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Andrew Bayley

Dynomax Sidepipes Mocked up and ready to go!

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After discovering that the Patriot sidepipes had an ultra restrictive inner diameter of 1 and 5/8th inch in the muffler section, I ordered the ($100 more expensive) Dynomax kit that advertises a 2.5" inner diameter.

 

Nope, they lied.

 

The Dynomax muffler is just as poopy as the Patroit. However, the Dynomax muffler section easily slides out of the 3 inch exhaust pipe it is housed in. After sliding the muffler piece out, I drilled about ten 1/4 inch holes on both sides of the retaining ring and removed all the fiberglass. Not sure how loud this will be, but it's got to flow at least a little better now.

 

Earlier tonight I heard a 350 SBC with the Patroit side pipes at a local car show. I was pretty bummed at how quiet his setup was. Hopefully my "cutsomization" of the muffler inserts will wake it up some. If all goes well, I plan to have this wrapped up by next week some time.

sidepipe_2_thumb.jpg

sidepipe_2_side_thumb.jpg

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Dear lord... this kit is a steaming pile of dog poop! :(

 

The holes for the heat shield do NOT line up and the clamps they provide are so rediculously HUGE it almost forces you to hang the exhaust a good 2 - 3 inches below the frame rail.

 

This is not an option.

 

I'm going to try and weld up something tomorrow to see if I have any more luck (or lack of). However, I don't feel too confident about the outcome.

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Too bad. Andy, I bet you end up fabricating a complete system from scratch and throwing away the Dynomax poop. Best of luck!!!!!!!!!!!!!!!!!!!

 

Why sidepipes anyway? Is it the '70's thing. Hah, and here I thought I was older than you ;)

 

Davy

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hmm. I am still thinking that I would like sidepipes but there are some things I would want to do. I would have to figure out how to get pipes on both sides of the car other than hanging them below the frame rails. The pipes would be the same as the real Daytina coupe pipes. The rockers and rear part of the front fenders would have to be cut and replaced with a dished piece:thus giving ground clearance. My car has to be functional and can't have the exhaust hanging down too low.

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Sidepipe_and_mounting_hardware_001_2_.jpg

 

This is one way to address your mounting problem that we used on my car. BTW I don't think you are going to like the sound of your set-up after what you did to the internals. I've found that with time your exhaust sound improves and gets louder and lower pitched by leaving the internals just like they are. Good Luck on this....

 

 

LARRY

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I’m trying to run the pipes along the sides of the rocker panels to not loose any ground clearance. If I use the Dynomax mounting kit, I can only get about 2 or 3 inches of ground clearance. Plus, there is a rather large sized gap between the rocker and top of the pipes when I do this. I’m trying to make everything look tight and clean, but it’s not happening with those HUGE clamps Dynomax provides. The sheer size pretty much guarantees your pipes can’t be mounted closer than a couple inches away from the rockers.

 

As for the internals, my biggest concern is the 1 and 5/8th inch inner diameter of the muffler section. I don’t think that is going to flow 500hp very well. :(

 

Right now, I’m ready to give up the whole side pipe idea. I am very frustrated with this kit as a whole. I’ve already stripped two of the screws they provided to attach the heat shield to the clamps simply because the shield wouldn’t line up with the clamps. Nevermind the sheet metal SCREWS they expect you drill through the floor to hold up the pipes. Yeah, that ain’t gonna happen.

 

Thanks for the advice Larry, but I’ve got a feeling if I can’t figure out something tonight… it’s back to the drawing board.

 

Davy, yeah I’ve been on a “retro” kick lately. Also, I drove my friends factory five Cobra last fall and immediately fell in love with the sidepipe idea.

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Update after last night:

 

Well, the pipes are now securing fastened to the car. :D

 

However, the more I look at my setup, and the more I look at “Coze Z Cole’s” setup, the more I think I need a flex piece between the pipe and header. Gonna try to shop around today and see if anybody locally (Detroit area) has a 2.5” flex piece. If not, I’m sure Summit sells them.

 

As for the mounting, I basically took half of the Dynomax brackets and threw them in the garbage. I wound up keeping the rounded section of the clamps and used those to connect the heat shield to the muffler section. I had to cut off the threaded section of the clamp so just the raw rounded metal section of the U-shaped clamp was left.

 

First, I welded one of these pieces to each end of the muffler pipe. Next, I took the heat shield and placed it over the muffler section with the U-clamps provided a good ½ inch spacing between the two. I started welding one edge of the heat shield to the U-clamp on both ends of the pipe. Then, I had a fairly burly friend squeeze the heat shield and hold it in place against the other end of the U-clamp as I welded it in place.

 

With the muffler section and heat shield now permanently connected as one, I took to hanging the pipe from the car. I drilled holes for the front and rear hangers and installed the Dynomax supplied hangers and rubber isolators. Instead of the cheap shiiit metal screws, I used thru bolts and fender washers. After all, these Datsun floor boards aren’t known for the superior thickness. Anyway, I then held the pipes in place then welded the hanging section of the bracket to the side of the pipe.

 

Overall, it came out a lot better than I had originally expected. It is impossible to see any of the mounting hardware from outside the car. There is maybe a 1/4 inch gap between the top of the heat shield and the rocker panel. Even go, the gap is outwards and not hanging down. While I would have still preferred to hang the pipes along the rocker panels, it just wasn’t going to happen with what I had. I’m pretty happy with what I came with instead.

 

I would have tried to finish more last night, but it was already 11:30 PM by the time I made it this far, and the Wings just tied it up in the second period. Still need to finish up the two bends coming off the header and insert a flex piece. Once that is done, she should be ready to fire. I’ll hopefully be able to post up pictures and a video clip when it’s all done.

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Just finished the final install and... wow, I was (am) very pleased with how these sound. I got a feeling what little fiberglass I left in the muffler isn't going to last very long. Just blipping the throttle in nuetral blasted all sorts of fiberglass material out of the tailpipe. Oh... darn!!! :D

 

After tacking everything in place I had my friend "big Jer" stop by and finish the welding job. He also helped lift the pipes in place and bolted them in. Even suckered him into doing collectors. Hehe...

 

I would have shot a short video with sound. However, the camera battery was on its last millivolt and my new rubber valve cover gasket is already leaking. :rolleyes: Gotta love SBC valve covers.

 

Anyway, here are a few pictures:

sidepipes_05_thumb.jpg

sidepipes_06_thumb.jpg

sidepipes_08_thumb.jpg

sidepipes_10_thumb.jpg

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That sounds great. It wouldn't pass inspection in VA because the pipe has to exit 10" past the door seam/window (by code) although one might get away with it. I had side pipes (reversed cherry bombs) on a '66 Chevy truck running a modified 250 L6. Sounded awesome on and off idle but the droning on highway would give me one hell of a headache. I ended up using dynamax mufflers to quiet it down. It would still whip most V8 trucks in the quarter.

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