Does the TOO SC use a mechanical or electronic boost controller? Can
you shed some hints on how the controller works?
Posted by NITRO on June 15, 1999 at 19:09:22:
The boost control is electric. We couldn't possibly do it via vacuum
or mechanically fast enough to really work.
The only way to actually adjust the boost is with the unit that makes
go from NA to boost from the get-go (the bypass valve.)
Ours is a patented rotary piece that has four windows. The valve is
stationary when at max boost or no boost. We spin the valve to adjust the
boost to virtually anything we want. The motor and bearings are very efficient
and the mass of the rotation valve and the armature are very low and therefore
the inertial is also low, allowing almost immediate reaction time.
TOO's just finished a project he began 10 years ago. The chips from
Burr Brown were finally released for us to use exclusively.
The unit's function is to measure both cylinder pressure and cylinder
wall deflection. The sensors produse a small electric current, which is
converted to a digital signal prior to transportation from the A/D box
to the cockpit processor via shielded coaxial cable. The processor compares
the digital code with the crank angle and rpm, as well as manifold pressure
/ throttle angle. It can provide more fuel by lengthening injector duty
cycle, control timing, lower boost,etc. It works in addition to the SafeGuard
which is still used as a detonation back up.
The sensor system will allow the engine to run at maximum boost until
it's reading undesirable data, then it'll automatically adjust tuning and
roll down boost and keep the engine a maximum power level with maximum
safety. Have your cake and eat it too?? Pretty much so.
Frank's got some pics of the first Honda in-car adaptation, so you
might see if he can send you a pic or two. The coaxial cable hadn't been
attached in the photos.
Yes, it'll be standard equipment with our "system".
I might mention that since we've patented almost every concievable
way of doing this, we believe that from innitial response by the OE's,
this little jewell will easyily become the largest volume seller we've
ever had.
It's a unique little gadget and it can also be installed inside the
blocks, so people can't mess with it.
Wow, very interesting! Why didn't you guys use sheilded twisted pair wires instead of coaxial because they aren't susceptible to RF inteference. What resolution are you using (# of bits) for the analog to digital converter? I'm assuming your using a multiplexer with the AD and using pulse width modulation to control the motor events. I hope you guys are clamping your voltages when reading your sensors because minute mV changes can happen due to RF and induced flux from the ignition leading to false reads. Is your boost sensor an absolute referenced solid state pressure sensor? Lastly, what kind of microprocessor are you guys using?
OBTW, what do you mean you have the boost controller mechanism is inside the block?
The pictures of the typeR prototype (Frank's TOO page) doesn't seem
to have the boost controller in place nor is the final prototype conception
(the SC blowing directly into the manifold) the same as in final prototype
in the R. Instead the picts. of the R show the normal JR configuration
of the intake manifold, what gives?
Posted by alloy_625 on June 16, 1999 at 19:23:17:
Hey zip, just a couple of comments. For a single output sensor, coax
will typically be superior due to the symmetrical construction (closer
to ideal L/C characteristics) and superior shielding in general compared
to garden variety cat3/5 cabling. Twisted pair is cheap, has low loop inductance
(due to close coupling of signal and return) and is easy to terminate.
You can shield multiple twisted pair runs, but then you have coupling between
runs. Really low noise stuff is sometimes done with triax, signal, return,
and ground. Also, voltage clamps are to prevent spikes and other macroscopic
noise from fouling up the input circuitry (some amps don't like to see
voltages near the rails let alone power surges), not reduce noise. Noise
reduction is a function of layout, shielding, input filters, and low source
impedance (for voltage output) among other things.
While there is a fair amount of EMI in a car, lots of other simpler
things can kill you first.
Posted by zip on June 17, 1999 at 14:27:19:
Just reread my post and yes your right voltage clamping is used to prevent
CMOS from going over their threshold value. Using coax is kind of archaic
because why would risk getting false positives from the sensors, just look
at LAN lines they now shying away from "vampire" lines and using the cheaper
and cleaner twisted pair. As for noise reduction you can run your digital
signal through an inverter using a Schottky barrier diode and a Schmitt
trigger. As for EMI in the car their are lots of it...trust me...if you've
ever reversed engineered a HONDA ECU they have various shielding and filtering
techniques to "clean" the signal as best as possible so the microcontroller
knows what's really going on. As for analog filtering hmmm....
Voltage clamping: for CMOS (most of which has ESD protection), you do need some sort of clamp as higher voltages (15V+) can break down the gate. However, various analog circuitry (whether FET/BJT/MOS) may also need clamping as certain overvoltage conditions can cause latching or even breakdown which in general is bad.
TP is used for network stuff because the format is differential; the construction is inherently better for that as it is balanced. It still radiates a lot compared to coax though which is why these electrons are going through a fiber from my office... Also, coax is very expensive. Compared to inexpensive insulation and solid core wire for TP, high end coax has foamed/solid PTFE dielectric, silver plated copper center conductor and a braided/foil shield and that's just the garden variety stuff, not the exotica from Gore for 20+ GHz stuff. Look inside any high-frequency stuff and you'll find some coax along with $$$ SMA/SMB connectors or god forbid Kamac/Lemo. Depending on the sensor design, some form of balanced conductor might be more ideal, but in a high noise environment, some form of shielding is still required.
Now as for this digital noise stuff, sure you can run signals though Schmitt triggers to clean up a little bit of noise and get clean edges, but if you have a couple of volts of ground bounce due to sloppy layout, nothing is going to save you. That schottky diode ref must be to LS TTL which has long been superceded for fast stuff by some form of alphabet soup like *HCT. Consider the noise margins for high speed digital vs as you stated mV or uA outputs from a sensor too.
Front end filtering for an ECU or any other piece of well designed equipment
is analog. I think we agree here, but I'm not sure. I've never taken a
Honda ECU apart, but I'd hope it had a lot of ferrite beads or R(L)/C filtering
on the front end.
Posted by NITRO on June 16, 1999 at 08:37:44:
We have yet to show the electronic valving with the new system in any
photos. The Frank Pics were the final configuration with the M-62, and
while there are a few similarities, a lot has changed.
One reason that we've been protective of this is the fact that nobody
has actually researched the technologies and patented them. As with the
"Soft Head" technology, TOO's always said that he's not going to give away
the farm for publicity or magazine articles.
On the cable, the easiest method during all the years of testing has
been the coaxial units. There are a number of other lines available, should
they be needed.
As for the processor, it now does the traction control, as well as
the other "controls" mentioned previously. I'm really not at liberty to
discuss all or any of the electronic details at the present.
The Honda open deck doesn't relate to what we're doing, however, should
the pressure be to high, or the cylinder flex, the proper action is taken
immediately.
We can plant the sensors directly in the water jacketing, or run them
externally as in the pics. For the aftermarket and testing purposes the
external mounting is the ticket, but the internal mounting is simply an
option designed for OE applications.
There will be more information regarding all this shortly.
Posted by zip on June 17, 1999 at 14:10:15:
Those sensors have been drilled into the cylinder walls. I hope that's
only needed for prototyping purposes.
Occasionally a few prototypes are made to be easily accessable and are
therefore somewhat "ugly" in configuration. People have wanted to "see"
the early stuff and we have made that possible. These particular units
are actually quite friendly, as we can easily reconfigure certain components
with minimal fuss. The fact that they do indeed pass through the outer
block wall and the water passages on their way to the cylinder is a case
study in itself.
TOO has even placed cooling fins on them so they can easily radiate
heat to the coolant rather than causing hot spots.
There are several other mounting combinations, which are already undergiong
tests as I speak. Rest assured that OE manufacturers don't want to drill
holes in their blocks either, so there shouldn't be too much alarm at what
you see.
If you ever saw some of our cylinder heads during rework, you'd say
we'd ruined them. As TOO says "We have to make them ugly before they get
pretty", and it's true. That's one reason we do not show sequences of "how"
we get from here to there. People'd think we were butchers!
Follow ups will be coming shortly on the picture front and the system
will not scare people so much.
Keep in mind that one of TOO's other great passions is high end stereo
systems. He has years of experience designing and building D/A converters
for several high end manufacturers. I won't go into what his reference
"system" cost, but it's safe to say that it cost more than his 5500 square
foot home.
He spends days listening and measuring sounds that are so delicate
and tiny that his dog is the only other one that can hear it. He tunes
systems with cable that's made of terribly exotic materials in various
countries and I know that some of it runs over $10K per 8' run. I'll not
get involved in a lot of EE jumbo, but TOO is a degreed audio engineer
and a degreed audiophile His designs are known world wide by high end buffs
and companies he works with, so it's safe to say that he's picked certain
components for a reason rather than the fact that they were simply "on
hand".
I used t shake my head at the money spent, but I now agree with him,
cable does indeed change in sound presence as it breaks in and cable is
very much unidirectional as well. It may be smoke and mirrors to some,
but the difference is cetainly audible.