So I have a fairly stock 2006 Parklane R53 with factory lsd with only ~100k miles and own it for about 5 years now. The only changes I made when I got the car was installing the Valeo SMF clutch kit. Last year my exhaust blew so I installed an AMD tuning catback which sounds like a popcorn machine but makes me smile every time I drive the car.

This car is my daily driver, and don't do track days but spirited driving. So why am I thinking about a pulley upgrade now? Wel first of all the sound of the supercharger is addictive and second of all I think I got used to the 170bhp (or did the world around me got faster?)

Anyway I was thinking about going for a 15% pulley. Nothing crazy just a bit more supercharger sound and +20bhp(?)
But what I can't seem to find is whether I need a tune or does the stock map handle the 15% pulley? And what about injectors, should I go for 380cc ones or not? Or should I even go for a 17% pulley since I don't go above 5k rpm anyway?

I appreciate your thoughts about this.

 

Do it. 15% reduction SC pulley will give you more than 20 HP gain even at stock tune.

 

I have a 15% and switched to one step colder plugs with no change to injectors or tune. That was about 23 years ago and I still love hitting it in second gear, feeling the car pull, and enjoy the supercharger whine as the revs rise. Do it!

 

I started with a Dinan CAI, and then put a UUC exhaust on, which really opened it up. So, I advise you look at that first.

 

First of all, a 15% S/C pulley by itself will not give you 20 additional horsepower. I gained 17hp with a 15% pulley, 380cc injectors, colder plugs and a tune (Adrian Nastase). And yes, I have before-parts and after-parts dyno sheets. You're only working with 1.6L. It's extremely hard (and expensive) to coax more horsepower out of a small displacement, non-turbo engine.

 

Years back I installed a (WMW)15% pulley, 380cc Siemens/JCW injectors, NGK colder plugs + wires, custom "wide mouth" CAI and 210 Adrian tune. The mods made a significant difference. I chose not to go with a performance header/exhaust - I love hearing that SC wind up = (I've had loud performance cars in the past. I'm an adult now... and really dislike loud cars. Pops, burbles and bangs remind me of exhaust and intake leaks...)
In hindsight; my only consideration (not regret), is not going with a 17%....
Although it has been mentioned that there is little difference in gains between a 15% vs 17%.... (?).
As for the need for a tune by just adding a 15% pulley + colder plugs? As I understand - No.
With consideration to your current performance exhaust installed.... I think I would suggest having your Mini tuned anyway. Never hurts.

 

ok i'll be the bad guy. why spin the supercharger even faster when its a known weak point?

leave it alone. if you are going to do anything, make it spin less

buy a v8

 

You are not making the choice easier but I do conclude that if I go for the 15% I should do the injectors and tune too. That makes it a bit more expensive but let's call this my midlife crisis so let's go for it. I doubted to purchase the exhaust too and then it turned out to be awesome too.

I would love to own a v8 one day too but gas prices are insane here atm; ~$11 per gallon. Filled the mini up this weekend which cost me $118... The government is also pushing EVs and hybrids for years now and the EU is stopping sales for all new non-EVs as of 2035. So it a bit of a now or never moment for me.

p s. I do have a spare Eaton compressor laying around so I can always go back to stock if it breaks.

 

I don't think you need or should bother with larger injectors unless you can afford to be frivolous. That's up to you.
In my case; I just happened to come across my genuine JCW 380s at a salvage yard at rediculously low price of $30. I really don't know if they make a difference in hp gain.
I'll let the more informed help you in making that decision .
With respect to gas mileage?
I dunno - I get (IMO), crazy great mpg on the interstates cruising between 65 - 75mph. Around town? - eh? Not so much at stop & go 35 - 50mph.
I would wager that it has more to do with driving habit and conditions than it has to do with the 380s...

BTW: What is the max octane out there in the Netherlands?
Just curious.

 

So, this is my setup - Dinan Cold Air Intake. UUC catback ( they have been on since 90k miles ). That setup has been a blast. The Dinan CAI made some difference, but the exhaust really woke things up. This is on a 2005 with 6 speed Auto. That combo was in place until Aug 2021 - @ 151k - used Dinan pulley - the one that came attached to a used supercharger. Just those 3 things, and stock injectors. I felt the pulley made it more peppy on highway, but not as much difference as the original combo of the cai and exhaust. Now at 185k. Mileage - 28-30 highway ( 70/72 mph ). 18/20 city.

 

For a pulley a 15% or 17% NO tune is needed. The internet loves to tell people they have to have a tune, but that just isn't the case. I've been working on MINIs for 24+yrs now and over 95% of MINIs with a pulley still have the stock ECU and stock tune and clearly they are all running fine. I personally have installed pulleys on about 700 MINIs over the years and most of them again on the stock ECU. So get a pulley and enjoy. You won't need a tune till you go with bigger injectors, or cam and head work. And remember a tune is for performance, not to fix an issue.

But do note you do need the proper cold heat range plugs, and proper belt with the pulley, that is why we offer a kit so customers can do it right.

Happy to help with parts or a tune when you want.
https://waymotorworks.com/wmw-pulley-package/

 

Thanks Way. You are actually the reason for this post as I came across your shop on eBay. I'll be putting in an order in the next week or so.

 

To conclude this topic: I have just ordered a 15% pulley kit from @WayMotorWorks I could have ordered it locally but I wanted to support the forum sponsor and be grateful for the advice.

Thanks to all who replied, it drawed me over the line. It'll be some time before I can install the kit since I have to put back and engine and gearbox into a Mercedes which is currently occupying my garage.

 

Just wanted to welcome you (in advance) to the "Whiner's Club".
Enjoy!!!

 

2004 MCS 5-Speed.
Tune will extract more HP & TQ.
I have 15% Alta pulley, 380cc JCW injectors, NGK colder plugs & MSD wires, Mynes Headers 200 cell cat, IE cat-back exhaust, Ultrik CAI.
Before and after dyno tune by RMW gained more HP & TQ using Dynapak dyno - June 2008 Tacoma, WA. At 15% loss factor, my car is around 215 HP.