View Full Version : exhaust cutout size
I'm starting to fit the body on my roadster. I have the bulb seal in place, the rear door opening is positioned barely ahead of the striker panel maybe 1/8 inch, the front splash guards are in place with bulb seal, the body is centered in the front by measuring from the shock tower to the outside of the upper fenders and the floats just above the 3/4th inch frame rails with the front quick jack bolts in place. I have a stroked 351 with the FFR headers and polyurethane engine mounts. I know the factory cutouts are made for j pipes and I need to open these up. I don't think I can get the engine any lower with these mounts. Presently I think I need maybe 1.5 or 2 inches more height on the openings on both sides to give adequate clearance. . I was hoping some of you with more experience can tell me how much larger these cutouts usually have to be in width and height. I'm a beginner so any advice would be appreciated!
AC Bill
01-07-2020, 05:04 PM
Don't start grinding on them till the the pipes have been fitted with the body on. I've never heard it suggested that the factory cut outs were designed for the J-pipe. Where did you get that information?
My side pipe cut outs did need some tweaking, with the BBK headers supplied by FFR, but not such an amount your suggesting. It may seem like that, but until you actually mount the side pipes, your really just guessing. When tightened up, you may be surprised at how they actually sit. You can also determine if you may need some shims to keeps the pipe parallel to the ground, or evenly distanced from the body.
Hint-Mounting the side-pipes, before dropping the body on, is far easier then with it on. I found it a real PIA, tightening them up with the body in place.:(
Jeff Kleiner
01-07-2020, 08:43 PM
...Hint-Mounting the side-pipes, before dropping the body on, is far easier then with it on. I found it a real PIA, tightening them up with the body in place.:(
It’s impossible to install the body when the pipes are in place on a Mk4.
Jeff
Bill,
I think you have an older MK? Pretty sure you can’t install or remove the body on a mk4 with the pipes on due to the body curving under the chassis. It has to flex outward and the pipes would be in the way.
To the OP.
It looks like a lot more material needs to come off than actually does, because of the angles, the drivers side looks further off than it is too.
Try installing them, get close as you can and take a bit off. Try again. I didn’t have factory cut outs but probably had to take 1/2” to 1” all the way around from the initial cut I did with the template.
Thanks for the comments, I had previously bolted the pipes on while go carting and they are level and parallel to the frame. I tried to bolt them on with the body in place but would need to take about an inch at the top of the cutout to do that and I figure another half inch for clearance, I was just wondering if this was typical. I cant remember where I read the factory cut out was designed for j pipes. Thanks to all
Until the body is in its final position with all panels fitted, don't try to get the opening perfect. Just get it so that the body isn't touching the pipes or so close that the heat from the pipes is melting the body. My openings are way different after Jeff did the final position than what I had with my rough fitting.
AC Bill
01-10-2020, 04:28 PM
Bill, I think you have an older MK? Pretty sure you can’t install or remove the body on a mk4 with the pipes on due to the body curving under the chassis. It has to flex outward and the pipes would be in the way. .
Ahhh OK.. yes, I have the 3.1 model. I can see now where the MK4 body may not allow for that.
Sorry Jim C, for the misinformation.
j.miller
01-10-2020, 08:47 PM
Very common for me to go UP 1 3/4-2in on driver side....a little less on Pass side....it has a little bit to do with EVERYTHING...yep, cut outs for -pipes...da bat
Thanks fellas! I’ve been taking small amounts off while working with the position of the splash guards and roll under portion of the body. I have them on now, not much clearance but I hope to give the paint and body man as much to work with as I can.
If you’re going to drive it at all note the torque from the engine will raise the drivers side up about 1/2”. Make sure you have at least that much clearance on the drivers side.