yep, it pulls on the valve, but the valve can't move.

But this is the same thing that happens even if the valve does move... because the valve still hits its "stop" position and the vacuum is still pulling on it....

or in other words the vacuum doesn't care... it pulls whether the valve swings through it's motion or not...

I hope this makes sense to you (because it does in my head ....scary....)

regards.....

 

Perfect sense. I guess had I thought more about that adjustment screw, I would have realized that the vacuum can't care how far the valve moves.

Thanks again.

 

Closing off the bypass valve (sorry for the typo last time!) can NOT hurt the engine - and bypass valve-less systems are commonplace in the Hot Rod scene. The engine does not know if the bypass valve is there or not, and just meters in whatever fuel according to the air density in the manifold. Not having a bypass valve is likely to hurt fuel economy, because it's easier to run on-boost under light load (no bypass to keep a vacuum, basically).

My dealership "forgot" or "hasn't gotten to" sending my research to MINIUSA Engineering yet (grrr) :evil: however I'm patient, though this delay only delays a fix for us, narf.

---> cpeters - when the bypass valve is tied shut - I found out the throttle body does not oscillate per se, but is not critically damped. As you said, it has too high a Q, and overshoots the inital throttle position request from your foot. This overshoot, I believe, excites the mechanical instability in the bypass valve design. When the bypass valve is in use, I do not know whether it's the bypass valve or the throttle body that is oscillation, however the net result is virtually identical. (oscillation in intake manifold pressure)

Hope that helps out,
Ryan

 

Thanks for the info.... I know I'm keeping my bypass valve tied up so all the air flows through the supercharger!!!!

I had three more "incidents" of DSC kicking in when I stepped on the gas. Definitely much better throttle response!

It feels like a new car, I love it. THANKS!


Just an editorial comment.... I'll bet the BMW/MINI engineers know all about this but the Corporation won't fix it due to the huge cost of testing the fix, getting EPA approval (since it effects fuel mileage) , making upgrade kits, shipping them to the dealers, dealer training etc.
Recalls/fixes like this are HUGELY expensive undertakings. Since this is just a “occasional quality” issue and not a “NHTSA SAFETY” issue they won’t touch it.
Their fundamental problem is that they designed an open loop feedback system. In Engineering 101 we learn that this is a no-no. They probably did it due to the cost of a closed loop system.

 

---> tme: thanks for your NHTSA vs. recall cost comments, very insightful!

 

but if enough owners take there cars to be fixed and they do not then we could all file lemon laws aginst them and i am sure the judge would side on our side. one ride in ryans car and it would be all done. no car should do this, it's just not right. i know i have read of at least one person here that has had his mini bought back because of his yo-yo.if it starts to pop up all over the place then they start to listen. it took a while but we have gotten V36, and the fog lights. the yo-yo is next.

 

Build date 05/02, TD51401, noticeable yo-yo just at the 3K RPM point. Just got the car with 943 miles on the odometer, and first thing I noticed was the bouncy acceleration in th mid-range.

Just zip-tied the bypass valve closed. No more YO. This fix is very similiar to the boost-dump mod I did on my '02 Ford Lightning, with the bigger brother to our Eatons, the M112. Its a common procedure for Lightning owners to unplug or disconnect the vacuum line to the solenoid that dumps boost between shifts. Makes for a more linear acceration.

Only issue is you always are in boost at anything above idle. Not sure how that effects long term wear and tear and fuel efficiency.

 

--->2cool: when you tie the bypass valve shut - you're not always under boost. This is because the supercharger can only compress as much air as the throttle body lets in. Most of the time you're still in vacuum - this is where my vacuum/boost gauge has come in very handy, because I can see exactly what the engine is doing.

Latest News:
I picked up MM2 today from the dealership. They replaced the bypass valve - to no avail, the Yo-Yo is still there, so I had them tie it back shut like I had it before going in. I LOVE how the car feels with the bypass valve tied shut, btw, it's SO smooooove.

Anyways, next step is putting in a brand new ECU, to rule out any hardware issues with the ECU. If that doesn't work, well, then I'll install my In-The-Works modified bypass-valve, and then continue to harass MINIUSA to write actual real code for the ECU. Provided my dealership already ordered the new ECU (I'll call and confirm tomorrow) it should come in next week, and then I'll bring the car in again.

update, My first almost full tank with the bypass valve tied shut, including my dealership "testing" it (and after hearing feedback from the MINI tech "WOW, your MINI is major quick!&quot, my fuel economy has plummeted from an average of 26MPG to this past tank being 21.1MPG

...the saga continues...

_________________

 

While we all wait for the latest on the Yo-Yo saga...

...may I make a proposal?

When the community accepts a fix for the Yo-Yo (whether it is from Ryan or from MINI), I propose that we formally refer to it as the "Ryephix" in honor of all the work that Ryan has put into this.

Frankly, MINI ought to reward him as a honorary member of their Engineering Group!

Just a thought,

 

I second the Motion. All in favor?



Craig

 

hee hee [blush]
thanks guys - I certainly hope MINI does recognize my efforts! I wish I had more of the right tools to help fully diagnose the issue (FEA analysis, access to their ECU code and a team of software and engine management guru's, a bigger espresso machine... lol)

 

Ryan,

Some great research you've done!

I know you and I have touched upon this before, but the AmD Technik OneClick eliminates the hunting ("yo-yo&quot problem, and the first gear stumble.

We've just had a customer confirm this on Mini2.com

Please email me or post here for details. i don't want to get into any sort of heated debate with you about this, but essentially, because we remap the timing, fuelling and THROTTLE, we eliminate these issues. We've proven it in the UK and now we've made prgress addressing this concern publically in the US.

We worked with Stratmosphere for a long time on US cars to do this.

The reason we don't offer a money back guarantee is because there is no economical way to check that the customer hasn't retained our modified program when they send the unit back - also, it costs us $75 in labor to erase the unit and replace the outer casing so we can ship it again.

Price is $449 + S&H

Best wishes,

Ram

 

>>I second the Motion. All in favor?
>>
>>
>>
>>Craig

YO!

 

OK, I'll bite. My June 2002-build MCS has the yoyo for sure, and I will go ahead and take matters into my own hands in fixing it. Who wants to help me better understand the process?

I recommend a DIY, along the lines of what Randy Webb does. I think that most folks would jump on this fix after seeing the steps in an easy-to-follow, make-them-think-it's-super-easy-and-why-have-I-been-waiting-to-do-this sort of way.

Thoughts?

Thanks for the hard work, Rye. It's guys like you that make the difference in this community!

 

I appreciate the help Ram, however I've already ruled out that changing the ECU throttle mapping (with the Webb Motorsports ECU) yields no effect on the Yo-Yo. Part of the issue is with the P.I.D. controller for the servo - unless you have the tools to re-tune that controller (which is not a map), I'm afraid your marketing is a bit erroneous. You never did reply to my questions over on MINI2!

Let's say your reworked code does happen to retune the PID. Why don't you sell that part of your code for some huge amount to MINI? No offense, but this is MINI's issue, and I don't feel I should have to pay for an aftermarket solution for their problem. Selling that part of the code to MINI makes you money, and us happy. THEN, if we want optimized mapping, an aftermarket solution is acceptible.

Not trying to come down on you - however this thread will not become a marketing ploy. If I buy your product and it doesn't do what you advertise......

--->capsfan: I did a quasi-how-to tie shut your bypass valve back on page 2. If my camera cooperates, I'll snap more/better pictures and post them for you.

Cheers,
Ryan
_________________

 

I too would like to see a more dumbed-down, in-focus version of the instructions for lashing this bypass valve thingie closed. (open?)

Yes, at this point just I have to laugh when someone (vendor or customer) claims that "Product X totally fixed my yo-yo!" Yeah, yeah, we've heard that everything from spark plugs wires to exhaust headers "cures the yo-yo", and it's obvious that they don't.

That's a little disturbing that Ryan's mileage went down so dramatically. In the year I had my car I've NEVER exceeded 23 MPG, and 21MPG is a more typical figure. With the bypass disabled I'll get, what, about 14 MPG?

-Dave

 

>>I appreciate the help Ram, however I've already ruled out that changing the ECU throttle mapping (with the Webb Motorsports ECU) yields no effect on the Yo-Yo. Part of the issue is with the P.I.D. controller for the servo - unless you have the tools to re-tune that controller (which is not a map), I'm afraid your marketing is a bit erroneous. You never did reply to my questions over on MINI2!
>>
>>Let's say your reworked code does happen to retune the PID. Why don't you sell that part of your code for some huge amount to MINI? No offense, but this is MINI's issue, and I don't feel I should have to pay for an aftermarket solution for their problem. Selling that part of the code to MINI makes you money, and us happy. THEN, if we want optimized mapping, an aftermarket solution is acceptible.
>>
>>Not trying to come down on you - however this thread will not become a marketing ploy. If I buy your product and it doesn't do what you advertise......


Hi Ryan,

I'm not going to give away all our trade secrets, but as I've mentioned to you, we map not only the timing and fuelling, but the throttle also - yes - that's the servo you mention! This is where we're unique.

Just a little background on AmD Technik - We have been in business for 17 years as a tuner. Last year we were voted Audi tuner of the year by Autometrix's readers, we're in the top 3 tuners in the UK and top 5 in Europe. We co-develop most all of the Milltek products on the market and a lot more to boot! We also do development work with major manufacturers as VAG and GM that you find in road going vehicles that come from the dealership.

We're one of three tuners who are permitted to modify brand new dealership vehicles to such a degree of performance and quality that the dealership honours our work under the manufacturer's warranty!

We've spoken to BMW through the UK, we've had good conversations, and the people we're talking to are doing whatever they do with regards escalation through the ranks - that's all we can do for now.

You say that your findings (and I have a great deal of respect for the time, effort you've invested and the conclusions you've arrived at) show that "ECU mapping yields no effect on the Yo-Yo".

What you haven't done as far as I can see is test our product - you've just advised BMW mini owners to disconnect and cap off a breather pipe - which may address the issue short term, but when the dealer see's what's happened, they'll be merciless with you (and those who've carried out your modification) in the event of any problems in the future, unless perhaps you have a really good relationship with them or reverse the mod before the car goes back in.

We're not trying to scare people into buying our product - we just offer a choice.

The term we use for the yo-yo is actually called "hunting". We've invested thousands of dollars into our BMW Mini product, and as such, I think your presumptions regarding AmD are perhaps unwarranted?

Our product was developed not only in the UK, but the US, Asia Pac and Europe with real live beta testers and a year of development which is still in progress as we refine our products even further. We're also the closest tuner to the BMW Mini factory in Cowley, Oxfordshire and we have good contacts.

Bottom line is that our product enhances performance, provides increased driveability, maintains fuel consumption when driven normally, eliminates the hunting ("yo-yo&quot and 1's gear stumble issues, is upgradeable depending on your modifications and works!

If there's any part of your post I didn't quite answer, please let me know and I'll do my best to help!

Best wishes,

Ram

 

Quantifying the mileage change...

Might I also propose that those folks who perform the Ryephix keep very accurate records for several tankfulls (3 - 4) of gas before the change and for some time (say 10 tankfulls) after the change? Dont use the OBC for this, calculate the mileage mathematically based on gallons needed to fill and miles travelled since last fillup.

When you have reached the 10 fillup mark, post your pre-Ryephix average and your post-Ryephix average.

Data-R-us!

 

[Great idea Koopah - I've kept close track of my mileage since Mile 1]

(since Ram copied and pasted his response here and MINI2, that's what I'll do too)

 

Ram, I can understand your not wanting to ofer a blanket money back guarantee but, what about offering that guarantee to just Ryephile and Webb Motorsports to test. If either or both post on internet that your claims are correct, you'll sell a ton of them with no other advertising required.

 

>>
>>What you haven't done as far as I can see is test our product - you've just advised BMW mini owners to disconnect and cap off a breather pipe - which may address the issue short term, but when the dealer see's what's happened, they'll be merciless with you (and those who've carried out your modification) in the event of any problems in the future, unless perhaps you have a really good relationship with them or reverse the mod before the car goes back in.
>>
>>We're not trying to scare people into buying our product - we just offer a choice.

>>Ram

Dear Ram,

I am glad that you 've taken the time to inform Rye that his proposed fix may cause warranty issues; can you now speak to how my dealer will react when he learns that I've changed my stock MINI ECU for yours? Wouldn't that also subject me to "merciless" persecution by the dealership?
Can you provide me with written documentation that your product maintains the manufacturer's warranty? If you can, then I am interested.
Please respond to this string (instead of a PM) - I'm sure others here would also like the same info.

Minimoto

 

Hello all,

Rye...
I just re-read the entire thread.... :smile:.

I'm truely disturbed at the lack of effort MINI DIVISION has taken to acknowledge, address and/or correct this yo-yo/hunting issue.
What exactly are they waiting for....??????

I have a few questions:
1. How widespread is this problem ???
I've seen 25+ VIN numbers offered up here in this thread...but how wide does this problem stretch???? Does anyone have a guess-tamate of a total affected population number???

2. I'm sure there are many members reading this thread who are now asking themselves..... "Do I have this yo-yo/hunt problem? How can I tell??? What can I compare it to???? How can I confirm it ???? Any suggestions on how to confirm or diagnose this probelem???????

3. My last question is more a..... request.
I live on Long Island in NY and would like to ask someone to please let me drive their car afflicted with this yo-yo/hunt issue. I will certainly ante up my car as well...to use as a comparison.

Thanks for listening...
Again.. great work.....

Peace,
D




_________________
PM d-mini-ero

 

[sidenote] I called up Ram at AmD NA and discussed some of the communications obstacles that seem to be occurring right now. Basically, he's forwarding my contact info to the Director of Operations for AmD, and hopefully he'll be able to provide us with more technical backing as to how they feel they've corrected the issues they claim to. I also spoke to Randy Webb today. Seems that AmD is trying very hard to get Randy to carry their products. Randy and I thought of a great validation idea; AmD send me a unit to test out - I'll do dyno comparisons between the OneClick and the Webb ECU, and also determine if it fixes the Yo-Yo as they promise. (just like apexer suggested!) also - MINImoto - excellent point about warranty!
[/sidenote]

--->Dennis: Since Randy test-drives every MINI he does Perf Mods for, he's noticed that virtually all '04's have the Yo-Yo, whereas it's almost unheard of in earlier years. On that note, I'd say a rather large percentage of late '03s and most '04's have the Yo-Yo. From all of Randy's test drives, he still feels mine is among the very worst (in terms of amplitude of the oscillation).

The Yo-Yo is very easy to confirm! It's easiest to feel in 2nd and 3rd gears, due to the loading versus throttle angle. Step on the throttle about 60% and hold it there while accelerating through each gear. If the vehicle exhibits an oscillation in acceleration, this is the Yo-Yo.

Dennis - If I were closer to you - I would happily hook my bypass valve back up and let you have a go around the block.

Cheers - and more updates as soon as possible - and when my camera doesn't act up in this ccccold weather.
Ryan

 

>>Ram, I can understand your not wanting to ofer a blanket money back guarantee but, what about offering that guarantee to just Ryephile and Webb Motorsports to test. If either or both post on internet that your claims are correct, you'll sell a ton of them with no other advertising required.

Bingo.

Mr. Ram, I don't know you, but if you want my respect and my dollars, send your product to Ryephile and let him test it. If he says it works, then as was pointed out above, you'll get the business that you so clearly desire.

Belly up to the bar and let a respected member of these forums test your product. Short of that, nothing you say here is going to convince me, for one.

 

Some good questions...

Warranty? Well, with our product, you can switch back to standard map at any time so when the car goes back to the dealership, it can have the original ECU content in it - not that the dealers can detect our modified code anyway (unless they drive the car of course)

So I should put up or shut up? - I've done this. On the Mini2 forum, I've offered 5 people a "money back" guarantee (with reasonable conditions) on the product.

Take a look then get back to me!

I haven't debunked Ryan's work, but it would seem that people think I have!

Best wishes,

Ram