Dedicated Exhaust Discussion

[Striker01]

These header flanges point down way too far for my taste, they could also be much closer to the transmission. I cut the flange off the rear set so I could actually get them mounted flush on the head. I think the only work required will be behind the collectors. My plan is to get the front set turned towards the rear of the car and moved up and in closer to the transmission then pull the engine to get the rear set matched as close as possible to the front. I want both flanges above the CAB.





Lots of clearance between the frame rail and headers, about 1/2 between the headers and sway bar.


This flange is too low and pointed down too far.

[JRowe]

Great feedback. Thanks for sharing.

[Striker01]

Did some more work on the headers. The front set was just a couple cuts and took a couple inches length out.


Rear set took a few hours of messing with it in the garage. Multiple cuts, tacks, and re-cuts but I think I have them sorted.

Once I had it close to where I think it will work, I drilled a scrap piece of thick sheet metal to mount on the other flange. Clamped the flange to it and tacked it together.



I have no idea how that weird bend after the collector will affect performance but they fit now.

[Striker01]

Here is a shot from above




Clearance from the sway bar, about 1/2"



From the side, it doesn't hang down past the frame rail anymore and should give me plenty of room to work around the CAB for the mid section.

[hoveringuy]

I mean, that bend isn't the greatest thing in the world but it's not a big deal, either. Oxygen sensors have room, sway bar and CAB clear, room for AC.

This is legit, and I'm guessing it would be easy to duplicate if the motor was out of the chassis once you know where the flanges need to fall.

good job!!

[Striker01]

I mean, that bend isn't the greatest thing in the world but it's not a big deal, either. Oxygen sensors have room, sway bar and CAB clear, room for AC.

This is legit, and I'm guessing it would be easy to duplicate if the motor was out of the chassis once you know where the flanges need to fall.

good job!!

Thanks! It should work fine, i did tilt the O2 sensor more toward the engine just to keep the cable clear of the firewall. I probably could've tried pie cutting sections out of the primaries to get the whole thing tucked closer to the block but this solution seemed easier.

[hubcapboy]

Ugh thank you so much for doing this. Great work, great pictures. Welcome to the "it's really hard to get a picture of this and explain to everyone what's going wrong" club. I LOVE the plate to align the flanges. I wish I'd done that. hoveringuy and I did a bunch of "do we need a flex on one side before they come together?" arguing, so we'd love your thoughts on that.

Is there any hope to match up to an existing catalog rear section or rear and mid?

[Striker01]

Ugh thank you so much for doing this. Great work, great pictures. Welcome to the "it's really hard to get a picture of this and explain to everyone what's going wrong" club. I LOVE the plate to align the flanges. I wish I'd done that. hoveringuy and I did a bunch of "do we need a flex on one side before they come together?" arguing, so we'd love your thoughts on that.

Is there any hope to match up to an existing catalog rear section or rear and mid?

I think you guys went into a single exhaust, if I remember correctly. My plan is 2" dual with an x pipe before the cats. I want it to match up to my M20 stromung catback. I didn't even look at any of the existing mid section stuff, figure any catalog option will need adjusting so probably easier to just start from scratch. I ordered a 2" "build your own" kit, 2 high flow cats, flanges for the front and a donut/flare connection for the rear. I'm hoping the flare donut thing will work for the rear as the stromung pipes are slightly smaller at 1 7/8" OD. Have to play that by ear as I go, I don't really want to modify the stromung in case decide to go a different route. As far as the flex, I'm thinking about doing one on each mid pipe, fairly close to that flange. Reasoning is that I'm pretty sure the stainless will move between tacking and fully welding but I'm open to suggestions, figuring this out as I go.

[hoveringuy]

As far as the flex, I'm thinking about doing one on each mid pipe, fairly close to that flange. Reasoning is that I'm pretty sure the stainless will move between tacking and fully welding but I'm open to suggestions, figuring this out as I go.

you don't want two flex pipes, because then it will flex. Constantly. And you'll be replacing cracked flex sections in short order.

You just need one, if any, so you can align the second flange.

[Striker01]

So I tried to mock up the exhaust with the wrong engine mounts. My engine was about an inch closer to the driver side frame rail, didn't realize until I tried to fit the intake with the bosch ibooster installed. Lesson learned, Revshift 24 mounts will not work. I got the AKG ones and now that the engine is centered one of the flanges is closer to the CAB than I would prefer. I cut the rear header primaries just past the flange and shortened until the rear set just cleared the front set.

It got rid of the weird bend in the rear set and I tucked the front one a little closer to the transmission.



I should even be able to use the stock heatshield with just a minor modification.

[moatilliatta]

why no vbands?

[hoveringuy]

why no vbands?

I had V-bands and now I have flanges.

Much, much prefer the flanges because they're so much easier to align and connect, and they fit a tighter space. With the studs welded into the header flanges, just slide the mid pipe on and tighten the nuts.

V-bands were always a wrestling match for me. hated them!

[Striker01]

why no vbands?

Never really considered them, just figured Flanges will work better and be easier to build.

I had V-bands and now I have flanges.

Much, much prefer the flanges because they're so much easier to align and connect, and they fit a tighter space. With the studs welded into the header flanges, just slide the mid pipe on and tighten the nuts.

V-bands were always a wrestling match for me. hated them!

Great idea welding studs. never thought of that!

[digger]

i like the good old flange myself, but IMO you dont want the connection too far downstream from the bell housing otherwise its a headers off job to remove the gearbox.

I would also think about whether adding studs might make it more difficult as you need to the clear the studs to drop it down. it depends on the layout overall

[hoveringuy]

Never really considered them, just figured Flanges will work better and be easier to build.



Great idea welding studs. never thought of that!

I love having the studs. It lets me slide the mid pipe up and it just sits on the studs while I secure the back. Plus, just a single ratchet/extension and M13 socket and done. No wrestling with two separate wrenches. It's Lux!