Turbo mufflers: are they really louder than regular ones?

[robroy]

Hi!

During my investigation on which mufflers to put on my truck I came across advice somewhere on "Turbo" mufflers.

It said that "Turbo" mufflers are intended to be used on cars with turbochargers, and hence do less to reduce noise than standard mufflers, since turbochargers absorb part of the noise somehow.

Is this true? If not, why do muffler companies call some of their mufflers "Turbo?"

I'm specifically interested in this as it relates to the Borla Turbo XLs.

Thanks very much!
-Robroy

[Fordlorn]

If my memory hasn't failed me, I think the "turbo" muffler came into being when Chevy put a turbocharger on the Corvair. Hotrodders found out that when they put the muffs. on their hotrods the sound was "just right". Not too loud like fried Cherry Bombs (the insulation burns out rather quickly in them) and not too quiet as the stock muffs. were. It didn't take long for the aftermarket to pick up on the new "craze" to make a buck. No self respecting muffler/exhaust co. in the USA would be caught dead without a "turbo" or "super turbo" (whatever that is? ) muffler in their lineup. Could be urban legand, could be truth. I think I got this one pegged though!

[Ranchero50]

http://www.broaderperformance.com/muffl ... _tests.htm

What does your engine builder recommend for that HP level? I finally read the whole thread on your engine.

I'd recommend 1 3/4" longtube headers, 3" mid pipe with a 2.5" H crossover, 3" magnaflow mufflers and every bend mandrel, not muffler shop crimpy bends. It's all about pumping air.

What's going behind the motor?

Like Fordlorn said the turbo's were 'the' muffler to get when there were only cherry bombs and stock replacements. If you are curious, pick up a popular hot rodding from '69 or '70 and see what was availiable in the ads. Not much.

Jamie

[robroy]

Hi Jamie! Thank you for your reply! It seems like you have a lot of experience with exhaust systems so I take your recommendations seriously. I'm curious to know more about why these recommendations are made (please read on for some specific questions).

http://www.broaderperformance.com/muffl ... _tests.htm

That's a very interesting chart, and it's one of the things that made me look favorably upon the Borla Turbo XL mufflers.

What does your engine builder recommend for that HP level? I finally read the whole thread on your engine.

I heard from Steve that I should choose either 2.5" or 3" pipes (although he thought that 3" was the better choice) and 40-series Flowmasters. But I've heard so much positive stuff about MagnaFlows, Dynomax, and Borlas that I discounted his Flowmaster suggestion.

I'd recommend 1 3/4" longtube headers

When shopping for headers it's not always easy for me to identify which ones are longtube and which ones are regular. It seems like they don't always specify that. Do you have a specific example of a longtube header for the FE (that's OK on the truck application)?

3" mid pipe

It seems that about 85% of the responses I received in this forum indicated that 2.5" was a better choice for this engine. What is your basis for the 3" suggestion over the 2.5", and what would your guess be about why so many others recommend the 2.5"?

with a 2.5" H crossover

What's your basis for choosing an H over an X? Is it due to the way I'll be mounting it in a spot that's not an equal distance from both headers?

3" magnaflow mufflers and every bend mandrel, not muffler shop crimpy bends. It's all about pumping air.

If I do go for the 3" pipe, I'll probably go with the Magnaflows since the Borla Turbo XL's are only available in 2.5".

What's going behind the motor?

The clutch is a Centerforce dual friction, the transmission is a T18, and the rear is a Dana 60 3.73.

Like Fordlorn said the turbo's were 'the' muffler to get when there were only cherry bombs and stock replacements. If you are curious, pick up a popular hot rodding from '69 or '70 and see what was availiable in the ads. Not much.

Hmmm. Interesting. Thanks!

Thanks for your great advice Jamie!
-Robroy

[fomocoguy]

Just to answer your original question, YES! Turbo mufflers are definetly louder than stock type mufflers, and the more hp your engine has the louder they will be. On a stock engine (or mildly built) I would recommend the Hooker max flows or Magnaflows as they flow about the same, but for your truck you need to think about how loud you want it to be. With the hookers or mags it's gonna be VERY loud, especially if you go with 3" pipe. Just soemthing you may want to think about. If you want a very agressive sound without it scaring little children and rattling your neighbors windows (and your teeth), I'd check out the Hooker Aero chambers. They sound kinda like a flowmaster but flow much better. FYI I've personally used turbos, glasspacks, flowmasters, magnaflows, hooker aero chambers and max flows, and my aero chambers were my favorite of them all. Just my

[DuckRyder]

Turbo muffler does not really mean anything anymore. Most of the time they are really just referring to the case style more than anything when they call it a "Turbo Muffler". I have had turbos that were quiet as stock (DynoMax super turbo and Carlson [now defunct]) and turbos that were pretty loud (Thrush). I also had a friend whose dad had an original Turbo (180HP) Corvair convertible when we were in high school and it was not very loud.

Pipe size and length play a part as well.

[69timemachine]

To me, it depends on whether you want it loud all the time or loud under just heavy acceleration. Flowmasters, Magnaflows, glasspacks, etc. are (for the most part) loud all the time, while turbo mufflers are usually mellow under part throttle and somewhat loud and aggressive under heavy acceleration. Turbo mufflers usually offer the best of both worlds. I have a pair of generic turbo mufflers on my 454 El Camino, and that's the case with it. When I put the Clevland in my bump though, it's going to be loud all the way. It'll be running shorty headers, an X-pipe, short polished MagnaFlows, and turndowns in front of the rear axle. That exhaust should rock out!

[Ranchero50]

OK, since I'm not sure what you want out of this truck, try not to hate me when I say that IMHO the engine doesn't seem right for the driveline or the driveline doesn't seem right for the engine. You have so many threads going it's hard to keep track of all the info and thought that went into this build. The cam selection is going to want to rev to move and have a pretty tight power band (peaky), the T18 is a glorified three speed with a granny gear, not something I'd want to try to drive in traffic with this motor. Just something to be aware of. I'd recommend a tremec 3550 or TKO 5 speed and possibly 4.10's in a locker depending on you tire diameter, that way you have more usable gears and OD so it can run the interstate if needed. The T18 isn't going to shift very well either at high RPM's.

The 3" exhaust is correct for a 400hp naturally aspirated 396ci motor, it needs all the help it can get moving air through the engine. The H pipe is going to help it have more torque before the cam kicks in to get your truck moving. Remember, the goal is to move air through the engine efficiently to create a flat torque curve so you have a usable powerband from off idle to 6k or higher, especially in a heavy truck. A peaky motor needs lots of gears to keep it in the tight powerband (gonna be harder to drive with only 3 gears). The magnaflows are going to be loud when you are on it hard, but aren't that bad cruising. They'll drone a good bit around 2k, but the cam won't want you cruising at that low of an RPM (it may get to bucking). Another good side of the 3" exhaust is it will be more mellow sounding. With a 2.5" system the pulses are stronger when they come out the pipe (with mandrel bent curves reducing the restrictions). I also figured you would run the exhaust all the way to the bumper.

2.5" exhaust is fine up to around 375hp. My '93 mustang would have higher HP with 3", but it's built for low end torque and the 2.5 forces the pulses to be stronger so they make the X work harder vs a 3" system. You can see the dyno sheet on the mustang thread in the general forum.

Oh yeah, as far as headers go, get something at least 14ga metal so they last a while.

Hope that makes sense

Jamie

[robroy]

Hey Jamie, thanks for your advice!

Thanks also for being honest about what you think of the setup. I understand that the driveline isn't the best match for the engine. I didn't pick it all out to work together in any special way; I'm just putting this engine in my truck with the existing driveline as a summer project. It's not a super calculated and planned setup. Next summer I'll probably do some upgrades to the driveline to improve it. I'm looking at the Gear Vendors overdrive in particular.

My goal for #50 is to have a "toy" vehicle with tons of get-up-and-go for driving around town and up steep mountain roads, and the occasional 0-60 experiment while getting on the freeway. It'll never be in competition of any kind, and I'll probably never drive it over 85MPH. It'll usually cruise at around 55 to 60.

Part of the reason I like the idea of retaining the T18 is that I love the way it feels to shift! I enjoy the heavy *clunk* when it goes in to gear. I even like the big, classic shift lever. And I've heard that it's very durable! The other part is that I'm trying to get #50 back on the road before Thanksgiving (which is just around the corner now).

When it comes to loudness versus quietness, I'm generally inclined towards quietness. I don't mind if it's loud at high RPMs but I prefer something reasonably quiet at idle and low RPMs. I don't think my neighbors are interested in hot rods at all! They drive a Prius. This said, it doesn't have to be as quiet as a stock setup! And I like a good rumble sound. I've heard that the Borlas are a good match to these preferences. What do you think?

Thanks again for your advice Jamie!
-Robroy

[fomocoguy]

I've never heard the Borlas, but as a general rule any "turbo" muffler is just the next step up from stock. A turbo is probably the quietest performance muffler. On a truck with cats it would only be a tad louder than stock. On your truck, it's gonna have quite the rumble, but I think a turbo muffler will be the quietest you will get without putting stock mufflers on it, and that would really choke off your new engine's performance.

[Ranchero50]

I'd probably run the magnaflows. My ranchero is actually pretty quiet driving around and cruising, but wakes up at WOT. The Borlas are really expensive so I don't have much experience with them.

Jamie

[ezernut9mm]

i have dynomax super turbos on my 360. it is a horrible video and you'll have to turn the sound up, but you'll get the idea.

[papabug71]

I have never had good luck with turbo mufflers. They always seem to bust up inside, then they rattle like crazy. I havent had any in a long time now, so the newer ones might be a vast improvement over the older ones.

I have always been a big fan of flowmasters, & thats what I have on my daily driver, an 01 Dodge 4x4. Had flowmasters on just about everything. From 4 bangers to turbo diesels.

I have the magnaflows on the Ford right now, & to be honest with you I am dissapointed. They sound identical to the 30" glasspacks that it had on it prior to the magnaflows. Quiet when you are just putting around, but talk when you stomp it. But thats what some guys want, so it all works out. Just depends on your taste I guess. They are a quality built muffler, I will say that for them.

[68BigRed]

While we're on the subject; can anyone suggest a good stock-style replacement muffler? Yes, I actually want to use a stock muffler, or at least one that is reasonably close. So far, I haven't found a vendor that has what I'm looking for. Any ideas?

cheers

[BobbyFord]

While we're on the subject; can anyone suggest a good stock-style replacement muffler? Yes, I actually want to use a stock muffler, or at least one that is reasonably close. So far, I haven't found a vendor that has what I'm looking for. Any ideas?

cheers

Walker makes a stock type replacement muffler.