I have an '05 MCS with 15% pulley, HAI, and 22mm rear sway bar, and I'm itching to put another engine mod in. I realize the normal thing to do at this point would be a cat back exhaust, and I've read thru these threads ....um... exhaustively. Seems like most people report little noticeable change in power from the cat back, mostly they like the sound and tip style. There do, however, seem to be quite a number of reputable vendors claiming of 5-10 Hp with an exhaust change.

Contrast this with the TB, which is about half the price of an exhaust (let's compare the M7 TB at $350 with Milltek exhaust at $700), but the measured Hp gains from reputable sources are minimal, like 1-2 Hp. Interestingly, though, many of the first-hand reports of adding the larger diameter TB are glowing -- great throttle response, more power, etc.

I'm not looking to have the fastest MINI ever, but I do want to feel an improvement in acceleration or handling when I change something. The mods I've done so far meet this criterion. Any thoughts on which way to go, especially considering bang for the buck? (19%, MTH - don't go there, these scare me a bit. I wouldn't do the one-ball, either, after I heard the sound clip.) Thanks in advance .... :smile:

 

YES

 

Switch out your HAI for the AGS/Throttle Body. They give you a good deal (like 500 for the whole thing) and you will see alot of power. It will be basicly a straight shot of cool air into your intake manifold. Then you can sell your HAI and recoup some of the costs.