OK, so I've had my JCW MCS for about two years. Have added a Madness CAI, ALTA rear sway bar, lighter wheels, and have the B3 BBK on order. Have done driving schools and track events. Love the way the car feels, but want a little more power -- ok, alot more .

I'm considering Unichip or MTH, the Millitek header, or even adding a 17% pulley to the JCW SC.

I'd appreciate any thoughts anyone has on these mods to a JCW-equipped car, particularly if you HAVE a JCW car and have done any of these.

And please, no discussion about the warranty....Thanks!

 

you are probably getting around 180 at the wheels right now.

changing a pulley (about $400, installed( might get you 5-10 more hp; adding the apexi fuel management controller might get you another 10 (about $600 with dyno tuning). that would get you to around a real 200 at the wheels.
the real power mod is to drop 5k and go twin; that will get you to above 250 whp.

 

Might want to PM D1JL, he has the JCW with most of the mods that JLM has posted and made 210whp. Ported head also. The biggest bang for buck is a good head and the apex-i AFC after you have done the pulley.


Like JLM said, if you want mucho power/torque.... GO TWINCHARGE

 

I'll check with D1JL about his stuff. Not familiar with apex-i AFC though. I'll do a search on it.

I'm guessing a 17% pulley would add some better low-to-mid range ooomph too -- even more important to me than peak HP since I rarely even run it up to redline, on the street anyway.

 

I also will have a JCW Kit on my Cooper S soon, will I have to get a new download if I change the pulley size?

Sorry I don't want to hijak this thread but...

Thanks this has provided great info so far...

 

I think the JCW already has a 14% pulley... I'd think that you would have to go to a 19% to notice any difference at all.

Would you really expect to see 10 hp difference going from a 14% to a 19%?

 

Just got my 2003 upgraded to the 05 spec (injectors, airbox, and remap ECU). Lovin it right now, but already thinking about what else to do!

 

Some threads mention that there is a noticeable increase going from a 15% to a 17%. If true, I would think going from 14% to 17% would be an even more noticeable improvement. I'm just a bit hesitant to go up to a 19% for fear of burning out the SC.

 

...or water pump

 

OK, now I'm reading the other thread about this set up that Helix is doing, and it sure sounds good. Any downsides to adding the 19% pulley, GIAC software and 380ccinjectors to an MCS already fitted with the JCW tuning kit? (ignoring possible warranty issues)

Would MPG suffer?
Would these mods be easily detectable when I bring the car in for servicing?
Any ideas on whether it would still be able to pass emissions testing in California?

Any thoughts appreciated

 

I still can't fathom why you would spend so much money on the JCW, just to trash the component layout. But I guess it is your money. Yes it would be detectable. Anyone who is knowledgeable about the Minis could visually detect the aftermarket pulley. With that said it is up to the dealership on whether it would affect any warranty issues. But the Helix upgrade is a pretty significant pulley size change over stock or the JCW.

 

Has anyone tried adding the Unichip to a JCW installation? If so, any dyno results?

 

I will have by the end of July. Unfortunately, I won't have any "before" plots, though. I will scan and post the "after".

Theo

 

Please post when you have the results. Out of curiousity, how long have you had the JCW kit on your S (was it on the car from the outset; or, did you add it afterwards)?

 

comparing a/f ratios alone, MTH made a big difference compared to JCW both pre 05 software and post 05 software: the following is a dyno graph comparing my MTH with that of a 05 JCW software, a 03 JCW software, and 2 stock MCS maps



Blue graph line (mine) is running MTH
Red did not run
Purple line is running 05 JCW software
Green line is running 05 STOCK software
Burgundy line is running pre 05 JCW software

 

caminifan,

My 2004 MCS has a build date of September 2003. It received JCW kit #3424 and the 210 Upgrade Kit on December 2004, about 14 months after delivery. At installation time, it had 14,000 miles on the clock.

Six months later, I have 24,000 miles on the car. I think there is a message regarding driving satisfaction in there!

Theo

P.S. I'm trying to get down to the dyno before the UNIchip install but I'm not sure I'll be able to.

 

Why did the car's gear ratios change when the software was changed?

 

If you truly want ALOT more power, then follow JLM's advice, and go twin.

A point to consider is where in the rev range you want to enhance power. I don't think you'll get any lower end help with a header (might even lose some low end torque), but you should gain at the upper end. The 17% should give power across the range, and modding the program should give power 'under the curve' as well as high end gains.

I think there are quite a few JCW owners that would be interested in seeing if the JCW program can be enhanced for power gains without giving up any driveability and day to day liveability.

I would also like to see results with the GRS i/c and Randy's honed runners, but I haven't convinced myself the impact would be big enough to notice.