"25 Hp. Hmmm... How much this this bump cost you? I was just curious. I would be interested to know exactly what modifications you have made with which products and how much each cost roughly. You probably did not get each mod dyno'd and have no idea what each component contributes in the overall 25 Hp gain."
Cost, ouch, that is a sore subject. When I first joined the forum when I got the car, other members warned me about the slippery slope of getting into modifications. The mods have been very expensive, but it has been a lot of fun doing them and dialing in the car.
I think I have done 4-5 dyno runs with the car, but it has not been in an organized sequence of parts added. The first runs were with just the intake and chip, the later runs were with different exhaust combinations (I went through several).
As best I can tell the chip and intake added about 20 hp, the complete exhaust system another 5 hp or so (I am putting out a little over 200 hp to the wheels). The Autothority chip is not optimized for max hp, but a high, flat torque curve and throttle response in addition to hp. The car is very responsive now with that chip and very different from the stock ECU tune.
Also, in hindsight, the TTP parts, though high quality, appear to be some of the most expensive you could use. I think the numbers for HP mods are something like this:
TTP carbon fiber intake: 800.00
TTP headers 1300.00
100-cell cats 1200.00
Custom Autothority ECU mod 1000.00
Dansk Sport muffler 800.00
"Lastly, what does your car sound like? I know Randall initially liked his Deluboz header and exhaust but I seemed to recall a post where he was interested in changing the exhaust due to resonance issues. Any issues with resonance or droning that you dislike?"
Its kinda hard to describe the sound. I like the low rumble at low rpm's and the scream at high rpms with the exhaust on the car now. Also, as most members know, adding an aftermarket intake adds some nice sound to the car. The car sounds quite civilized with normal driving, not like with the gemballa and other mufflers I tried.
What I dont like about the exhaust is a sorta metallic sound (not loose cats or baffles, just free flow and engine sounds). You can hear the metallic sound I am talking about if you find the link to the Dansk website, one of their free-flowing exhaust combinations has that sound. As best as I can tell, the intake and headers made the most difference in the character of the sound, as the muffler is similar to stock, except for a higher flow rate.
Ed
