routing the exhaust

[miket]

Now that I have an engine in the car, I can think about routeing the exhaust.

I appears that I'll have to cut a pass thru on the passenger side of the X frame.

Can anyone offer a few tips on how to best do this.

And a photo of the finished product would really be helpful.

I was just looking at some photos of the white Tiger that is on Ebay. He has several photos of the underside. Does the cutout have to be oval? I was thinking that if I cut three sides of a rectangle (bottom, top and one side) I would have a flap that I could bent front side to back and then vise versa.

thanks, Mike

 

[V6 JOSE]

Now that I have an engine in the car, I can think about routeing the exhaust.

I appears that I'll have to cut a pass thru on the passenger side of the X frame.

Can anyone offer a few tips on how to best do this.

And a photo of the finished product would really be helpful.

I was just looking at some photos of the white Tiger that is on Ebay. He has several photos of the underside. Does the cutout have to be oval? I was thinking that if I cut three sides of a rectangle (bottom, top and one side) I would have a flap that I could bent front side to back and then vise versa.

thanks, Mike

Mike,

What makes it look oval, is the 3" round pipe you need to weld in to stiffen the cruciform again. It appears like an oval, because the hole doesn't go through the cruciform at a 90 degree angle, so appears like that. I6t's like cutting balogna on a miter, it looks like an oval.. Just make the hole and weld in the pipe. Be sure to weld it good, so it is strong.

Jose

 

[miket]

Got it.

Do you somehow use a 3" drill to cut the holes. Or do you trace the outside of the pipe and cut with a torch?

And would you happen to know how many degrees, to cut the pipe?

 

[Alpine 1789]

Jeff Scoville talked me through this same process a few months ago. Here's the thread: http://saoca.org/protected/forum/showthread.php?t=281&highlight=exhaust

Jeff's process worked very well and I took a bunch of pictures intending to write this up one day as a tech tip. In the meantime, I'll put the pictures on my Snapfish site and post the link here.

I do have a couple of suggestions to add to what Jeff gave me. First, I found that the 12" bits broke very easily when I was cutting the holes. I was fine drilling through the frame, but there was frequent kick back from the saw and this is what broke the bit. Those bits are expensive and I went through two of them when it suddenly hit me that once the hole was drilled I was only using the bit as a guide for the saw. So, I switched to 1/4 rod which worked great. I bent a few of them along the way, but at about 50 cents each it was no big deal.

My other suggestion is to consider using 3" conduit, if you can get it, rather than 3" exhaust pipe. I recommend this for two reasons. First, I think it is a little heavier gauge then the exhaust. Second, it is a little larger - 3.25", IIRC. I only happened on this by accident because there was an electrical crew working in my office at the time I was doing this and one of the electricians cut me a piece of conduit to use. I didn't know that it was larger until I got it home, but since I'd already cut the 3" hole, I had to scrap it and buy a piece of exhaust pipe.

"Scrap it" probably isn't true; I think I have it laying around the garage someplace. Its free to a good home, if someone who is going to the Invasion would like it.

 

[weaselkeeper]

I just finished the right side exhaust pass through on mine this weekend. I used 3 - 1/2 inch exhaust pipe that I slightly ovaled (not much). I cut the exhaust pipe to the same angle that the x frame is to the centerline of the car, which is very close to 45 degrees, but not quite. I used a band saw to cut the pipe. I then used that cut pipe to mark the x frame before cutting the holes to shape. I'm challenged and didn't have a plasma cutter, so I used a small die grinder to cut the holes (total of four, two holes for each x frame piece). Took a long time. First, I had the pipe dream of using one piece of pipe through both sections of the right side, but had to admit defeat when the holes were too close to the point where the two pieces meet near the centerline. I used one piece of pipe for each x frame piece and they very nearly line up. They line up enough for a 2" exhaust pipe to pass through w/o rattling. Not perfect, but with the tools I had available, it did the job. Glad that's done.

.

 

[Alpine 1789]

Here are the photos I took of my pass through, complete with descriptive captions on most of them: http://www1.snapfish.com/thumbnailshare/AlbumID=166630338/a=61458443_61458443/t_=61458443

 

[miket]

Thanks everyone. This looks like a challange.

 

[Alpine 1789]

All in all, it wasn't as bad as it probably seems, although its no picnic. Going through the cross frame also requires that you modify Jose's headers, although I am no where near that point yet.

One important thing to keep in mind is that you do not have to do it this way. I want this route because my wife is very sensitive to exhaust fumes and I figured this would be better for her. However, it is easier to just route the exhaust out the sides ahead of the rear wheels. I am sure there are people on the board who will be able to talk you through this process.

 

[miket]

Jim you are right, there are two other optiions. Go under the frame, but likely the exaust will get crushed. (Actually I was looking at how low the oil pan is last night and that's a concern.

Or get a pair of lake pipes. But I think that's they are not within the spirit of the car.

 

[weaselkeeper]

Jim. Well done. Mine looks indentical, except used two pieces. One for each leg of the x-frame. The large hole saw looks to be the key to getting one piece of pipe through both legs. I also drilled a centering hole through the entire lenght using a LONG 3/8 bit. Helped get them in the right spot.

 

[V_Mad]

I cut the two holes in the X-member with a "nibbler" running on a power drill. Sometimes it would not cut because the metal was too thick or crooked, but I got there eventually.

I did some school math to work out the shapes needed to form the tubes and cut the oval holes. I measured the X-member angle and thickness, then I drew out the shapes on ceral packets. I made the tubes from 1.2mm sheet steel, easy to cut when flat, which I then bent into a two 3 inch tubes of the correct shape. I also cut two plates with oval holes to reinforce the ends of the tubes, then assembled all together, trimmed to shape then welded up. Yes, a bit long winded, but I could not get 3 inch tube, and it was fun making them.

I like the Tiger style arrangement as it looks neat, and gives good ground clearance. I think side exit tubes would rule out use on our local roads with all the speed humps.