to get some stainless mufflers at a reasonable price. Good tip!

 

[Rezarf <><]

FWIW, I went to a muffler shop and asked for the quietest muffler before I started to loose performance. They gave me some kind of offbrand, but man it quieted down my exhaust note to the point I was shocked... and pleased.

Most non-chain muffler shops really know their stuff, and I would recommend trusting them for a quiet system.

Also, keep the flowmasters, and sell them on Ebay. The model # will be stamped on them, and they always sell. Heck, you might break even that way.

Just my .02

Drew

 

[Azrocks]

FWIW, I went to a muffler shop and asked for the quietest muffler before I started to loose performance. They gave me some kind of offbrand, but man it quieted down my exhaust note to the point I was shocked... and pleased.

Most non-chain muffler shops really know their stuff, and I would recommend trusting them for a quiet system.

Also, keep the flowmasters, and sell them on Ebay. The model # will be stamped on them, and they always sell. Heck, you might break even that way.

Drew

Thanks Rezarf! I have found the same thing with the smaller shops. Anybody know a good place in the Tucson area?

I have been lucky with my headers so far. I need to add an additional gasket at the collector as I'm getting a small leak there.

Also a little off topic. Did you do anything to reinforce your rear fenders after cutting them? I love the look sans flares.