Headers Causing Exhaust Tips to Stick Out

- Aj -

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Hey all! Been a few years since I have been on the forums. Still have my '08 GT500.

One thing I never got around to was modifying the exhaust since the header install. The exhaust tips stick out farther than normal. From what I remember, I think the rear of the mid-pipe needs to be cut 1" to compensate.

Can anyone confirm?

Thanks!
- Aj -
 

Harry08

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Do the tips always stick out or is the issue only when the car is warmed up? The exhaust will expand and the tips will stick out further when up to temp.
 

Catmonkey

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I've had that issue and cut down my over the axle pipes in the front to get fitment where I want it.
 

- Aj -

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@Catmonkey good to see you are still here. I thought it was something along those lines. How much did you cut off?

FYI to the other two replies, the exhaust tips stick out about 5 inches past the rear bumper since the header install. Does not change with temp.
 

Robert M

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I've had that issue and cut down my over the axle pipes in the front to get fitment where I want it.

That is also what we did with mine during the full 3" Shelby/JBA install, the tips were just a little bit further out than I wanted, so we trimmed the front ends of the OTA pipes to get the tips in a better position while also paying attention to where the 3" was positioned around the axle.......

Picturedownload5-2-09035-1.jpg

Picturedownload5-2-09035.jpg


R
 

Catmonkey

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Well, it was sort of the end result of my resonator install. I ended up a 3" mid-pipe going into 3" resonators. I have a 3 x 2 3/4 adapter that feeds into the over axle pipes. So I cut the OTA pipe probably 18" or more, but the way the OTA pipe fits into the adapter, it's sort of adjustable. What you could do is make sure you don't have any play between the mid-pipe and the OTA pipe because if they're not butted up, you can gain a little clearance by loosening the clamp and butting them together before tightening. If that's a no-go, just look at how much you'd want to move them forward and then remove the OTA pipe and cut that amount off the pipe. You could cut the mid pipe too, but they're more of a challenge to remove. I used a sawzall.
 

Robert M

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Well, it was sort of the end result of my resonator install. I ended up a 3" mid-pipe going into 3" resonators. I have a 3 x 2 3/4 adapter that feeds into the over axle pipes. So I cut the OTA pipe probably 18" or more, but the way the OTA pipe fits into the adapter, it's sort of adjustable. What you could do is make sure you don't have any play between the mid-pipe and the OTA pipe because if they're not butted up, you can gain a little clearance by loosening the clamp and butting them together before tightening. If that's a no-go, just look at how much you'd want to move them forward and then remove the OTA pipe and cut that amount off the pipe. You could cut the mid pipe too, but they're more of a challenge to remove. I used a sawzall.

When I added the MAC ProChamber, it also required some work to get it into the OTA pipe location............while also making sure the tips stayed in position.

20191014-141022.jpg


R
 

XP900

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I'm not sure how you could be off 5 inches without the OTA pipes hitting obstacles around the axle....even the rear muffler support won't don't give you that much play without bending the support rods.

You can cut off some of the front of the OTA pipes but watch for the bend....there is a slight angle change on one of the pipes (I think it was the drivers) and you need to leave enough straight pipe support ahead of the bend to clamp correctly to the front pipe, otherwise you'll have an exhaust leak at the joint or alignment issues going to the rear. I encountered this when I changed my pipe size and welded adapters to the OTA pipes after cutting them.

Those pipes are heavy duty but I used a Harbor Freight band saw - it cut through that metal in three seconds.

10 Amp Deep Cut Variable Speed Band Saw
 
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CobraSam

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lol I was kidding around
and I agree with you. My wife spit her sweet tea out when I showed her that reply

Haha I honestly thought you were joking with your reply. I hope the poster was being sarcastic though. Otherwise, I fear for our future.
I already fear for our future, but that’s another story.
 

- Aj -

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Did any of you have to use a spacer for the panhard bar brace to drop it down a little bit, so it would make room for the over axle pipes?
 

Robert M

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Did any of you have to use a spacer for the panhard bar brace to drop it down a little bit, so it would make room for the over axle pipes?

Not with mine, and I have 3" mandrel bent all the way around the 8.8......Mine does not touch anywhere and no rattles, but it is tight in the area you are asking about.......

R
 

Robert M

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WOW!!!! I can't believe I have a picture of the 3" clearance!!!

This was taken when I had my 2008 8.8 out for the de-rust a restoration.......

0052-2.jpg


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XP900

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Did any of you have to use a spacer for the panhard bar brace to drop it down a little bit, so it would make room for the over axle pipes?

I replaced that thin bracket with a solid bar that created even less clearance for the driver side pipe but I was still able to get enough clearance. You should be able to get clearance by slightly twisting the pipe or moving the pipes forward as much as possible. If not then your OTA pipes are pushed too far to the rear of the vehicle and you may have to cut some from the front of the pipe. You really need 1/4 to 1/2 inch clearance everywhere for heat and movement. When I thought it was set properly I jacked mine up by the axle and pushed and pulled on the rear body to verify I still had enough clearance everywhere. Warning: Keep exhaust about 1/2" from those plastic hoses attached to the body over the axle on top by the drivers side or you will cause major issues.
 

Robert M

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I replaced that thin bracket with a solid bar that created even less clearance for the driver side pipe but I was still able to get enough clearance. You should be able to get clearance by slightly twisting the pipe or moving the pipes forward as much as possible. If not then your OTA pipes are pushed too far to the rear of the vehicle and you may have to cut some from the front of the pipe. You really need 1/4 to 1/2 inch clearance everywhere for heat and movement. When I thought it was set properly I jacked mine up by the axle and pushed and pulled on the rear body to verify I still had enough clearance everywhere. Warning: Keep exhaust about 1/2" from those plastic hoses attached to the body over the axle on top by the drivers side or you will cause major issues.

^^^I agree with that, it requires some twisting to position the OTA's so there is no contact, and I used a couple of small Black tie wraps to keep my plastic lines away from those big 3" OTA's.

R
 

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