need help w/ST215W Caldina GT4 CoP ignition coils

[solrac]

I'm considering using the Caldina GT-T Coil-on-Plug ignition coils on a
different engine with an aftermarket standalone ECU setup to be able
to ditch the distributor-based single coil ignition of that engine.

To ensure that it would fit I'd need the following measurements:



A - diameter of the round section that seals the plug hole on the valve cover
B - height of the coil casing upwards from the edge sealing the plug hole
C - total length of the "leg" of the coil downwards from the edge sealing the plug hole
D - depth of the pit that electrically contacts the top of the spark plug
E - diameter of the "leg" of the coil at it's thickest
F - inside diameter of the plug hole at the top of the valve cover
G - depth from the edge of the plug hole to the top of the plug

When correctly measured, G should be equal to C minus D.
I would GREATLY appreciate if anybody could take the time and
make these measurements!!!

I would also appreciate any other form of help, like detailed
PHOTOS of such a plug or Toyota and/or Denso part numbers
as read from an actual plug, ideally along the model code/manuf.
date/chassis no. of the particular vehicle it was taken from.

Please help because it's rather hard (and expensive) to get such
coils over here so I really have to make sure that they will fit
without ever seeing one in real life before actually buying them...

[RunningRich]

I have all that info. What engine are you planning to fit them to? I'm fitting them to a ST205 3S-GTE.

What ECU are you planning on? Motec can drive then directly, while a Autronic SM2 needs an internal dwell board.

[RomanV]

If you can find a 'GT' Caldina instead of 'GTT', these also come with the coil pack ignition. Must be from the beams 3SGE engine though.

[strx7]

dont go with COP ignition, go with the likes of either MITSI or Mazda Coil packs, if you want lots of spark power, go with S4/5 rx7 trailing coil packs.

[fivebob]

If you're planning on using these coil packs then you need an ECU that allows you to set the dwell down to around 1.8ms, or preferably one that uses the 0-5v square wave signal they're actually designed to run on. Most aftermarket ECU's use a 12v (or higher) ignition trigger, and if you can't set the dwell low enough they overheat and stop working.

[strx7]

Most aftermarket efi systems can just use the toyota dizzy 'guts' as a pick up and just run 4 coil packs and plug leads.

[solrac]

RunningRich: I'm going to fit it into the ST185CS in my avatar, so it's
a 2nd gen engine with a 9 bolt 2nd gen head and valve cover.
Maybe tell me your measurements?
By the way, do they perfectly fit the ST205? As far as I could tell
both the Caldina head and valve cover differs from ST205. Neither
the ST215W nor Beams has ever been sold here in Europe so I
cannot just go to a scrapyard and take measurements... Most
probably I'm going to use a Megasquirt clone that is manufactured
locally here in Hungary. Not the best ECU in the world, but it's quite
versatile, affordable, and I would have relatively good support for
it here in town.

RomanV: thanks for the hint, in fact I've found that the SW20 9712-up
and the ST202 9712-up also have these coils, maybe 9712-up 3S-GE
automatically means Beams and having these CoP coils?

Strx7: Well, my project currently aims at 1.2-1.5 bar maximum using
a CT20B (1.2bar stock and later 1.5bar with upgraded compressor wheel)
which I'd call a small flowing turbo or maybe 0.8-1.0bar with some higher
flowing turbo later on, so I'm currently aiming at 320-350bhp at the
flywheel and at most 400bhp later on. I'm hoping that for this level of
performance I won't need a really powerful spark.
CoP seems to be a nice solution otherwise: get rid of hi-tension cords
(failure prone), get rid of distributor and external coil packs, and one
coil only needs to ignite one cylinder, not two or four. These are the
pros that come to my mind. The only con I've heard of so far is that
most of them are unable to produce a really powerful spark.
Why do you dislike CoP?

Fivebob: thanks for that info! I tried to g00gle up some info about
that ECU I'm going to use and it seems it can drive ignition coils either
with 12V or 5V outputs, and it can set a dwell even below 1ms.
Does this mean I will be able to drive such CoP coils properly with it?

[strx7]

Why do you dislike CoP?

Cause i've worked in the 2nd hand car parts industry for 6 years and COP ignition coils would be one of the most commonly requested items. with the coil sitting on top, it gets no cooling airflow, all the heat from the engine, all engine vibrations etc and all the factory coils that i've ever struck that are mounted on top seem to give issues for the above said reason We sell lot sof coils of this nature for vehicles that are only 5-8 years old, very very rarely do people request the mitsi & mazda type coil packs and there is a helluva lot of vehicles out there running them, alot over 15 yrs old and they are still going strong, as far as relibility goes you'd be hard pressed to find a more reliable factory coil set up.

[3SGEMAD]

im running a beams 3sge with factory Cop coils, running on megasquirt v3, gose well, (only on base tune) but coils work fine running up 10k rpm.

[Mr Revhead]

Cause i've worked in the 2nd hand car parts industry for 6 years and COP ignition coils would be one of the most commonly requested items. with the coil sitting on top, it gets no cooling airflow, all the heat from the engine, all engine vibrations etc and all the factory coils that i've ever struck that are mounted on top seem to give issues for the above said reason We sell lot sof coils of this nature for vehicles that are only 5-8 years old

i just HAVE to quote that..... for emphasis!
so true.

[solrac]

Cause i've worked in the 2nd hand car parts industry for 6 years and COP ignition coils would be one of the most commonly requested items. with the coil sitting on top, it gets no cooling airflow, all the heat from the engine, all engine vibrations etc and all the factory coils that i've ever struck that are mounted on top seem to give issues for the above said reason We sell lot sof coils of this nature for vehicles that are only 5-8 years old, very very rarely do people request the mitsi & mazda type coil packs and there is a helluva lot of vehicles out there running them, alot over 15 yrs old and they are still going strong, as far as relibility goes you'd be hard pressed to find a more reliable factory coil set up.

Well, all this sounds reasonable and also it's absolutely sure that you
as a dismantler have a much better overview about what's reliable
and what's not.

But!

1.) Is CoP also less reliable when you compare it to an entire oldschool
setup? I mean that it consists of the high voltage cords, the distributor,
the coil, the igniter and the ECU while the CoP setup consists of the ECU,
a low voltage wiring and the CoP coils. If you combine all the possible
malfunctions of the igniter, the coil, the distributor (like broken cap,
burnt rotor), and the high-tension cords (contact problems, insulation
problems) is it still more reliable than a CoP setup? Is it easier to
diagnose a problem with the old setup compared to a CoP setup?

2.) My car is not really an every day car and surely not a commuter car.
It's not going to be a race car either, it's mostly a weekend fun car.
I'm driving it around 15000kms a year. It's now 16 years old,
5 years later it will be 21 so for various reasons I might even not be
able to keep it on the road until then when the CoP coils are going
to fail. Maybe my engine will blow up 2 times until then or I crash
the car in a blast or who knows... Maybe I won't even be alive in
5 years...

3.) These CoP coils cost around NZ$150 each from Toyota brand new.
Is it so bad having to replace one or two after 5 years or so?

What do you think about all this?

[strx7]

you dont understand the set up configuration i've described. The only reason you use a dizzy cap in it, is to keep the dirt outta the dizzy. there is no rotor used you simply use the 24 tooth pick up and the home pick up to trigger the ignition system which uses either a 2 channel or 4 channel ignitior and 2 or 4 coils.

You should be able to pick up a 4G63 DOHC Coil pack and ignitor for say $85 2nd hand and I'd be suprised if you ever need to replace any part of it. Mount the coils somewhere away from all the heat, get a good set of plug leads and you're set.

[SUBARUCONVERT]

is there any acctual problem with using the factory ignition system, ive havnt herd many complain about stock gen2 3sgte ignition set ups

[strx7]

individual coils just gives you more things to play with ie, anti lag.

[fivebob]

is there any acctual problem with using the factory ignition system, ive havnt herd many complain about stock gen2 3sgte ignition set ups

Then you haven't been listening much

They commonly need the cap, rotors and leads replaced on a frequent basis. This is probably far more common than COP failures, but I don't have any data to support this. I do however wonder if a lot of the COP replacements are a "try it and see" approach when misfire problems arise.

Contrary to popular belief COP setups do provide better spark than distributor bases systems, especially at high RPMs. This is due to the longer coil saturation time that allows a stronger magnetic field to be built up.

Going to a coilpack setup like the Mazda or Mtisubishi setups removes the cap and rotor from the equation, but still leaves the leads and high tension voltage leaks. There is also the problem of where to mount them.

[Mr Revhead]

They commonly need the cap, rotors and leads replaced on a frequent basis. This is probably far more common than COP failures, but I don't have any data to support this

cap rotor and leads would be the most common thing sw20 owners buy off me!

that and new vanity mirrors

[SUBARUCONVERT]

hmmm, well once u replace the cap, rotor and leads, you will get an easy 80k from them. on my subaru i went backwards to what solrac is doing, i got rid of the standard subaru COP set up and went to bosch HEC71X coils and ran leads into the heads, hasnt missed a beat since

[fivebob]

hmmm, well once u replace the cap, rotor and leads, you will get an easy 80k from them.

Nope, not on a 3S-GTE, you could get as little as 10k from them, average seems to be about 40-50k

[solrac]

Well, thanks to everybody for the above information bits, apparently
all solutions have it's pros and cons, and your comments did have
valuable infos about that part, but I'm not seeking to decide it right
now which solution I'm going to employ.

The TTE race cars (the ST185/205 GR-A and Corolla WRC real rallye
cars) have employed two external coil packs, I could not determine
which car (if any) they have been taken from but they were series
production looking Toyota/Denso units. I guess they may have been
using wasted spark ignition. But the Corolla WRC has been first test
driven in 1996 while the first street cars with these CoP plugs have
appeared in 1997/8 (the Caldina GT-T itself I believe) so there may
not have been enough real world testing info available at the time
about that type of ignition. Maybe today if Toyota still had a car
competing in WRC they would be considering using CoPs.

The main topic here is that I would like to analyze whether those
Caldina CoPs fit my 2nd gen 3SGTE head or not. Obviously this
won't be the only deciding factor. I'll have to compare general
technical advantages and drawbacks, it's controllability by my
future ECU, expected diagnosability of problems, availability,
cost, and some other factors like cleaner engine bay.

So PLEASE if you can supply me with fitment info, the measurements
I've requested in my first post, or detailed photos of these Caldina/Beams
CoPs either in car or out of the car, or dependable statements about it's
fitment like "I've fitted it to my ST185RC and it's perfect" or similar,
please don't hold it back!

[strx7]

they wont bolt onto the 2nd gen cam covers as there is no provision for them. I have 3 of these coils at work i'll get the measurements next time i'm there if someone hasn't posted them before then