With the Air Conditioner on, it's tough to get this puppy pulled out from a dead stop. It's got so much hesitation I just about get rear ended when I pull out in front of traffic. I saw mention of an ECU fix by BMW/Mini Dealers. Is that the case? Is it possible to program the little black box not to react the way it does? I'm guessing the timing is way off in the low rpm range.

As soon as it gets above 3000, it takes off like a rocket as usual. I sure wish someone would disect the computers and figure out how to manipulate all this.

 

Well, I didn't log timing differences with a/c on or off, but that's a good idea and I'll do that tomorow. Unfortunately I don't think it's primarily an ECU problem so much as a physical load problem for an engine already weak at the lower RPM ranges. I too am shocked at what an extreme toll the compressor seems to exude on the engine's performance. I have accidentally stalled it, as I am not used to it being on, and you most certainly can not take off aggresively the same way when it's on or off.

 

As far as I know, an ECU flash isn't supposed to fix this problem. A 15% reduction pulley does however. That was how I sold my wife on getting the pulley done.

 

The car needs a lot of revs to get going with the a/c on, that's for sure.
There's a fine line between getting rolling and chirping the tires.
This is definately the achilles heel of an otherwise nice car.

 

Since installing the 19%, I sometimes forget the a/c is even on. There is little difference now. And pulling into traffic is much easier!

 

Looks like a pulley is in order for my problem solution.

 

I don't have this problem at all. My '05 MCS pulls very strongly from a dead stop with the A/C on. The car is 100% Stock.


There is something wrong with yours. Have the dealer look at it.

 

With all your due respect, but if you have stalled the engine just because you have the A/C turned on, either you don't know how to drive a stick shift car, or there is something else wrong with it.

I honestly don't understand these complaints coming from '05 MCS owners. My car is driven with the A/C on 99% of the time and never once I have had problems with hesitation or stalling just because I have it on. The car pulls strongly as ever from a dead stop and having the A/C compressor has never been an issue.

Ditto with the '04 MCS I used to have with a little less power and much taller first gear.

Maybe since I don't have heavy Xenons, Sunroof and 17" S-Lite wheels that could partially explain why my MCS literally pushes you against the back seat out of 1st gear.

May be I am misjudging the problem, so please help me understand what's going on, because this has fortunately not been my experience so far.

 

I don't quite understand how MINI could have fixed this problem without upgrading the physical power. Ma' daddy done always told me that AC power sap was life-as-usual in 4 bangers. And his wisdom has been proven in every 4 cylander car I've driven -- though admittedly to varying degrees.

I will admit that the MINI seems to suffer an unusually severe case (speaking from an 03 MCS point of view) but I expected it to lag. What cars were you people driving that you didn't expect power-suck and...

C4: You have had about the best run of luck with your MINI's. Are you taking something that you should be sharing with the rest of us? How do you have no AC lag at all when everyone else has at least some? Maybe YOU should take your MCS to the dealership -- there is clearly something wrong with the quality you've been experiencing.

 

No, I have a 15% pulley. No pulley is going to help at off-idle.

 

Then yours isn't as bad as ours, because I have a 15% and it's still day and night ompared to a/c off. I have to hit the gas 1/2 second sooner than before to get the revs up before letting out the clutch.

 

EXACTLY

 

Well, I completely see how you wouldn't think it's an issue if you drive with it on 99% of the time. I drive with it OFF 99% of the time, so that's what I am accustomed to. If you were also, turning it on would show you what we're talking about. But since you are used to it being on, you have learned the correct timings for gas and clutch for driving with it on. For those of us that are used to the timing of it off, it's quite different.

 

Do you think a pulley will help me with my regular Cooper? I wish there was a solution, because it really is irritating to have the low end performance further compromised. Normally, I will just elect to forego the A/C altogether and have the windows down, but lately it has been around 90 with high humidity here and there is no relief from having the windows down. I have had the ECU updated each time I have been in to the dealer (twice, once for the recall and once for the first routine service). Last time (July 2004), the ECU update seemed to help a LOT with the lag. For a while. But it has returned this year.

 

I just got my 05 MCS and when i have the a/c on and go from a stop, the car has little power. You have to push it more/give gas more to get it to go. You can feel a huge difference in loss when the a/c is on. I hate using the a/c, so i try not to use it much, but when i do and i am at a stop I just turn it off and then once i get moving ill turn it back on. Yes its a pain in the @$$. But the a/c will hurt power for any car. Its actually fullfilling when you turn your a/c off and give it some go and the damn thing just moves like h3ll! I do not think there is any fix for this as again many people are saying that the a/c puts much load on the engine when the compressor needs to be turned. A pulley may help, but its not the end all solution. We just have to work on improving how we drive the car when the a/c is on.

Garrett

 

the lag is viscious in the MC. i shut off the A/C a second before i take off. once up to speed, i switch it back on. i wonder if the guy who made the 'auto-up mod' could make a mod to shut the a/c off at low rpms?

 

Boy, Kaelaria is right on about this topic. 15% pulley issue isn't going to cure this (just in case that's the reason your thinking of adding a pulley). Now that I've been running the A/C the last few weeks, I now remember how bad it can be just off idle. The action to pull out is similar to pulling out on an incline. You have to think ahead, and heaven help you if you have to, let's say, leave the light in a hurry.

 

Exactly what I was going to say.

 

I wholeheartedly concur. I too drive without using A/C as much as I possibly can, because I simply enjoy having the windows down and the panoramic sunroof open. It is only on the hottest of days that I break down and use the A/C. When I do, I notice that I too, have to give it about another 1000 or 1500 RPM's on the old tach before I start to let the clutch out, or the car will protest by jerking and threatening to stall.

This is not due to my lack of ability to drive a stick shift. We have to all face the truth. It is because this car has a weak 1.6 liter four-cylinder engine, (even though S models like mine are supercharged). It has low power and torque down that low, and the compressor is draining lots of power. I am not convinced that a car with a smaller pulley is going to help much, since you're typically not letting the clutch out at 3000 or 4000 RPM's in first gear (in NORMAL stop-and-go traffic, that is), where the supercharger is actually helping. No, normal take-offs occur in the lower depths of the tach, where the supercharger's efforts go pretty much unnoticed.

So please don't go and criticize the driver, saying they don't know how to drive stick. Also, each MINI is unique too, and some may be smoother off the start with A/C on than others...

 

Well, I appreciate everyone's comments. I don't want to criticize or point fingers.. All I am trying to do is understand the problem that everyone is taking about.

Let's talk about those heavy boat anchor 17" S-Lites that are known to be power robbing. People that have ditch these wheels or gone to standard tires report much better pick up from the get go. I still believe that the "lighter" nature of my MCS has minimized these problems to the point I don't really get to experienced them.

So how many of you have accessories that add weight? 17" wheels? Sunroof? Xenons?

 

As a 19% pulley owner... I still have to give more gas with A/C on, but I only have to keep RPMs up closer to 2000 to have any kind of reasonable take off...
It has been shown the 19% 10-15 ft-lbs at 2K RPMs so there is benefit by adding a pulley.

I also strongly agree with the comments about being used to driving w/o A/C on. It is an adjustment to learn the gas/clutch timing when starting off with it on.

 

The shorter first gear in the '05 MCS does help...

 

To settle this, someone should do a pair of Dyno runs with and without the A/C on. That will show where and how much power is sapped by the compressor.

In the dark ages of carburators, when you turned on the A/C, a solenoid would open the throttle a little bit more to counter the drag of the compressor. It sounds like MINI needs to look at the electronic throttle algorithm and compensate a little more when the A/C is on. With all the computer control it should be transparent.

 

This has nothing to do with equipment. The effects may be slightly different, but you clearly don't understand what we are focusing on, and that's fine. This is purely a low-end torque issue.

 

OK, I agree is a low end torque issue. But there is no denying those heavy wheels make matters worse. Is there something hard to understand about that?