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As usual, not everything is as easy as it seems. Did you know Hooker makes three inserts?
One is quiet. But to be quiet, it is VERY restrictive.
The next one (like a glass pack) is more free flow and allows more noise.
The next one is Hooker Max Flow Side Pipe Mufflers. The least restrictive and so loud you will have to shout in the passengers ear.
There are also other aftermarket side pipe inserts, which I will not address as I had not used them. I have had all three. The restrictive ones just killed the HP. The next one, like glass packs still had a noticeable loss of HP but not too bad. The Max Flow were like running open headers power wise, but I couldn’t take the noise (I’m getting older)
Regarding modifying the car: When people ask, I say its your car, your money. Do what you want. But an important question for you. Did you buy it as an investment or to drive and have fun with? If you purchased as an investment, leave it stock and low mileage. If you want to have fun, maybe even do a HPDE or Time Trial, modify it or get another car to modify.
My Dad had hooker side pipes with an L-48 and the quietest reverse flow Hooker muffler inserts back in the late 70's. The Hooker quiet "reverse flow" inserts hurt power much more on a modified higher HP engine. I chose not to use them on my car as my 383 is setup with an aftermarket cam.
My opinion - Stock, low compression L-48, "929" cam engine will not loose as much power as a higher performance engine with tighter lobe separation and increased cam overlap. Exhaust restriction kills the power gains on a cammed (increased overlap) engine. It is just not as much of a factor with lower HP, base engines.
If I was running an L-48 in a cruiser application, I would consider using the quieter restrictive reverse flow inserts. The sound those inserts make is truly amazing. Nothing else sounds like it. You might want the look and the sound more than the power, but obviously that is your call.
As usual, not everything is as easy as it seems. Did you know Hooker makes three inserts?
One is quiet. But to be quiet, it is VERY restrictive.
The next one (like a glass pack) is more free flow and allows more noise.
The next one is Hooker Max Flow Side Pipe Mufflers. The least restrictive and so loud you will have to shout in the passengers ear.
There are also other aftermarket side pipe inserts, which I will not address as I had not used them. I have had all three. The restrictive ones just killed the HP. The next one, like glass packs still had a noticeable loss of HP but not too bad. The Max Flow were like running open headers power wise, but I couldn’t take the noise (I’m getting older)
Regarding modifying the car: When people ask, I say its your car, your money. Do what you want. But an important question for you. Did you buy it as an investment or to drive and have fun with? If you purchased as an investment, leave it stock and low mileage. If you want to have fun, maybe even do a HPDE or Time Trial, modify it or get another car to modify.
I made my choice back in 1974.
From what ive read most people concerned at all with performance run one of those "aftermarket" (Ironic because the hooker branded ones themselves are just an aftermarket brand as well) options like chambered or spirals.
From what I've read most people concerned at all with performance run one of those "aftermarket" (Ironic because the hooker branded ones themselves are just an aftermarket brand as well) options like chambered or spirals.
I have not run them. Therefore, I could not comment with any firsthand knowledge.
For me the best compromise of sound and power was the Borla. Plus they are so low restriction they never get blistering hot like the Hookers or Doug Thorley.
From what ive read most people concerned at all with performance run one of those "aftermarket" (Ironic because the hooker branded ones themselves are just an aftermarket brand as well) options like chambered or spirals.
If you look at @cottoneg's photo, that is neither of those options. It looks like the muffler you need to run at Lime Rock.
EDIT: Borla mufflers, he posted while I was typing
I heard mixed things about the sound of the STS baffles, though I'm sure they work great. I have a set of Doug's D952 inserts. It helped to knock down the noise, and driving around is fine. Ear plugs are still required on the highway. I haven't tried the more restrictive D950 inserts. (Amazon links).
I have not run them. Therefore, I could not comment with any firsthand knowledge.
For me the best compromise of sound and power was the Borla. Plus they are so low restriction they never get blistering hot like the Hookers or Doug Thorley.
it is also possible with the large diameter that they have some batting in there thats acting as heat insulation. I tried that with the sweet thunder inserts but the pipes still got hot so I added the heat shields. When I switched to the vette packs I didnt bother with the fiberglass batting material..
The exhaust note on most of the inserts is a bit more raspy and not as deep mainly because as you mentioned the lack of real-estate inside the pipes to work with. The compression ratio and cam choice also have a lot to do with the sound they produce.
My car is not that bad sound wise now that I finally installed both new door cards/ panels after 10 years of driving without. With the windows up its pretty quiet imo considering.
If you look at @cottoneg's photo, that is neither of those options. It looks like the muffler you need to run at Lime Rock.
I heard mixed things about the sound of the STS baffles, though I'm sure they work great. I have a set of Doug's D952 inserts. It helped to knock down the noise, and driving around is fine. Ear plugs are still required on the highway. I haven't tried the more restrictive D950 inserts. (Amazon links).
As for the car, drive it, or sell it.
I see seen he was running a different more traditional aftermarket muffler modified to work. I was commenting on the hooker options being a minority choice for many looking for performance.
I really wish there was an episode of engine masters comparing the sidepipe options lol.. I know thats too specific to happen.
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2025 C4 of the Year Finalist - Unmodified
2025 C8 Stingray of the Year Finalist - Unmodified
I cant add to the horsepower discussion and I don't think adding side pipes will affect value extensively. If you like the way they look then get them.. I LOVE mine.
Just get in touch with Eric at Classic Chambered Exhaust. These guys know what they are doing. I swapped out the very restrictive (1-5/8” flow path!) inserts that were in my site pipes for Classic Chambered 2-1/2” Vettepacks, and the sound is amazing. No official dyno, but the butt dyno says it really woke up my low compression crate motor. Sound is just right, nice rumble while cruising, but really sings a pretty tune when you get hard on the throttle.
Here it is, windows down, recorded on iPhone held near steering wheel:
I see seen he was running a different more traditional aftermarket muffler modified to work. I was commenting on the hooker options being a minority choice for many looking for performance.
I really wish there was an episode of engine masters comparing the sidepipe options lol.. I know thats too specific to happen.
That would be so easy to do, too. Instead of changing a cam, or whatever, all they have to do is loosen two slip couplings and change the pipe inserts.
I'll just leave this link here for anyone doing an LS or (Gen V) LT swap. Engine Masters could do the test on a modern GM engine and not even have to retune anything.
I cant add to the horsepower discussion and I don't think adding side pipes will affect value extensively. If you like the way they look then get them.. I LOVE mine.
The Look is by Far the best thing about side pipes.
I have the classic chambered exhaust louvered 3" core inserts in my side pipes. I originally talked with Eric at chambered, and that was his recommendation for my super charged 385. The 3" core is louder than the 2.5" core. The 3" core flows a lot more than the 2.5 - yet the 2.5 flows pretty good. They have chambered exhaust with 3" cores as well for the 4" OD aftermarket side pipes. Running side pipes are a constant compromise between aesthetics, performance, and sound. In my opinion, they look too good on the C3s to not have them, then you have to balance the sound and performance.
If you look at @cottoneg's photo, that is neither of those options. It looks like the muffler you need to run at Lime Rock.
EDIT: Borla mufflers, he posted while I was typing
Wow! That is one of the reasons I tried the Borla mufflers. I wanted to run at Lime Rock. I spoke to Dave Borla (he actually answered the phone himself) and discussed options.
I have not made it back to Lime Rock yet. But going to Summit Point raceway the end of September with my son.
I created a Borla option for my side pipes, and I loved it in terms of performance. They were 3.5" through the middle, but they were loud. If I could figure out how to make it work and have an acceptable decibel level, I'd do it.
Here is a side without the heat shields...
Here's the pair with the heat shields installed. You barely knew they were there with the heat shields...
I created a Borla option for my side pipes, and I loved it in terms of performance. They were 3.5" through the middle, but they were loud. If I could figure out how to make it work and have an acceptable decibel level, I'd do it.
Here is a side without the heat shields...
Here's the pair with the heat shields installed. You barely knew they were there with the heat shields...
I guess there isn't enough demand for side pipe mufflers for Dave Borla to make one for us. I have no idea the amount or research and tooling that needs to go into it. But if he could design replacement muffler, I think it would be accepted.
The primary culprit on the side pipe loss of horsepower isn't the long primary tubes, but the often restrictive side pipe inserts. Dyno's of hooker style side pipes with 1-7/8 primaries and 4" collectors (open pipes no muffler or inserts) are similar / close enough to open headers (usually 6-10 HP loss). For a street driven car, that is negligible. As we try to keep our ears from bleeding, we add inserts to control the sound. I'm not trying to rehash what we all know, but my frustration is how we can't solve the problem of sound and performance with the side pipe. I think we are close, but just not quite there.
I believe if someone made a high performance muffler (like Borla) that would slip on to the end of the Hooker style 4" collector, be long enough, and have turn outs / downs at the end - all the inserts would be obsolete. You could even go up to 4.5" to 5" in outside diameter and still fit next to the car for most cases. The Borla's fit for me, but they weren't long enough to knock down the sound enough. I'm happy with the 3" core on the louvered classic chambered exhaust, but I'd love to find that silver bullet with the side pipe muffler system.
With the windows up its pretty quiet imo considering.
So Funny & SO TRUE
