I was wondering what the exact differences were in making the big price jump from a Cooper S to a JCW 2-door hatch, so I dredged through the official press releases and found all the differences, both subtle and significant. Here goes:

Body
*Length: Cooper S = 3850mm, JCW = 3874. The JCW is 24mm longer due to the aero kit
*Engine Oil: Cooper S = 5.0 liters, JCW = 5.25 liters.
*Unladen Weight (DIN, which is "wet" or ready-to-drive, but no fuel): Cooper S = 1160kg, JCW = 1205kg. I understand this is Euro-spec, and here's where it gets tricky. MINIUSA puts the Cooper S = 2785 lbs and JCW = 2845 lbs. This is 68 lbs and 29 lbs respectively more than the Unladen EU weights, which is ready-to-drive with >90% fuel and +75kg for driver and luggage. So, are the advertised USA weights really "EU + additional NHTSA-mandated equipment"? Just a guess.
*Aerodynamic Drag: Cooper S has a Cd of 0.31, frontal area of 2.09 square meters, for an effective total drag of 0.65 m^2. The JCW has a Cd or 0.34, same 2.09 m^2 frontal area, and a total drag of 0.71 m^2.

Engine
*The engine is code B48A20B [versus Cooper S being B46A20A]. The JCW engine is the exact same engine as is installed in the BMW 225i Active Tourer in Europe. All indications indicate it's a lower boost version of the engine in the forthcoming facelifted 252HP BMW 330i.
*Compression Ratio for the Cooper S = 11.0:1, and JCW = 10.2:1. This easily highlights the new pistons in the JCW. It also meshes nicely with the additional [unspecified] boost the JCW runs.
*Obviously the added power and torque, but interestingly, the torque curve is advertised as being 50 RPM wider in the JCW, 320Nm from 1250-4800 RPM. Very nice.
*JCW factory "sports" exhaust. This is different than the JCW dealer accessory exhaust that has the bluetooth key-fob to control an exhaust flap. This factory JCW exhaust, from all indications, is a non-active.
*Extra "AMOeK" cooling module that resides in the location vacated by the left fog light. This is why the JCW can't have front fog lights.
*JCW specific radiator, Intercooler, and boost tubes

Transmission
While both the Cooper S and JCW use the same basic gearbox, the ratios and final drive are quite different. The Cooper S uses a 5.2:1 ratio spread, whereas the JCW has a wider 6.2:1 spread, meaning 1st is shorter and 6th is taller. Specifically:
Cooper S vs JCW
*1st gear: 3.923 vs 3.923
*2nd gear: 2.136 vs 2.136
*3rd gear: 1.393 vs 1.276
*4th gear: 1.088 vs 0.921
*5th gear: 0.892 vs 0.756
*6th gear: 0.756 vs 0.628
Final Drive: 3.588 vs 3.824

Multiply the gear by the final drive and you get total ratio from engine to axles. This new ratio set is presumably why the manual trans JCW is taking longer to bring to production.

Suspension and Brakes
*The Brembo front brakes are the big ticket item here. They're 4-piston fixed calipers, and the new rotors are 335 x 30mm, versus the Cooper S's 294 x 22mm.. The rear calipers are "painted red" but the design and rotor size are otherwise the same Cooper S.
*The Brembo calipers are so big that all the wheels for the JCW are model specific, despite having similar styles to the JCW-package Cooper and S.
*JCW specific master cylinder and vacuum booster. This is to improve the inherent balance of the brake force distribution and to tailor the pedal feel. As such, a factory JCW will feel and stop "better" than a Cooper S retrofitted with JCW brakes.
*Sport suspension: The $500 option on the Cooper S is standard on the JCW, which claims to be "30% stiffer", though it doesn't explain if that's spring rates, sway bars, dampers, or combinations of each.
*A curious nugget in the press release says that the JCW uses a model-specific front knuckle, what BMW calls "swivel bearing". MINI parts via RealOEM.com shows there are currently 3 pairs of swivel bearing part numbers, with factory, +0.5°, and -0.5° of camber. Time will tell if the JCW is simply using the -0.5° option [just my guess], or if it's something entirely different.

Features & Aesthetics
*JCW Aero kit as factory standard, including the front and rear bumpers, side sills, and rear spoiler, the latter which is claimed to generate downforce "at high speeds".
*JCW-specific wheel arches with the little tiny extension, most probably to vertically cover the factory wheels. Some states have laws that require the wheel to be fully covered from above.
*Standard LED headlamps
*JCW "Sport" seats with integrated headrest. I hope everyone is within their design target for body size, whatever that is!
*JCW-specific badging and extras and tidbits throughout the car, including gauge bezels, gear lever, stainless pedals, steering wheel, anthracite headliner, side scuttles, entry sills, key, etc. No shortage of JCW branding here.


As a comparison, if you equip a Cooper S with JCW Exterior and Interior packs, LED headlights, 17" Race spoke wheels [a $0 option on the JCW], a Cooper S "JCW-clone" would cost $28,700, yet would be missing quite a bit. For the $31,450 JCW base MSRP, or $2,750 more, the JCW model adds:
*JCW Intercooler and boost tubes to handle more boost pressure
*JCW ECU tune with 39 more horsepower and 29 more LbFt of torque
*revised low-compression pistons
*JCW factory exhaust
*Transmission ratios
*Brembo front brakes and red rear calipers
*JCW specific wheels to clear the Brembo's
*Additional cooling module
*JCW Sport seats
*JCW gauge bezels, gear shifter, exterior badging of course

In my eyes, this amounts to a solid value-added for the dollar amount. Of course it's not all gravy. Fuel economy isn't rosy. According to FuelEconomy.gov, the Cooper S manual is rated at 24/34 (27 combined) and the JCW manual is rated at 23/31 (26 combined). You also can't have front fog lights on a JCW, or an exterior chrome pack [good!], but those things are not missed by me.

Cheers,
Ryan

 

Some other things worth noting:


*If you equip a Cooper S with the JCW Aero kit, the coefficient of drag and thus total drag numbers will likely mirror the JCW model, and as such it can be inferred that highway fuel economy will suffer slightly.

*The JCW will most likely get equivalent, or only slightly less highway FE than the standard-body-kit Cooper S. This is a speculation on my part, deduced from the taller 5th and 6th gears, so the engine will be operating at a lower RPM for the same speed versus the Cooper S. So, the lower engine speed usually means improved FE, but the higher aero drag means it'll wash out. Based on my knowledge of EPA FE testing, MINIUSA very likely did not push the ECU calibrators as hard to perfect the JCW's highway number, knowing the figure is not as important as the high volume selling Cooper and S for CAFE and also because the target demographic isn't as concerned with the FE numbers.

*Sifting through BMW press releases, I found the BMW 218d Active Tourer, which is a platform mate to the F55/F56, has the exact same ratios for its 6-speed manual except for the final drive ratio. This means BMW already has most of the JCW-manual in production, just not the final drive gears. Regarding the JCW Automatic, it appears to be identical to the 218i Active Tourer's 6-speed automatic with the exception of the final drive.

*The JCW's engine compression ratio of 10.2:1 is identical to the BMW 225i Active Tourer's, meaning it's entirely likely the engine would have no problem matching its 350 Nm (258 LbFt) peak torque at 1,250 RPM, and peak power of 231 HP from 4750 to 6000 RPM, given the appropriate ECU tune.

*It's entirely likely cooperative dealership parts departments, or aftermarket vendors, will generate a kit to retrofit the JCW oil cooler onto a Cooper S. I see this as a valuable addition for those that HPDE/track-day their Cooper S.

*More research is needed into the part numbers for the suspension pieces in the JCW. It'll be interesting to see how different the front knuckles are. Also if the verbiage in the press release talking about the rear suspension having "a larger proportion of highly rigid steel types" is just marketing gloss or if the rear lateral control arms are indeed unique.


Anyone else have insight into the specifics of the JCW that I missed?

 

Thanks Ryan, for the excellent technical comparison! This is going to be a difficult wait, but well worth it!

 

Awesome in depth write up!

The exhaust is confirmed different from the JCW accessory bi-modal exhaust and is just a beefier version of the stock Cooper S exhaust as it has always been.

Not sure on the fJCW brake sizes, but I believe they are the same as the JCW accessory brake kit which are 350mm x 30mm. I have heard the caliper comes out a little more as well, indicating different calipers than the Cooper S, but I haven't been able to verify. I've also heard the fJCW exclusive wheels, which are different than the JCW-exterior wheels available on the Cooper and Cooper S (different part numbers), allow for the bigger calipers.

 

Wow what a great post. The different knuckle part numbers are probably available for the purposes of correcting camber after a car has been crashed. It's fairly common when the car doesn't have factory adjustable camber. The R56 only had a little camber adjustment because of slop in the upper strut mount to body bolts.

 

You guys will get a kick out of this. It's a graph charting the torque delivered to the tires contact patch on both the Cooper S and the JCW. This highlights the notable difference in torque output from the engine, but also how gearing affects the torque to the ground along with speed ranges in each gear.

Since the entire drivetrain is usually an underdrive, even in top-gear, torque is multiplied. In 1st gear, the JCW's 15.0:1 total ratio multiplies the engine's 236 LbFt and [in conjunction with the torque radius of the loaded tire] transfers 3,616 Lbf to the pavement from 6 to 22 MPH in 1st gear at full load. This is a huge amount, way more than most small cars I've owned. As perspective, a Subaru BRZ only puts down about 2,100 Lbf in 1st gear, a Fiat Abarth 500 puts down about 2,500 Lbf in 1st gear, and some of you might remember my white Lotus Exige S, puts down about 2,430 Lbf peak in 1st gear. This means that despite the Cooper S having excellent 1st gear torque, the JCW will positively ROAST the tires to oblivion.

The JCW's super-overdrive 6th gear means it'll feel fairly average in terms of top-gear acceleration, but also at 70 MPH the engine will only be casually turning at 2,404 RPM, compared to the Cooper S's 2,716 RPM at the same speed.

16970683377_da9097e92b_o.jpg by Ryephile, on Flickr

 

Holy Moly!

 

Hmm, looking at the JCW as a possible SCCA DS car. That short 2nd gear really hurts - we have lots of digs from 35mph or so (where the car would kick ash if it can hook up) but we've been seeing a lot of courses that hit low 60s and above lately. Judging by that chart the car starts running out of steam at 45 and runs out of revs before 60mph.

The optional 18s are 7.5" wide which means you can also use a 17x7.5. The WRX gets 8" wheels, but is a wider, longer, heavier car.

Ryan, what do you know about the front diff? The press releases all use acronyms. Reads like it is similar to VWs XDS / Ford's Focus ST diff in that it's brake based, but not sure.

 

FWIW, the torque in 2nd is darn near some cars in 1st. It's plausible that you could do most faster bits of an auto-x course just in 3rd. Compared to other cars, I wouldn't use the term "run out of steam" until you get to the top of 3rd gear. That said, do expect to shift more vs. long-geared cars like a Stingray.

It appears the 17" wheels are 7.0" wide, and the 18" Cup Spoke is 7.5" wide. You'd also have to stay within whatever the class limits are for the tucked-in 54mm offset.

Reading between the lines of the press release, the differential appears to be open and uses "Electronic Differential Lock Control" (EDLC), aka torque vectoring via brake application. This is similar to the Ford Focus ST, but nothing like the e-clutched LSD in the Mk7 GTI Performance Pack, the latter being similar to BMW's //M active differentials. As such, the effectiveness of the EDLC will remain to be observed and will come down to software tuning and brake thermal capacity.

An open diff in a FF street car doesn't surprise me anymore. Suspension kinematics engineers [sweeping generalization here] are able to achieve remarkable mechanical grip, rendering an LSD from "mandatory" to "can kinda do without", especially when combined with the EDLC. Having driven a non-PP Mk7 GTI, it's EDLC was phenomenal in around-town shenanigans without inducing torque steer inherent in an ATB (e.g. Torsen, Quaife). That said, for dedicated track work, an ATB will still result in quicker lap times, but they are spendy and admittedly make the car much less fun on the street.

I can't make a good comment on whether the JCW would make a good auto-x car versus a WRX. Either would be fun at the Dragon or the racetrack, but how serious you are at winning your auto-x class might dictate what car you buy, and it might be beyond those two choices. That kind of decision is all up to you.

 

FWIW, I've noticed on the ordering sheets that the 18" cup spokes for the fJCW (which are different the the 18" cup spokes available with the JCW ext pack on the Cooper/Cooper S) are 18 x 7.5, so they are actually a little wider.

 

Thanks for the correction. I see that on the Build Your Own now.

To address your previous post, do you have access to the new part numbers for the 4 JCW wheels offered? It seems wasteful MINI would introduce those wheels in the Cooper/Cooper S JCW Exterior pack and then redesign them after only one model year to accommodate the Brembo's.

 

I'm not sure how you can end up with LbFt at the contact patch, as I would have expected the Ft to drop out of the units, leaving Lb or Lbf (pounds force). This would give you the traditional presentation of the same information, a Tractive Effort Curve showing the thrust available:



It's interesting to see that the JCW has 10% more Cd and so 10% more drag than a S, so quite a lot of the extra power will go in pushing air.

 

I'd be wary of misinformation on the MINIUSA Configurator. It shows the tire size for the Race Spoke wheels as 205/55-17.

RealOEM lists the width of all 18" wheels for the 3rd Gen as 7".

 

RealOEM does not list any fJCW specific parts yet though and the wheels on the fJCW are different than the wheels you would normally select with the JCW exterior kit on the Cooper and Cooper S, despite similar names and size options. The ordering guide also lists the 18" cup spokes for the fJCW as 18x7.5 205/40 R18

 

You're correct, that is a typo on my part, I'll go edit that. My graph also doesn't account for any frictional or aerodynamic drag, however I do agree the change from 0.31 to 0.34 Cd is significant.


Do you have this document? You've referred to it multiple times and it would be helpful to share it until we get actual part numbers.

Thanks.

 

RealOEM lists the 17" Race Spoke wheel, which according to the MINIUSA Configurator is only available on the JCW.

Also, why would MINI make two different 17" Track Spoke wheels, one for the JCW Exterior Package and one for the no-cost option on the JCW?

 

I don't have a copy of it, but my MA was nice enough to show me. I'll ask him to send me a copy of it, but I don't think he will considering it's a MINI corp document. It definitely has two different sets of wheels for the JCW kit and the fJCW though with different option codes.

You got me on why there's different wheels, but according to the ordering guide they are. I seem to remember reading something, maybe on MotoringFile, that they are different to accommodate the larger brake calipers.

 

You can actually get the exterior chrome kit on a JCW. It changes the red divider on the grill to chrome.

 

Perhaps it's different in Sweden. [by the way you should fill out your location so we're not hunting posts to decipher where you're from]

The USA configurator allows for chrome mirror caps, and the chrome line interior, however no exterior chrome line is listed for this side of the pond.

 

I should. How did you figure it out then? :-)

It's half the price than the chrome kit for the Cooper S, because there's less chrome. I'll upload a few images later.

 

I'm a ninja.

Just as a datapoint, the exterior chrome pack is not on the mini.co.uk configurator either. Now I'm curious which countries get which options!

 

Here's the JCW with exterior chrome kit (and without for reference). It's a 900 SEK (roughly $100) option, and it changes the grille divider and the boot handle.






Interestingly, there's also a "no model name" option, which does nothing. It doesn't remove the JCW badge on the hatch.

 

RealOEM.com just updated and now has the early JCW builds. Here are some of the changes:

*The engine for the JCW is called B48A20B, whereas the Cooper S is called B46A20A
*Piston is now #11258618503
*The cylinder head, cams, valves, and springs are identical to the Cooper S
*The turbocharger/exhaust manifold is listed as the same part number. hmmmm.

*Manual trans flywheel is #21208600213 (auto trans flexplate is the same)
*The clutch is #21208631870, and has a note of being 228mm, likely the diameter.
*The manual trans is #23008617543 and called GS6-59SG - TBFN, the last letter being different than the Cooper S
*The automatic trans has a few part numbers depending on options, but they're all different than the Cooper S



*The Radiator is now #17118603089 and the Intercooler is now #17517617600. It'll be interesting to see what the functional differences are vs. the Cooper S.
*The exhaust downpipe [#18327634633] is the same as the B48 Cooper S. The B46 engine uses a different part number.
*The center muffler is now # 18308616390, and the rear muffler is now # 18308615431


RealOEM hasn't yet updated the front suspension part numbers for the JCW.
*The rear suspension arms appear to be identical
*The rear dampers and rear sway bar are identical to the Cooper S Sport Suspension, as promised.

More to come! The Brakes are a big change!

 

How about the turbocharger itself (not the manifold)? Mine's different than the R56 MCS for sure. That's the main reason for the HP boost. The F56 should be a different part too.

 

I missed something from the engine. The JCW injectors are listed as a different part number, but with a note that it's already "ended", with no new part number. Strange.

Also, the charge air ducts to and from the Intercooler are new. Either improved airflow and/or different terminations to the Intercooler, given that's new too.

The turbine and exhaust manifold are one casting on the F56, and the part number is listed as the same according to RealOEM at this time. Personally I think it makes sense in order to get the same 1,250 RPM boost threshold, but it is counter to the glossy verbiage in the press release.

---------------------------------------------------------------

*The new Brembo front brakes are 4 piston fixed calipers using 2 bridge pins and a retainer spring to locate and quiet the front pads. The JCW pads appear to have much more volume and area than the Cooper S pads. This is good for brake torque and thermal capacity. The pads will also be very quick to change, meaning a swap from street to track compounds can be done quicker than the time it takes to unbolt the wheel.

*The new rotors are 335 x 30mm, versus the Cooper S's 294 x 22mm. That's a big increase in both diameter and width.

*The rear brake rotors are still 259 x 10mm, same as Cooper S, however the calipers and mounts are new part numbers, perhaps because they're painted red.

*Given the much larger front brakes, it's not surprising the Master Cylinder is different [#34336868997]. The proportioning and/or bore size is likely changed to maintain hydraulic balance. Interestingly, the ABS servo is the same as Cooper S. The Vacuum booster aka Servo is also different, now #34336869016.

*The wheel part numbers are still not updated.

*The body skeleton is the same part number, meaning no fundamental changes to structure or strength.

*Of course, the wheel arch plastics are new part numbers:
51777387889 & 51777387890 front no PDC
51777403264 & 51777403265 front w/PDC
51777387893 & 51777387894 rear for both
The rest of the black plastics appear to be the same as the JCW Exterior Pack on the Coopers S

*The JCW emblem on the front grill is not listed as a separate part number, however there is a "chrome line" [#51137368129] and "Chili Red" [#51137393456] grille.

*This page shows the air duct for the "AMOeK", let's see if we can figure out what that means. The oil cooler on the JCW is listed as identical to the Cooper S, so that doesn't appear to be it. A quickie Google shows that most current BMW's also have an "AMOeK", whatever that is. hmmm...