So, in all the discussions I've ever seen about Axle-backs, everyone says they do nothing for performance. Been hearing it so much, I got to the point where I agreed and just let it go. Well, today I checked out the June 2008 copy of DRIVE! magazine, and there is an article about a "new" ( I'm not sure if these are the same Flows everyone has or some new edition ) but they're Flowmaster Axle-Backs, Part Number: 17410. In the article, they are claiming that with those mufflers, proven on a dyno, they picked up 8hp/10tq on a completely stock convertible 2008 GT... Anyone with thoughts??? Marketing ploy or is it possible???

 

they may hve picked up 8hp and 10torque but not to the total hp/torque amount.

Around 2800rpms they may have gotten a 8rwhp difference but if you car dynoed before the mufflers at 280(just a reference) afterwards it might dyno at like 281. You get what im saying?

 

but I dont understand... why if the comparison between before and after the mufflers at 2800 rpms there was a difference, it doesn't mean a total difference? You mean like they only picked it up on the low end orrr... I'm confused, sorry[8D]

 

I wouldn't trust the magazine.. Even if you get an O/R mid pipe you won't see 8 rwhp on a dyno. If anything you lose a little torque and gain 2hp at most.

 

The thing is that the mufflers may change the power curve in a particular section but over all there won't be a noticable gain.
The biggest change will be the sound. If you want to make a real power gain you will need a complete exhaust system but, there again it won't be a really big gain.

Magazines will do whatever they have to to sell ad space.

 

Absolutely correct. You can find several online magazine dyno tests that show a gain with axle back or cat back systems, too. If you look critically at all of these tests the extra horsepower comes at some ridiculously high RPM. You're not going to feel something that gives you 2 hp at 4,000 RPM, finally building to 8 hp at 5k something.

 

this is the only thing I've seen and trust as far as gain.... but its a GT500 so they pick up more with better breathing

http://www.livernoismotorsports.com/...rsavsstock.wmv

 

I have read that the GT500 will lose power with most of the axlebacks out there?

 

you've read completly wrong, the GT500 is supercharged meaning that all flow enhancments are super important.

 

Magazines are good at recommending products for $. It's almost common knowledge our cars may gain a little power or may even lose a little power. maybe he had a hot car? Weather conditions and heat soak,etc on dyno to have different readings?