Hello, I was hoping to get an update on the performance and gas milage. I'm looking at doing this but with Flowmaster 50 series. Wondering exhaust you've found with noticeable performance gain and also any change in milage...at all?

 

No change in mileage any time that I've ever made an exhaust change on these trucks. That said, you can get modest but noticeable performance gains. I know of one other user who has installed headers and noticed a gas mileage increase so perhaps it is possible, but I haven't experienced it. For best results, combine higher flowing exhaust with a better flowing intake which I've also got a write up for.

As far as Flowmaster is concerned, I'm personally not a huge fan. That's not to say they don't sound good, they do, but they drone a lot especially on these Discoverys and they don't flow particularly well. Also, if you go without the catalytic converters, the 50 series will be quite loud. I'd very much recommend something more akin to a Magnaflow or Borla.

 

How much did that exhaust setup cost you? Also, do you have a sound clip yet?

 

Rough estimate, $600. I can't remember if that's including the muffler or not, so maybe $750-$800 with both muffler and resonator.


I have since stopped daily driving the truck, it's off the road and is now a pavement queen. Since I'm not driving it much I have not grabbed a sound clip. I will tell you, since I've stopped driving it and I only get in it occasionally.... It is obscenely loud. I love it, and it makes me belly laugh every time I give it a little throttle, but it is extremely loud. If you're going to have this in a daily driver, you will want catalytic converters because they make the biggest change in volume on these trucks in my experience. A couple of Magnaflow or Flowmaster catalytic converters added to the mix would make this a great daily driver setup.

 

When I looked up those headers, it said they don't fit. Which hedman's are they?

 

They're the ones for a Range Rover. They'll say that they wont fit, but they will.

 

Will the Hedman Headers work on a Disco I ('96)? Do you know the diameter on these headers?


QUOTE=Alex_M;577262]They're the ones for a Range Rover. They'll say that they wont fit, but they will.[/QUOTE]

 

From what I've heard, yes, though I have no first hand experience. Seems like you have to switch some sensor with the D2 version.

As for diameter, I feel like the primaries are 1-5/8". The collectors I've seen come with both 2-1/4" as well as 2-1/2", though I recommend cutting off the hall and cup and using a 2-1/2" v-band.

 

[/QUOTE]
I have a set of Hedman Headers I ran on my 98. You have to replace the driver's side knock sensor with a D2 one.

 

UPDATE: This setup has been on her for over a year and a half now. Of that time she's been parked for about a year. I've since taken off everything but the headers to rebuild the exhaust... again.

She failed inspection a few months ago for no cats and I'm saving up right now to re-build the exhaust. The Borla ended up moving to my DD Silverado. Very tame, nice match for the truck. I will note that I was planning on adding cats back anyway because at some point in the past year I decided that I really liked the environment the way it was.

I'm also pulling the headers back out to ceramic paint them and wrap them with header wrap. Then I'm cutting off the ball and cup, I'm going to weld a couple inches of pipe to each collector, and I'm going to be using these clamps. I'm going to be using them through the whole system in both 2.5" and 3" so I can disconnect the y from the cats and the midpipe from the muffler which is going in the rear now.

I'm going to be putting the cats where the muffler is supposed to go because they won't fit next to the frame rails. I believe that the O2 cables are just long enough to reach. These are the cats I'm using because I already had one.

I'm going to y the two banks together after the cats using this coupling. The coupling will also house two of these O2 bungs for the rear O2s.

I'm going to be using this Thrush Hush turbo muffler. I want to daily the Disco again and this muffler should do well the quieten it down without restricting flow terribly, and it's cheap which is great for me. The muffler is going to be rear mounted where the factory resonator would've gone. Also, the muffler isn't supposed to be red despite the picture. Just aluminized.

I do still want the ability to get obnoxiously loud once in a while, and I think I still have the throttle body off my old parts truck. I'm planning to weld a piece right after the cats to mount the throttle body to so it acts as a butterfly valve exhaust cut out. If I do have the throttle body like I think then I'll do that and I'll just run a choke cable into the cab. Easy peasy.

When I get all the parts together I'll take pictures and hopefully do a better write up this time than last.