Notices
Series I Tech Garage The place to discuss anything technical about the RX-8 that doesn't fit into any of the categories below.

Question for automatic owners – weird shifting

Old Feb 10, 2004 | 10:09 AM
  #1  
310Guy's Avatar
Thread Starter
4AT poor mileage king
 
Joined: Jan 2004
Posts: 587
Likes: 0
From: now... 818 area code
Question for automatic owners – weird shifting

I have just passed 500 miles on my 8. I have been very "nice" to the engine during the break in period. However, just yesterday I was on the freeway and I needed to get around another car quickly. I stomped on the gas pretty good. All of a sudden it seemed like the car was "confused" as to which gear to be in. I went though three gear changes (car did this, not me) in a matter of a few seconds. All I thought was, "WTF?"

This didn’t seem normal to me. Anyone else with a similar experience?

This is my first rotary engine so I’m getting familiar with its temperament. My previous automatics (V6s) never had done something like this.

Thanks for any feedback/info.
Reply
Old Feb 10, 2004 | 05:08 PM
  #2  
zoom44's Avatar
Administrator
 
Joined: Jul 2002
Posts: 21,958
Likes: 115
From: portland oregon
so at highway speeds top gear and low rpm you stomped on it?

you should have had 3 things happen- downshift,port openings and vfaid opening. haven't stomped on my freinds auto that much but this could conceivable feel like a coupl of shifts. push in the back, push in theback.

anyone else?
Reply
Old Feb 10, 2004 | 05:22 PM
  #3  
310Guy's Avatar
Thread Starter
4AT poor mileage king
 
Joined: Jan 2004
Posts: 587
Likes: 0
From: now... 818 area code
The thing that "concerned" me was there was major hesitation; again, it was like the engine was confused on what gear to be in.

Thanks for your input.
Reply
Old Feb 10, 2004 | 07:46 PM
  #4  
mikeb's Avatar
100% Italian
 
Joined: Jul 2003
Posts: 9,422
Likes: 0
From: orange,ca
this happened to me once months ago while I was going uphill

I thought the engine was gonna fall out

Hasn't happened to me since though
Reply
Old Feb 10, 2004 | 10:13 PM
  #5  
MyLadyDeb's Avatar
Registered User
 
Joined: Feb 2004
Posts: 96
Likes: 0
From: Palm Beach Gardens, FL
I have this happen with my automatic too....if I stomp it shoots out like a bullet or almost feels like it's going to stall. The service guy told me that the computer will learn to recognize the way the driver drives and will program itself. It happened alot during the first 1500 miles - I've noticed lately tho that it doesn't happen quite that often. There are times when I start to accelerate up a hill and fill like I'm in a volkswagen - no power at all. If I floor it it shifts into a higher gear and shoots forward. I also don't have any experience with a rotary engine and just assume it's a learning period for both of us.
Reply
Old Feb 11, 2004 | 05:06 PM
  #6  
mikeb's Avatar
100% Italian
 
Joined: Jul 2003
Posts: 9,422
Likes: 0
From: orange,ca
Originally posted by MyLadyDeb
The service guy told me that the computer will learn to recognize the way the driver drives and will program itself.
that would be cool
but I'm not buying it

no way does the car program itself to my driving
Reply
Old Feb 11, 2004 | 07:43 PM
  #7  
Positron's Avatar
Registered User
 
Joined: Dec 2003
Posts: 170
Likes: 0
From: Arlington, Virginia, USA
When I first got my car I noticed that if I went down on the accelerator too hard the car would downshift "dramatically", the engine would roar, and I would then accelerate like a little bat out of hell. After the first month or so of driving I found that I could get the car to downshift and accelerate less dramatically. I don't think the ECU learned anything, I think it was my right foot!

I much prefer to slip the gear shift into the manual mode and do the shifting myself in those situations. In fact, I was wondering the other day if I get better gas mileage when I shift or when I let the car do it in full auto. I will just have to drive more to test it out. (I know its a hard job, but I will make the sacrifice :-)

mm
Reply
Old Feb 11, 2004 | 07:59 PM
  #8  
zoom44's Avatar
Administrator
 
Joined: Jul 2002
Posts: 21,958
Likes: 115
From: portland oregon
the ecu is adaptive. so , yes it does learn the way it is driven and adjusts to it.
Reply
Old Feb 11, 2004 | 08:21 PM
  #9  
therm8's Avatar
Bummed, but bring on OU!
 
Joined: Sep 2003
Posts: 2,036
Likes: 1
From: Charleston, SC
I have never experienced this, but I don't think I have ever just "stomped" on the gas in full auto mode. I rarely drive the car in full auto, but when I do and I need more go, I just slap it over to manual and downshift once or twice.
Reply
Old Feb 11, 2004 | 09:18 PM
  #10  
310Guy's Avatar
Thread Starter
4AT poor mileage king
 
Joined: Jan 2004
Posts: 587
Likes: 0
From: now... 818 area code
Well, I'm being VERY conservative with my auto. I haven't even tried the paddle shifters yet. I'm waiting until after the break in period. I know as soon as I start using them, I'm going to be always near redline.
Reply
Old Feb 11, 2004 | 09:47 PM
  #11  
MyLadyDeb's Avatar
Registered User
 
Joined: Feb 2004
Posts: 96
Likes: 0
From: Palm Beach Gardens, FL
ah - the paddle shifters - I haven't touched them since I got the car - they're so intimadating. I haven't done much with the manual either - so you can shift it from D to M without coming to a full stop? That might changes things. I also have found my right foot has been reprogrammed and I feel proud when I accelerate to where I want to be without the bullet shot....although it really does give you a great surge or power, doesn't it? Pity the poor gas mileage - but if we were going to be conservative with the gas - we wouldn't have gotten the RX-8 now would we?
Reply
Old Feb 12, 2004 | 01:07 AM
  #12  
DrComputer's Avatar
Registered
 
Joined: Dec 2003
Posts: 34
Likes: 0
From: Sherman Oaks (LA), CA
Welcome to the world of drive-by-wire. My other car, a Lexus LS430, was one of the first drive-by-wire cars. It takes a bit of getting use to. The ECU tries to figure out what you are doing and then react accordingly. Sometimes it makes poor choices. If you are driving at a constant speed in 4th gear and then stomp on the pedal, it will pause to make sure this is what you really wanted to do. The worst thing you can do at that point is let up off the pedal before it makes a complete downshift. It then has to decide what to do next... continue with the downshift or go back to 4th. If you do stay on the pedal and go to 3rd, for example, and then let off the pedal completely after the downshift, the ECU will keep you in third for a while just in case you are about to stomp down again. Drive-by-wire just takes learning how the pedal will react to different situations. Once you learn how it reacts you can make the car respond how you want it to. I've also noticed that the gear indicator on the dash will show the gear that the ECU plans on going in to... not necessarily the gear you are in at that exact moment. I find that rather annoying.
Reply
Old Feb 12, 2004 | 12:07 PM
  #13  
310Guy's Avatar
Thread Starter
4AT poor mileage king
 
Joined: Jan 2004
Posts: 587
Likes: 0
From: now... 818 area code
Hey, another So Cal owner!

Thanks for the input DrComputer. That is what may have happened to me. I pressed on the pedal, felt some hesitation, eased up on the pedal and the pressed it again.
Reply
Old Feb 12, 2004 | 03:56 PM
  #14  
Rotary Nut's Avatar
"...I'm a Dapper Dan man"
 
Joined: Nov 2003
Posts: 840
Likes: 1
From: Newport News, Va
Originally posted by mikeb
that would be cool
but I'm not buying it

no way does the car program itself to my driving
Actually that is correct. It is sometimes refered to as "Fuzzy Logic" or "Adaptive computer control"

The transmission contol module monitors things like RPM, Speed, throttle position and gear selection. It then over the course of say 100 miles memorizes the way you apply the gas pedal. It then calculates how you drive by monitoring your inputs and compares it to the driving environment. If it knows you like to floor it in certain situations or go easy on the gas, it will change the timing, and duration of the shift points when in full auto mode.

Last edited by Rotary Nut; Feb 12, 2004 at 03:59 PM.
Reply
Old Feb 12, 2004 | 04:46 PM
  #15  
mikeb's Avatar
100% Italian
 
Joined: Jul 2003
Posts: 9,422
Likes: 0
From: orange,ca
I guess I should take my foot out of my mouth.
Reply
Old Feb 12, 2004 | 04:53 PM
  #16  
Rotary Nut's Avatar
"...I'm a Dapper Dan man"
 
Joined: Nov 2003
Posts: 840
Likes: 1
From: Newport News, Va
I wouldn't go as far as putting your foot in your mouth!

Just takes a bit of research!

My last four VW/Audi products had the that kind of transmission and it took some getting use to the way it would program the shifts untill it reprogrammed itself for my driving style.

Check out this PDF file. and this then try this one (this one is by far the best one).

Last edited by Rotary Nut; Feb 12, 2004 at 05:05 PM.
Reply
Old Feb 20, 2004 | 05:06 PM
  #17  
310Guy's Avatar
Thread Starter
4AT poor mileage king
 
Joined: Jan 2004
Posts: 587
Likes: 0
From: now... 818 area code
Thanks for the links.
Reply
Old Feb 22, 2004 | 07:21 AM
  #18  
Trx8's Avatar
Is Scarce
 
Joined: Jan 2004
Posts: 214
Likes: 0
From: Ann Arbor, MI
I drive my car in two modes:

- 6 miles to and from work, 8 stops along the way, 2k-3k RPM
- Fun driving, full RPM range

After reading this post, I started watching the tach more closely. If I accelerate quickly it downshifts and then stays in the lower gear for a while even my speed has stabilized. Then it "decides" I don't need the power and shifts back to the higher gear.

I finally tried the paddles yesterday, but not aggressively, and they seem to work pretty well. The downside is that requires me to think about which gear I am in.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
akagc
RX-8's For Sale/Wanted
7
Aug 11, 2015 07:07 PM
robd1337
New Member Forum
11
Jul 31, 2015 09:35 PM
Rx8Lovin
New Member Forum
4
Jul 25, 2015 08:39 PM
Bamaham
New Member Forum
2
Jul 23, 2015 08:08 AM
reverse01134
RX-8's For Sale/Wanted
0
Jul 16, 2015 10:27 PM


Thread Tools
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -5. The time now is 07:41 AM.