Actually it won't show it very well, because the dyno has no idea how much power is being absorbed by the clutch. The problem is ONLY just off idle while you are engaging the clutch. One you get rolling and the clutch is out, you don't even notice it.

The difference is much more than even 10 ft.-lbs. of torque lost, it feels more like ~30 when the compressor is on.

 

Any MCS owners with 16" V-spoke wheels and no sunroof care to comemnt?

I am hard headed!

 

No it doesn't. The problem is just off-idle, while you are engaging the clutch. The gearing is not NEARLY different enough to effect this, we're talking about a 1500 RPM range here.

 

I agree. I have a summer launch and another normal launch for the rest of the year. It takes me about a week to re-adjust for summer when I start using the AC. It takes about 10 minutes to go back to my normal launch... because it's just too blasted quick!!!

For those running AC 90% of the time...could the ECU (which theoretically adjusts somewhat to driving styles) have helped compensate and smooth things out somehow? Maybe this is a dumb question.

 

Ok, I have the 16" rims, run-flats and the sunroof. If we're taking all sniggling weight into consideration, then we've got to examine WOD (Weight of Driver) so, I offset about half the weight of the sunroof (200lbs?), as I am small. If we consider that the average driver is maybe 150-175, and I am about 120 my actual dead weight inventory goes to 16" rims, run-flats and somewhere between 8 and 9/10 of the sunroof.


I also have a Wahlen shift **** -- perhaps tripling the factory weight of the **** has resulted in poor performance.

 

OK guys my MCS and me are probably from another planet...

I have no winter/summer launching techniques. In the few weeks/months a year when the weather is nicer/cooler and the A/C is not really needed I don't have to re-adjust my launching technique...

 

C4... have you considered that your MINI is abnormally slow at normal launch?

 

Well then either you don't launch as hard as us, or you aren't in tune with the feel of the car as we are, that's fine. We know what we're all describing.

 

From all the recent posts the problem looks like an issue with the electonic throttle adjustment. Since the emission recall update, our MC has done better launching with a cold engine and the A/C on. Sometimes, when stopped at idle, the revs drop low enough that the car shudders and feels like it might die. There is enough power in either engine that the ECU should be able to hide the compressor.

 

With such a small engine, it almost feels like the idle needs to be set higher with the A/C on. It does this slightly already, but not enough to avoid that dead spot you feel when your waiting for things to get going. It would obviously hurt gas mileage, so it won't happen. Lack of low end torque is the issue or result. I've also wondered if it is the ECU idle settings (heck a lot still have idle issues period), or maybe related to the wireless throttle system too. Maybe low throttle input by your foot needs to have more of an effect on the ECU, etc.

 

The whole 'it's a 4 banger so you're going to have lag" theory doesn't hold water with me. My car feels like I'm towing a boat with the A/C on, while my wife's Matrix with its 130HP 4 cylinder doesn't lag much if at all with A/C going full tilt.

 

If one lives in a hot and humid climate like Florida and have the A/C
on 99% of the time and think their car takes off fine, they're
definitely missing out on the potential of the car.

the MCS is a dog with the A/C turned on especially in 80F+ temps...
and I use a 15%.

 

I don't think anyone is saying that - we all agree it should NOT be like this! Our new Turbo Beetle has the same torque and you can't even tell the A/C is on. The mini is definitely not right.

 

200 Lbs! Who told you that??? No way man. It's more like 60 Lbs max I believe.

Note that I'm not tying to single you (nor anyone else) out here, but I doubt very seriously if 99.9% of all MINI drivers out there could tell any performance difference whatsoever between similarly equipped MINIs with and without a sunroof (heck I'll even give you 16" vs 17" OEM rim difference as well ). It's just not going to happen. I'm continuously laughing at all the weight weenies around here. I bought my car to enjoy it and there's just no way that the average MINI driver is ever going to notice any performance difference between the two cars. Thus, you might as well go ahead and get what you want on your MINI and just enjoy it for what it is. There's no sense in worrying about the weight (if it really bothers you, go ahead and get the sunroof - come on you know you want it - and just leave your shoes at home and go on a diet instead. It'll all work out the same in the end and I'll bet you $1 that the non-sunroofed MINI isn't going to pull on you in a race. ).

Back on topic... I have a 19% pulley on my 05 MCS and the AC still kills it off-the-line for sure. It's just part of life in a tiny 4 banger like our MINIs.

 

Hm... thought I read it here somewhere. Ok then -- even better for my point that it's that light.

That was my point. Your sarcasm meter needs recalibrated.

***

I think the 4 cylander theory IS a substantial part of the problem (I was the one saying that, by the way). I've never driven one without lag. My boyfriend's jetta lags, my stepmother's old Subie lagged, my mother's old Saturn and her new Golf lag, and my mother's boyfriend's Integra lags. The only 4 cylander I've driven that didn't lag was my old '86 Omni -- probably because it didn't have AC.

Lag, lag, lag.

I also said, however, that the MINI seems to be at the more annoying end of the powersuck spectrum. But it feels (as far as throttle timing) like the other cars (to me)... just more extreme. Certainly far more extreme than any of the aforementioned vee-hikles.

Heat doesn't bother me, so I don't really care. I just don't think you guys are going to find a simple solution to this issue -- save for a larger, torquier engine.

 

I don't understand why people think that there is a problem with the car on this issue. It is a driving problem. It doesn't matter one bit that your 'x' brand car works similarly with the A/C on or not. Your MINI needs more revs to launch when the A/C is on.

I keep reading that the 'problem' is just off idle. Well, then, don't launch the car 'just off idle'. Launch it with some revs!

The MINI doesn't have a lot of torque down low. Torque launches cars. It takes torque to turn the A/C compressor. Put this all together, now. The solution is simple. Use more revs, so that you get more available torque. If you can't launch the car without stumbling, stalling, or spinning the tires, you aren't doing it properly.

I'm sorry to seem so harsh, but people need to realize what they are buying when they buy this car. If you want to idle off the line without giving the car any revs, buy a car with a bigger motor.

 

Part of what some of you are experiencing is the heat soak issue. On hot days in heavy traffic with the AC on the Intercooler gets very hot, and thus the intake charge gets hot. When you crack the throttle to go, the CPU tries to advance the spark to help spin up the engine, but that hot air causes a knock, and the computer jerks the advance back down and leaves you half dead. See if you can't corolate the degree of the problem with lack of airflow and excess heat. The longer you are sitting still with the hot motor the more likely the issue to occur. Some people have tried IC sprayers and coolers for this very issue. AC adds to the heat soak, and also means its a hot day!

Wes

 

But if you go WOT doesn't the computer turn the A/C compressor off?
Thus making this test difficult.

 

Yeah no crap - the POINT is that the compressor is saping MUCH more power than other cars, even of similar size and power. For example out Beetle with a 1.8 and ~160 peak torque, still very low off-idle, requires NO DIFFERENT launch teqnique whatsoever. You can't tell if it's on or off. You SHOULD NOT HAVE to change your driving style as dramatically as you do in the Mini - that is the whole point!

 

No, it's just as bad in the morning going to work right out of the parking lot.

 

Shhh, that's a secret. The point is that the power is there, the drive by wire algorithm is not responding quite smoothly enough.

 

Yes, probably so. Sorry I didn't mean to jump on you (nor your post) about the weight stuff as I was just trying to generalize it all (did a poor job I guess ). I just get a real kick out of the weight weenies is all (not that I think you're one BTW - I probably just read over your post too fast and over reacted is all).

Motor on...

 

BINGO!

 

I don't know whether it is a fixable issue or not; but it is kind of scary sometimes. With the A/C, if I don't get above ~2500RPM before releasing I get the slow start (like 5mph). The instictual reaction, then, is to floor it; which doesn't do a heck of a lot until the RPMs get up there. There is a point (right around 3000RPM) that it just takes off like a bandit.

 

Of course, another fix that MINI could do is to temporarily shut down the A/C compressor when you're taking off from a dead stop. My '96 Eclipse turbo did this - another overburdened blown motor that was otherwise flat off the line. If Mitsu did this 10 years ago, why can't MINI???

Oh, and FWIW, I, too, notice a noticeable dip in power with the A/C on, but like everyone said, a few more revs on the clock takes care of that. But an A/C compressor cut-out from a dead stop would make threads like this totally unnecessary!!