Gains from performance exhaust

[clhorton]

I've heard many times that exhaust systems do not have any real gain of hp on our cars. Well dinan's website shows different. Maybe I'm still too new and reading it wrong, but their website says 51 hp@6250. So what gives. School me.

[BigKriss]

They claim 51 @ 6250 rpm (which is redline) and 229 @ 5250 rpm (stock is 210). They also say that with the peak horsepower a chip is needed also. So the 51 hp that they claim is basically saying, with the stock setup you will get a lot less power revving it this higher compared to the dinan setup. With a chip and free flow exhaust its 19 hp (peak) more.

[Jay 535i]

I think that, with every aftermarket performance-enhancing goody out there, there should be a horsepower:dollar ratio. Here are some examples (prices and hp are estimates): :)

EAT chip: $200, 20hp = $10/hp
Stage I turbo kit: $3500, 100hp = $35/hp
Dinan exhaust: $1000, 19hp = $52/hp (yikes!)

Oh, BTW, I'll be glad to add 1hp to anybody who sends me $52. :D

[Paul in NZ]

I m sorry but I just cant beleive BMW would sacrifice 50 hp to a poor exhaust design....50HP 50! thats like 25 percent!!!!