2008 GT Exhaust Recommendation

[MaxDestruction]

I know this subject has been killed to death but I want to see if any new updates on exhaust would warrant new thoughts.

Car; 2008 GT with Steeda CAI with tune, thats it.

Wanted; Exhaust obviously for better performance and HP gains but requirement is tone which is throatier than stock but not neighborhood disturbing loud.

Any inputs are appreciated.

 

[Marc S]

Long tube headers, O/R Prochamber with stock mufflers.

 

[Steel Horse]

Boomtubes are the best sounding IMO. Put a set on about a month ago and love them.

 

[gmantheman]

Everyone is going to give you their opionions/recommendations, so here is mine: Prochamber w/high flowcats and magnapacks. Louder and throatier than stock, but neighborhood friendly. I leave my condo between 4:30 and 5:15 A:M and none of my neighbors complain.

 

[walter]

HP gains will be minimal with just axlebacks. That's more for show then anything, you'll pick up HP when you bolt on some longtubes with a matched midpipe section.

That said I love my Steeda Axlebacks. They sound deep, and rumbly all the way to redline. Couldn't even begin to imagine how awesome they would sound with a catted MRT H-pipe and some good headers.

 

[GreyDiesel]

I have boomtubes and also love them --have received many compliments. If you stay out of the throttle, they are quiet-ish. My neighbors have said that they know when I come and go, but they also said they dont mind because its sounds cool and is not window rattling by any means.

That said, going off your original request, your only HP gains will be had from new headers and/or a new midpipe. And, of course, those are more costly. If you do plan on a serious investment, start with the longtubes and midpipe with the stock axleback, and then see if the tone is to your liking. I would bet it will be.

If you've only got 300 to spend, get the boomtubes. No HP gain, but very cool tone.

 

[Slapyo]

Your best bet will be to look on YouTube for some clips. See what you like. For the most part they are all going to gain HP and TQ, it's the sound that will be different between the systems.

I know Magnaflow has a section on their site called "Hear It" and they have video clips of like the launch, drive by, in the car. The other manufacturer's may have the same.

 

[Defiance GT]

Honestly I have like no $ so i got corsa long tubes( THATS WHERE ALL MY $ WENT ) and took off the stock mufflers and i love it. Great idle and just act calm around the neighborhood. Also watch for backfires. I ran stock no mufflers, sounds good but no HP gain

 

[MaxDestruction]

Header Recomendation

Ok, now I understand. I will shoot for headers, who recomends what? As it relates to performance gains and ease/quality of installation.

 

[FenixBirdWing]

Don't mean to divert this thread too much with a side question - I know axle-backs don't give you HP gains but would cat-back systems typically give significant HP gains?

I've seen cat-back exhaust systems advertised as providing HP gains but at the same time it seems that cat-backs are inherently limited by the same mechanism as the axle-back - in other words, the diameter of the pipe that's the source of the exhaust (ie. whatever pipe the cat-back / axle-back will connect to)??

 

[40th GT]

Don't mean to divert this thread too much with a side question - I know axle-backs don't give you HP gains but would cat-back systems typically give significant HP gains?

I've seen cat-back exhaust systems advertised as providing HP gains but at the same time it seems that cat-backs are inherently limited by the same mechanism as the axle-back - in other words, the diameter of the pipe that's the source of the exhaust (ie. whatever pipe the cat-back / axle-back will connect to)??

Cat-backs won't net you much gains either, unless your car is supercharged/turbocharged (which stock Mustang GTs aren't).
So the only benefit to cat-backs in this case is the mandrel-bent exhaust tubing (which again, don't net you any performance gains). So if you want a better sound, you'll be better off by getting just the axle-back, as it'll be much cheaper than the cat back.

 

[ViperNuge]

Ok, now I understand. I will shoot for headers, who recomends what? As it relates to performance gains and ease/quality of installation.

I have never read a thread that mentions a header install as easy! LOL

You might want to research that one first. If you have a lift its doable....otherwise I hear its quite a long weekend. Dont get me wrong, I would like to get headers myself, I just dont want to break my back doing it.

patrick

 

[NastyStang113]

I'd say the Magnaflow mufflers with a offroad mid pipe if you can get one in your state.

Don't mean to divert this thread too much with a side question - I know axle-backs don't give you HP gains but would cat-back systems typically give significant HP gains?

I've seen cat-back exhaust systems advertised as providing HP gains but at the same time it seems that cat-backs are inherently limited by the same mechanism as the axle-back - in other words, the diameter of the pipe that's the source of the exhaust (ie. whatever pipe the cat-back / axle-back will connect to)??

If you're lightly modded than no. The reason is because the stock exhaust tubing is 2.5" and so are most of the catbacks. 2.5" tubing is perfect though for these cars though. Magnaflow is the only one that I know of that sells one that is 3" as well. The only way you'd need that is if you're making 750+ rwhp.

If you're making big power than the catback will gain a few rwhp but not much! I'm running an offroad x pipe with the Magnaflow catback (Not Magnapacks) and with 524 rwhp it sounds awesome!

Michael

 

[Slapyo]

Magnaflow has a dyno sheet page you can look at.

MagnaFlow Performance Exhaust

Below are the 2 dyno sheets Magnaflow uses for their exhausts. All of the axle-backs had the GT500 dyno so I included that but the other full cat-backs had a dyno sheet for the 4.6L.

 

[40th GT]

Those numbers don't mean that much to me as the dyno runs were done by the manufacturer.

With that said I've seen some 03-04 Cobra guys that saw 18-20 hp gains on the dyno.
Most GT guys claim that it'd be worth all of 0-2 hp.

 

[Slapyo]

True, but you have to remember that these cars are bone stock from the manufacturer and those other guys may have some other mods done as well. They give an ok ballpark figure though.

 

[NastyStang113]

Axlebacks do not gain power on the S197.

 

[GilmourD]

Axlebacks do not gain power on the S197.

My theory on this is that Ford may actually have just put a good exhaust on the car to begin with. Flow is probably more restricted in the exhaust manifolds and even with a good set of headers everything behind them is still good.

It seems that exhaust replacements seem to be good for a different tone rather than a gain in power.

 

[walter]

Word on the street is that Ford rated the GT's exhaust for up to 450HP and 300HP for the V6. I read in the past that they actually spent a LOT of time doing research and testing on the thing to get the right flow and sound out of those.

 

[J.Cagle]

If you take a stock gt muffler off you can look straight thru it. There doesnt seem to be any restriction inside of them. I got my axle back just for the sound anyways,lol