Sancho805

My AEM CAI kit/Predator combo is on its way and i cant wait to install into my Stang! Now that i got this step covered, i wanted to modify my exhaust. I was curious on how much of a performance gain (if any) i can expect from a "TRUE" dual exhaust modification alone. On top of that, how much more can i get from adding headers. I personally inspected the stock exhaust manifolds and they "appear" to look as freeflowing as some of the headers on the market. I'm not very knowledgable in this category and was wondering if headers would be necessary or worth buying. Thanks in advance for any feedback on this topic.

MHShockey30

I have heard that headers dont add that much power. The headers on the 05 stangs are allready good and I think new headers would just be a waste. I would recommend the dual exhaust though.

hamidlmt

headers added a nice gain to my seat-o-pants dyno meter... the sound improvement was even greater... even surprised me when I first fired 'er up. Ford plugged up the exhaust on the 4.0... headers and true duals would be a great mod!

dafaic

Defintily go with headers back. I was going to when i decided to cut bait and sell it to get the Impala. I bought the second Mustang my local dealer sold first week of Nov. 04 and I had massive issues and got tired of jacking with it. I had installed 4.10's auburn posi, xcal v1, home made cai, and flowmaster muffler. The stock exhaust is very restrictive. The stock muffler is very very restrictive. I put the stock muffler on my Durango thinking it would give a decent sound but no it just clogged things up and it ran like crap. The stock muffler is actually more restrictive that the Durangos huge resonator and muffler which combined is about 4 feet of restrictiveness. Any just my 2cents

Sancho805

thanks for the feedback guys.......i'm a little confused now though.....i'm getting two opposite opinions on whether headers will be necessary on the new Stangs. i guess i need to do more research on this interesting topic. as for true dual exhaust...any testimonials or experience on that subject?

dafaic

I had a 95 mustang gt back in 1999 and i went and spoke to Lone Star performance. Going true duals with an xpipe or hpipe is going to let go of some of your torque. And this guys recipe for go fast was to start with gears, then go exhaust and on up. That way everything done after gears makes the car faster. This is true i raced a 95 5.0 a month later i had gears only and he had upper/lower intake, cai, exhaust and stock 2.89 gears i think that came in those. Anyway needless to say we were side by side and he spent alot more than $450. True duals is the ultimate way to go if you plan on expanding if not then don't bother dropping alot of money into pipes. Just do what you need to do to make it sound good. Full exhaust opens the door for future bigger mods and will only add 15-20 maybe at the top but you will feel the loss in the bottom. I would do headers but i had major plans also. Too bad the car had to be a lemon. I see chargers are already out too. That was my ultimate goal. Thats why i bought a car that had a charger.

scrming

I agree with the folks that say headers give you a minor gian... 4 or 5 RWHP... And at your level there really isn't any big gain vs. a good single axle back... If you some has a good dyno run before and after I will glad change my mind... Especially if someone has a before/after for just the headers...

jthorn9

Yea headders will only give you a 2-5 rwhp gain, but add that in with a true flow dual exhaust system and youll get a realistic gain of around 15 hp. Believe it or not, but the more you add on to your exhaust the more each add on cansuls out the other. Exhaust alone, about 8 rwhp on a stock 6, add an x or h pipe and change to a GT cat system, around 12 rwhp, add headers, about 15 rwhp. Well at least these are the approx numbers on the 94-04s, so your year may be a tad higher.

TJ

Jthorn/ OP's I have read more than a few post & more than one web site that you will lose HP/TQ on a Mustang 2005 V6 with TRUE dual exhuast. The V6 needs back pressure (unlike a V8) to prodruce all its HP and running true dual exhuast it loses HP/TQ . I read here the opposite anyone here in the know want post thier opinions. Seat of the pants is not accurate.

jthorn9

How does back pressure raise hp? Last time I checked back pressure reduces hp because it limits the amount of air that the engine can release.