VVTi Tiptronic Speedm8 speedo converter

[spartan]

It would be good to find out what mechanism the ECU actually uses to limit the speed. Now I m undecided as to whether to tell the garage to delimit the car and put up with any spurious behaviour or to go with the undelimited route, the later is winning at the moment, as 100% of the time in day to day use this wouldnt be an issue. Track or airfield would be the only issue honest officer:search:

 

If you look back to post #5, you'll see I describe how to 'undo' the speed delimiting function. There's no reason at all why this couldn't also be achieved through a simple (changeover) switch: leave it off normally; flick it on when you want (to risk) it. Best of both worlds?

 

That reminds me of something else I thought of: it would be equally easy to put a switch on the speedo input signal, enabling you to revert to a kmh readout when required (e.g., driving on the continent). Odometer would be affected too mind.

Edited July 24, 2008 by spartan (see edit history)

[Pete]

Odometer would be affected too mind.

 

It would be all over the place. You're better off not making your car look like it's covered more miles than it has I reckon.

[spartan]

You're right, of course. Maybe as an instantaneous check if you're not comfortable with the 5/8 or 'knock the last zero off and multiply by six' mental arithmetic?

Edited July 24, 2008 by spartan (see edit history)

[CWD]

So has anyone tried fitting two devices to get the ultimate 3 channels.

 

I like the sound of the scenario using

The SpeedM8 analogue version to sort out my speedo and then another delimiter version to sort out the speed limit.

 

My thinking is that the ABS/TRAC ecu is down wind of the speedo so wouldnt then be effected as it would be getting the correct pulses.(Snow issue has gone after its installation on spartan's car)

 

The only time the delimiter would be active is after 110 and would only stop the signal at the ECU potentially getting around the change down issue, as the box utilises the ABS/TRAC ECU for changes (Perhaps or then again perhaps not)

 

What do you think?

[spartan]

OK. Just to be clear on this, there are currently three versions of the SpeedM8 that are available to be fitted to the VVTi Tiptronic:

 

1. 'VVTi Tiptronic' - does speed conversion and removes top speed limit BUT doesn't generate an unconverted speedo output so active spoiler (if fitted) is messed up (and also speed sensitive steering?)
   
2. 'VVTi Tiptronic - A/F spoiler mod.' - creates an unconverted speedo output signal to correct above problem (and also speed sensitive steering?)
   
3. 'Analogue' - does speed conversion and generates an unconverted speedo output signal (nothing else messed up) BUT doesn't delimit.
   

 

Presumably someone must've fitted versions 1 & 2 at some point otherwise why would've SpeedM8 have made them?

 

Those just with version 1 fitted may not be aware of the effect it could be having on speed sensitive steering (subtle - it's progressive not on/off), especially if they don't have an active spoiler fitted; I don't think cruise control was ever available as an option on VVTi cars.

 

The 'Snow' issue appears to only have affected my car when using the Thor/TRL VVTi unit. I still don't know if anybody using the SpeedM8 device (version 1 above) gets this problem. However, it most definitely IS related to the 'capped' speed input signal sent to the main ECU. When I made the mod. explained in post #5 above with the Thor unit fitted, the 'Snow' issue went away.

 

It was when I started contemplating what other effects interfering with speed signals sent to the ECU might have (gear changes, traction control, ABS, air-bag deployment?) that I decided it was time to steer clear of the ECU completely and find something 'simpler'. Hence, the start of this thread.

Edited July 24, 2008 by spartan (see edit history)

[CWD]

Thanks spartan, most infomative

[suprabrown]

hi,

just wondered if there was any update on this thread?? I've got a tiptronic and I'm probably as frustrated as pete with the speed limiter issue, the conclusion I've come to is that to remove the speed limiter fully I would have to replace the ECU and leave the original one in there taking care of the gbox and stuff

I've got the thor unit fitted, you just have to remember to knock off the trac control when you get in the car........who needs it anyway...LOL.....

 

the problem with the speed limiter is when you have a plonker in a 911 (private road of course) and need to show him where the supras advantage is

 

Cheers

[spartan]

Apologies for thread resurrection but another member asked me where this specific device could be purchased and I found that a direct link was possible:

 

http://www.ncs-systems.com/speedm8/index.php?action=show&man_id=13&model_id=254

 

N.B. I'm not connected to this organisation in anyway and, whilst this device has worked perfectly for me, the results might be different in your own car.

[vvteye]

I have an old thor vvti auto delimiter licking around in my glovebox should anyone be interested. Don't go asking me any technical questions though

[nick_karkie]

i would be interested if it will help with my low speed traction problems, can Pete confirm if this would help ?

[spartan]

The Thor VVTi auto. unit was the one I replaced with the SpeedM8 specifically to be rid of the low speed traction control problem ... consequently I've got one of these in a drawer somewhere too!

[Pete]

i would be interested if it will help with my low speed traction problems, can Pete confirm if this would help ?

 

I bought a SpeedM8 and it's been absolutely fine. I don't get any flashing on the trac lights (mind you, this is always off as I've got RLTC now!)

[Jurgen-Jm-Imports]

we fit NCS and had no issues too;)

[Pudsey]

I don't have any issues with the active spolier or the traction control that I am aware of, but the thought of a massive kickdown sounds a little worrying.

 

Guess that's what the speed limits are for, still interested in whether this has been fully resolved though.

 

NB: Certainly interested to find out what type I have fitted, now I have seen this thread.

Edited March 4, 2010 by Pudsey
addition of the NB: (see edit history)

[spartan]

...

 

Guess that's what the speed limits are for, still interested in whether this has been fully resolved though.

 

...

 

I don't think it has been resolved. I believe the top speed (red-line) in a VVTi auto in 3rd gear is about 130mph; the SpeedM8 (NCS) VVTi delimiter caps the speed sent to the ECU at 105mph.

 

Unfortunately, I think this means that if you were travelling faster than 130mph in top gear, the ECU would still think you were travelling at just 105mph. If you boot it under these conditions the ECU would probably still kick-down because it thinks you have some "head-room" revs wise when in fact, in 3rd gear, your revs would be past the red-line ...

 

Any one care to test this theory?

 

Seriously, I don't think there is a way to resolve this issue by 'tricking' the standard ECU by modifying external inputs. I think you'd need to open it up and 'blow' some EPROMS or something ... OK, I admit, I'm totally out of my depth now.

[Pudsey]

I don't think it has been resolved. I believe the top speed (red-line) in a VVTi auto in 3rd gear is about 130mph; the SpeedM8 (NCS) VVTi delimiter caps the speed sent to the ECU at 105mph.

 

Unfortunately, I think this means that if you were travelling faster than 130mph in top gear, the ECU would still think you were travelling at just 105mph. If you boot it under these conditions the ECU would probably still kick-down because it thinks you have some "head-room" revs wise when in fact, in 3rd gear, your revs would be past the red-line ...

 

Any one care to test this theory?

 

Seriously, I don't think there is a way to resolve this issue by 'tricking' the standard ECU by modifying external inputs. I think you'd need to open it up and 'blow' some EPROMS or something ... OK, I admit, I'm totally out of my depth now.

 

Thanks for the reply on the thread.

 

I can see how it has become very technical reading the thread from start to finish.

 

3rd gear ceiling is 130mph cricky.....

 

Its a shame that the car has this niggle, if I ever see that sort of speed I will definately be gentle with the throttle.

[Miguel]

I think you'd need to open it up and 'blow' some EPROMS or something ... OK, I admit, I'm totally out of my depth now.

 

I've always wondered if the Stock VVTi ECU could be cracked but never looked into it in any depth, one on the list of things I wished I'd done. Might be worth a chat with someone like Ecutek. I'm sure one of the resident ECU gurus on here could shed light on this too.

[wile e coyote]

I know of a spare ecu but they would prob need the car also ?

[Pete]

Easiest possible fix would be to possible interrupt the gearbox signals from the ECU?

 

If

If > 105 mph and receive a g/box change down signal then ignore it.

 

Of course I've no idea how the ECU and g/box communicates, on what type of signals or anything like that I'm afraid.

[wile e coyote]

So pete how do we go about sorting this ?

[Pete]

So pete how do we go about sorting this ?

I've given up.

Might return to it if I'm bored one day, but I've got so much on at the moment it's crazy. The Tiger is in bits too and needs re-assembling before I start any Supra tasks. Somethings to do on the ZR too. Never enough time!

[wile e coyote]

Ok mate i have emailed speedm8 to see if they can help out with the problems we got not holding my breath

[wile e coyote]

Ok this is the reply i got

 

Hi Darren;

 

Unfortunately, it is not possible to change how the converter works on your vehicle. In order to remove the top speed limit from the VVTi Tiptronic, you have to 'Freeze' the speed signal going in to the ECU at around 108 MPH. The ECU never sees the 112 MPH limit speed and so the limit is never applied. The down side to this is that the ECU also handles the gearing control and hence above 108 MPH, it is being supplied innacurate information regarding the vehicle speed.

 

Below the 108 MPH, the signal that the converter generates for the ECU is similar to the factory signal and so vehicle speed related operation should be as standard.

 

Our conversion for these vehicle is a cost effective solution and we advise customers of the possible outcomes when driving beyond the limit speed. If there is a 'kick-down' switch on the acceleartaor, it may be possible to disable this when the de-limit function is active. This would in theory prevent the gear changing at high speeds. As far as I am aware, the only other solution would be an ECU re-map.

 

I hope this clears matters up.

 

Best Regards

George Thomas

[wile e coyote]

I have replyed asking for any other options

[Pete]

I don't think there is a kick down switch on the VVTis due to the By Wire throttle is there? Not sure.