Who is running OPEN side pipes?!?

[RedBarchetta]

I just had my car professionally appraised yesterday (for insurance purposes). The gentlemen that performed the appraisal, while remarking on the car's overall outstanding condition, did mention that mine was "quieter" than others he had heard.

I knew going in that a small block powered car would not have the additional thunder afforded the larger cylinders of a big block engine. And I've run open-headered cars on the street before (mis-spent youth), so I know what LOUD is.

I'm curious now....how many here have NO BAFFLING at all within their sidepipes? And due to their welded construction, is it difficult to reduce/remove said baffling/packing if one were so inclined to do so? I would suspect that some back-pressure is positive for torque (as well as sound control).

Inputs, please.

-Deano

[coyled]

Deano, with open pipes or the same mufflers on a small block and a big block, the motor that makes more power will make more noise. I have only heard one cobra louder than mine with the mufflers and he has slightly more power. It has nothing to do with the big block, small block thing. Scott

[RedBarchetta]

Scott, I understand the "power" component fully, i.e. more compression and creating a bigger bang in the combustion chamber should result in a louder exhaust note.

For now, the sound of my pipes suits me just fine. I'm just really curious how many enthusiasts here run them wide open all the time. Like I said, I've run open headers before and that is LOUD. I can only imagine what running open pipes whose exits are roughly 24 inches below your left ear would be like.

[RACER X #99]

Scott,
Right you are. Two of the loudest cars I ever heard were a Boss 302 Trans /Am racer driven by Sam Posey at LRP and friend Peter Basalice, with his very High Comp. 289 GT350 that will break your ear drums.
On second thought those Indy cars or F1 cars can also make some noise and all without a lot of cubes.

RD

[cobradriver]

Goooooooooooood Mornin Vietnam!

"What do you do?"

"I'm in artilery!"

"What can I play for ya?"

"Play anything; just play it LOUD"

[scottj]

Deano- Contrary to popular myth backpressure, which is a resistance to exhaust flow, decreases exhaust gas velocity and does not increase torque. Primary, secondary, collector, and exhaust pipe diameters and lengths combine to affect the velocity of the exhaust within the system. Generally, the reason a 3” exhaust pipe will produce more torque at a lower rpm than a 3-1/2” pipe is because optimal exhaust velocity will occur at a lower rpm. Low rpm = less exhaust gas volume(quantity), so pipe diameters need to be smaller to maintain velocity. Higher rpm=greater gas volume, therefore larger pipes produce optimal velocity.
I run a 3” or a 3-1/2” perforated core straight thru muffler …and earplugs with either.
Scott

[badrich]

Scott: My new engine is a lot louder than the old one and I need ear relief. What kind of earplugs did you purchase and how happy are you with them? Rich

[Wayne Maybury]

I have the ability to open my mufflers and empty them, which I have done on a couple of occasions. It is far too loud to drive it like that on a regular basis but it is fun.

I was always afraid of breaking something when taking the mufflers apart, therfore not being able to put them back together. There is a threaded sleeve deep inside the mufflers that holds everything in place which would be impossible to fix without cutting the mufflers open. So I decided to make a set of shorty pipes. I only have 357 cu in but I believe that my Cobra with these shorty pipes is one of the loudest cars I have ever heard. For some reason it seems to be much louder than normal open headers.

Wayne

[scottj]

The rubber kind that look like 3 little umbrellas, connected to each other by a plastic cord. I get them at the track. Work great.

[RedBarchetta]

Wayne,

The SPF factory pipes are of the welded variety. I can not see how they could be modified without cutting into.

Deano

[maxrpm]

When I learned my mufflers were were 2" ID I knew they had to go. I cut the mufflers off at the 3.5" ID collectors, headed down to the nearby diesel truck chrome shop and picked up two 3.5" ID chrome truck stacks with the curved ends. I butted the 3.5" ends together so there would be no overlap seam and used 2 inch wide polished stainless steel truck bandclamps to secure them without welding. I welded mounting tabs to the pipes at the original chassis mounting points. No leaks, looks pretty, strong enough to stand on and interchangable at any time. Worth 2tenths & 3mph at the dragstrip with no other tuning on my smallblock. Noise wise the car sounds so much better and even people with trained ears mistake it for a bigblock. I haven't put the mufflers back on since. No earplugs necessary and I can hold a normal conversation while driving with my wife. I can't imagine that a big inch motor would be as livable as this but it may be worth the mods for track racing.

[Tom Kirkham]

My car has a true open exhaust. It has no baffles, no fiberglass, no sound deading at all. The engine is a 427 (Not a stroker) with about 10 to one compression. The car is LOUD!!! I can not drive the car with out ear plugs. On the race track with ear plugs and a helmet it gets to be painfull after about 15 minutes. I have driven the car once on the street to a car show. I was turning the engine off at every chance to coast. I did not let the engine get above 2,000 RPMs. It was not fun to drive on the street. On the track it is a lot of fun.

My brother David will NOT drive my car because it is so loud.

I have slip fit side pipes on this car and some day I will build a set of mufflers so I can drive it on the street.

If you want open pipes, I would strongly suggest that you make it so that you can change back to mufflers very easily.

Just my $0.02

[RedBarchetta]

Originally posted by Tom Kirkham


If you want open pipes, I would strongly suggest that you make it so that you can change back to mufflers very easily.

Tom,

That last line was probably the best advice (for me or anyone else that wants to someday venture down this path). Just like switching wheels occasionally (15's to 17's and back), perhaps some interchangability with the pipes would be a cool option to have. You've given me something to think about!

-Deano

[coyled]

I have the slip fit pipes. It takes 3 minutes per side to switch them out (1 bolt in front and 1 bolt in back)for the open pipes. And, I don't know why, but they don't leak. Ear plugs are a must with both set up's. Scott

[maxrpm]

I didn't think a big block would be fun with open pipes. A buddys 11.1 428 is so painful to stand along side at idle that I don't know how he drives it! I used to walk over to greet him when he would pull up somewhere but now I wait for him to shut it down. Its actually louder than standing next to an open headered track car. I guess its because the pipes are aimed right out. But my car with the full length straight thru 3.5" sidepipes comes off sounding like a slightly muffled big block. It is deafening during full throttle blasts but otherwise acceptable(to me). Takes 5mins. to change over if I want but what I liked about my mods was you can't hardly tell the pipes are removable. The polished s.s clamps are barely noticable on the chrome pipes.

[misfit41]

My car had open pipes when i got it,I thought it was funny when I found a handfull of ear plugs in the left door pocket,I am thinking of buying the cone type racing baffles and trying that,I love the look of the straight pipes,and I want it loud.
There are lots of variables on what makes one motor louder than others,compression,port size,pipe and header size etc,but make no mistake,an fe is louder,all you have to do to prove this is stand in the enclosed section of the stands on a track when all kinds of motors are running,after a bit you can close your eyes and pick out the 427's,even in the golden years of the motor,everyone complained that they were so loud,run the open pipes,be a rebel,,lol
whats that Jesse James said ? it's not a chopper if it dosent wake the neighbors kids,,hahah,I think cobras deserve the same notoreity,,,Tim k

[RACER X #99]

While the FE does have a unique sound (probably because of its strange firing order), they are not any louder than any other engine of equal HP. Any 358 CI cup motor will silence any FE.
I have the same exhaust sidepipes on my 408 that I had on my 427 FE and it is twice as loud with the 408. Of course it makes 150 more HP.

I think everybody agrees, nothing sounds like a big block. That does not mean they sound good.

[coyled]

I have never seen an FE that is a loud as my 358ci. HP makes the noise. Personally, a high rpm small block sounds better than a low rpm anything. Its the scream versus the rumble, I like the scream. Cranky, are you going to Road America this year? Scott

[misfit41]

I am only judging by my days inside the enclosed stands at salem Motor speedway and other places, and not putting down or building up any thing, it's been a few years and maybe things changed,but out of all kinds of wicked motors,the 427s were the only ones for which you saw everyone cover their ears,maybe it isnt the decibles,but the base,,lol,Tim K

[RACER X #99]

Scott,
Regarding Elkhart lake.
That is a definate maybe.
I am putting on the six piston calipers right now and if I got the brakes I am hoping for then Elkhart lake looks good. They're is no sense in hitting 175 if I can't stop it.


BTW nothing sounds better than a couple of open pipe sb's side by side at 160+

Cranky