Please, please, please....don't turn this into a JCW-hater post. They'll come in droves. Let's keep this thread "Pro-JCW".

This IS exciting- finally the impossible has happened and a JCW MINI hit the big lotto number! Just imagine if we could get two...or three...nah, sha, that's crazy talk....

 

The Magic 8 Ball answer......

You would make more power, and sooner, but forfeit your warranty. Same goes for better intercooler, camshaft, header, magic beans, fairy godmother pixie dust---all add power like regular MCS but you forfeit that $1500 premium you paid.

Think of it as $500 for each letter J-C-W. But never having to hear the words, "Not covered by warranty due to aftermarket parts"- priceless!

Plus someone has to support that bloody saggy UK economy you know.

 

I saw the same thing on my MCS... it went away when I upgraded the intercooler.

D.

 

I agree, that's why I'm asking about a reduction pulley, say around19%, or another 5% above the stock JCW pulley. That's all. I'm not planning any other engine mods, just a pulley if it makes sense to me. 5% may make a difference, but laso, where the difference in the power band is important to me. If it's all top end I'm not interested. If 5% adds something decent to mid range, where I drive most of the time, then it's worth the effort to me.

 

There's no doubt switching to a 19% reduction pulley will give you more torque and at lower RPM. But putting on a different pulley voids the warranty on the kit and wipes out the value of having a kit tuned specifically for it's components ... two things you paid big bucks for in the first place.

If I wasn't happy with the performance of a Works car, I'd sell it (before devaluing it with aftermarket mods) and buy a stock MCS to mod with aftermarket parts which generated the performance I craved. But then that's just me

 

I carry all the same thoughts. The car is a company car; the cost for the car plus the JCW was picked up for me. I will averge about 45,000 miles per year, so the warranty is not an issue for very long. Just looking for a potential pick-me-up - if worth it - after the warranty is up. In reality I'll spend substantial dollars on suspension and brake upgrades first.

Your thoughts are valid. Thanks.

 

Well then to answer your question, meb, the 19% will add gobs and gobs of power down low. A 19% to 15% comparison is night and day at lower RPMs, a pretty big difference at mid RPMs and a mild-ish difference at high RPMs. Just what you're looking for.

For example, just this morning I passed a car while going uphill on an interstate. After I passed him I went to shift thinking I was in 4th but I already was in 6th! The passing power in 6th gear on the highway at 3k RPMs fooled me into thinking I had to be in fourth. It was 24 degrees this morning and I did hit 13lbs of boost at 3k RPMs so there's no surprise that the power was there.

 

As a piece of information to the higher redline argument, I now use the stock redline for all of my ECU tuning.

SpiderX had a stimble due to the STOCK ECU tuning - we actually could make it go away with a custom map, but it would require a load bearing dyno and me going out there to do the tune.

I think the JCW kit has a great place in the market - I am pro JCW and pro aftermarket!

Randy

 

Is your company hiring

You might want to investigate whether it's OK to run a 19% pulley with the JCW ECU remap before going that route.

Happy Motoring :smile:

 

Good idea. I believe Helix has upgraded a number of JCWs to 17% pullies but I'm not sure if anyone went to 19%. Give 'em a call.

 

19% may be too aggressive for the length of time I'll be with the car, say 200,000 miles. I would definately do my homework, beginning with questions here, before moving on. The fuel/air ratio, timing etc as well as spark plug heat range are concerns. Big air generates bigger heat.

Well thank you all for you thoughts, and thanks, I guess, for not bashing JCW. I didn't realize that there is some 'whatever' towards the JCW kit.

Miniac, yes we are hiring, but I'm head of a 7.5 million dollar a year design office. Truth be known, I almost got an Evo, my first choice. The accountant asked this question during a meeting, "Does Michael really need a near 300hp car to go to and from work?" That little question, plus an extra 3-4k budgeted for Evo fuel costs killed any hopes for an Evo in my future. Since I don't own the company, I could only appeal emotionally, not economically. It wasn't pretty, trust me. Ever see a grown man cry? The owner still stares at Evos when they drive by...then he smiles at me...my new bumper sticker - KILL BEAN COUNTERS. THEY ARE DREAM SLAYERS.

 

Just kidding about a job. I'm happy in my "semi-retirement", providing tech support for software I co-wrote for the start-up company I worked for after taking an early retirement from PacBell in 1992

My 'S' is paid for and I'm satisfied with the way it performs with the upgraded Works kit

 

For my 3rd pull (188hp, 163 lb-ft), the air/fuel ratio looks something this:

1500 rpm - 17.4
2000 rpm - 14.8
2500 rpm - 12.7
3000 rpm - 12.5
3500 rpm - 12.3
4000 rpm - 11.7
4500 rpm - 10.8
5000 rpm - 10.7
5500 rpm - 10.6
6000 rpm - 11.0
6500 rpm - past 18.0, off the chart
7000 rpm - past 18.0, off the chart

It started to climb at 5700 rpm and changed to a near vertical line at 6300rpm. The other two pulls are a little different in terms of numbers but have similar curves.

 

ok a little help here i understand hp and torque ratings but can someone explain the fuel/air ratios......
good stuff minicoopermike very very good both for you and redbaron looks like we have some catching up to do .....hope to do dyno monday i will call mike and go see....

 

Awesome but it definately shows there room for improvement. Send your dyno and air/fuel to MTH and he'll lean it out at high rpms and take you up a few or 10 hp.

 

MCMike, thanks for the a/f ratios. I'm curious for opinions about the numbers - does it appear to anyone else that the a/f's richen around 4500, which is when the second air inlet opens? I agree with MMotor, it appears there is room for improvement above 4500 rpm, but can the JCW software be modded in this way without setting off dealer alarm bells (the whole warranty issue)? Thanks again for this info, this is very educational and helpful.

 

that richening is typical; what seems more suspicous is that the A/F runs so lean at the top. if he were really running 18 his pistons would be toast. makes the whole chart suspect.

 

JLM, do you think that first value is really at part throttle/idle, whereas the other values represent the a/f as the engine comes under load? Might that explain the lean reading at the top?

 

I haven't actually had my foot on the throttle during a dyno run, but it was my impression it was wot all the way