[Keano]

Hi all.

Im considering fitting a 15% reduciton pulley to my 210JCW but wanted to know a bit more about the supercharger first.

Are all superchargers fitted to cars which have had the JCW conversion got the latest generation (gen 5?) teflon coated supercharger fitted? My car had the 200bhp JCW conversion (i later got the extra conversion to 210) as it is a prefacelift car so will it have the latest version of supercharger?

I was thinking that if it doesnt have the latest gen SC i may as well get one when I get the pulley...

Anyone already gone from a works pulley to a 15% reduction? Any idea of expected HP and TQ gains?

Thanks in advance.

Keano

[TRISTO]

Quote: Originally Posted by Keano (original)

Hi all.

Im considering fitting a 15% reduciton pulley to my 210JCW but wanted to know a bit more about the supercharger first.

Are all superchargers fitted to cars which have had the JCW conversion got the latest generation (gen 5?) teflon coated supercharger fitted? My car had the 200bhp JCW conversion (i later got the extra conversion to 210) as it is a prefacelift car so will it have the latest version of supercharger?

I was thinking that if it doesnt have the latest gen SC i may as well get one when I get the pulley...

Anyone already gone from a works pulley to a 15% reduction? Any idea of expected HP and TQ gains?

Thanks in advance.

Keano

Hello mate,

I don't have a john cooper works just a cooper s (prefacelift) like yours. You certainly won't need to upgrade your supercharger to the teflon coated one when putting a pulley on, i would save your money on the new supercharger and put it towards an uprated intercooler.

With a 15% pulley it obviously spins the supercharger faster and heats up alot quicker so you need the extra air going through to cool it down.

I have a 15% Alta V2 on mine and had it done at 1320autos which costs £283 inc VAT and fitting which is an excellent price and excellent service too, saves you money on conversion kits if you just ant one or two items. Intercoolers cost around £350-400 depending on what one you choose there are many good ones out there.

Hope any of this helps

With just a pulley and depending on the strength of your engine you are looking at gains of 15-25bhp . An intercooler is about 8bhp.

[batou]

The JCW Supercharger Pulley is notoriously difficult to remove when compared to a stock cooper S. Make sure you take it to someone who specialises in Minis

[Keano]

Quote: Originally Posted by TRISTO (original)

i would save your money on the new supercharger and put it towards an uprated intercooler.

I have a GP intercooler on mine

The figures you quote, is that the gain you expect from 11% to 15% pulley or is that from OEM to 15%??? I realise its only ball park figures here but those numbers look quite promising...

All further info/advice welcomed..

[MINIAC]

Quote: Originally Posted by Keano (original)

Im considering fitting a 15% reduciton pulley to my 210JCW but wanted to know a bit more about the supercharger first.

Are all superchargers fitted to cars which have had the JCW conversion got the latest generation (gen 5?) teflon coated supercharger fitted? My car had the 200bhp JCW conversion (i later got the extra conversion to 210) as it is a prefacelift car so will it have the latest version of supercharger?

All were 5th Gen.

Quote: Originally Posted by Keano (original)

The figures you quote, is that the gain you expect from 11% to 15% pulley or is that from OEM to 15%???

They're OEM to 15%.

If you're going to the expense of changing the pulley why not fit a 17% reduction pulley.

[Keano]

Cheers for the info Miniac.

With regards to the 17% - I have been reading alot about the different pulleys and turning the SC too fast - i.e. beyond its design - and although the 15% I think gets into the problem area at high revs too I think of it as a good compromise - more power/torque compared with JCW pulley and not quite as much risk as 17%/19%pulley....
15% is a good balance - just want to know more about what I would be getting from it... am i right in thinking that from the JCW pulley to the 15% would only be about 5bhp increase ? What would we be looking at in torque gains?

What are the different choices for a 15% pulley? Would prefer one that looks as much as possible like the JCW/stock pulley - i.e. dont want Alta written on the side and give the game away!!

I also plan to add a 4-2-1 mani and sport cat following the pulley...

[sef]

The Alta pulleys are blank so don't have Alta written on them... They do provide a sticker for it if you want to go that way...

[jdchrome]

Am I correct in thinking that 11% reduction is the max that will allow you to keep the existing belt etc.?

[James@fomsport]

Quote: Originally Posted by jdchrome (original)

Am I correct in thinking that 11% reduction is the max that will allow you to keep the existing belt etc.?

its always best to change the belt out (its a £15-20 part) but the jcw has its own shorter belt, we use this on the m7 16% we sell

[Keano]

Quote: Originally Posted by sef (original)

The Alta pulleys are blank so don't have Alta written on them... They do provide a sticker for it if you want to go that way...

....so how likely are BMW to miss the change of pulley...????

[adamos o3,cooper s]

hi, have been down this route , save your money , the supercharger "aint broke so dont fix it"
intercooler, cai induction, mani fold, miltek, head, cam,
this is the best way forward, one mod leads to another, however you can stop at any stage and still enjoy the car.
remember, if the car does not start, or breaks down , over heats etc, its good for nothing . so pick a tunner, and enjoy the results,
10k miles on GTT 230 KIT, still flying!

[Lucky Dave]

Remember to upgrade your spark plugs if fitting a pulley.

Myself I would fit a 17% pulley

[Keano]

Have already got a GP IC so what would be best next, a pulley or a manifold? Has anyone got access to some performance curves for a 15% and 17% pulley in comparison with stock? (or JCW pulley!! )

Lucky Dave - you recommend a 17% but would you go as far as a 19% ???