With 16 days and 2200km of sheer driving pleasure under my belt I've found something to whinge about but I'm not sure if this is a general issue or a fault with my car.

When using cruise control 101km/h in the 100 zome on the way to Bathurst I've found the cruise control to be perfect on the flat and surprisingly, even better on the down hill , it seems that on the uphill, the speed holds well until the crest and then seems to continue to accelerate well beyond the 101 and I had to intervene regularly when the speed hit 110.

Has anyone had a similar experience??

Rob

I have not had any touble with the cruise control. It has been holding the speed for me +/- 1km/h regardless of the slope of the road or speed.

No hassles here... works a treat. Love the kick in the pants when you bump it up 1 mph even in sixth gear.

Sorry but you are still on your own. Drove back from Stawell to Melbourne (200k) and it didn't vary by more than 1km in speed all the way.

I've seen this...

I've assumed the cruise control has a problem on steep down hills, I think it only controls the throttle not the brake, hence it is fine if the engine can control the speed, but on steep down hills it can't slow it enough.

I haven't really tested it closely, but I'll raise the issue at my 10,000K service on friday.

My cruise control works perfectly. I'd get this issue looked at asap.

Did 1000kms of driving over the weekend... I noticed something similar once or twice, although don't think it went more than about 4 or 5 above the cruise thing, but that may have been because I killed it before it went anymore. It only did it up hill, both times.

Originally posted by msydd
I've seen this...

Sorry for butting in (I'm in the states), but I have noticed the same phenomenon. Whenever I let the speed drop significantly (more that 20-30km/hr), and press the "resume" button on the cruise control, it shoots past the mark I had set, and takes several (10-15) seconds to ease it's way back to the standard speed. Sometimes, it goes a significant way above the set mark (the first couple of times, I thought it was broken) before returning.

Set and forget, it's always been fine.

Sorry again for butting in, just wanted to assure you it's not just the Aussie cars with this phenomenon......

Originally posted by pricer01
it seems that on the uphill, the speed holds well until the crest and then seems to continue to accelerate well beyond the 101 and I had to intervene regularly when the speed hit 110.
Rob

We've seen that problem in the U.S. See post http://www.rx8club.com/showthread.php?s=&postid=109986#post109986

damn yanks, hijacking the thread. ;) he's not talking about using resume, just constant cruising. I've seen neither problem with mine.

After 8,500k, I can report the 'surge' effect after hitting resume, overshooting the set speed by, say, 5-6km/h and then settling back but it is nothing more than I have experienced with other cruise controls.

Timbo

I've just completed a 4500 km round trip from Adelaide, to Sydney, up the coast to Byron / Federal via Dorrigo, and then back to Adelaide via Armidale and Hay. So you might be getting a few posts from me shortly.

Anyway, I tended not to use cruise control for a couple of reasons I will get to in other posts, but when my wife was driving she tended to use it a lot.

We did notice a problem with the speed overshooting by up to 15 kph. The control was set to 109 kph on the roads just west of Tenterfield in northern NSW, and only seemed to occurs after just cresting a rise.

Rob,

are you still getting this? I'm heading to Newcastle today [ i's 00:36:00 AM ] so I'll test it on the couple of perfect test spots for what you've seen as I suspect I'd had this a couple of times but both times I can recall I off'ed the CC to pull back in top of hill traffic - so stay tuned till tomorrow as I'll give it a good shot to either replicate or prove otherwise.

++dez;

Here's another yank's 2cents.

There's a long steep hill on my way home. The speed limit is 35mph and I usually have the cruise control on my AT set at 35 during the last stretch home (3 miles). Going up the hill, the car down shifts 4 or 5 times - each time it takes me about 2-4 mph faster than 35.

Going downhill, I sometimes drop it into a lower gear to keep from going faster than 40.

Hmm..

clearly it's repeatable then.

1st rule of problem solving is to make sure it's a reproduceable problem.

will post once I get back toay [ in around 10 hours ] if I can reproduce it.

++dez;

Dez

Its still irritating me although its the sort of irritation that is easily soothed by the leather, xenons, road holding and celebrity appeal of the 8 .... he he he

Of course when I gripe to the dealer service manager I may be less amiable!

How was the trip ???
- I'm interested to see how your reseach on the resume failure - reminds me of teh old toshiba T1200s !!!!

R

Toshies... yech... after my 8100 experience (5 times the same simple fault with the FL invertor had to be fixed in 3 years).. never again.

(Sheepish)

Well, I did a drive on the weekend that really exposed this problem, and realised that my normal drive -- Cbr/Syd & Syd Cbr (virtually all freeway) -- every week doesn't really expose this weakness. When using CC over more varied conditions, especially pressing Resume going uphill, boy does that baby overshoot.

I reckon that little controller found itself in an 8, and just can't help itself :D

well,

first days road testing to see if I can re-produce the "missile" cruise crontrol issue.. bzzztt.. I failed.. sorry..

I have to say I really did give it a good bash.. there as some pretty bloody good testing grounds for this sort of road test infact between Sydney and Newcastle [ where I was heading to and from yesterday ].

I did a range of tests..

1 - in 6th gear at 120km p/hr into down hill run and then back up a long winding curved hill

2 - in 5th gear into very big steep up hill section at 110km p/hr

3 - in 4th gear 500m before crest of rounding hill at 100km p/h

I did a range of other small tests but bloody cars kept getting in the way so I didn't include them.

But I could not repeat the "curise missile launch" effect, yet!

Rest assured I'm going to take the car out to the hills this weekend so I'll run another series of tests to see what I can get - I'm keen to experience this now.

Call me the cruious cat if you will.

sorry Rob, nothing conclusive yet * sigh *

but it has made me speed up my want to suck data from the car now, as I think the real acid test would be you driving into a steep hill in 6th gear, hit this curous cruise missile launch you're getting - catch the data on the old "palm pilot ECU OBD2 data sucker" gizmo - and see if we can play back to where the speed kicked in and perhaps write to Renesis / Mazda with out findings and see what comes of it.

Stay tuned!

++dez;

I have had these issues with cruise on several cars in the past, particularly when on overrun down a hill where speed climbs above the set-point, and then you start climbing a hill. The speed tends to drop way below (5-10 kph) the set point before the cruise susses things out, then accelerates to 5-10 kph over set point before figguring it out again...
I think this is fairly common and not particular to the 8...
Someone needs to figgure out a "preemptive" cruise system... one that can tell if you are about to climb a hill and react before dropping speed off.

Dez

Something to bear in mind is that the concensus seems to be that these 'launches' are observed often when pressing resume ...

Rob

this is way off the thread but has anyone else had their rear windows regularly "pop" open from the suicide door being closed, the main front door being closed normally, or even just driving along with the air con on?

it's driving me f*cking mad but randomly I get the little driver side read window pop open and I have to reach back and click it closed again, and now I have to make a note of checking the window is closed - and I reguarly find a reason to go get a hot choc and pass the car to check the frigging window is closed!

++dez;

Reminds me of my old Cooper S (sniff!)

No, have not had that problem, but do note the window has a double-click latch, so make sure you are getting the second engagement

ok,

I managed this week [ late post sorry ] to conclude the following:

"the issue with the crusise control is only on resume, it's easily repeatable, and should be watched closely if you're a few license points away from a permanently parked RX8!"

it's now a game I play, that is, enter a hill in low revs, high gear, resume CC, and watch the little blue bird attempt to fly!

every other possible combo I could dream up to put the CC through it's paces passed with flying colors, and as someone said here previously, that little "kick in the pants" every time you touch the "increase speed" button is just bliss!

I'm pretty ok with it all now, but if anyone is interested in the full boring details, in perhaps the interest of writing to Mazda / Renesis about it - PM me and I'll put you to sleep 100% gauranteed [ like I prolly did just now sorry ].

So there you have it Rob.

Real live demo's will be available on the next Wednesday Nightly Drive * grin *

++dez;

Dez,

Give us the boring details and I'll see if I can repeat it. If enough of us complain then maybe Mazda can rev the software in the ECU for us to fix the problem.

Cheers

sco

Mine has exhibited the resume overshoot problem since day one. Not every time, but enough that I have to be carefull. Maybe about 3 or 4 times a week. When I click resume, it overshoots the previous mark by about 5km/h, before I intervene. A couple of times I have noticed it settles down by itself. When it is in steady cruise it is an absolute pleasure. Rock solid.

Problem is we spend more time looking at the speedo, that watching ahead and anticipating danger. "Every K over is a Killer". That really irritates me. They are saying if we do the speed limit we can't kill anyone. Wankers.

And - I heard about the speed camera's operators getting privatized. Bonuses for the more "speedsters" they nab. Out of control!

Cheers,
Hymee

Hymee... your comments abut "every K over" are spot on! One of the problems with the system is that when they analyse a smash they often site speed as a factor when all the vehicles were travelling under the speedlimit.
i recon it says more about the skill of the driver f you still manage to crash with our "low" speedlimits.

Originally posted by MadMAX
Hymee... your comments abut "every K over" are spot on! One of the problems with the system is that when they analyse a smash they often site speed as a factor when all the vehicles were travelling under the speedlimit.
i recon it says more about the skill of the driver f you still manage to crash with our "low" speedlimits.

That's the thing. The laws of physics mean speed will *always* be a factor. So what! What was it that caused one or two moving objects to collide? While the outcome in terms of damage does increase (exponentially) with speed, there is no similar correlation with the risk of impact and speed, unless either (a) the road conditions do not support the speed or (b) the skills of the driver do support the speed. :mad:

Sorry - think I hijacked the thread ;)

The 8's cruise control works fine on motorways (surge is <5kph) but is decidely less so on more varied highways.

IMNSHO, I think this ought to be taken up with Mazda. I certainly shall, at my next service (or before, if I get pinged again :eek: )

(timbo's conscience speaking here: no, he wasn't using CC when he was last pinged ;) )

How about we get organised [ shit, there's a scary thougth ], and do a group letter?

I'd be happy to co-ordinate if anyone is interested, and protect privacy etc?

I'll do some homework anyway on who exactly in Mazda AU we shoudl talk to [ will ring them tommorrow ] and Japan as well [ will email them on this - hey - it's my dime! ].

Anyone interested? I'll start a thread and take votes to be included in the letter, pen a draft, and perhaps with Rob's help [ et tu Kev and Mark? ] we could prepare on behalf of as many rx8forum members [ 5,000+ voices would be hard to ignore right? ] we could present a pretty compelling reason for them to:

1) review the issue based on a detailed responce in writing of what and how to reproduce it ( that I can do! ) on demand

2) address what clearly is a software issue

3) prepare some means of distribution such as free visits to your dealer's work shop or one of choice [ vetted by Mazda of course ] to have the ECU blown with the update

4) ideally open source it! whahoo! imagine that! yea.. as if..

Thoughts?

++dez;

ps: I'd love to use my current user icon as our group letter head * grin * - that would give the darlings something to think about!




--- 2nd edit! sheeze I suck at self review ---


ok, forgot to add the fact that we would make it an open letter, posted for review and such here in the forum, then to Mazda C/- www.rx8forum.com ( with a hard copy in post of course ).

--dez;

While we are at it asking them to play with the ECU, lets get them to open up some more power too!

hee hee.. small steps ellie, small steps!

let's fight the battles we think we can win first.

I can do the impossible, it's the inevitable that I'm finding difficult.. oh, and miracles.. they bear a standard 10% surcharge..

++dez;

ps: point #4 was me typing with "one hand on it" of course - and no that's not the way I drive ok - let's just clear that up right now!