Side Exhaust Pipes that are Close to Original Sound?

[Mike T.]

I've looked at old threads on Side Pipes and Side Exhaust but haven't found what I'm looking for and that is to find members who've bought aftermarket side pipes and have been satisfied with the sound. Over a year ago I bought a 65 Maroon 396 Roadster. The original engine was long gone but a lot of the cosmetics had been addressed...I'm now working on the mechanical stuff.
In the last 10 years along with the cosmetics, a previous owner added new side pipes that have maybe 100 miles on them tops. From what I can see, this 65 actually was an original side pipe car. Anyway, when I went for a test drive in late 2019, I remember thinking 'holy cow, the neighbors are going to start throwing things' because the exhaust behind the mild 454 was obnoxious. Not pleasant at all and I have two smallblocks both with GM side pipes, had another midyear with them and two friends with Bigblocks and again GM side pipes and always loved the sound. There are no identifying markings on the 'almost brand new' pipes on my 65 now but after posting a pic over on the Corvette Forum, the consensus is that they are Sweet Thunder pipes. They have an unusually large inner dimpled area but they aren't great on the ears. I have contacted other folks about various types made by Allens, Sweet Thunder which I believe is now called HiFlow Performance and Gardners. So far, the closest I've come across, regarding sound since most of the vendors seem to make a decently manufactured product...exterior wise that is, to the original sound is Gardners. They provided a couple customers contact info and both said they liked them 'but' were a bit disappointed in the sound. I'm building a roller cammed 427 for my Roadster and it should be plenty strong but I'm not planning on hitting the high notes above 5500 rpm so loss of engine breathing due to a restrictive side exhaust is okay...sorta. Love the sound of side pipes (I was the kid that had multiple playing cards attached to my bike's spokes with clothes pins) and would like to hear from those of you who've bought and installed the available side pipes in the last few years. Pic below is looking into the chromed tip of the Sweet Thunder pipes on my 65 now.
Thanks,

[Patrick B.]

Re: Side Exhaust Pipes that are Close to Original Sound?

GM side pipes are a lot louder than you would think with a high compression big block. Years ago I had a L-36 67 coupe with side pipes that I remember as mellow and pleasant. I bought the car in West Texas and drove it home to the DC area without thinking it was obnoxious.

I recently completed the restoration of a 67 L-71 convertible using side pipes I bought 30 years ago over the counter from the Chevy dealer. They are new and in perfect shape but they are much louder than I remembered from my L-36, especially at idle. I would never drive it 1500 miles on a trip.

[Peter M.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Mike,
Have you talked to "High Flo Performance" or checked their web site? They make many different configurations including what they call their original sound pipes. They describe the 2 1/2" inners are for people who don't like their neighbors.
Kind regards

[Joe R.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Originals were not exactly smooth and quiet. Back in 1976 I drove my 63 Coupe to Orlando, FL for the NCCC national. It had 340hp, 097 cam all stock with GM side pipes (not stock on a 63). When I returned to Memphis, Tn. and regained my hearing I took the side pipes and covers off and tossed them in the trash. Never to return to them again!

JR

[Harry S.]

Re: Side Exhaust Pipes that are Close to Original Sound?

I the late 70's I passed on a red/red 65 BB with pipes. The noise was deafening. Swore I'd never own a pipe car.

[Don H.]

Re: Side Exhaust Pipes that are Close to Original Sound?

A friend had a '67 427/435 with side pipes that he drove quite a bit before restoring it. We drove it to Bloomington around 2000 and on the way back we stopped about 30 miles from home and put the top down, that was a HUGE relief! He routinely wore ear plugs when driving it! Don H.

[Owen L.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Forum feedback on what is pleasant vs. obnoxious is going to be so subjective it's not of much use. I like Gardner's offer to give you customer contacts to hear the pipes for yourself. Do any of the companies have a return policy that says you can try them on your car and return if you don't like them?

I love my 30 year old GM over the counter pipes on my L-36. Sweet, sweet music to my ears and those are about the only ears that matter.

[Richard G.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Just listened to this video;

Joe Rogan's 1965 Chevrolet Corvette Stingray Restomod - Jay Leno's Garage

https://www.youtube.com/watch?v=4MaVFMwWIWA

I used headphones so no one but me had the silly side pipe grin on their face.
The guys that recorded the video this did the best job I have ever heard. Superb.
Rick

[Mike T.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Thanks All for the input. Let me try to answer up to the comments made.
Patrick - Yes, a couple of those friends with midyear Bigblock Corvettes were a 66 L72 and a 67 L71 and to me, the sound is still just right, even if it is noisier than a smallblock with factory side pipes.
Peter - High-Flo Performance, from what I've read, is the renamed company that used to sell Sweet Thunder. I have looked over their website and they do offer different side exhaust systems including one they call NCRS Correct and they show the internal components in one pic but would still like to find someone who's got those actual pipes on their midyear.
Joe - First off, thanks for the great job of squaring away the speedo and tach from my 65 396 Roadster, you do very nice work. Okay, back to pipes, I definitely like the GM side pipe sound and understand that when you add in the element of time behind the wheel, that nice sound can get to be a bit much but my kinda driving is usually short distances, with maybe an hour of driving the absolute tops so I'm still okay with good sounding side pipes...and a whole bunch of Dynamat under the carpet ;-).
Harry/Don - Same sorta reply as I just wrote to Ray, my typical driving time is around a 1/2 hour tops and I can live with it for that long. I should also say that one of my friends with the 66 L72 Coupe does keep a pair of foam ear plugs on the console and he's always worked in a machine shop which would make you think his hearing has already had it's share of high decibels.
Owen - When I contacted Gardner, after seeing a video on their site of a customers 67 L71, I asked if they could pass my email address onto the customer to see if they might contact me. Surprised when they said they knew him well and he'd have no problem with me contacting him, which I did. Nice guy living in Rhode Island who talked at length about his Gardner Pipes and while he liked them, he still preferred the sound of original GM side pipes. Gardner also put me in touch with another customer on the West Coast and he thought his pipes were 'okay' but he too felt a bit disappointed with the sound, just not what he was looking for.
Last time I bought GM side pipes I'm guessing it had to be back in the 90's and a friend was a Service Manager at the Chevy Dealership in Petaluma California. He ordered new pipes for me and they cost under $100 a pop.
I'm betting someone makes what I'm looking for, since GM no longer does, it's just going to be a bit of a challenge to find someone who's bought what I'm hoping to find.
Thanks all for the input.

[Donald H.]

Re: Side Exhaust Pipes that are Close to Original Sound?

I have a 67 small block (L79) with the Sweet Thunder pipes. When I bought them, I believe they were referred to as original sound. I don’t think they are obnoxiously loud. Neither does my wife.

Don

[Mike T.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Don - I've looked over every inch of my pipes and no marking or stamped characters to be found so all I have to go on is that pic I posted at the top of this thread which others have seen and on that alone have determined them to be from Sweet Thunder. The 'new' company, now called High Flo Performance (I believe) does list more than one model side pipe so maybe their NCRS 'Correct Sound' pipes will do the trick and maybe that's what you have. It's not the easiest thing to do but I'm hoping someone (wink-wink) might find the opportunity to take a pic looking into their more correct side pipes.
Thanks,

[Timothy B.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Mike,

I put over the counter (mid-late 1980's) GM side exhaust on my 1967 300hp convertible and it's actually not that loud IMO. The car has a 3.36 rear axle so the engine RPM's aren't as high compared to the solid lifter engines with the low geared ratios.

I remember the out the back exhaust was very quiet, so quiet that it seemed the intake noise was more noticeable than the exhaust. I also like the look of the side exhaust on the car.

[Dan B.]

Re: Side Exhaust Pipes that are Close to Original Sound?

I'd recommend you take a look at Allen's aluminized GM original sound pipes. I just installed a new set of 2.5" in my 64 and they look, sound, and fit great.

[George J.]

Re: Side Exhaust Pipes that are Close to Original Sound?

My impression is that the solid lifter cars, with more overlap, have quite a bit louder sound than the more mildly cammed cars. This seems to be true whether the car is a small, or big block. Using the same, original GM pipes, of course.

George

[Donald H.]

Re: Side Exhaust Pipes that are Close to Original Sound?

Here's a picture. Look nothing like yours. I can't say positively, but I pretty sure these are the Original Sound. I bought them from Sweet Thunder at Carlisle maybe 5 years ago.

Don