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Old 07-20-2014, 11:44 AM   #1
tjsblazer
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Dual Exhaust Routing??

This is regarding a 4wd Blazer. I'm wondering best route to go regarding Dual Exhaust. What is the best muffler configuration to get the pipes to route properly. Center in - Offset out or Offset in - Center out or?? .Would also like to put an H pipe just behind the transfer case and keep the tailpipe outlets behind the tires similar to stock. I would like some insight and pictures would be awesome if you have them showing routing and hanging. I am leaning towards Spintech mufflers.
Thanks for any help.
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Old 07-20-2014, 03:11 PM   #2
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Re: Dual Exhaust Routing??

Here is how I did mine.
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Old 07-20-2014, 07:40 PM   #3
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Re: Dual Exhaust Routing??

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Originally Posted by turp mcspray View Post
Here is how I did mine.
Thanks for the pictures. Ive seen the H-pipe mounted in that location but always bent under the Transfer case tailshaft. Never seen it over before. Looks very clean. Is there lots of clearance to the body when mounted? No body lift is there? Is that 2.5" pipe? Thanks for your help.
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Old 07-20-2014, 10:28 PM   #4
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Re: Dual Exhaust Routing??

This is how mine was when I bought it. It doesn't have a crossover pipe. It looks like the inlet and outlet are both on the edge of the muffler, neither are centered. I'm not sure what brand of mufflers they are. Notice there is a bend to get the right side over the transfer case and they dump out the side just behind the rear wheels.
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Old 07-20-2014, 11:02 PM   #5
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Re: Dual Exhaust Routing??

I put this together, 2.5" tube exiting out the sides in front of rear tires as my fuel tank is in the way.





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Old 07-21-2014, 12:02 AM   #6
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Re: Dual Exhaust Routing??

Definitely getting some great ideas here. Really appreciate the pictures. Thanks.
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Old 07-21-2014, 11:24 AM   #7
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Re: Dual Exhaust Routing??

here is how i routed mine. i put the crossover in front of the transmission.
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Old 07-21-2014, 09:27 PM   #8
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Re: Dual Exhaust Routing??

Mine is 2 1/2". I think the cross over is 2". With it going over the yoke, there is no clearance problem. Ideally the balance tube should be further ahead than mine is. I am running full length headers, so in my case, there just wasn't any good place to put it.
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Old 07-21-2014, 10:28 PM   #9
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Re: Dual Exhaust Routing??

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Originally Posted by JJH Jimmy View Post
here is how i routed mine. i put the crossover in front of the transmission.
That is gorgeous.
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Old 07-21-2014, 11:23 PM   #10
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Re: Dual Exhaust Routing??

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Originally Posted by JJH Jimmy View Post
here is how i routed mine. i put the crossover in front of the transmission.
Looks great. Do you have any other pictures of the H-pipe area once mounted?
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Old 07-22-2014, 11:02 AM   #11
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Re: Dual Exhaust Routing??

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That is gorgeous.
Thank you!

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Originally Posted by tjsblazer View Post
Looks great. Do you have any other pictures of the H-pipe area once mounted?
This is the best pictures i could find of the H pipe. I can take some more if you like.
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Old 07-22-2014, 03:05 PM   #12
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Re: Dual Exhaust Routing??

I routed mine out the back like this:
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Old 07-22-2014, 04:57 PM   #13
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Re: Dual Exhaust Routing??

One thing to keep in mind when tucking the exhaust up so high is that the radiant heat will really warm the floor up a bunch and heat up the interior. You don't want the mufflers too close to the floor or the tub. I installed my cross-over under the transfercase rear output and put a mechanical union in it so I could remove each side of my exhaust system seperately if I need to, to perform maintenance or whatever. With a fully welded cross-over, the exhaust system is pretty much stuck in place unless you cut it out. Just my $0.02.
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Old 07-22-2014, 10:49 PM   #14
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Re: Dual Exhaust Routing??

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I routed mine out the back like this:
I like that exit look. Very clean.
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Old 07-23-2014, 08:07 AM   #15
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Re: Dual Exhaust Routing??

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Originally Posted by cleszkie View Post
One thing to keep in mind when tucking the exhaust up so high is that the radiant heat will really warm the floor up a bunch and heat up the interior. You don't want the mufflers too close to the floor or the tub. I installed my cross-over under the transfercase rear output and put a mechanical union in it so I could remove each side of my exhaust system seperately if I need to, to perform maintenance or whatever. With a fully welded cross-over, the exhaust system is pretty much stuck in place unless you cut it out. Just my $0.02.
Don't really know why you would have to take out the entire exhaust for maintenance other than pulling the transmission but, if that was the case mine will pull straight out the front over the front axle. I have band clamps on the mufflers and that is how i installed it. Also, i really don't like the looks of mufflers hanging under the frame rails.

Here are a couple of shots of the crossover.
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Old 07-24-2014, 01:54 PM   #16
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Re: Dual Exhaust Routing??

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Originally Posted by JJH Jimmy View Post
Don't really know why you would have to take out the entire exhaust for maintenance other than pulling the transmission but, if that was the case mine will pull straight out the front over the front axle. I have band clamps on the mufflers and that is how i installed it. Also, i really don't like the looks of mufflers hanging under the frame rails.

Here are a couple of shots of the crossover.
You just answered your own question You installed mufflers with band clamps so you could remove system if need be to perform maintenance! I was just trying to recommend against fully welding the system in. You did it one way, I did it another. Nice system by the way.
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Old 07-24-2014, 01:58 PM   #17
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Re: Dual Exhaust Routing??

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Originally Posted by JJH Jimmy View Post
Don't really know why you would have to take out the entire exhaust for maintenance other than pulling the transmission but, if that was the case mine will pull straight out the front over the front axle. I have band clamps on the mufflers and that is how i installed it. Also, i really don't like the looks of mufflers hanging under the frame rails.

Here are a couple of shots of the crossover.
In that position, I would be concerned about added the heat blowing around transmission and pan. But nice set-up though. Anote about cross over pipes is that, from research, it seems that if you don't have a high HP/Torque , it can rob some lower end grunt. I run OE regular 2'' rams horns/straight dumps on all of my auto trans 4x4, open it up to 2.5" after mufflers, no crossover pipe. I want to create as much back pressure, coming out of the heads to get that low end torque. On my blazer - SM465, I run OE 2.5" all the way out. I want the heads to flow as easy as possible because I drive it on the roads the majority of the time, plus I like to race Camaro's, which I always lose. But fun...
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Old 07-25-2014, 08:40 AM   #18
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Re: Dual Exhaust Routing??

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Originally Posted by D.PASSMORE View Post
In that position, I would be concerned about added the heat blowing around transmission and pan. But nice set-up though. Anote about cross over pipes is that, from research, it seems that if you don't have a high HP/Torque , it can rob some lower end grunt. I run OE regular 2'' rams horns/straight dumps on all of my auto trans 4x4, open it up to 2.5" after mufflers, no crossover pipe. I want to create as much back pressure, coming out of the heads to get that low end torque. On my blazer - SM465, I run OE 2.5" all the way out. I want the heads to flow as easy as possible because I drive it on the roads the majority of the time, plus I like to race Camaro's, which I always lose. But fun...

My cross over pipe is in the exact same location that the factory Y-pipe would be on a truck with a LS motor. I have never heard of any factory problems with the transmission getting hot due to the Y-pipe? Since my exhaust does not have cats or a restrictive stock muffler and it is way more "free flowing" than a stock system i don't think there will be a problem.

From what i have read a crossover pipe on a stock ls engine does not add or take away from torque or power it just helps with the exhaust drone. So that is the reason i went with it.
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