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1) When I first got my side pipe headers, I purchased the quiet inserts. They were quiet, but chocked the engine. I felt like I had 100 HP. Not sure how they would do on a stock 1978 with a 350.
2) Then I purchased a Glass Pak type of insert. Sorry not sure of the Hooker designation for it. The car became apppricably louder and beter HP. But not quite the same as when I ran open headers.
3) Then I purchased a set of Max Flow inserts. Now this was the HP I was expecting! The only issue was when I drive with my son, we had to lean over and scream in each other’s ear. Plus I wanted to run Lime Rock, and I would never pass the sound limit set by the track.
Looking for an alternative I call Borla. Believe it or not, Dave Borla himself answered the phone. We had a long conversation where he asked me about the car and intended use. He said he had a Jeep racing muffler that “might” pass Lime Rock noise requirements and would be super low restriction. I purchased a set. My car has the F-41 suspension and is lower than most other 1969. The fit is a bit tight. But I am super happy. I will run Lime Rock in 2022 and think I can pass the sound limits. Car runs like open headers. The restriction is so low that after a drive you can touch the mufflers.
Anyway, something to consider. Pic is of my son at a HPDE.
1) When I first got my side pipe headers, I purchased the quiet inserts. They were quiet, but chocked the engine. I felt like I had 100 HP. Not sure how they would do on a stock 1978 with a 350.
2) Then I purchased a Glass Pak type of insert. Sorry not sure of the Hooker designation for it. The car became apppricably louder and beter HP. But not quite the same as when I ran open headers.
3) Then I purchased a set of Max Flow inserts. Now this was the HP I was expecting! The only issue was when I drive with my son, we had to lean over and scream in each other’s ear. Plus I wanted to run Lime Rock, and I would never pass the sound limit set by the track.
Looking for an alternative I call Borla. Believe it or not, Dave Borla himself answered the phone. We had a long conversation where he asked me about the car and intended use. He said he had a Jeep racing muffler that “might” pass Lime Rock noise requirements and would be super low restriction. I purchased a set. My car has the F-41 suspension and is lower than most other 1969. The fit is a bit tight. But I am super happy. I will run Lime Rock in 2022 and think I can pass the sound limits. Car runs like open headers. The restriction is so low that after a drive you can touch the mufflers.
Anyway, something to consider. Pic is of my son at a HPDE.
Darn, I don't know. After speaking with Dave Borla, he made the recommendation and took care of my order. So I never actually ordered with a part number. I would call Borla. If they can't help you ask for a call back from Dave. I'm sure he can help.
BTW: I know they don't look great, but the functionality is there.
Darn, I don't know. After speaking with Dave Borla, he made the recommendation and took care of my order. So I never actually ordered with a part number. I would call Borla. If they can't help you ask for a call back from Dave. I'm sure he can help.
BTW: I know they don't look great, but the functionality is there.
OK, so this isnt an insert, it's a muffler that has a 4" in thelet that matches the size of the header collector?
I just enlarged the picture and see what it looks like.
I put Hookers on my 80 with glass pack inserts and added the shields to protect from burns. Great deep rumble at idle and around town. At highway speeds it’s fine. Not as loud as you would think. More like a perrrr. Better than listening to music
I put Hookers on my 80 with glass pack inserts and added the shields to protect from burns. Great deep rumble at idle and around town. At highway speeds it’s fine. Not as loud as you would think. More like a perrrr. Better than listening to music
it's fine in your car because you have a 3.07 rear end ratio, so lowered engine speed compared to 3.55 or 3.70.
they also have multiple sizes to choose from so be honest with yourself with regard to noise tolerance. They list a decible number for the different sizes.
I believe they now have some packing material. That quiets the sound but doesn't really hurt flow
I have side pipes with spiral inserts. They are loud when you get on it, otherwise they are ok. Driving with the windows down is much louder, both wind and exhaust. If you go for long periods at highway speeds ear plugs are your friend. I have some in the car all the time.
got a 3.55 RR with TH350 trans, engine turns 3200ish @ 70mph and 3800 @ 80mph. When not on the highway I take the plugs out and it's fine.
Definitely get the heat shields. Deans shields are expensive but of fantastic quality. I can lay my hand directly on the shield at any time and not get burned.
If your engine is of a lower CR then they are quieter. I noticed quite a difference going from stock 8.0 CR to 9.9CR to now 10.6 CR in the volume of the exhaust.
When you look at the exhaust on a Harley, what you are actually looking at are the chrome heat shields that wrap 70% around the header tubes with billet aluminum end caps.
In most cases the muffling systems inside the tubes are quiet and need to be replaced or modified to get the sound and performance you are looking for.
The aftermarket manufacturers of motorcycle exhaust systems are far ahead of anything designed or available for automotive side pipes.
If they could design and incorporate the heat shields like they have on motorcycles, they would look even better than they do and the safety issue with getting burned would be gone.
Here is a typical example and what I used on most of the customs I built.
Last edited by OldCarBum; Dec 26, 2021 at 11:27 AM.
At least two benefits of side pipes I have noticed;
1) Significantly better access to transmission, bottom of engine, and rear diff area.
2) A lot less heat in the cabin of the car since exhaust no longer runs under the floor boards.
However I STRONGLY suggest getting your side pipe manifolds ceramic coated. There is a lot more surface area with these headers vs rear exhaust headers. Without ceramic coating it's gonna be HOT under the hood. Maybe melting plug wires hot. They also pass very close to the rear of the front wheel well, too much heat there may burn things I imagine.
Side pipes are more of a look and sound than anything else. They are not a performance enhancement vs rear exit exhaust with long tube headers, unless you're comparing it to stock config of 2 to 1 catalytic converter back to 2 configuration with stock manifolds.
When I went from stock exhaust on the 77 to side pipes it really opened up the exhaust flow noticeably. Took a re-jetting of the carb after install. Performance was also improved noticeably.
At least two benefits of side pipes I have noticed;
1) Significantly better access to transmission, bottom of engine, and rear diff area.
2) A lot less heat in the cabin of the car since exhaust no longer runs under the floor boards.
However I STRONGLY suggest getting your side pipe manifolds ceramic coated. There is a lot more surface area with these headers vs rear exhaust headers. Without ceramic coating it's gonna be HOT under the hood. Maybe melting plug wires hot. They also pass very close to the rear of the front wheel well, too much heat there may burn things I imagine.
Side pipes are more of a look and sound than anything else. They are not a performance enhancement vs rear exit exhaust with long tube headers, unless you're comparing it to stock config of 2 to 1 catalytic converter back to 2 configuration with stock manifolds.
When I went from stock exhaust on the 77 to side pipes it really opened up the exhaust flow noticeably. Took a re-jetting of the carb after install. Performance was also improved noticeably.
I disagree about them not being a performance enhancement compared to a stock exhaust when they are Hooker/Doug's/OBX which are long tube header systems. Back in the day when they were run in various race classes they were predominantly used as opposed to under the car. The insert is the key to whether or not they are a performance increase, 2.5" core or larger or Spiral type.
I disagree about them not being a performance enhancement compared to a stock exhaust when they are Hooker/Doug's/OBX which are long tube header systems. Back in the day when they were run in various race classes they were predominantly used as opposed to under the car. The insert is the key to whether or not they are a performance increase, 2.5" core or larger or Spiral type.
Not sure I understand your statement. They are not a performance enhancement as compared to a modern well thought out rear exhaust system. They are a performance enhancement compared to a poor or old rear exhaust system.
Back in the day they didn't have the tech and understanding of exhaust performance enhancement that we do today.
they also have multiple sizes to choose from so be honest with yourself with regard to noise tolerance. They list a decible number for the different sizes.
I've looked and looked, can't find the decible number for the different sizes. Can you share a link to it?
Thanks!
Personal opinion here so take it for what it’s worth. Put a set of regular long tubes on it and put a decent 2.5 dual rear exhaust on it. Very little fits right on these cars aftermarket. If you have to cobble something to make it work at least it will be buried under the car. Side pipes make clearance for everything else a PITA.
i'm sticking with the side pipes. Love the looks and looking forward to the sound. Spoke to Ryan at HighFlo a couple times and he helped. I will get the inserts from them and use Sweet Thunders.
I am going with stainless headers. Not sure how they are hotter than regular headers. I have a set of old ceramic coated ones with a swiss cheese exhaust system and dead cc's. The change should be nice.
