I realize this has been beaten into the ground, but not finding the answer im looking for. I know the power differences at stock, just not sure how they result in the same path

05 Cooper S with 15% pulley, plugs, Alta intake, Milltek exhaust

vs

05 Cooper S JCW - with the EXACT mods as the Cooper S.


Is the result the same? if there is a 40ish hp difference stock, once you do the mods, there is no way the JCW would be 40hp more.. so...how much difference would the end result be with the above mods added?

basically, how much more does the head and injectors really make?

 

The JCW has a mildly ported head..and has bigger injectors since most 05 jcw cars had the JCW 210 package with 380's and an CAI, plus an exaust...and if the car has not been tuned, a different factory tune, so the maps are different.
Since it is an 05' they both have an upgraded (coated) SC. But like I said, the ported head helps the jcw make more power...if you were to replace the head, injectors, exaust, and tune it, it would bevthe same if you had the same intake....

 

If all the mods are exactly the same...the jcw will stll make a few more hp...like I said above, the head is ported a bit, and it has bigger injectors, and a differnt, more agressive factory tune. 40hp differance? I doubt it...much of the inital differance on an 05 is from the pulley size...so with the same pulley, things will be closer, but not the same...the jcw will still have more hp....remember, cars can make big hp with a bit of headwork, and even a mild port like a jcw helps!
I am guessing about 20 hp...but it is just a WAG.

 

when I referenced the 40ish hp, i was more meaning the 163 vs 210 of CooperS vs JCW

I know I want the 05-06 for the tighter gearing. Just debating if its worth paying the premium for the JCW. Either way, I would be putting on a aftermarket intake and exhaust. Couple extra ponies, but also that sweet sweet sound. Pulley is also a no brainer.

If the end result is 5-10hp at best for the head work, the 1500$ premium id be paying for the JCW equipped car would be better spent towards a better aftermarket head and tune.. More gain for minimal more $.

 

Actually the 40 hp difference is about right. I've seen stock MCS's dyno'd in the 140 whp range where the stock JCW's dyno in the 180 whp range.

 

Pretty much what I was saying in a very long meandering statement!
The JCW is great for folks who did not want to mod, or folks who wanted to keep their factory warrenty. But since the warrentys are gone for most gen1 cars, it comes down to how much modding you will do (and you will be removing almost all the JCW parts...). If you put the 1500$ saved towards bigger injectors, and a cam, maybe a head, you will have more hp. On the plus side, it will also have a fresh head if you change it (less worries about previous owners using crappy gas and making cracks) and a fresh head gasket...a win win IMO if you are willing to deal with a bit of down time!!

 

You will see a MUCH better result if you drop a performance camshaft in a JCW than with the S.
JCW has an upgraded Cylinder head over the S. Thats where the JCW has the edge over the S. Heads cost alot of $$$

 

Yeah and the JCW is at the top of the list $$ wise... And Dyno #s dont mean a damn thing unless the two cars were done on the exact same dyno. My car can put down 190whp on a dynojet, and then get 170whp on a mustang, with NOTHING changing on the car...

 

The JCW head has hardly been touched, so if the price difference between two cars allows for a decent head and injectors (as they are the only difference excluding ECU tune), then the non-JCW is better value. I would then chuck a cam and tune on the car to tie it all together. Perhaps a manifold too, if you don't mind the extra noise.

 

the proof is in the numbers, guys who fit cams in a JCW gets way better gains than on standard S. I have seen it.
You might be able to pick up a JCW for a reasonable price somewhere if you are lucky. Remember if you going to buy the head, its not only the head you'll be spending on, you would need bigger injectors, plugs, cam and ecu retune lets not forget labour costs as well! YOu are going to get to a stage where you feel that you need to go faster and the only way is the head/cam/injectors/ecu tune route once the basics have been done.

 

That's why I said, if you can get the non-JCW one for cheaper and it leaves you with more money for a decent head, cam and injectors (450cc+), tune then you will get better bang for buck from the non-JCW and adding those mods to the already modified MCS. The JCW head is rubbish. Polished exhaust ports really don't do all that much.

Bugs, what's the price difference between the two cars? If they are the same price, get the JCW.

 

how can the jcw head be rubbish if im sure you have seen how much better they outperform a non-jcw car with the same cam???

 

JCW also came with larger 380cc injectors, and an airbox that allowed additional air from the scuttle area.

If the non-JCW was $3000-ish cheaper, I would go for that, get a RMW head, 450 injectors, cam and a Jan tune. That's then a huge increase with the listed mods.

 

at the end its all about your budget on the car. That will ultimately decide what route you are heading for.

 

, not rubbish at all. Maybe not as good as say a RMW or Thumper, but hardly rubbish! They didn't get 40 more hp out of an 11% reduction pulley, air intake and injectors! I'd say a good portion of that is the head work.

And I have the proof to show it! Only mods are cam and header and I'm 223 at the wheels. Show me a MCS with only cam and header that does that!

I'm not ragging on you, just pointing out that the JCW head is better than many people think.

 

Im not sure I get what your trying to compare ?? If both cars have EXACTLY THE SAME MODS but one USED to be a JCW then they would be basically the same car so the results would be down to the health of the original engine rather than the mods...

JCW cars start out as just a standard S but have the following JCW parts fitted: cat back, head, 11%pulley, intake and filter, injectors and map.

For the JCW car you mention above to have the same mods as the S you would need to remove all the JCW parts and add those you list.... ???

What are you actually trying to compare ? A stock JCW vs a MCS with those mods ?? If so I would guess the MCS would have more power as it has a smaller pulley so would be creating more boost and torque - the difference the JCW head would make with those mods would be small, it would help more when a cam+tune is done but marginal differences....

 

FAIL lol.

 

I'm not so sure about that. I've been told that the initial difference between the JCW pulley and a 15% is about 5 WHP. On the track, that difference will disappear as the 15% overspins the supercharger and increases the temperature of the blowers air, thus leading to less dense air and increased temps making it harder for the intercooler to cool down (unless running meth). The JCW pulley size is designed to run the Eaton to it's maximum design speed. Obviously, on the street, this isn't as much an issue, as you aren't WOT all the time. I do believe though that the weak link in the JCW head is lack of a unique cam to take advantage of the, albeit small, head work done. Also, a stock JCW car will feel more refined than an un-tuned modded MCS.

 

I have a cam fitted to a JCW. Gains were the same as a standard MCS before and after a tune.

In other words, you are saying you will get to a stange when you want to rip the last few bits of JCW off the car to make power. Why not start with a cheaper car that has near enough the same power, and spend the money saved on doing that?

My JCW was no more refined than a stock MCS. It was faster, but that's it. There is still a safety margin with the 11%. I have had no problems with a 17%, much like everyone else that have been fitting 17% pulleys for the last decade. Perhaps because people upgrade to a decent IC?

The weak link in the head is the lack of actual head work. Stick a JCW next to a stock head and few people can tell the difference. what would you do for a unique cm for the JCW head? Polish it slightly, like the head? Existing cam's aren't wild.

If you had such big gains from your JCW you have a very strong engine. Have you been on a dyno with others to compare to? end of the day, dyno's are great tuning tools, but they can show massive differences on different days, conditions and from one dyno to the next.

 

Wheres the gains and dyno graphs?

 

At the time I was told these results were not the norm and higher than expected. These are before and after fitting the cam and nothing else. May have been due to my car going on the rollers first after a 50 mile drive, then being cooler after having the cam fitted.

Baseline:
WHP 163.8
BHP 197.2
Torque 169

Newman camshaft
WHP 179.2
BHP 217.0
Torque 187

 

?? If you interpret the question literally there should be no difference between them.... or is that what you mean ?

If interpreted loosely the main differences to affect power is the pulley (circa 3-5whp difference between the JCW and 15% at most) and the JCW head... minimal effect with those mods IMO...

The effect of the 15% turning the charger faster wouldnt be seen on a dyno run for an isolated fun - peak numbers would be higher with the 15%... the greater heat produced by the 15% would only be felt on a good beasting of the car with small recovery - like track work...

Exactly, glad Ive now stopped chasing numbers as it can prove to be costly.....

 

When I added a cam it made an extra 12BHP without tune...

 

I beg to differ with you. Before I chose my JCW, I test drove peoples cars with 15% and 19% pulleys, Alta intakes, etc. The JCW was more refined. I'm not saying it is a huge difference, but it is discernible!

 

I think I said that!