I went with intake and catback first as that's what the car needed replaced I feel there was 0 impact on the butt dyno, so take that as fwiw but the sound is much more enjoyable

 

I would imagine you would feel nothing, catback isn't restrictive stock neither is the intake =)


now slap a pulley on, youll feel the difference. you may have better throttle response now.

 

Put a 17% pulley on it.....great for a daily driver. Even over my stock JCW pulley, the 17% pulley made a difference you could feel. Over a stock one...I'm sure it's like night and day.

 

soon as I find someone local with a pulley puller and a tensioned tool I'll be getting a pulley/belt

 

I tried a puller on mine, and I still had to cut it off with a dremel/grinder.

As far as the tensioner tool......you can use a socket and a long screwdriver/crowbar to get by. It's not pretty, but it works just fine

 

At 17% and 19% the car launches but I recommend water meth. However, the m45 reaches adiabatic effeciency at 14000rpms which is about redline on the engine with the stock pulley, so the smaller pulley lowers the peak power. Plenty of people will say it's BS because they're boost gauge was still rising, well that's because boost is pressure, and heat creates pressure. Just because boost is high doesn't mean the SC is returning more power than its using. At 14000 RPMs the m45 only supplies a 30% return on parasitic loss, and then drops off completely after that. Meaning the power sapped by the SC is not being made up for. Once adiabatic efficiency is passed the air becomes turbulent and hot, and oxygen density is diminished. The boost you see is the pressure caused by particle expansion from excess heat.
If you only launch and stay in lower RPMs the 16% is a blast, and don't worry about the highway, the over gear drops rpm and bypasses the SC. I don't think however such a small pulley would be ideal for racing where the car reamains in high RPMs, however IAN could tell you what pulleys he's used racing.

 

so what shift rpm for 16 % ? I do not value redline HP as much as I value 4000-5000 rpm HP, it's rare for me to hang out at redline unless it's just not quite long enough a straight to shift

 

you can go to redline, but you are fine in that RPM. 17% is fine, as long as you don't hang out at redline say tracking for 10-15 min, but a few pulls will be fine to redline, it will create some heat and warm up that intercooler, but it will still work

 

I have a 17% pulley. If I was tracking the car (which I don't), i would run a 15% pulley because of the reasons emini explained.

But for a street car, a 17% pulley works great.

 

I'm tracking & autocross in the car, so what is best rpm to shift with 17%

I prefer to gain power in lower rpm and shift earlier if that's what it takes to run 17% on the track

 

At 6500rpms.....

the stock pulley is turning the SC 12,360 rpms
the JCW pulley is turning the SC 13,966 rpms.

with a 17% pulley the SC is turning 14,400 rpms at 5,800 engine rpms. According to all of the dyno data charts I've seen, once you get the SC over 14,000 rpms, you start loosing efficiency.

I would think that as long as you stayed under 6,000 RPMs, you should be fine.

 

I run 17% around town, only problem on the track is you run wide open for so long so it generates a lot of heat

 

ok sounds reasonable I prefer to have more power from 3-6k rpm I'm ok with a slight penalty over 6k rpm I dont make it a habit over 6k unless it's a situation like shifting in a turn or at the very end of a straight

 

yeah, torque really comes in at around 3500, which still gives you another 2500 rpm to play with, plenty for the track, autocross you wont have to worry as much