So for the past few years I’ve heard about, read about, and
researched this ignition device:
The Okada Projects PlasmaDirects - described as a
replacement for the stock coils, but with increased performance, as described
here on the
Okada Projects USA website and specifically for the R32/R33 GT-Rs, here on the
dedicated Okada Projects (Japan) website.
Here are some graphs taken from the Japanese Okada Projects website showing:
1) Difference in spark energy (black is stock, red is PlasmaDirects):
 |
| Normal spark |

Spark is twice as powerful |
|
2) Showing reduction in ignition noise
 |
| Showing noise |
 |
| Reduction in noise |
3) Multiple discharges
 |
| Only one discharge |
 |
| Multiple discharges |
For the R33 and R32 GT-Rs, as the amplifiers are contained within each of the Okada coils themselves, the PlasmaDirects, in addition to having more spark energy and multiple spark discharge, also do
away with the transistor unit, which, being susceptible to
early degradation due to the heat of the engine, is often a cause of ignition
problems.
Here you can see the transistor unit, it's the grilled silver metal box on the back of the coil cover:
The Okada product itself seems similar to the direct
ignition coils sold by Splitfire, which are priced less. Much less. While
normally that would be an attractive proposition, I had heard and read about
problems associated with this brand. And so, having spent LOTS of money for the
Mine’s engine, there was no way I was going to risk being cheap this time.
Research on the Okadas revealed either glowing reviews (all in Japan with
GT-Rs) or “blah too expensive, not much difference” write ups on English
language forums (for various other vehicles). But in any case, no reports of
problems associated with the part.
Here ares some of those Japanese links:
Consistent with my goal of bringing my car into the 21
st
century, one thing I’ve wanted to do with the engine is to improve its
efficiency, but maintain its performance. In the past, I messed around with a
homemade
“ram-air” system which I (placebo effect?) honestly believe made a slight difference
in engine sound and pick up, but have not, to this date, experimented with
spark or fuel. And when I say “efficiency”
– I am talking about gas mileage, cleaner burning, fewer hydrocarbons produced
(standing behind my car with the engine at idle, one notices how poorly the
fuel is burnt – especially as I think the sport catalytic converter may be on
its last legs…)
So, having also asked around (and as my friend Thomas Mangum
installed a set without any apparent problems), I decided that the next step
would be these PlasmaDirects. Especially as he claims to run NO catalytic converter,
yet his exhaust is not as “stinky” as mine!
Hence I began searching for the best price I could get on
the Okadas, but soon discovered that well known tuning shop
Jing TechnoEngineering (aka simply as "Jing-R") – claimed to sell an improved version of the PlasmaDirects - having done something to the circuitry to improve upon the originals (unfortunately, their asking for price for their unit negated any discounts I could find). Exactly what Jing-R did so is not stated
anywhere, but the differences in this "kai" (
改) version are supposedly
as follows (translation below):
“Using the Okada as the base, Jing-R has pursued the basics
of improvements in acceleration, response, and boost onset. By increasing the number and strength of the
spark, and changes to the timing, we were able to make following
tangible improvements:
1)
Improvement to response
2)
Improved acceleration
3)
Improved boost onset
4)
Reduction in percentage of carbon build up
For 1-3, normally upon acceleration, needed
additional fuel is injected into the cylinders, resulting in a high
concentrate of fuel, but not all of it can be burned during acceleration and
this unburnt fuel is can be seen as black smoke expelled from the exhaust.
With more efficient combustion due to the PlasmaDirects, there
is an increase in combustion pressure, which leads to quicker onset of boost,
and faster acceleration. As there is now
more combustion pressure, there will be a change in the exhaust note.
As for 4), with a reduction in the percentage of carbon
build up due to more complete burning at all engine rev levels, the life of the
O2 sensor will be extended, and there will be less carbon buildup in the
combustion chamber, the pistons, piston rings, and valves.”
Anyway so that is the theory. Just how different the
standard PlasmaDirects are, compared to this Jing-R version, will probably be difficult
to determine, unless someone has driven the same car back to back with both
versions. I found that for the price
difference, and given all the glowing reviews I found on Minkara about the
Jing-R version, that I would take a chance and go with this version - figure any little bit extra to help, right?
So anyway, had a few spare hours today, and the weather was right, so went down to the garage and did the install - but not before taking the car for one last spin to provide a baseline for comparison.
Stay tuned, my next write up will be on the install process, and then my impressions afterwards after I took the car for a spin.