DTM-II Firmware "Update"

So a couple of Thursdays ago, I had some free time so I swung by Do-Luck.

The main reason was to receive an "upgraded" DTM II.

If any of you have recently bought the DTM II, don't worry - because I was one of few who had bought a very early model.  Most DTM IIs sold overseas, already incorporate the following change- if you bought yours through an authorized dealer, then you need not worry.

Ito-san told me that the change was necessary from early customer feedback. The issue specifically was that, on the racetrack during high speed cornering, the DTM II was too quick to activate and deactivate, due to the sensitivity of the onboard digital G-sensor.

So, the firmware was slightly rewritten so that the there was more of a "lag" in how the ATTESSA responded.  More accurately, it is not a "numbing" of the sensors but a reprogram whereby the unit now knows that, in certain cornering situations, to keep the torque going to the front wheels a bit longer, allowing the more average driver to better feel the ATTESSA doing its work.

Naturally, I asked Ito-san about future upgrades. He told me that, so long as you buy a DTM II from an authorized dealer, then the upgrades such as this one, which "refine" the product, will be free.  Any big changes to the programming - for example "maps" appropriate for certain racetracks, for example, may or may not be at nominal cost, however.

I don't have any pictures of the upgrade, which was literally a replacing of the circuit board on board my DTM II control box, for a new one.

The swap was done in literally five minutes - just access, then unhook the leads, pry off the old one, replace the circuit board, and tape it back into place.  Then teach the unit the closed and open throttle positions, and that was it!

Ito-san and I then popped open the hood (bonnet) of my car, and spotted some things that needed improvement...so we agreed that in the near future we'd have some work to do.

As for the improved DTM II - I really have to take the car to a track soon, or on the twisties, but I have at minimum 2 more mods I want to do before that...stay tuned!

Do-Luck's DTM II, Part 1 - The Installation

Courtesy of the Do-Luck Website: http://www.do-luck.co.jp/product/1452

In perhaps another world's first, I was given the honor of being one of the first R33 GT-Rs on the road to be fitted with the DTM II - Do-Luck's even more advanced G-sensor - now with throttle position input and being driver and tuner programmable as well.  (I am certainly the first to do a full write up in English, so I hope I get this all correct!)

To review, the Do-Luck digital G-sensor devices (both the Digital G-Sensor model and the Tarzan GBOX) replace only the OEM G-sensor, located under the center console in the RB26 GT-Rs.

The Do-Luck Digital G-Sensor

The TARZAN GBOX

The DTM II adds not only 7 different settings, (1 of which is user programmable and 2 others which are programmable by select tuners; and the user also is able to modify all the maps simultaneously) but also an organic EL display unit with 5 input keys and compact enough to be mounted almost anywhere in the car.  Installation is straightforward, but since a picture is worth a thousand words:

The very plain box the DTM II comes in

The contents of the box

 The first step is to remove the shift knob, shift knob surround, and ashtray, and then undo the screws holding in the center console, in order to access the G-sensor installation location.  In my case, in my effort to keep my car looking as stock as possible, I chose to install the EL display unit inside the console box (and thus chose to give up the ability to be able to read the real time G readings displayed by the unit).

Fits very well indeed.

Of course this means having to drill a hole for the wiring...

Once the console box is removed, step back and review the scene: In my case, as I had previously installed Do-Luck's Digital G-Sensor, the gold OEM analog box was no longer there.

The Red Arrow on the Digital G Sensor shows the direction it should be installed

A closer look

 Remove the old G-sensor. With my car, installation was easier than usual because I had already removed the OEM G sensor. (click on this link for my blog post showing how to).

Removing the Digital G-Sensor

And here is how the DTM II looks, installed

So slightly larger than the Digital G Sensor

 The next step is to wire in the throttle position sensor leads. The instruction manual simply said to "splice in" but when I asked Ito-san about this, he clarified that you cut a particular wire coming out of the ECU loom, and then one wire from the DTM II is connected to one cut side, and the other wire to the other cut side.

Found on gtr.co.uk...Refer to the Instructions... they will say "Throttle Output Signal" which is Pin 56 ( I think this is common to the BNR32, BCNR33, and BNR34, but please verify).

Once that's done, all you have to do is thread the lead under the carpet so it ends up under the main unit. 

So this lead connects to the DTM II main box...

Like so.

Wait? What's this? Two EXTRA leads? 

 That's right. Two outputs. There are three input/output leads, one of which connects to the lead coming from the throttle position. The others are labelled "OPT" and "LOG." The "OPT" one, Ito-san tells me, will soon allow control of the A-LSD (active LSD) found in the V-Spec models (he's working on how it can be done).  The "LOG" lead is for those who like to datalog what is going on in the car.  The unit produces variable voltage according to the front/back and left/right G-forces, and so if you can record that, then you can log this data.

Install finished! Quite easy. No messing around with anything that will get your hands dirty (i.e. perfect for me).  In my next posts, I will go into HOW the DTM II works, how it can be programmed and other details NOT mentioned in the install manual (that I've seen) and yes, my driving impressions (in a word, AWESOME).

Do-Luck's DTM-II, Part 2 - Initial Set-Up and the Settings, Explained

Once installed, the first thing you will need to do is ensure the DTM-II unit "learns" the voltage outputs for closed and open throttle positions on your particular car.

Here is a video clip where Ito-san and I demonstrate how this is done.

This shows that in my car, the voltage ranged from 0.4V at close to 4.1V at full open throttle. This is consistent with what's to be expected, as shown here:

Ok so now we're ready to roll... except you'll need to figure out which setting you want!

There are 7 settings for the DTM II: 4 in "G" mode (displayed as G1, G2, G3, and G4), and 3 in "ARX" mode (displayed as A1, A2, and A3).

Here is a video I shot (at night, sorry it's blurry - the actual device is super crisp and clear) that shows how to switch between the various settings.

Before I describe each of these settings, we first need to review what the DTM II device is doing. Recall that the ATTESA ECU bases its decision making on various inputs, 3 of which are, the car's longitudinal and lateral G forces (from the onboard G-sensor), and throttle position.

Here is a diagram showing the ATTESA map in 3D, showing just how G forces affect ATTESA output. The right axis is lateral acceleration, the left axis is longitudinal acceleration, and the vertical is amount of power going to front wheels.

Taken from the 1997 R33 GT-R catalog

The impetus of Do-Luck to develop its original Digital G-sensor was that due to age, the OEM G-sensors, which are analog devices (basically a pendulum in oil), were degrading to the point where the signals being sent to the ATTESA computer were inconsistent, slow, weak or non-existent, thus preventing the ATTESA from performing as it should.  And an OEM replacement cost somewhere around 130,000 yen and were still analog.  Digital G sensors are now commonplace (most smartphones have them), are inexpensive, ultra accurate, and fast. So it was only natural that the Digital G-sensor was developed.

Both this Digital G-sensor and the Tarzan G-Box, however, do not simply send back the actual raw G force data to the ATTESA ECU.  Both devices actually modify the signal being sent by multiplying the actual raw G reading by a pre-set variable (or set of variables, in the case of the Tarzan G-Box), which, as can be seen from the map above, means that the ATTESA is engaging faster than before because it believes that the car is experiencing higher Gs than it really is. As an example, if the car is actually experiencing an acceleration of 0.3Gs, but the Digital G-Sensor multiplies that number by a pre-set number, say 1.5, so the ATTESA thinks the car is accelerating at 0.3x1.5=0.45Gs.

In "G" mode, the DTM II is acting as a standalone G-sensor.  Specifically, in G1 mode, the DTM-II unit is outputting the same modified G signals as the Do-Luck Digital G-Sensor; in G2 mode, the unit is outputting the same modified G signals as the Tarzan G-BOX; however in G3 mode, the unit is outputting what the OEM unit would have put out when new (i.e., a "pure" unadulterated G signal).

G4 mode is user programmable - that is, the user can choose by what percentage each of the 4 (front, rear, left, right) G forces should be multiplied by, as sent to the ATTESA ECU. The user can choose an amplification between 0% to 200% for front, left and right G forces, but for the rear G force (i.e. braking), the amplification range is between 100% and 115%.

Here is a video where I demonstrate the G4 mode:

So what is ARX mode? Remember with the G mode settings, the raw G-force signal was amplified by a set variable.  In ARX mode, the throttle position comes into play along with the G-forces (however there must still be enough G-forces first, as throttle position alone won't activate ATTESA).  Further, unlike in the G modes where the raw G-force signal is essentially only "multiplied" by a set variable, in the ARX modes both the throttle signals and G-force signals are outputted according to a unique "map" (still based on the original ATTESA ECU map).  Ito-san explained that, rather than a linear output (where all the incoming data is mutliplied by the same variable), in ARX mode each data point is specifically associated with a specifically amplified (or de-amplified) data point which is then sent to the ATTESA ECU.

Ito-san calls A1 mode the "street" mode, and the A2 mode the "circuit" mode.  A3 mode is again a "pure" signal mode for both G forces and throttle position.

Speaking of throttle position, the user can also adjust the throttle position signal being sent to the ATTESA unit, as I show in this next video clip.

Note that I was getting tired and lost my train of thought at about the 2 minute mark, and mistakenly said that at 100%, I would get the "maximum of the ATTESA working to pull me out of the curve." Note this is only true if there are G forces in play as well, as noted earlier.

Also during the video at around the 3 minute mark, I referred to the Optional Map Edit, which refers to one of the two leads which the DTM II has.  Originally, the OPT lead (as shown below) was designed to hook up to the AYC in the Lancer Evolution cars (this unit works with them as well); however as I mentioned in my previous post Ito-san is working on using this to control the Active  LSD found in V-Spec 33 and 34 GT-Rs.

So that's pretty much it for now. I apologize if I left anything out or was unclear.

Finally, in response to a few questions that I have already gotten:

1) No, this unit will NOT allow you to switch to a pure rear wheel drive (FR) car.  Remember in 33s and 34s, there is always some power going to the front, so the only way to get around that is to essentially have a separate switch that cuts power to the ATTESA ECU. (but then you'll get warning lamps). Although I wonder what would happen if you set the front G force setting to "0" in G4 mode...(theoretically, that would mean no signal gets sent to the ATTESA unit, no? Maybe someone will tinker and find out!)

2) The difference between the DTM-II and something like the below, is that traditional ATTESA controllers only amplify the signal from the G-sensor. The DTM-II has its own G-sensor, and further allows for manipulation of the throttle signal.

3) Is it possible for the user to have another channel to self-program? No, however Ito-san has indicated that select dealers will be given the ability to change the programming found in A3 and G3 modes, giving users even more choices (e.g. a setting specific to a certain circuit?)

4) Is it possible to change the ATTESA "map"? No, because that map is onboard the ATTESA ECU.  However given the ability to send different and amplified G and throttle position inputs, it is possible to use only certain sections of that base map (e.g. the most aggressive portions), or distort the map so that the ATTESA unit's lowest/highest thresholds are raised, lowered or both.

In my next blog post, I'll post my driving impressions, as well as address anything else I left out! Leave a comment or question if you have one, thanks!

Do-Luck's DTM-II, Part 3: Some More Info and preliminary Driving Impressions

So I had a few minutes today to take the car out for a spin. Unfortunately, most of it was in stop-and-go traffic, so I was unable to fully explore what the DTM-II could do. I plan to take the car out for a spin in the mountains or track soon, after which I promise to provide a full report on the driving experience.

However, I was able to shift between the various settings, G-1, G-2, G-3 and A-1, A-2... and yes there IS  a difference, EVEN in city traffic. There is a marked delay in how quickly the ATTESA sends torque to the front wheels, for the G settings versus the aggressive A settings. Even amongst the G settings, I noticed that G-2 (Tarzan G-box) appeared to react the quickest.  However, it was in A mode where I saw the front torque gauge meter needle shoot up to the max of 50kg...in the other modes I saw the needle go up to 10kg consistently, which Ito-san had told me is about 30% power to the front.

Now, an addendum to my previous posts and the instructions.  While driving I realized that, perhaps hiding this device in the center console may be a waste for those of us who like to have interesting info displayed.  In fact, I am almost tempted to put this up on the right corner of my dash, next to the heads up display (I needed something to read speed above 180kph as I didn't want to change the speedometer).  This is because the device displays peak G forces, front, left, right and rear (and the right side of the two vertical bar chart), AND, on the left side of the two vertical bar chart, the real-time longitudinal Gs (as indicated by the "V") and side Gs (as indicated by the "H"):

Very entertaining to see what kind of Gs you can generate while driving...

So my next task is 1) to take the car on a fast drive, and 2) to play around with the driver programmable settings.  Apologies for the relative lack of information in this post, but schedule permitting I hope to be able to at least do one track day before year's end.

Next Steps at NISMO Omori Factory

So as I hinted in my previous post, Nismo Omori Factory technicians have now begun focusing their attention to the outside of the car - among other things, the wheels and tires!

And that's why the car has been on "borrowed" wheels and tires for the last few weeks. Although I have to admit, those NISMO LMGT4s look VERY nice on the car...

So I wonder what suspension the car was on while the Ohlins were being serviced...

The Ohlins DFVs, from what I understand, were removed from the car almost immediately after I dropped it off, and sent to Labo Carrozzeria to be rebuilt with the same specs as before.  A few years ago they let me tour their factory and I did a blog post to show how they do a rebuild!

So the coilovers came back quickly, in about a week... what took time were the TE37 wheels that were being refinished, fixing up some minor curb rash and the usual scrapes that come when you actually drive your car.

Damn. Gorgeous! And yes, a glass coating has been applied - both outside AND inside...

You may also have spotted the odd looking/colored valve stem. That's because they are a non-Nissan/Nismo part that Nismo Omori Factory actually agree to install - an aftermarket Tire Pressure Monitoring System (TPMS).   In fact they had an aftermarket one (made by Orange Electronic) designated a "sports model" (to allow for high inner tire temperatures) in a box when I visited, and were even kind enough to open it up for me to show me how it worked.  Unfortunately the screen display was a bit large and I've already got enough stuff (Blitz exhaust valve, Do-Luck DTM-2, ETC card reader, boost controller, heads up display controls) in the car already so I wanted something stealth.

So a few internet searches later I stumbled on this - a TPMS where the display is an app you download to your smart phone (either iPhone or Android).  I've actually already used an aftermarket one on my Lexus, but this displayed its output on a small screen that had to be installed in a blank switch location.

Of course, I have no idea if these work yet. Of course once I test them out, I will post the results! Fingers crossed...

Back to the wheels and tires... I was surprised when Ochiai-san sent me the following photo.  I had always thought that Nismo Omori Factory had tire changing equipment on premises, but for whatever reason they outsource to this guy who arrives with all of his equipment on a truck!

Look closely and you can see my name on the tire...

I know mobile tire fitters aren't a new thing (and in fact I need to find one to do the tires on my Lexus...) but I wonder how Nismo does the tires on their racing cars? And yeah, I ended up going with the Michelins, the price was TOO GOOD to pass up...

And talk about attention to detail! Or maybe they know me a bit too well...

Yep, blackened wheel weights so they don't stand out.

Oh and yes that missing ashtray? A long time ago I think I broke it like this when I tried to drill a hole in the back... I was experimenting with LED lighting of the ashtray and tried to get it to light up via the LED I had attached to the cigarette lighter ring. This was during my pre-Dremel days.  Buy the right tools, people!!

But guess what - new stock still exists for this part! So a new pristine one on the way! Cannot wait to get back into a car with an "OEM" look dash!

So what next? There is one more item I asked them to take care of but I haven't received any photos or messages on that yet. I'm also curious about whether we can get an alarm shop out to Nismo to help remove that crap alarm.  I'll keep you all posted of course...