DIY Traction Control

Tue Apr 9 05:12:58 GMT 2002

It is great to hear from direct experience.

Mike D.
----- Original Message -----
From: "Bruce" <nacelp at bright.net>
To: <diy_efi at diy-efi.org>
Sent: Wednesday, March 27, 1996 7:27 AM
Subject: Re: DIY Traction Control

>
> Once in wheelspin with a healthy v8 20d wasn't hardly enough to stop it.
It
> took a 1 in 7 and 1 in 5 cylinder firing defeat strategy.
> The trick is stop the wheelspin before it gets out of hand.   At least
with
> the simple stuff I was working with
> Bruce
>
>
>
> ----- Original Message -----
> From: "Perry Harrington" <pedward at apsoft.com>
> To: <diy_efi at diy-efi.org>
> Sent: Tuesday, March 26, 2002 3:15 AM
> Subject: Re: DIY Traction Control
>
>
> > I was thinking about traction control on my Mustang.  Since I have
> > a Crane HI-6 that can pull out 20 degrees via a boost reference (simple
> > analog input), you could use that retard to do the same thing commercial
> > traction control does.
> >
> > You would use the abs sensors to read wheelspeed, simply compare the
> pulsewidths
> > of the front and rear wheels.
> >
> > Simply retard the ignition based on the percentage difference between
the
> > sum of the front wheel speeds vs the rear wheels.
> >
> > --Perry
> >
> > On Thu, Mar 21, 1996 at 03:08:04PM -0500, Bruce wrote:
> > >
> > >
> > > I'd first tackle things a bit differently.  You way seems to really
beat
> on
> > > the engine.
> > > I'd start with a timing and fuel map, that is referenced to TPS, and
VSS
> (of
> > > a none slipping wheel).  It would be just enough timing and fuel to
> possibly
> > > haz the tires, and then use the Traction Control to fine tune that set
> of
> > > maps with some feed back.
> > >    With a displacement of 1.8L that would seem to be a 4 banger,
> dropping
> > > one cylinder is going to be like a 30+% drop in power, which is alot
> > > Bruce
> > >
> > >
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "Jorgen Karlsson" <jorgen.m.karlsson at home.se>
> > > To: <diy_efi at diy-efi.org>
> > > Sent: Thursday, March 14, 2002 6:53 PM
> > > Subject: RE: DIY Traction Control
> > >
> > >
> > > > Hi,
> > > >
> > > > Lets assume that you have a turbo car with no catalytic converter.
> > > >
> > > > I think that we want to keep the boost as high as possible even when
> TC is
> > > > doing its job, this would require us to alternate between cutting
> sparc
> > > and
> > > > fuel.
> > > >
> > > > Cutting spark will limit power and send raw fuel out into the
exhaust
> > > > manifold where it will ignite, this will cause very high exhaust
> > > > temperatures and lots of exhaust energy that drives ther turbine.
> > > >
> > > > Cutting fuel will limit power and will not provide any energy that
> drives
> > > > the turbine.
> > > >
> > > > Changing spark timing would be nice as it can act like something
> between a
> > > > cut spark and a normal combustion. It will provide some power and a
> bit
> > > more
> > > > exhaust energy to drive the turbine. But lets stay away from that
for
> now.
> > > >
> > > >
> > > > If we want to do this right we need to know: if the clutch is
> released,
> > > real
> > > > vehicle speed, driven wheel speed, Boost, throttle and exhaust
> > > temperature.
> > > >
> > > > The exhast temperature tell us if we can cut spark without melting
the
> > > > manifold or the turbine.
> > > >
> > > > The throttle position can be used to tell the system what boost
level
> we
> > > > want to keep when the TC is working.
> > > >
> > > > The boost tell us if we need can cut fuel without letting the boost
> drop
> > > to
> > > > much or if we need to dump some fuel to keep the turbo spinning.
> > > >
> > > >
> > > > Example.
> > > > Car:
> > > > Honda civic FWD, manual, 1.8l, turbo, no cat, lots of power.
> > > > Maximum boost 1.2bar gauge, maximum exhast temperature 1800oF.
> > > > We want to optimize this car for streetracing on low profile tires,
> this
> > > > mean that we can let the exhaust gas temperature get as high as
1800oF
> and
> > > > that we will have our share of traction problems.
> > > >
> > > > We want to keep the boost above 1.0bar if the EGT permits.
> > > >
> > > > A two step rev limiter will simplify the starting procedure a lot on
a
> FWD
> > > > dragrace car and that function is best built into the TC box too but
> we'll
> > > > ignore that for now.
> > > >
> > > > The TC is not activated until the clutch is released and this occurs
> when
> > > > the speed is high enough to keep the engine above 5k. Because of the
> TC
> > > the
> > > > throttle is floored until we reach the finish line.
> > > >
> > > > The front wheels lose traction at once and are spinning 70% faster
> then we
> > > > want them too, EGT=1300, BOOST=0.5. This tell us that we want to cut
> lots
> > > of
> > > > power, we want more boost and the EGT is very safe. We try cutting
40%
> > > power
> > > > by running this sequence:
> > > > no spark, fire, no spark, fire, fire.
> > > >
> > > > After a few cycls of this we find:
> > > >
> > > > 30% wheel spin, Boost 0.8bar, EGT 1350(probably sensor lag.)
> > > > Need to decrease power a bit, Boost still to low, EGT still safe.
> > > >
> > > > We don't want to cut one spark after an other because we pay our own
> > > turbos
> > > > and are forced to run this sequence (40% of total power):
> > > > no spark, fire, no spark, fire, no fuel.
> > > >
> > > > After a few cycls of this we find:
> > > >
> > > > 5% wheel spin, Boost 0.9bar, EGT 1400.
> > > > Need to increase power a bit, Boost still to low, EGT still safe.
> > > > We jump back to the 60% power sequence:
> > > > no spark, fire, no spark, fire, fire.
> > > >
> > > > After a few cycls of this we find:
> > > >
> > > > 15% wheel spin, Boost 1.1bar, EGT 1450
> > > > Power is ok, Boost higher then needed, EGT still safe.
> > > > We modify the 60% power sequence:
> > > > no spark, fire, no fuel, fire, fire.
> > > >
> > > > After a few cycls of this we find:
> > > >
> > > > 15% wheel spin, Boost 1.2bar, EGT 1500
> > > > Power is ok, Boost high enough to open the wastegate, EGT still
safe.
> > > > We modify the 60% power sequence again to limit exhaust energy:
> > > > no fuel, fire, no fuel, fire, fire.
> > > >
> > > >
> > > > Depending on the amount of wheel spin compared with the current
engine
> > > > output we decide the amount of power we want to try next time. The
way
> we
> > > > decrease the power is decided by the boost level unless the exhaust
> > > > temperature is to high.
> > > >
> > > > Power to high>cut more cylinders.
> > > >
> > > > Power to low> cut less cylinders.
> > > >
> > > > Low boost> cut more spark and less fuel.
> > > >
> > > > High boost> cut less spark and more fuel.
> > > >
> > > > High EGT> cut less spark and more fuel.
> > > >
> > > >
> > > > The software pick the right power level depending on wheel spin and
> the
> > > > right sequence depending on boost and EGT.
> > > > Sequences suitable for a four cylinder engine:
> > > >
> > > > 80% Power
> > > > spark, fire, fire, fire, fire
> > > > fuel, fire, fire, fire, fire
> > > >
> > > > 60% Power
> > > > spark, fire, spark, fire, fire
> > > > spark, fire, fuel, fire, fire
> > > > fuel, fire, fuel, fire, fire
> > > >
> > > > 40% Power
> > > > spark, fire, spark, fire, fuel
> > > > spark, fire, fuel , fire, fuel
> > > > fuel, fire, fuel, fire, fuel
> > > >
> > > > 20% Power
> > > > spark, fire, spark, fuel, fuel
> > > > spark, fire, fuel, fuel, fuel
> > > > fuel, fire, fuel, fuel, fuel
> > > >
> > > >
> > > > This system would only need an rpm input to allow it to double as 2
> step
> > > > revlimiter, launch control, flatshift, ALS and ALS cooldown idle
> control.
> > > > All of them very cool functions.
> > > >
> > > > Comments are welcome!
> > > >
> > > >
> > > > Jorgen Karlsson
> > > > Gothenburg, Sweden.
> > > >
> > > >
> > > > ----- End of forwarded message from owner-diy_efi at diy-efi.org -----
> > >
>
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> >
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> >
> > --
> > Perry Harrington             Linux rules all OSes.               APSoft
> ()
> > perry at apsoft dot com                  Think Blue. /\
> >
> > Those who would give up essential liberty to purchase a little temporary
> safety
> > deserve neither liberty or safety. Nor, are they likely to end up with
> either.
> >                              -- Benjamin Franklin
> >
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