[Rockeyes]

Can someone please educate me on the exact differences between a standard MCS cylinder head and supercharger and that of the JCW units? Thanks.

[jimskater]

Check here:

http://www.mini2.com/forum/faq.php?f...q_tech_details

You should be able to click through for more info.

[Rockeyes]

Thanks … What I’m looking for is the physical defences as opposed to performance.

Cooper works don’t go to the expense of producing their own supercharges and heads but modify ready available standard units (I presume).

How would a polished standard head compare to a JCW head?

What would the difference be between a standard super charger fitted with the same size pulley as a JCW unit and a replacement JCW unit?

[Rockeyes]

Thanks … What I’m looking for is the physical defences as opposed to performance.

Cooper works don’t go to the expense of producing their own supercharges and heads but modify ready available standard units (I presume).

How would a polished standard head compare to a JCW head?

What would the difference be between a standard super charger fitted with the same size pulley as a JCW unit and a replacement JCW unit?

[Rockeyes]

Surely someone must know, 104 views and only one reply?


I have been told that the JCW cylinder head goes through a 30sec CNC process and the supercharger is identical apart from the pulley.

I am not in anyway trying to undermine JCW, I’m an owner of one myself but due to the lack of details I’m becoming rather suspicious.

[:: Jon ::]

Valve size is different both inlet and outlet..

also the pully size on the super charger

[Capsaisin]

Quote: Originally Posted by Jonmorgan

Valve size is different both inlet and outlet..

Can this be true What are the sizes?

Quote: Originally Posted by Jonmorgan

also the pully size on the super charger

True.

Physically, externally both sets are identical (OK except pulley). Thought JCW head had just a light polish on the exhaust ports compared to MCS?
JCW S/C is identical to POST July 04 MCS with coated rotors, just has approx 14% reduction pulley. There are numerous previous posts about the exact ratio and size of the JCW pulley.

If you consider how other tuners get a claimed 210bhp with very little more than a reduction pulley, you may appreciate that in tuning terms the JCW kit cannot be anything too unusual - you are really paying for a name, an air intake, a pulley, an exhaust, a remap and to keep your warranty intact. Also bear in mind, I believe, BMW trade price on the JCW MCS kit is £2000 - so not actually bad value for money really, shame about the dealers' mark up and fitting. Dealer price was accidentally posted on Mini2 a while ago.

[faster,Tobias!]

Quote: Originally Posted by Capsaisin

Can this be true What are the sizes?
True.
JCW S/C is identical to POST July 04 MCS with coated rotors, just has approx 14% reduction pulley. There are numerous previous posts about the exact ratio and size of the JCW pulley.

Cap,
The way I read this it seems you are saying that all post July '04's have ceramic coated rotors in the S/C, but I am pretty sure it is only the JCW. But then, maybe it is just the way it reads.
The head is polished, but I didn't know that the outlet/inlets are larger, but I do know they also change up the injectors.

[Capsaisin]

Quote: Originally Posted by faster,Tobias!

Cap,
The way I read this it seems you are saying that all post July '04's have ceramic coated rotors in the S/C, but I am pretty sure it is only the JCW. But then, maybe it is just the way it reads.
The head is polished, but I didn't know that the outlet/inlets are larger, but I do know they also change up the injectors.

Yeah, I thought the injectors were too small to mention!!! Ditto plugs

But I am pretty sure that all post July 04 s/c got coated rotors, just like the JCW. Only difference now is the pulley. For sure the s/c DID change somehow in July 04, I think it's the coating on the rotors. Accounts for a few of the extra BHP on facelift models and a few of the extra £££ I got charged!!!!!

[SalemMINIDriver]

I recall reports that claimed altered water pump drive gearing to keep the water pump at stock speed with the reduced SC pulley. Does this ring any bells?

[Capsaisin]

Quote: Originally Posted by SalemMINIDriver

I recall reports that claimed altered water pump drive gearing to keep the water pump at stock speed with the reduced SC pulley. Does this ring any bells?

Well there has been some speculation about this but I've seen nothing I would call definitive. No idea what the relative gearings are at that end of the s/c. I would accept it's probably not direct drive from the main shaft so it could be reduced. But if a 19% pulley runs OK on a MCS s/c, would JCW have to reduce the speed of the pump for a 14%?????

ps
I ought to add that this water pump reduction theory and also the coated rotor difference, was put about in the early days to warn people off adding 15% pulleys to the standard MCS. Apparently it couldn't be done without overheating the s/c causing premature failure!!!!