Yesterday in Oklahoma City we had a great MINI turn-out for some runs on a Dynojet. I am going to try and pull the numbers together for all the cars, but until then here the best numbers for my car.

My Specs: '04 MCS JCW with 17" S-Lites.

The run specs- Run 1: Run 1 was in third gear from 2k to 7k rpm. It was the first run on the Dyno and the car was well warmed up from the drive in that morning. It was 75 degrees with 55% humidity.

The run specs- Run 5: Run 5 was in third gear from 2k to 7k rpm. I removed the entire stock intake box so I only had the intake tube still attached. It was the fifth run on the Dyno but about 3 hours after my first set of runs. The car had just reached operating temperature. It was 84 degrees with 37% humidity.

My Observations: We were all pretty amazed that removing the intake resulted in a 12 hp increase at the wheels!!! We also ran the air/fuel ratio during my second set of runs. Below 3k rpm the ratio was above 13. Above 4k rpm the ratio steadily decreased and by 6k the ratio was at or below 10 (the instrument wouldn't not read below this).

So it is obvious that my MINI can benefit a lot by a more open intake design. As well, it appears that some ECU tweaking to better utilize the extra fuel above 4k rpm may also help unlock some hidden horsepower.

Any thoughts on this would be appreciated. Let me know if you have any questions.

 

Run 1 with 160hp at the wheels is very low for a JCW, no? Any reason why yours might have dynoed like this? That's only 180HP at the crank, not the advertised 200.

 

Even 171hp is very low. That is good to only about 192hp at the crank as well.

 

Not a big suprise here - most of the JCW's I've dyno'd calculate (with 12% drivetrain loss) to less than 200HP

 

That's not very encouraging. I am waiting until January to order a MCS with JCW kit. Sounds like the new JCW kits will be around 210hp. That's good so maybe I can actually get 200?!?!?!

Has anyone complained to MINI about this? I can understand 4 or 5 HP but more than 10 is unexplainable and unacceptable for someone spending $5000 plus...

 

A handful of people I know have contacted MINI and/or JCW directly asking for an explaination. They politely responded that, basically, "results may vary due to production tolerances". Ouch, but true. This can also be applied to regular aftermarket products; not everyones' car will react the same, and yes there will be production variances.

 

too bad mazda couldnt get away with that response. they had to pay with a buyback on their rx-8's and their miatas from earlier.

i think the loss on the rx8's were more substantial though.

 

I thought you're supposed to dyno in 4th gear because the ratio is 1:1, i.e. the crank is spinning as fast as the wheels. The one time I dynoed my car, it was done in 4th gear, I pulled 155hp to the wheels on a high 80 degree day.

 

I'm rather cynical when it comes to dynos. Too many variables or something. I'm not smart enough to know. Mine has dynoed anywhere from 151 to 192 at the wheels. Let's go to the track!!!!!!

 

Variances do occur, but has anyone dyno'd 200? Somethings fishy when there are no reports of anyone getting 200... Variances indicate that there will be equal numbers of HP ratings both above and below 200...

 

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I agree. I don't think the JCW makes 200hp at the crank. Yes there are variances, but there are also problems. The Mustang Cobra is an excellent example, even more so than Mazda. Because here was a tuning company with a special relationship with the manufacturer (i.e. factory warranty), building a car in which hp is a great concern, and studies showed that the car did not produce the power it was suppose to. SVT had to recall all the Cobras and found there was a problem with manufacturing of the parts.

The numbers do make sense though. In order for the JCW to make 197hp, which I think is the official number, it would have to make an additional 34 crank hp. I think that the numbers have shown that drivetrain loss is about 11%. This is based on the 145-147 that most are seeing. The parts and hp are numbered below:

• 13.8% pulley - 13hp at the wheels (extrapolated off of the 15hp that the 15% makes)
• Exhaust - 5hp at the wheels (based off of Randy's numbers)
• Supercharger 5th Gen - 0hp (no claims from Eaton)
• Gas flowed head - 10hp (typically a good gas flowed head is making this much)
• JCW ECU - 5hp (this is a moderately given value)
• Badges - 0hp

Total = 33hp * 11% = 36.6hp + 163hp stock = 200hp.

Just somehow the numbers aren't showing it at the dyno. We should be seeing a consistent 180hp on the dynos, but instead many are seeing in the high 160's to mid-170's.

 

I agree, the numbers are not quite what I expected. I have no reason to think that the dyno was reading low either, since there were several other MINIs there being tested. All of the MCS's had at least a CAI and many had additional mod like pulleys, chips, etc, however they all tested at what would have been expected, 150 to 170 hp. Several MC's were there as well and they were all testing at about 100 hp.

I would be interested in the everyone's thoughts on one theory. My understanding is that the MINI ECU is adaptive. Since I use my MINI as a daily driver on long highway drives daily it does not always get used for fast driving. Many of the other MINI's getting tested that day regulary get un hard every time they go out. So, are the differences in horsepower related to the ECU??? If so, then this is another reason to begin looking into the aftermarket tuning to take advantage of what the car can really do.