Yes it pings no mater what
TRD says.
All most all of the people
that have installed the TRD supercharger on their 3.4 complains of
pinging, some more then others.
I think I have been one of the lucky ones and I never really
considered that I had a pinging problem.
It would ping on occasion and I could intentionally induce
it, but with my driving style it rarely presented its self.
There are two conditions
that will cause an audible knock or rattle sound from the engine.
One is detonation and the other is spark knock.
Detonation is a
condition that exists in the combustion chamber when the fuel/air
charge or mixture is ignited by something other then the spark of
the spark plug. This
can be cause by hot spots in the combustion chamber like carbon that
is glowing red and igniting the mixture.
It can be caused by excessive compression like in diesel
engines that generate so much heat the mixture just lights off.
Forcing lots of air into the engine with a supercharger can
also lead to detonation. I
am sure there is dozens of other things that can cause detonation,
but the important thing to remember here is that detonation is when
the mixture is ignited by something other then the spark of the
spark plug.
Spark knock is when the
spark of the spark plug ignites the fuel/air charge in the
combustion chamber sooner then is should.
If the ignition is to far advanced it can lead to spark knock
and you can hear the engine rattling like marbles in a coffee can.
There are things that can contribute to this like a lean
mixture, a faulty EGR system and probably a bunch of other things.
Again the important thing to remember here is the mixture is
lit by the spark of the spark plug, but just to soon.
Back
to Index
After a few years of
tinkering with larger injectors and tons of other things and with
the help of my friend Ron, we have determined that the pinging that
people complain about with the TRD supercharger is spark knock.
Here is how it presents.
While cruising along at highway speeds you come to a hill and
attempt to maintain speed, or try to accelerate a little bit.
It is not enough to unlock the torque converter or cause a
downshift and as you apply the throttle and the supercharger starts
to make boost and then you start to hear the engine rattling.
This seems to occur more in truck with manual transmissions
because they don’t down shift them selves.
This can make tooling along with cruise control very
annoying. This is when
you are in 5th gear or overdrive with the converter
clutch locked and the engine RPM is around 2000 RPM and you advance
the throttle into boost and you get the engine knocking and
pinging. I call this
the High Gear/Low RPM Ping or HG/LR Ping for
short.
TRD just denied that this
problem existed. Then
they came out with an upgrade we called the “ping kit.”
It included rerouted some vacuum lines and removing the Fuel
Management Unit (FMU). It
is my opinion that removing the FMU was a real bad thing to do as it
compounded the high RPM lean out problem I discuss under another
topic. Some
supercharged engines pinged so bad that the owners had the
superchargers removed in fear of serious engine damage.
The nice thing is that TRD did cover the cost of removal.
Back
to Index
There is some hope here.
A company called Split
Second was hired by TRD to do some development work on the
supercharger kit for the 4.7 Tundra V8. Apparently it also suffers from the same low RPM high gear
spark knock problem. Split
Second developed a device that retards the ignition timing in the
narrow part of the RPM band where the spark knock problem occurs.
As of this writing there is no information on whether or not
the Split Second device will be included in the Tundra supercharger
kit.
The nice thing is that the
very same device also works on the supercharged 3.4.
Initially the device was going to be available through TRD
for people that wanted to install it on their trucks if they were
having the HG/LR Ping problem.
For some reason TRD decided not to market the device under
their label. The lucky
thing here is that Split Second has seen a market for their device
and decided to market it under their own label.
They are calling it the TMC1.1 for Timing Map Controller
version 1.1. It is a
scaled down version of their TMC1.
Many of the features have been eliminated to reduce the cost
and simplify installation.
Installation is
straightforward and there are four wires that need to be spliced
into the ECU wire harness. A power, ground and then the signal wire from the crankshaft
angle sensor is cut and run through the device and then onto the
ECU. The device
modifies the signal from the crankshaft angle sensor to trick the
ECU into retarding the ignition timing in the narrow range where the
spark knock occurs.
This
is a picture of the TMC1.1 with the cover removed.
You can see the adjustment pot in the upper right hand corner.
Because some engines suffer
from the spark knock more then others the device has an adjustment
that lets you control the amount of ignition retard so you can dial
in just what you need to suppress the knock.
The original prototype unit
was installed on a supercharged Tacoma with a serious spark knock
problem. That truck
needed 9 degrees of retard to suppress the spark knock.
I received the very first production device and it came
preset with the 9 degrees of retard that was needed on the test
truck. I found that to
be way to much for my truck and that much retard caused the truck to
be very sluggish between 1500 and 2800 RPM where the device retards
the timing. Once the
RPM when past 2800 I got a big surge in power.
It was clear that I needed to reduce the amount of retard.
After a little test-driving I found that my optimum setting
was just a hair up from zero. Set
a zero as if the unit was not there it would ping and with just a
hair off of zero it does not. After
consulting with Split Second, that setting should work out to be
somewhere between 1 to 1.5 degrees of retard.
There is one thing that I do
not like about the TMC1.1. It retards the ignition all the
time and not just under boost where it is needed. I asked
Split Second to include a pressure switch that would be activated by
boost pressure like their ESC1, but it is just not going to
happen. I had some concerns about reduction in MPG with the
TMC1.1 retarding the timing all the time, but after a test it
appears that with the low setting that I am using there is not a
reduction in highway MPG. There does seem to be a very slight
reduction in normal driving MPG by about .5 MPG as far as I can tell
on my truck.
Now after years of denial
that the problem existed, and after a failed “ping kit” with the
removal of the needed FMU there is a real and true fix for this
problem. It is sad that
is not from TRD.
Back
to Index
