I fully agree with WpgDSMer on this one. I have done similar tests, and have just voiced the same opinion in the "little things" thread after a comment about the supposed "really off" feature of DSC.

Many forum members claim there is a DSC and TCS system on the RX8, and disabling the latter is only accomplished by holding down the DSC OFF button for 7 seconds. If there was such a feature, you would think Mazda would be touting it in their brochures.

Holding down the DSC button does trip the DSC system into an error condition - which is why the DSC traction light stays lit. This is to let the driver know there is a problem with the DSC. This is why the light doesn't come on when you turn DSC off manually - there is no problem, it's just off and obviously the driver knows about it.

This is also why the secret "TCS disable trick" only works when the DSC system is on - try doing it after you turn it off - it doesn't work. If this was truly a two-stage system as some claim, it wouldn't just work when the system is on - it doesn't make sense.

This is also why you have to turn off the car to reset the light - if this was a two stage system you would think you could just turn the secret TCS system back on with a touch of the DSC button. However all of this does make sense if you are just throwing the DSC system into an error condition.

I have seen threads on this where an AUTOXer stated he couldn't feel the difference between DSC on and DSC off - he could only feel it after doing the 7 seconds trick. That's just laughable, and doesn't lend credence to the subject. Some seem to think the ABS system is disabled after doing the 7 second trick - again laughable because it's so easily proven wrong - do people actually try this stuff or just make it up as they go along. Perhaps some people can't feel the difference between having ABS and not having ABS - also something that does not lend credence. I think this whole thing has come about through myth and plecebo.

 

I'm with you Mobile - always wondered WTF people were going on about with the 7 sec push thing . I track my car lots and I can't tell any difference between DSC off & the 7 sec secret squirrel handshake behind your back disable .....

 

With only DSC off, it will kick in if you get way loose. If you hold it for 7 seconds, it will never kick in.

I speak from first hand experience.

 

so a 1080 at 6-8k rpm isnt way loose??????????

 

Thanks Brettus and mulkio - glad to see I have some backup on this issue.

GlenAnderson your saying that if you turn off DSC, get the car into a slide - at a certain point you can feel the car kick in a mysterious "backup" traction control that straightens you out? Wow, I must really be loosing my touch.

I have racing experience, lots of time behind the wheel and a good feel for the subtle cues a car gives you - and I don't feel anything "kick in" when you get loose. I can slide the car through corners, do crazy donuts and figure 8's and 180's from a standstill - all without feeling anything fighting me when DSC is off.

What exactly is that your saying you can't do with DSC off that you can by holding the button for 7 seconds. Give specifics and show me any documentation that says the RX8 has a TCS system.

 

TCS is part of the DSC, pushing the DSC button disables them both. If you hold the button for a few seconds, the system will detect a switch trouble, and hence the TCS/DSC light stays on.
Directly from the manual...

 

Thank you ZoomZoom - real proof. Interested to see the 8 does have a TCS system, but not surprised to see it's incorporating into DSC and everything is disabled with the touch of a button.

Hopefully that settles the issue for those believing otherwise. Holding down the DCS button does nothing to change the characteristics of the car. The power of the placebo effect over some drivers floors me.

 

phew - thanks for bringing this out Mobile and to Zoomzoom28 for providing the proof

which reminds me - here are some other common myths that need to be squashed

RX8 uses more petrol at idle than when cruising at 3-4k rpm - wrong
the oil pressure guage is not hooked up to anything - wrong
synthetic is bad for your engine - wrong
Rx8 does not respond well to mods - wrong

can't think of any more right now . Maybe we need to start RX8 mythbusters thread

 

I believe I read somewhere a magazine noted that the slalom time of the rx8 went down a few mph when the TCS was disabled.

 

I wouldn't doubt it - but we are referring to the myth that DSC and TCS are controlled and disabled separately. When you press the DSC off button, you in turn disable the TCS system as well. There is no need to hold the DSC button down and trip the computer - this is not a two stage system.

Yes NaarLeven, this undoubtedly gives you a higher degree of control over the car, allowing for better lap times and more fun.

 

It is a 2 stage system.... Well 3 stage with the 3rd being ABS not designed to be turned off.

1 push - disable DSC (allows oversteer).

1a) Reason Why you cannot hold it down with DSC already disabled, because the expected push value from the DSC able state is to turn it back on. Hence you are right you have to enable DSC to have the 2nd system (TCS) off with the 7 second button push.

2a) TCS - indicator will flash showing it is in an active state, by either managing your throttle input 1st, and engaging the rear ABS. I do not know if it manages speed differentiation between the two rear wheels, as this would seem counter-intuitive to the LSD. Only data logging can very this to curb pseudo science. TPMS sensors do report a speed value, i don't know if TCS utilizes this or not.

7 sec push - Disables DSC intervention & TCS Intervention, so no intervention to the electronic throttle control is done. Nor are interruption requests sent to the ABS system that BOTH the DSC Controller & TCS Controller utilize.

1b) My alternate reasoning as to why you can't just TURN THEM BOTH on, is the error flag that gets sent to the ECU, requiring a startup diagnostics test.


End Result:

When you look at the outcome of DSC being on with TCS off if this was implemented, is fishtailing at the entrance/apex/exit of a turn if not also possible on a straight line. Which would engage the DSC to mediate throttle control & ABS. There's a drivers perspective at this point, if they should be comfortable enough to drive with TCS off, they should able able to manage the throttle control to manage oversteer/understeer and apply brakes when necessary.


Summery:

The DSC & TCS are seperate controllers that are dependent on the ABS system. During startup, the ABS does a calibration test, if it fails your ABS light will trigger & the DSC & TCS will be lit showing all 3 systems as in a disabled status. If you receive a CEL with the ABS, it's a good idea to get that code verified, as it may be a faulty ABS sensor or faulty caliper.



TCS debugging:

This system seems to have a threshold value, there is no way to confirm without hashing out the code on the ROM. As some have referred to 'Nanny', it typically does this as a last resort if the blinking light indicator doesn't convince you to let off the throttle, it will engage the ABS to regain traction. Whether this threshold value changes with DSC off, I don't know. My experience is i've seen TCS engage at a higher rpm point then with both TCS/DSC on, but without logging its pseudo science. You can always do the stonehenge method of datalogging, but if you really want full tire management control, and have an LSD, then just turn it off.

 

Did you read the posts above, including the quote from the manual? Show me one bit of proof regarding what your saying.

I have never once seen the traction control light flash after turning off DCS. As clearly stated in the manual, the TC is part of the DSC systems, and everything is disabled once DSC is off. The manual also clearly states that holding down the button will trip the system into an error condition.

You stuck a lot of unnecessary fluff in your post - lets see some sources, lets see some proof. My statements are backed up in black and white right from Mazda. If your reading something that contradicts the manual, I would be genuinely interested in seeing it.

 

^^^^


https://www.rx8club.com/showpost.php...5&postcount=20

read that post. then go do it yourself. then rethink what you posted. and re read the owners manual.

assuming you are in north america...

beers

 

i have a test here.. go out a push the button once..

the dsc light will light up..

now here is the easy part.. rev the engine to 6k rpm and drop the clutch, see what happens..

i will tell you it will not be a lot of wheel spin..

duh....

beers

 

lots of stuff they dont tell you in the manual.. they hint at some stuff, but really dont tell you how to do it..

beers

 

Don't even need 6k rpm. With V710 on 50 degree F. day, 3K is plenty enough.
Why is my car not moving forward

BTW, on page 5-23, "Note: To turn off the TCS, press the DSC OFF switch".

 

If I have to drop the clutch at 6K to see any difference, then there might as well be no difference. Can you give me a real-world scenario, or another test. Not interested in abusing my car like that. How come nothing stops me from doing a perfect 180 from a standstill - plenty of wheel spin there!

 

Umm, the owners manual agrees with what I'm saying, and that link only stated what I'm already aware of - what some people think is supposed to happen.

https://www.rx8club.com/showthread.p...=1#post2324725

read that post. then rethink what you posted and re read the owners manual.

If your still on the other side of my argument, can you please post a couple sentences of what you can and can't do with DSC off vs DSC 7 second off?

With DSC off: You say no clutch dropping at 6K because there will be no wheel spin - if there really is something stopping you, lets hear what else it stops? Also please answer why you are allowed to do 180's, donuts, figure 8's, mega corner oversteer and drifiting by only pressing the DSC button.

 

ok,

then do the same test from 2k rpm on dirt, grass, or snow..

beers

 

When I drove around here in the bit of snow we had this winter, after I turned off DSC the back end just kicked out when applying too much throttle getting going...No TC light came on. Was awesome for donuts!

Also, I edited my above post with more questions ^^^^

 

your really need to know that traction control just stops the rear wheels from spinning. low traction or clutch drops the same thing..

it works by killing the throttle, timing, and brakes if needed..

all you have to do is follow the steps, it will become clear real fast..

beers

 

Yes I read it. As you READ the definition below.. it is DSC & = And TCS, meaning it is 2 functions... two. Riddle engineers this, If they are the same then why label them seperate?




Correct... they integrated the processor the DSC & TCS fuction into 1 controller, but they serve separate functions. To be repetitive of myself, there are 2 indicators instead of one... is the squiggly traction light a DSC light? nope... Read that last bullet in (Notes). It specifies "it will be impossible to achieve high rpm when the TCS is on" meaning.. even with the not he same as TCS light = DSC light on, Traction Control System (TCS), will still manage your throttle input...







fluff? dude, i'm not even going to get into this.. i felt that it would be good to explain and isolate each systems function for those that don't understand the separate function of each system. And also went to the extent to cause and effect as to 'why can't you have TCS on and DSC off'.... in short, again loss of traction will lead to drifting... engaging DSC.......

On a flipside to why you never experienced this, your PCM may have learned differently and have it's engage points different.... you should be getting a TCS light blinking with the DSC off when your spinning wheels. I drift my car daily with the TCS on, but that isn't the debate here.... the issue is what do the 2 functions do & does holding the 'magic button' for 7 seconds make a difference.

Yes it does. That or it's a cruel joke the japanese engineers are having out our expense well knowing we would start a thread like this and have a pissing contest. .. hehehehe... thank god i didn't post the Service Manual info eh?

 

I am not disputing there were two systems. I am only saying that TC is a sub-system of DSC (as stated int he manual), and both are dis-engaged when you turn off DCS (as stated in the manual)

I am not sure what you are trying to achieve here. As I already stated, I am not disputing that there are two systems, only that both are disengaged when you turn off DSC. I have also never seen my TC light come on at any time when DSC is disabled - so you can see why I have trouble believing that others have their light come on when DSC is disabled when I have never experienced it and the manual says TC is disabled without DSC.

I am sorry for the fluff comment, I didn't intent to come off like a *****. It just read like a very indirect answer to some direct questions. I am only trying to get some answers with this discussion. A lot of my direct questions are going unanswered by those who sound like they might know what they are talking about.

I have a 2007 and I started driving it with the DSC off right away, never seen a light while doing all sorts of crazy stuff. You would think in all my drifting, donuts, 180's and driving in the rain and snow that no matter where my threshold is, I would have seen it by now? I am in Canada, don't know if that could make a difference. Can others post their experiences with this? Does your TCS light flash with DSC off when your wheels spin?


Please do post the service manual info - I would love to see it. This isn't about a pissing contest, only trying to get to the truth. Considering I have never seen the TCS light come on while DCS is off AND the manual states TCS is disabled when DSC is switched off AND the manual states holding the DSC button send the computers into an error condition - I think it's a fair argument.

Plus with all that aside, I still don't understand what I can't do with DSC off vs the 7 seconds off? If TCS is supposed to manage throttle, then you would think after turning off DSC it would kick in when your wheels spin and stop the spinning (nevermind the light) - I and others here have experienced no such thing. If I can drift, donuts and spin the tires like mad by turning off DSC - then what do I gain with the 7 second trick, what else could it allow me to do that I couldn't before?

 

I know what and how traction control works. I don't get ANY type of traction control once my DSC light is off - there is nothing to become clear. I am no fool behind the wheel with plenty of racing experience with open wheel and cars - I am a skilled driver with a good feel for the car - I would know about it if my TCS was trying to manage the vehicle. The way you're talking it feels like we are driving two different cars.

Instead of talking down to me like I'm some kind of ignorant fool - how about answering the questions I posed to you?

 

There's a Drift day starting in March at the Evergreen Raceway i think if not April. I'll data log 3 laps with DSC off, then another 3 with DSC & TCS off. This really is the only way to confirm without praying a Mazda Engineer chimes in, or if somebody happens to have a whitepaper to the DSC controller (TCS function & DSC are combined into 1 Controller when i looked at the Service Manual).

Previous forum members have reported slower launches with TCS on, and a better response time with both systems off. Why you haven't? couldn't tell you, it is odd... The PCM flash for Canada is different then Japan,EU & USA... so it can't be ruled out. Comparitively it looks like yours is set to be completely off when the DSC is off... depending on how you look at it can't complain right? In a ratio your case appears to be unique. Now hopefully i'll remember to bring the logger & laptop that day