Has anyone tried or heard of the results of 4% Alta pulley on a JCW. It seems that it would make appx. 19% without the draw back of the SC pulley getting to small...? Is there any reason why this should not rip?> Would it make for heat or reliability issues? I am kinda of new to Minis and am already finding myself on the quest for more rev...Nikki

 

Welcome to NAM!

I don't have a JCW or a 19% reduction pulley, but the more I think about this, the more it makes sense for JCW owners to change out the stock crank pulley for a oversized one (+2-4%). You've already got the larger 380cc fuel injectors (assuming your JCW has the '05 update) which you'll likely need with a combined 19% reduction, as well as the JCW belt.

The only drawbacks that I can think of are:
1. Losing the factory warranty on your JCW if a problem is determined to have been caused by the aftermarket crank pulley.
2. Reliability-wise, the crank pulleys have not been as time-tested as the venerable SC pulley reduction.
3. Possibly needing to upgrade your ECU beyond that of the JCW flash in order to accommodate your crank pulley mod.

HTH!

 

^^ What latte said. The biggest might be tempting with faith with your JCW engine warranty.

 

Thanks for the feedback. Here in lies the question. My JCW is an 03', it had only 18,000 mi on it when I bought it 3 weeks ago. The previous owner was an old fella who bought it new and said he never went above 70 mph or got more than 4000 rpm out of the motor, what a score! Anyhoo, I do not know exactly what injectors I have. I guess mine does not have the upgrade kit and I am unclear if I am able to run any oversized pulley without opening a can of worms, ie. chasing new parts to support it. Can I get away with running a 2% without changes or should I just go for the standard size and enjoy the benefits of 6lbs less rotating mass and forget the extra boost. The only other mods done to the drivetrain since the adoption have been a CAI.

 

Its been donr to good effect. Had it a year now and still happy...
http://www.mini2.com/forum/engine-dr...light=works+gt

 

Whats donr? Which one do you have 2-4%? Have you had the issues with vibrations? Thanks, Nikki.

 

and go ahead and bolt up that 2% crank pulley.

1) Vibrations may be a bit of an issues below 2000 RPM, but more and more miles are being logged with crank pullies, and there is little evidence yet that there's areal problem loosing the harmonic dampener.

2) Our cars run what's known as a speed density type of fuel injection. As long as you don't run out of injector, things that up the air in the manifold don't NEED a new ecu tune.

Have fun, and let us know how it works out.

Matt

 

Thanks for the feedback Doc. I have an appointment to have it done next week. I cant wait. Do you know anything about plug wires and ignition coils? Are they a true performance mod that is warranted? Or is it a "bling factor" mod? Reading descriptions on the parts in the Moss catalog they claim consistant 0-60 times of up to 1 sec quicker! For $160 bucks!? Thats got to be the best bang for you're buck around. Are these performance figures based on acceleration runs off the edge of a cliff with a tailwind or what? I have caught the mod bug and there is no cure insight. Like I said I have a 03' JCW with my only performance engine mods so far being a CAI and next week the crank pulley. What should be next on the list in my hunt for more rev. By the way eariler today I got into it on the back twisties with a late model Porsche C4S. To make a long story short we were both surprised. The dude was shaking his head smiling with a huge thumbs up. Nikki