Hey everyone, I've been looking all over this forum but i haven't found an answer to my pretty specific question. Here it goes. I have a 2004 MCS that was built in Sept. 2003. Obviously it has the Eaton supercharger with the grey coating(not the newer dark coating). I really want to install a 15% pulley but I'm really concerned about reliability. I'll probably be driving this car for another 5 to 6 years. It has 45,000 miles and I will end up putting 60 to 80,000 more on it. Could I install the pulley without any worry of major problems in the future. If anyone has any personal stories or input that would be great. Thanks for the help.
We have a 15% pulley on our 2003 MCS and have had no problems, but our mileage is less than yours so it isn't a definitive answer. In general though MINI's JCW kit included a pulley that is between 14-15% and they warrantied that so it's probably an OK mod.
I have seen this very thread on NAM and I think the concern is that JCW changes the SC. My guess on that is that it was for ease of pulley install rather than coating. Either way, I don't think that you are going to put any heavy pressure on the car with a 15% pulley and you should be safe. Many folks have been running 15% pulleys for years now with no problems.
Have been running an ALTA 15% pulley on my 04 MCS (April 2004 build) for the last 7000 kilometres with no apparent problems. I guess the best thing to do is take a very conservative approach to belt replacement (ie. replace it more often than perhaps you usually would). My car had 40,000kms when I fitted the pulley.
It's funny, at first, after having the pulley fitted, my car didn't feel that much quicker than stock. To me, at least. But now, it does feel quite a bit more spritely when compared to stock. Funny what you get used to.
With an ECU remap to go with and regular maintenance, I reckon you should have no major problems with a 15% pulley.
Thanks, I appreciate the input. After doing a little more research, I've figured out that the darker coating just adds a minute amount of boost and doesnt really change reliability. I'm pretty confident that I'll go with the 15% pulley. Also, does the belt that Alta sells work with the 15% or only for 17% and 19% and how often do you change your belt? Thanks again.
I ran my 05 MCS with a 17% pulley for over 50,000kms including track work and it never missed a beat. Now have an 06 JCW and am about to put a 17% pulley on that next week ( I used a Promini pulley with BMW to do the install)
I'm doing installs this weekend for pulleys and told all the guys to bring new belts. The reason is that since you have it apart, you might as well change it. Other than that, it is the standard "check your belt" every now and then for cracks and wear.
I am soon to upgrade my pulley too so have been reading threads like this with interest since I have a Jan 03 build MCS. I believe this has the uncoated vanes.
From my research, the reason coating was introduced was to gain tighter tolerance between surfaces in the supercharger, giving better sealing under high boost pressure. For some reason which I cannot determine, the matt black vane coating version was used with the smaller pulley. Maybe there was a reliability concern with the grey vane coating model, as all post-facelift cars are fitted with the black coated vane version. http://www.mini2.com/forum/engine-dr...nvince-me.html - another useful thread.
I am looking to pick up a 2nd hand supercharger with the matt black vanes, initially as I was concerned about reliability since I seem to recall a couple of horror stories of the gery coating breaking up following uprated pulley fitting. However I am not so sure that the early model superchargers without the coating have a relialbility concern (no coating to break up), they probably just can't hold quite as much boost ??
You guys are putting way to much thought into this. The pulleys that are on the market (minus the 19%) have been driven over and over on your model car with few to know mishaps. 15 and 17 percent pulleys are being used every day for normal and aggressive driving.
If you are going to buy a new SC, why not run the one you have then if it fails, replace it.
As the difference in performance between the 3 different models of charger used is probably negligible, and the chance of failure very slim, it probably isn't worth the extra effort.
As I said previously, my main concern was the reported issue with the coating failure on the grey-bladed model... but it seems I had that out of proportion (I spend too much time on car forums ). Blade coating failure could be very expensive though if that coating made its way into the combustion chamber, so I thought better-safe-than-sorry in that aspect (as changing the charger isn't a massive exrtra job if you are having particular other work done at the same time). Delivery mileage 2nd hand chargers on eBay go for around £100-£130, and they won't be there forever now the R56 is here.
I guess I am deeply paranoid about my car, or maybe just over-protective . Having to have the Harmonic damper replaced (fortunately covered by Mini goodwill) didn't help instill confidence in the durability of the early model components either
Totally see your point and I agree, sometimes car forums are our downfall. I would say that as long as you don't decide to go with a 19% you will be in good shape. We installed 3 15% and one 17% this weekend and had total success with all. The 17% went on a 2004 model and speaking to this guy (a mechanic by trade) he wasn't bothered. So, I think that you will be just fine.
BTW if running a 15% or larger pulley don't redline the engine regularaly in one run as the charger gets very very hot Sustained high rev drving eg...high speed on motorway in 5th instead of 6th will makes things very uncomfortable for the charger. Tne JCW pulley is not 15%, in fact many people who have tried to work it out seem to come up with the fact that its somewhere in the range of 11-14%, if anything its nearer to 11%. Therefore this is not so bad on overheating the charger at revs ... a 15% will get a lot hotter if you really thrash the **** off it for long periods ... but i think that it does take a fair bit of thrashing to do it as many folks use them on the track with little problem.
This is the most unprofessional bit of site management I have seen since I was banned from a certain other site...at least they had the excuse that they were enthusiasts who had strong views and not professionals paid to keep thier cool!
The 15% is also within the tolerances of the ECU. The heat that you need to worry about is the detonation. Most places recommend running a colder plug to offset the extra heat. However, I am currently running stock plugs (living in a colder climate) and have had no issues.
I don't live at redline (I give her a little slack up top ), and was thinking 15% pulley, so it seems I shouldn't be too concerned about problems then.
Defintiely agree though that forums are our own downfall As enthusiasts we are all hyper-sensitive to the nuances of our cars, I wonder how many prospective owners are put off when they read the 'faults & fixes' area, as things are a little amplified by it's nature. People are far less likely to post up purely because they are having no problems, after all.
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). Blade coating failure could be very expensive though if that coating made its way into the combustion chamber, so I thought better-safe-than-sorry in that aspect (as changing the charger isn't a massive exrtra job if you are having particular other work done at the same time). Delivery mileage 2nd hand chargers on eBay go for around £100-£130, and they won't be there forever now the R56 is here. 
. Having to have the Harmonic damper replaced (fortunately covered by Mini goodwill) didn't help instill confidence in the durability of the early model components either 
