How much more hp can I get?
Right now I am running on 15%.
Pros and cons on switching to 17%?

 

Depending on who you listen to, you will get highly diverse opinions - each based on 'facts'. You can choose the 'best way to go' 15%. Or the 'dont be a chicken' 17%. Or, you can be a fence sitter like me and go with the m7 16%

It boils done to which one do you want? They're all good. However, you can't say that about the manufacturers. Choose well, Grasshopper

 

How many degree difference is the JCW from the stock R53 pulley? I was told it was like 14%.

purplehaze05mcs.... how many miles are on your engine and how many miles have you been running the 15% pulley you have now? Because you might also be looking into a water pump change unless you have already done that.

Im just over 80K and my water pump that crapped out on me. My daughter was driving at the time.

 

JCW pulley is 11%.

 

DaGhost... thanls bro.... so with a 15% pulley and JCW 380cc injectors I wonder how many ponies Im putting out? 180?

purple... dude seriously... look into doing a water pump change if you already have not done so. Because with the pulley it is going to wear much faster spinning at higher rpms through the PTO off the back of the SC. I knew this but thought mine would last longer then it did. Then again I push my mini pretty hard through the canyons.

 

It's hard to say about the hp numbers. Not all cars are exactly the same from factory, let alone with mods. But it should be around that, I haven't dyno'd mine yet since I'm waiting for my exhaust to be done, but there's probably dyno sheets out there. With a 17%, injectors and a tune are recommended.

 

"Basic" pulley #'s are this:
JCW - 13.5-14 psi
15% - 14.5-15 psi
17% - 15.5-16 psi

These are just avg. #'s and will vary, car-to-car & gauge-to-gauge, but it will give you some idea.

Power #'s will again vary car-to-car, even more so than boost, but the above #'s are pretty close.

 

I run 12 psi with a 14% pulley and put down 250whp. Imo, make everything breath better for best results. RMW head n cam and header toss a tune on it and you re bullet proof.

 

I've had my 15% for about 60k now. It is my daily driver. So far WP is holding up. Since I have a couple of low miles SC's for spare. It's probably a good idea to install a water pump on one of them for a quick R&R. I also have a 06 MCS without a reduced pulley yet because I'm just waiting for my 7yr/100k warranty to expire so they don't try to blame it on the reduced pulley if anything goes wrong with the SC. But on my 05 w/o warranty I was thinking of updating my pulley.