duals for MPG?

[drhill]

I've been searching high and low....does anyone have a before and after MPG increase for replacing single exhaust with dual exhaust on a box panther? THinking about this for my wagon but I would need to justify cost with some MPG gain...

THanks!

[Dave804]

I've been told ~2-3mpg. Go read the thread I have in the performance forum on mpg. A lot of guys giving great info there.

[gadget73]

~2 is fairly typical. The stock single exhaust is horrible. Its very restrictive. Ford's own numbers give 10 hp and i think 15 ft-lb of torque increase just from going from single to dual exhaust.

[drhill]

Yep - I've been wanting to do this since I got it - I can't believe the y pipe goes from two 2" pipes to one 2" pipe!!

Unfortunately, I'm scrambling to get the car ready for a long road trip. Doing the math, I can't justify the cost of doing duals with the money saved just for this trip....so I will put it off a bit.

Theoretically if I go from say 19 to 21, I would save about $70. My costs for doing stock duals would be about $250. I think I may wait until I do an engine upgrade and do a better system....I have a 2.25 mustang 4 cat h pipe sitting in my yard. I couldn't even throw it away...trash guys took it out of the bin and left it on my grass! It would be perfect for an HO/Explorer engine swap.

[gadget73]

One thing that should help a bit and not cost much is a better muffler. Just replacing the stock muffler with something that flows a little better should help some.

[drhill]

Good idea, I think the stock muffler is just a slip on. Do you know of a good muffler with the bracket already on it for the hanger? If not, any suggestions on how to replicate the hanger? I would like to avoid a trip to the muffler shop!

[jpc]

drhill, let me know what you buy. I am tempted to do the same upgrade. Would really like an extra 2mpg.

[mercurygm88]

I had my duals put on by a local shop last september. I still have all 4 cats and 2.25" duals with no crossover and glasspacks. Ever since I got rid of the stock single the car seems to have alot more low end torque. It's got a nice rumbly idle but isn't to terribly loud even when you step on it. Even at 70+ mph with the windows down theres very little drone. I'd say I get about 2-3 mpg more than before.

[drhill]

as I'm doing research, it's hard to find a good performance muffler in 24" overall length, 2" offset inlet/outlet. The cheap walkers neck down inside the muffler, going to a 2.25 inlet/outlet there is a good magnaflow offset/offset (which are all fullsize straight through) but then it"s an $83 stainless muffler through summit racing and I have to use putty to fill the pipe gaps...

hmmm...I was just hoping for a slip on $50 or less muffler that I can do myself, finding this is harder than it seems.

[sly]

you can always get a shorter one and make up the difference with a section of 2" pipe.

[sly]

you could also use this one

http://www.ebay.com/itm/NEW-AP-EXHAUST-MUFFLER-2-2-OUT-O-O-26-TOTAL-LENGTH-MADE-USA-3757-/261060589699#ht_2460wt_855

and just cut off another 2 inches of pipe for clearance. Though contact the seller to make sure it's a design you want to use (flow through, baffled, chambered, etc)

It might be a good idea to wait until after your trip to do any work... just in case.

[drhill]

I think I'm going with the FLo Pro Max part # M11235. $46 on ebay and very similar in design(stright through perforated core) to the Magnaflow products except not stainless, which I don't need in the desert. I will have some sizing differences because it is a 2.25 muffler on 2 inch pipe, but with some reducers and clamps from autozone I should be at the correct 24" overall length and still be able to reuse the muffler on a 2.25 dual system in the future.

[sly]

sounds like that will work then.

don't skimp and get the u-bolt clamps. Get the sleeve clamps. They're mucho bettero. u-bolt style clamps like to bend the pipe up if you get a little too frisky tightening them up.

[GM_Guy]

Good idea, I think the stock muffler is just a slip on. Do you know of a good muffler with the bracket already on it for the hanger? If not, any suggestions on how to replicate the hanger? I would like to avoid a trip to the muffler shop!

See attached if you have the 89 and older muffler that bolts to the hanger. This bracket uses a muffler clamp to the pipe, and one set of holes line up with the holes in the exhisting hanger. (this does not replace the removable piece of the exhaust clamp, it goes on after).
You can make one out of some flat stock (I used some 5/16 x 1" strap I had lying around, bent it to fit and marked my holes). Old part numbers in the filename if you want to buy one.

as I'm doing research, it's hard to find a good performance muffler in 24" overall length, 2" offset inlet/outlet. The cheap walkers neck down inside the muffler, going to a 2.25 inlet/outlet there is a good magnaflow offset/offset (which are all fullsize straight through) but then it"s an $83 stainless muffler through summit racing and I have to use putty to fill the pipe gaps...

hmmm...I was just hoping for a slip on $50 or less muffler that I can do myself, finding this is harder than it seems.

Even a glasspack costs more than it should (goto cherrybomb and download the catalog to get the correct pn, scroll down to the full offset glasspack, 2" pipe, 24" OAL).

If you where seriously considering one of the straight through mufflers from magnaflow, keep your costs really low and straight pipe it. A straight thru muffler really offers nothing for muffling--its straight through afterall.

You can ghettofab a straight through setup with two 12º tailpipes and I think a 6" coupler from the generic muffler parts at the autoparts store. That'll cost you though, so goto your favorite exhaust shop and have them bend up a 2" piece of pipe, 6" from hole center line to hole center line, and bend it into a lazy Z and expand the ends to slip over 2" pipe. Before you do that though, make sure you can get your muffler off your pipes. If you need to cut your pipes in order to get the muffler off, just have them make the custom pipe a couple inches longer.

Alex.

[88Vic]

My duals were less than $200, parts and labor and I have a longer, more expensive Lincoln H-pipe.

Here's what you do: order the walker H-pipe and tailpipes (I ordered 2 so one isn't new and the other rusted) and take it to a shop and have it welded up. Don't buy mufflers at all, i'm runnung just the 4 cats and pipe and it's not too loud at all, and I gained at least 3 mpg city, probably 4 since I can get more than 300 miles per tank with ease. THat's the cheapest, best bang for the buck dual exhaust conversion you can do.

But since you have a Mustang H-pipe already, have a shop take the muffler out and put a pipe in place, that'll cost you all of 20 bucks and should hold you over until you can swap that Stang H-pipe in, with the Stang headers of course.