Update: Something I've noticed with V38 vs. past versions. The tachometer needle moves slower than prior versions. In the past, when I'd hit redline, the needle would be right there telling me that. Now, I hit the rev limiter, and the needle is still "catching up" to redline. Usually the instant I hit the rev-limit, the needle is reading about 6500, NOT 6950 (the redline). So basically I now have to guess what RPM my engine is at while accelerating. Why MINI decided to dampen the tach this excessively is beyond me, as there was no jitter to speak of. Looks to be another case of one step forward and one step back

 

Tach moving slower??? Top rpm now lower???

Is this just "tach lag" ?

or, gulp, is it v38-induced less top-end acceleration and/or a lowered rev limit? ( in other words, is the anti-yoyo mapping also affecting top end?). Harvey

 

no, the redline is still 6950, same as always, however now there is "tach-lag"

more not-so-good news; first full fuel tank yielded 23.60 MPG Keep in mind I have a global average of 25.7 MPG from day 1. Also, this tank consisted of one autocross day, and a freshly reset (aka learning) ECU. Otherwise, my normal commute.

 

With 1,000 miles on v.38:

(1) Still no yo-yo like before;
(2) Throttle seems much more sensitive to input;
(3) Average MPG = 25.4 (calculated) -- this included a 300 mile highway trip, the rest of the miles were a mix of mostly city/some highway;
(4) Cruise control actually quite nice, now;
(5) Tach-lag also noticed.

Here is my experience with the Tach-lag issue as posted on MINI2:

Grrrrrrr!

Theo

_________________

 

Well, at almost 2000 miles, you can add my name to the list of yo-yo affected 04 MINIs.

Hopefully my dealer will get v38 soon.

 

I had a chance to do a bit of test-driving today. What I found is quite interesting.

It seems the throttle butterfly angle is not exclusively based upon throttle pedal angle, but upon a new formula that interpolates what the drivers’ acceleration intentions are. The formula is based upon throttle pedal position versus time (I’ll call this Slope), and the PID controller damping, which is based upon an inverse calculation of Slope. This new damping algorithm for the PID controller does not correlate to my recommendations to MINIUSA (I recommended critical damping across the board). So what happens is the quicker you “stomp” on the throttle pedal (Slope), the less damping of the PID controller and subsequently, more “overshoot” (aka Yo-Yo).

OK, so it turns out the PID controller being inverse Slope (and subsequent “overshoot”) is actually de rigueur in e-gas programming. The problem comes in on the MINI with the unstable bypass valve, which amplifies the overshoot into a Yo-Yo.

The problem now with V38 versus the older programs, is Slope is now the big factor in throttle butterfly angle instead of throttle pedal position like previous versions (and any carbureted or cable-throttle car you’ve ever driven!)

In my estimation, MINI designed the throttle pedal in V38 as a literal “accelerator” pedal in which the quicker you stomp the throttle pedal the quicker the vehicle accelerates.

This philosophy and subsequent formula may work for those drivers that lack slightly experienced throttle pedal position skills, but it does not work for drivers that necessitate a specific throttle butterfly angle or movement. Basically, I can’t keep a steady speed through a corner or accelerate at a specific rate or curve without playing mind-games with V38 trying to interpolate my intentions instead of just doing what I input! GRRRR!

MINI definitely screwed up with this throttle pedal interpolation ordeal. I want the old software back, even if that means having the Stumble back!

Not Cheers (throwing beer-mugs at the software engineers at MINI),
Ryan

 

Ryan this is just awful news. I was hoping that v.38 would be a good fix but I guess not. I will just have to wait for v.39.

What I have found with my MINI is that part throttle acceleration in first gear is the worst if I apply the throttle alittle too briskly . Especially with all the mods that I have done so far.

Bummed to the max,

MeanGRN

 

Ryan, Have you seen or tested the M7 "device" that is being offered. Apparently it is some kind of valve that is installed on the vacuum line of the throttle body.

Here is the link to the post.

https://www.northamericanmotoring.co...ad.php?t=26252

Scott

 

No offense to M7, but their "device" has nothing to do with the software problems at-hand. The operation of the bypass valve has already been exhaustively discussed both in this thread and elsewhere.

 

I wasn't claiming that their device has fixed the problem. But I thought it was a cheap alternative to having a stonger spring installed on the throttle body as you did. I was simply looking for an alternative that would allow the sc to boost up faster.


Scott

 

Hi Ryan: What a bummer My YoYo is pretty bad and was REALLY hoping V38 would solve the problem. Have you discussed your findings with anyone @ MiniUSA engineers? Any reason to think they may PROMPTLY come out with V39? Its really pissing me off. Mini is sooo close to being a great car but, these nagging problems are going to catch up and bite them in the ***... mark my words...

 

Back to Square One?

I have a UNIchip en-route from Webb Motorsports. Let's find out if Randy's newly developed "extremely dense throttle mapping" helps smooth out the mess MINI created!

Also, I'm heavily considering buying an OBDII datalogger very soon. Anyone have experience with them, and can offer recommendations?

Also+, anyone want to Motor to the New Jersey headquarters and overthrow the monkeys in the software engineering lab?


...this is getting expensive

 

It is sad to hear about how incompetent those ECU programmers are..... I am up for going over to New Jersey and give them a piece of our mind.....

I guess I will keep my V36 then..... The tach lag, plus the funky throttle position control, definitely won't work for me........

 

Better yet...pick me up at 7B2 in the DA20 and I'll take the right seat! We can head to NJ, buzz the building several times and claim it was tach-lag and inverse slope dampening that caused us to lose altitude!

Theo

 

Katanas are too small and too slow though; those guys in BMW NA might not even notice us.....

 

Know anyone with a Citation that might not need it for a day?

Theo

 

I fly a Citation CJ2. When do we go?

 

Let's see...

You, Katana, me and 5 other MINI owners at, say, 400 mph right over HQ in Montvale for a "Yo-Yo Salute"!

That ought to stir things up at MINIUSA, and perhaps at the FAA as well!

Theo

 

i got a ride in Ryephile's car last night and i really like the cruse control on his car now. it woud be worth it just for that.

 

I use this one ELMscan ISO for $80


I can get charts like this


But I had to write software to perform the captures.

The only parameters you can read directly are these:
PIDs supported by MINI Cooper 2002

Service 1 PIDs
PID Sensor Returned value
--- ----------------------- ---------------------------
00 PIDs supported
01 System tests status
03 Fuel system status
04 Calculated Load Value 0% to 100% 100% = 0xFF
05 Engine Coolant Temp Degree C + 40
06 Short Term Fuel Trim -100% to +99.22% (0% = 0x80)
07 Long Term Fuel Trim -100% to +99.22% (0% = 0x80)
0B Intake Manifold Pressure kPa
0C Engine RPM RPM*4
0D Vehicle Speed KM
0E Ignition Timing Advance 0.5 degree-per-bit 0.0 degree=0x80
0F Air Intake Temperature Degree C + 40
11 Absolute Throttle Position 0%-100% 100%=0xFF
13 Location of O2 sensor
14 O2 Sensor 1 Voltage & Short-term trim -100% to +99.22%
15 O2 Sensor 2 Voltage & Short-term trim -100% to +99.22%
1C OBD standard
20 More PIDs 80000000
21 KM travelled while MIL lit

Andy@rosstech has some other means of reading more values from the onboard computers, and it might be good to check with him.

Were you going to send me a bypass valve to modify?

 

Thanks Trippy. I've been thinking of http://www.autotap.com/ because they have a program I can put on my Palm

I'd like to keep my stock bypass valve, well, stock [for now]. If I get this datalogger, then I can provide hard data w/out doing any more hardware modding.

Motor-On,
Ryan

 

Also, althought I hev never tried it, you can get some software for the ELM-ISO and the Palm.
Scantool thread information

I'll order a bypass valve and modify it to record the position of the valve and send it to a PC.

Would you be interested in getting one?

I can make two and send one to you and one to Andy if you like.

 

As a first pass I don't think this is necessary. My current understanding is that the source for the vacuum on the actuating diaphram is the inlet side of the SC. The valve's position is then related only to the SC inlet side pressure. It should be necessary only to calibrate the valve position vs vacuum, and then to monitor the SC inlet pressure to determine the valve's position. Andy has demonstrated the ability to monitor this pressure, I believe called "upstream" pressure in his earlier data dump. This presumes the absence of secondary effects like flow effect on the valve butterfly, differential drop across the valve affecting the actuating vacuum, etc..

-- Bradley

 

People are saying the bypass valve operates faster when the vauum line is restricted.

The idea of the monitored valve is to be able to compare unrestricted and restricted vacuum lines.

I don't see how to do that without monitoring the valve position, so I still think that this is a necessary experiment.

 

With a restriction orifice in the line? Like the M7 device? This is the wrong thread for that discussion but I agree, valve position itself would have to be monitored rather than its position inferred from inlet pressure.