VVTi Tiptronic Speedm8 speedo converter

yeh thought that myself

Speedm8 is still the only solution to go faster than 180 km/h with tiptronic gearbox without any problem ?

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.

i was thinking of the same idea, what could be possible is to make a speed sensitive switch to operate at 105 mph this then could disable one or both of the gear change solenoids via a simply relay? I have not looked into this fully as yet but i know that the gear selection is controlled by just 2 solenoids, or fit a switch to disable the solenoid/s when going above 130mph or a system that uses a mixture of just modifying the speedo so that the traction controll doesn't cut in when going slow and the pps, spoiler all work fine then when you want to go faster than 130 throw the switch as a save guard, may seem like a pain to operate a switch every time you want to go above 130mph but for me i can count on one hand the number of times i done this in a year, hope this all makes sense. regards chris.

Speedm8 is still the only solution to go faster than 180 km/h with tiptronic gearbox without any problem ?

I may be reading this wrong, but even SpeedM8 has the same issue with kickdown on a VVTi.

It cannot be avoided from what I can see.

I may be reading this wrong, but even SpeedM8 has the same issue with kickdown on a VVTi.

 

It cannot be avoided from what I can see.

Go manual or buy a solaris from ryang as he says it works

Go manual or buy a solaris from ryang as he says it works

been manual, didnt like it one bit. Will stick with auto from now on.

did someone find a solutions for the kick down gear down problem ?

HKS make a speed delimiter that controls the Auto Solenoid and also hooks into the TCS 4 wheel speed sensors, 16 wires in all.

HKS SLD T6

http://www.soarerworld.com/forum/showthread.php?t=25447

Just giving this a bump for member

Dragging an old thread back from the dead, as there's some good info here on the Tiptronic high speed kick down issue here.

Am I correct in thinking that the only thing that the only thing that activates 'kick down' is the switch below the accelerator pedal?

If that is the case, then surely it would be possible to make a relay that isolates the kickdown switch at speeds above say, 110mph?

Am I correct in thinking that the only thing that the only thing that activates 'kick down' is the switch below the accelerator pedal?

Wouldn't that make life easier?

No. Doesn't work like that on the VVTi and electronic accelerator gubbins, it appears to be ECU controlled. It's been so long I looked at it I can't remember anymore.

[edit] like I said above.

HKS make a speed delimiter that controls the Auto Solenoid and also hooks into the TCS 4 wheel speed sensors, 16 wires in all.

 

HKS SLD T6

 

http://www.soarerworld.com/forum/showthread.php?t=25447

That does sound interesting with the solenoids, but I used to have one of these and it gave me other issues with flashing trac lights and such like. I forget now.

Wouldn't that make life easier?

 

No. Doesn't work like that on the VVTi and electronic accelerator gubbins, it appears to be ECU controlled. It's been so long I looked at it I can't remember anymore.

 

[edit] like I said above.

Okay, I would still assume that there is a wire(s) from the ECU that activates the gearbox solenoid to initiate kickdown. In which case, it can be isolated, it's just finding the correct one(s).

Surely someone like NOD or Heckler would be able to identify the correct one(s) with a bit of time and a rolling road?

Okay, I would still assume that there is a wire(s) from the ECU that activates the gearbox solenoid to initiate kickdown. In which case, it can be isolated, it's just finding the correct one(s).

I guess there must be.

B76 Pins 1 & 2? - http://wilbo666.pbworks.com/w/page/57949268/2JZ-GTE%20VVTi%20JZA80%20Supra%20Engine%20Wiring

It doesn't mention anything about shifting between 4th (od) and 3rd on 1 and 2.

It doesn't mention anything about shifting between 4th (od) and 3rd on 1 and 2.

Could be pin 3 or 6 with all the ???'s on. AFAIK the VVTi info from Supra was only released in Japanese. I guess it'll be a case of sourcing that and then translating to get accurate information.

That's your homework set for this week

B76 pins 7 and 10 look worthy of watching to me.

B76 pins 7 and 10 look worthy of watching to me.

7- Automatic Transmission Lock Up Solenoid

Anything with Lock Up in it scares me. I've no idea what one of these does.

A quick Google says:

Lockup solenoids are electronic components found in some automatic transmissions. These solenoids are designed to lock a torque converter in place under certain circumstances, such as highway speeds. This is done for a variety of reasons, including to keep the transmission from overheating and to improve gas mileage. When a lockup solenoid fails, the torque converter may fail to lock into place at highway speeds, or can stay locked up even after the vehicle slows down. This can result in poor gas mileage, the stalling of an engine, and other problems.

Not sure that can help us?

10- Automatic Transmission Over Drive Direct Clutch Speed Sensor

"can be used to improve shift timing and ensure smooth gear shifts" - but would it prevent a gear shift? I wonder what the ECU would decide to do if there was a high or no signal here.

I am no auto box expert, but I assumed "4th gear" was achieved by locking up the converter as well? I will be speaking to my auto box guy in the near future about something else, I'll ask him, he's a Volvo guy and some Volvos used a version of this box i think.

To be honest i have never experienced the problem with the VVTi auto box.

I've been pointed here by j_jza80. While not an expert on the tiptronic auto this 4th gear kick down was first brought to my attention on the V300 Vertex VVTi when Pete fitted his speedo convertor to his own car and the thing kicked down at 130mph on the dyno. My guess is that they never bothered to do autobox mappings or gearshift lockouts above 112mph because these vehicles were purely JDM. The Kick down is initiated by throttle angle delta and brut forced using the button under the throttle pedal. This button can down as many gears as it can without over rev. This doesn't have much intelligence as it will kick down two gears as long as it's within tolerance even if that is only 100 rpm before over rev limit for that gear.

But at the end of the day I believe the gears are still controlled by two solenoids. S1 and S2. Data logging of these solenoids and the lock up solenoid when this kick down state occurs would no doubt bare some fruit in term of a solution.

Looking at the tps, speed sensor and rpm signal and intercepting the S1 and S2 and lockup and preventing the ecu from shifting or unlocking the torque convertor when it's pinned would be quite straight forward.

From memory, HKS did a speedo convertor that hooked the shift solenoid and a the TRAC ecu to sort this problem out years and years ago.

http://z4.invisionfree.com/lexusaltezzaclub/ar/t13577.htm

Lyndon.

Thanks for chipping in Lyndon.

So you're convinced the HKS SLD II will solve this issue?

If I could get hold of one of these (I assume they're discontinued?), and paid you to fit it, would you mind me sharing our findings on here, so that a definitive guide to this issue is on the forum?

Thanks.

Edit: I've just ordered one from Nengun.

Some pinout info here for the Aristo VVTi TT, and the HKS SLD II

http://www.clublexus.com/forums/performance/192792-needs-instructions-to-install-hks-sld-speed-limit-defencer-type-2-on-aristo-tt.html

The SLD T6 is the one officially listed for Supras, but I assume this is for the earlier ones.

Off to rummage through my parts bin to see if I still have it

http://www.mkivsupra.net/vbb/showthread.php?13215-vvti-tiptronic-owners

Glad this forum has a better memory than I do:

http://www.mkivsupra.net/vbb/showthread.php?56403-VVTI-Speedo-converter-question/page2

Just plonking this here for reference...

Black : Earth

Red : Power

Lt Blue : Option car speed signal

Purple : Car speed signal 1 input

Yellow : Car speed signal output

White : Car speed signal input

Green : Solenoid A signal input

Orange : Solenoid A signal output

Blue : Solenoid B signal input

Pink : Solenoid B signal output

Brown : NCO signal input

Grey : NCO signal output

Attached: Official HKS PDF showing the switch position required (SA-6) from http://www.hks-power.co.jp/aftersupport/faq/img/sld/type2.pdf

Also T6 SLD for wiring interest. Note it hooks into the TRAC ECU too.

HKS_SLD_T6-sr20det.ru_.pdf

type2.pdf