Inside a 289 roadster side pipe...

[Stangrob]

Evening gents,

I'm getting ready to send my side pipes out to Boig to have them modified so that they are a bit quieter. I've heard from multiple people that the factory pipes are really loud - to the point that you need ear plugs and Advil. While I like a good sounding exhaust, I already have bad hearing in one ear, and the good ear is on the driver's side ;)

To save on shipping Dan @ Boig suggests cutting the side pipes in half and shipping that way. I broke out my trusty chop saw and cut them up today, first adding some alignment marks and labels for DS/PS. It's amazing how the factory pipes are really not much more than straight pipes - the "muffler" inserts look to not add much noise attenuation. I thought you might enjoy a pic of the cross-section ;)

Thanks!

Rob

[jts359]

My pipes were made by Kook's and I put a baffle in them , My wife noticed it right away and was not to happy with my decision . It will be interesting to see or hear who has the quietest Cobra on the Circuit , Ed

[Stangrob]

LOL - I doubt mine will be quiet, just less likely to p*ss off the neighbors. I also want to drive this puppy and enjoy the sound without ear protection :D

BTW, no radio in this car. The engine and wind is all I want to hear!

Rob

[tundra2050]

I'm in the same boat. I don't want to have to wear hearing protection as well. I'd also like to drive while being able to somewhat carry on a conversation. Or listen to music through ear buds.

Has anyone tried CarChemistry's 3 disk insert or even their Silencer insert? It's supposed to yield as much as a 10db reduction. Maybe more with the restrictor caps.

[Stangrob]

I'm in the same boat. I don't want to have to wear hearing protection as well. I'd also like to drive while being able to somewhat carry on a conversation. Or listen to music through ear buds.

Has anyone tried CarChemistry's 3 disk insert or even their Silencer insert? It's supposed to yield as much as a 10db reduction. Maybe more with the restrictor caps.

I understand that the Boig-modified side pipes are good for a 10db drop. That should make a sizable difference.

Rob

[rickster991]

Can I ask how much it costs?

[Jim1855]

My "new" 289 FIA car has early production BOIG Quiter pipes. The 289/306 sounds great, getting good reviews from those that have heard it and ridden in it.

But I still won't run for any extended period without ear plugs. The exhaust sound while not excessive does get loud when using the gas pedal. Then there's the wind noise which I find more draining than the exhaust.

Jim

[J R Jones]

As mentioned in an earlier post I went with two glass packs and two Flowmaster 50 series chambered mufflers under-car. The sound is proportional to throttle position and idle is menacing. I can hear a bit from the back at 35-40MPH cruise and above that just wind noise. I considered chambering side pipes but the discharge is still too close to my ear.
jim

[mburger]

I bought used cat j-pipes that work well. Had them ceramic coated to match the side pipes.

https://thefactoryfiveforum.com/attachment.php?attachmentid=223115&d=1766246109

[Stangrob]

Can I ask how much it costs?

The Boig side pipe mod for the 289 costs $900, and that includes return shipping. You send him your FF pipes and he modifies them.

Rob

[Stangrob]

My "new" 289 FIA car has early production BOIG Quiter pipes. The 289/306 sounds great, getting good reviews from those that have heard it and ridden in it.

But I still won't run for any extended period without ear plugs. The exhaust sound while not excessive does get loud when using the gas pedal. Then there's the wind noise which I find more draining than the exhaust.

Jim

Yes, I remember reading the build thread on your car - it was a key driver for me to go with Boig for this work. Beautiful car BTW - I hope mine comes out nearly as nice!

Rob

[Stangrob]

As mentioned in an earlier post I went with two glass packs and two Flowmaster 50 series chambered mufflers under-car. The sound is proportional to throttle position and idle is menacing. I can hear a bit from the back at 35-40MPH cruise and above that just wind noise. I considered chambering side pipes but the discharge is still too close to my ear.
jim

I seriously considered an undercar exhaust with the exit right in front of the rear tires (because Jersey has side pipe requirements), but I could not find mufflers that were thin enough to fit without hanging below the frame. This is another NJ requirement - nothing can hang below the frame under the car. So, I'll make the side pipes work, which is fine by me. I'll either have to craft a set of covers for the pipes or wrap them with something like Thermo-tek (I still have a question into our DMV to see if the wrap will suffice...).

Rob

[EZ$]

Tundra2050, I used the Car Chemistry 3 disc insert. Instead of using the stainless-steel wool as a packing, I had some ceramic wool that I packed them with. Before I did this, at first start. I had my wife on the camera, and she couldn't stand how loud it was. I got the CC insert and tried to figure where to place it. Without cutting off the end of the side pipe, and then rewelding, there was no way to get it into the side pipe. Wouldn't have mattered, I wasn't going to cut my newly ceramic coated pipes anyway. I finally decided that I could get it into the bottom of the J-pipe which I did, but not without some serious persuasion. I ended up driving the in carefully with an old rubber mallet that I wasn't worried about. Good thing is they went in, bad thing is they're never coming out, but the other good thing is that they worked. My wife will even ride in the car! The only time I really notice how loud it can get is when accelerating onto the freeway. If I was to do it all over again, I'd go with under car exhaust even if I had to exit it in the same location as the side pipes. Good Luck

[ProfessorB]

I seriously considered an undercar exhaust with the exit right in front of the rear tires (because Jersey has side pipe requirements), but I could not find mufflers that were thin enough to fit without hanging below the frame. This is another NJ requirement - nothing can hang below the frame under the car. So, I'll make the side pipes work, which is fine by me. I'll either have to craft a set of covers for the pipes or wrap them with something like Thermo-tek (I still have a question into our DMV to see if the wrap will suffice...).

Rob

Rob, can you elaborate on the New Jersey "side pipe requirements"?

[Stangrob]

Rob, can you elaborate on the New Jersey "side pipe requirements"?

New Jersey's side pipe requirements stipulate that you must have protective covers over the pipes to keep passengers from burning themselves. I don't believe this is unique to Jersey, but I'm just not a fan of side pipe covers, which is why I was looking into using a thermal wrap as an alternative. As far as covers go, I'd have to fabricate something as I haven't seen anything for the 3" side pipes used on the 289 cars.

Rob

[mburger]

There are covers for 3" pipes, but I know you said you don't like them. This is just an example of a shorter 12" piece to go where the legs would usually hit the pipes.

SUMMIT RACING
Vibrant Performance Streethot Preformed Heat Shields 25312
Heat Shield, Preformed, Aluminum, Natural, 12 in. Length, for 3 in. Tubing Diameter
Part Number: VPE-25312

EDIT:
This tube (https://drifthq.com/products/dei-titanium-3in-knit-exhaust-sleeve-36in?variant=44670496342203&country=US&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&srsltid=AfmBOoopt_3E7POS1LJl-D--1kA-u-nlXF_e0R3gFjt6c_HXTfIBnd4UhbY) over the pipes might work as well.

[Stangrob]

There are covers for 3" pipes, but I know you said you don't like them. This is just an example of a shorter 12" piece to go where the legs would usually hit the pipes.

SUMMIT RACING
Vibrant Performance Streethot Preformed Heat Shields 25312
Heat Shield, Preformed, Aluminum, Natural, 12 in. Length, for 3 in. Tubing Diameter
Part Number: VPE-25312

EDIT:
This tube (https://drifthq.com/products/dei-titanium-3in-knit-exhaust-sleeve-36in?variant=44670496342203&country=US¤cy=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&srsltid=AfmBOoopt_3E7POS1LJl-D--1kA-u-nlXF_e0R3gFjt6c_HXTfIBnd4UhbY) over the pipes might work as well.

Thanks - I appreciate the info! Yeah, just because I don't like them doesn't mean I won't need to have them, so this is good info. God forbid my wife burns herself getting out of the car - I really don't want to go there.

Another option I'm looking into is buying some 3 1/2" pipe and making my own shields. I'll have to cut a slice out of it so I can slip it over the side pipe, and I'll need to weld on some standoffs for mounting. I'm also going to see if anyone local has a water jet to cut some slots into the pipe. Might as well make it look cool ;)

Rob

[mburger]

You can buy the universal hose clamp with the fiberglass lining so all you'll need is to drill the right size hole through your cover for the attachment screws. It'll give you a professional appearance.