It starts at 5Krpm and I tried lowering the dwell, which made it worse

 

With this talk about ignition coils, i've been doing some research.

whats more important, spark energy (mJ) or Voltage generated (kV)?
What advantages does a coil that makes 40kV and only 30mJ have over a coil that is 30kV and 100mJ?
Does a longer spark duration have any benefit to torque and economy?

Is comparitive dwell time directly proportional to spark energy?

i.e. if a coil takes 5ms to charge (at a set voltage), will it have double the energy of a coil that takes 2.5ms to charge?

Cheers, Mike

 

Voltage and spark energy are both important.
- Voltage required is dependent on the setup, which includes cylinder pressure, plug gap, etc.
- Think of spark energy as area under the curve or voltage applied over time. Spark energy will improve combustion efficiency

I would have to compare a bunch of coils, but dwell time is likely dependent on coil design. Dwell time is probably more important to make sure you don't exceed allowable dwell for a high rpm application.

 

Some interesting ignition info i found, might be of interest/use to you

http://www.dtec.net.au/Ignition%20Co...alibration.htm
http://www.dtec.net.au/Ignition%20Co...%20Testing.htm
http://www.dtec.net.au/Multi%20Spark%20Ignition.htm

Do you know if the Denso Pencil coils are all the same strength?
E.g. the Honda K20A coils and the Toyota Echo/Prius coils are both made by Denso.
The Toyota coils are more expensive to purchase.
I would assume that Denso would just make the internals all the same, and just change the bodies.

Cheers, Mike

 

Just my $0.02 on coils.

I believe newer cars that are setup for stratified combustion and lean burn operation have stronger coils then most others. Lean AFRs at high cylinder pressures are the hardest mixtures to light and those engines have both of those attributes going on so a strong coil are very important on them. As such, I think some of the strongest coils out there are probably in the place you would least expect them from a performance perspective.

Spark energy and voltage need to be considered almost separately. Voltage will help insure the spark forms in the first place. High cylinder pressures would be the highest concern there. Spark energy on the other hand while is an "area under the curve" you can have two very different curves with the same total energy under them.

For example, take a 50mJ coil that discharges in 1ms and another 50mJ coil that discharges in 3 ms. The first coil delivers that 50mJ quicker, and with more power then the second coil. As long as it hits fuel and nucleates a combustion event, you are golden. High power means a hotter arc temperature which is more likely to light the mixture if it hits fuel. The second coil has a lower power and cooler arc, but is going for 3X longer so it's more likely to hit fuel. Provided it has a hot enough arc to light the mixture, it will do the job just as well.

Short burst, high power coils are better IMO as you are going to hit fuel on a high power turbo 4 cylinder almost without question while under heavy load. The question is, are you going to have the voltage needed to ionize the arc path in the first place and is it going to have enough power to nucleate the combustion event by having a hot arc temperature.

The Denso coils having a shorter discharge time is not really a disadvantage under boost, IMO. It is a disadvantage while trying to cruise down the free way at 1.2:1 lambda AFRs on E85 where the longer spark duration will greatly decrease the chance of the arc not hitting fuel.

 

Great info.

Do you know of all denso coiks are created equal?
E.g. toyota vs honda oem coils

 

I highly doubt they are all equal by any means.

With in a given OEM manufacturer, and on similar applications, they are probably the same. I wouldn't expect the coil in a 14:1 compression DI motor in a car hitting 55mpg to be the same coil as the run of the mill 10:1 V6 family sedan.

Here is what Bosch offers...
http://www.bosch-motorsport.de/conte.../html/2847.htm
You can see, they have coils designed for very different puproses...F1 to DI gas sippers. If you look around, you can find the same coils on European applications. There are some nasty coils on there, some even have ION sensing capabilities.

I thought I had found similar specifications for Denso coils at one point, but I searched around quite a bit recently and never came across anything.

 

http://www.sytyperformance.com/index...hk=1&Itemid=26

Will this flange clamp to the discharge / outlet side of the tial v44?

 

I have a pte 5830 with that exhaust hsg...will be interesting to see results! thats alot of cutting / notching. I build manifolds for a living, i would do a long runner tubular any day over this...too much work :-P

 

also in the tial v44 which spring do you suggest I try first so that: the valve wont open with top port only vacuum, but will open really easy with bottom port boost combined with top port vacuum? once its open I will be requesting it to be held open with a boost accumulator (sas project)

1 bar?

 

It fits on the inlet side so you can mount the wg as a bov on aluminum piping

 

i think i ended up at 7psi.

 

UPDATE:

I have been working on plan B for the ignition system and will post pics soon of the new COP setup I am putting together. It requires that I machine the inside of the valve cover, but it is going to work and will supply 120mJ of spark energy.

Another item on my radar is figuring out this auto tranny swap. I performed the auto swap on my Z so I am familiar with digging through tranny manuals trying to understand what transmissions have the best parts. On my Z I used the L4N71b from both the Maxima and Starion to join parts that supported 500+ ft/lbs@wheels and 130mph quarters.

Here is what I have found so far. AWD transmissions compatible with the 4g63 are the W#a#x, but there are many different versions. The EVO 7 trans is the W5A51-3-DZH and the EVO IX wagon trans is the W5A51-2-D1Z. If we look the work of ER they are using the W4A4B-4-R2Z, which is in the same family.

A W4a5x is stronger than a W4a4x is stronger than a W4a3x. I did find a W4a51 AWD tranny compatible with the 4g63, which was used on the Mitsubishi RVR. You can check out some pics at the following link.
http://carbonus.ru/detail/yok-2613181/

I will be ordering some manuals, but it is my intent to figure out this swap and optimize the best parts available from Mitsubishi. Don't expect an answer soon, but I will get heavy into the swap early next year so I have a few months to do my research.

 

These coils are from Bosch Motorsports and are the P100-T coils. I will provide detailed information regarding the machine work required along with drawings of the mounting plate. Information on these coils can be found below...
http://www.bosch-motorsport.com/pdf/...oil_p100_t.pdf

 

so is that to say you gave up on the ZR1 coils?