Hi guys,

im looking to get a reduced pulley for my r53, around 15%, however i have no idea if you need anything else alongside it? like an uprated intercooler? can the engine cope with just a reduced pulley and nothing else or does it need reduced belt and performance plugs also?

if anyone could help that would be great :)

A shorter belt and colder plugs are all you need.

I'm sure some will even argue about both of those only to be on the safe side, but that's what I fitted. 15%, shorter belt and cooler NGK iridium IX plugs.

A puller will be needed for the pulley removal if you're doing the work yourself and make or buy a belt de-tensioning tool to make changing the belt easier. I got the proper mini tool from Derek Woodman mini and it was quite reasonable from there. Not too hard to make but I didn't have the time.

thank you! how did you feel the drive was after fitting them?

I just had a service done on my 04 JCW which was running 200bhp. While havin the service I had a 17% reduced pulley - nothing else. Car is up to about 210bhp and I really notice the difference. I used to smile lots driving my car and now I laugh out loud :-)

GTT in Dorset do a very good 210bhp kit. Well worth doing ;)

thank you! how did you feel the drive was after fitting them?

Sorry, missed the thread update message.

The power is much improved, the air filter was clogged though so it felt a bit flat after 4000rpm. It was listed as being changed at it's last service but clearly wasn't so I changed it and it now revs smoothly to the top end.

I was expecting it to bring it near the performance of my VR6 with 209bhp/210lbft but it isn't close, just the lack of torque being the main difference I think.
It's a definite noticeable improvement but I suspect I will do a little more tweaking to mine yet, probably just induction as I can't believe how small the inlet piping is and the standard air filter over the VR which in factory trim is rated about the same in peak power (176bhp). It feels like there's an increasing restriction the higher you rev it (it does pull well and revs cleanly) and I am fairly sure the inlet sizing is holding it back on a 15% pulley.
The standard VR6 air filter is over 50% larger, just for reference.

You'll never see the torque of us V6 in a MINI. Doesn't mean you won't have a blast though.
Been running a 15% pulley 8 years now. If you drive hard and fast an upgraded IC is nice. They plugs are just smart money.
I've run without and then with.
The 17% does generate more heat. That's simple physics but you won't see much ill effects unless you stay over 4500RPM a lot, a....lot. With a 17% a larger IC is more of a need. The JCW unit is a nice upgrade.

My 2¢. Graham of GRS Motorsport - Manufacturers of Quality Aluminium Products (http://www.grsmotorsport.co.uk/) GRS Motorsports is one of the nicest guys in the business AND makes a damn nice product.

Honestly though you'll get more fun from a lighter better flowing exhaust. For around the same money as a new IC.
Been years since I've been price aware in MIN parts but they probably haven't changed much.

I really do like the car, I probably didn't give that impression and I tried pretty much everything on the market looking for a suitable replacement for the VR which for me did everything pretty well.

Most of the time I'm driving very lightly with the occasional squirt to smiles. It's a good all rounder and quite responsive "spritely" even but lacks the never ending surge after that (I've been spoilt). Love the sharp steering though.

I'm pretty sure I will be modifying the airbox with a second inlet and either a panel filter or doing a hybrid design like the Dave F one.
I like don't like boomy exhausts as I getting old :) and prefer the OEM look so might try a one ball at some stage. Mild but interesting tweaks, the car isn't slow as it is either.