Wasted Spark Ingnition

[Bennett]

Ok scap my last post, my cooler pipe came off and i didnt know. Cars still missfiring though. Will changing the dwell time of the coils on the power fc affect this missfiring?

[mazda_feen]

can someone tell me the length of each HT lead when the coil is mounted on the firewall above the back of the motor?

thanks!!

[**RB2530**]

Hey all,

On the subject of wasted spark ignition I am thinking about making my own ignitor (I have an R33 S2 with inbuilt ignitors)...

I was gonna use 3 N-ch power MOSFETs as the power stage..Each of the 6 ECU ignition inputs would be coupled with small signal diodes...

Has anyone done this before????

[fr0st]

Hey all,

On the subject of wasted spark ignition I am thinking about making my own ignitor (I have an R33 S2 with inbuilt ignitors)...

I was gonna use 3 N-ch power MOSFETs as the power stage..Each of the 6 ECU ignition inputs would be coupled with small signal diodes...

Has anyone done this before????

Ignitor outputs will be pull downs, so they pull down to ground to charge the coil and then float again to trigger the spark.

To trigger the Fets reliably your going to have to pull the gates to 5v to charge and then ground them to float the coils and trigger the spark.

My advice is make an inverting buffer using discrete BJT's, use this to pull up and down the fets as fast as you can. You will probably only need a single FET, they'll be running at very low duty and will barely make any heat if switched fully on.

Keep in mind if your using aftermarket coils they will probably have a higher inductance than stock so they take longer to charge. Only way to really solve this is to raise the input voltage to the coil when its charging or by increasing the charging time. If your using the stock ECU you can't so the latter, but pulling off the former is feasible with a bit of DC-DC conversion.

[**RB2530**]

Ignitor outputs will be pull downs, so they pull down to ground to charge the coil and then float again to trigger the spark.

To trigger the Fets reliably your going to have to pull the gates to 5v to charge and then ground them to float the coils and trigger the spark.

My advice is make an inverting buffer using discrete BJT's, use this to pull up and down the fets as fast as you can. You will probably only need a single FET, they'll be running at very low duty and will barely make any heat if switched fully on.

Keep in mind if your using aftermarket coils they will probably have a higher inductance than stock so they take longer to charge. Only way to really solve this is to raise the input voltage to the coil when its charging or by increasing the charging time. If your using the stock ECU you can't so the latter, but pulling off the former is feasible with a bit of DC-DC conversion.

Yep, the plan was to use the MOSFETs (only 1 per channel btw) to pull down the coil to ground. I was going to use MOSFETs with a very low 'ON' resistance but pull the gate down with a 100kOhm resistance so it didn't float between charges. Thats a good idea about using an inverting buffer, although the higher the dV/dt, the shorter the spark duration. Obviously the peak secondary voltage is higher...Spark duration should also be considered.

As far as the dwell is concerned I measured the stock ECU dwell and it is about 2ms at idle and doesn't seem to change much with rpm. My CRO is pretty old though and not very stable so it is hard to tell but yeah, it makes sense that it is short due to the size of the nissan coils..

I actually have a data sheet for a Bosch motorsport 3x2 coilpack and at 14V with a 2ms dwell (charged to 5 amps) you get 34mJ of energy. This is about the same as a Splitfire (I think? I read it somewhere). BUT in wasted spark you are firing 2 plugs at once. I think the plug in the exhausting cyclinder will fire much easier than the charged cylinder because the exhaust gas will be dry etc etc. so the you will not get 34mJ at the plug you want.

BUT if the volatge input of the coil is increased to 20V at 2ms dwell(charged to 8 amps) the output energy of the coil is 68mJ. At 24V at 2ms (charged to 10A) the output is 86mJ. So the inverter DC-DC inverter is a good idea although 24V at 10A (240W) is a big ask...Although it could set up such that it runs in 24V mode at higher engine loads only so most of the time you are running in 12V mode, so the duty cycle on the inverter is low...unless you are doing circuit stuff...I also had the idea of using a second battery (smaller like a 7.2Ah gel cell) that changed from parrallel to series depending on engine load...Once again the duty cycle will dictate how practical this is...

[mazda_feen]

can someone please tell me..

i am in the middle of converting too wasted spark.. it says that i am ment too pair the pink wires in order.. eg. 1 and 6.. but on the cylinder 1 plug there isn't any pink wires. only two black, and one black with yellow trace.. do i just cut off the black one which is in the same position as the other 5 pink wires... but with saying that the black wire that is in the same position joins into the earth connector of the loom..

can someone please help

thanks

[super_s13]

I am running this exact setup and have pulled over 200rwkw with a ecu and tune on a rb25det. Works well and am very happy with it. Can get pick of the setup if some are interested.

[Angelecles]

Hey guys,

has anyone done this to an R34 Gt-t. Is the setup similar to the S2 GTS-T with the ignitors in the coilpacks or is there a seperate ignitor? Im sick of changing coils and want to give this a shot.

Cheers.

[Mr Jollwah]

I know this is supposed to be wasted spark discusion but was reading about the install on the series 2.

I bought a set of Gen 3 coils with looms for $160 off ebay. As best I can tell all I need to do is mount the buggers, wire em in and buy a set of leads.

I'll give em a go when the std ones pack up or I can find a spare coil harness.

Some info on the coils.

http://forums.hybridz.org/showthread.php?t=120533

STD coils haven't given up yet but I was thinking of trying LS1 coils as an upgrade.

[Dah_Hunter]

Hey..

I have a RB25 Neo 6..

and i wanted to do a Wasted Spark Set up..

Can someone PM me the parts i need to make this thing..

thanks Guys..

(New Guy from Canada.)

[-wj-]

Try reading through this topic.

put some effort in it man, it's all on the internet.

[BADR33]

for you guys with series 2 or r34s

you can get ingnitors off other cars like subarus and stuff. if you use mitsi coils you just use a mitsi ingnitor. you just pair up the wires from the ecu before the the ingnitor.

From what i have now seen through through my work with our new Dynapack hub dyno is that the factory configuration of 6 coils seems to work best with the red coil replacements, there quite a bit cheeper over here in NZ.

though in saying that were dealing with a lot of aftermaket ecus with only 3 coil channels hence running the factory coils in wasted spark.

when i get my car going again... been 5months since i blew the gearbox, just finishing my custom pleninum. im going to do some testing on the dyno to see if there is any change between 6x coils and mitsi wasted spark, although im running a plug in G4 Link ecu( called somthing differnt over there i hear) so it runs wasted spark no matter what.

though on a side note the red coils from what we have seen are good for up to 450rwkw on a rb26dett on 22psi before they seem to run out with the wasted spark setup.

factory ecu dwell time is 2milli seconds for the coils

[R33Skida]

Ok wondering whether I could get a hand with my wasted spark setup.

Im really not good with auto electronics but i've tried so far and given it my best go, but for some reason my car won't start.

I have a R33 series 2 RB25 and here is a diagram i drew in paint of what I've done... Would really really appreciate some help on this one guys, cheers.

http://img151.imageshack.us/img151/8297/pa...coilpicture.jpg

[r32u]

Ok wondering whether I could get a hand with my wasted spark setup.

Im really not good with auto electronics but i've tried so far and given it my best go, but for some reason my car won't start.

I have a R33 series 2 RB25 and here is a diagram i drew in paint of what I've done... Would really really appreciate some help on this one guys, cheers.

http://img151.imageshack.us/img151/8297/pa...coilpicture.jpg

hey try connect the one from ignitor pack to ground and other to the same join as 1 & 6 on the coil

let us know how it goes

[smokup]

Hi this is my first post on here.

I've done a wasted spark on my non turbo R34 RB25 Neo with Mitsi Diamante coils and Igniter making a new wiring loom that paired up the Trigger wires that run to the coils with Diodes on each of the trigger wires before they are joined to stop any current going up the wires back to the computer,Make sure you put them around the right way otherwise it wont work at all.

Now you have your 3 paired trigger wires (cylinders 1 and 6, 2 and 5, 3 and 4) for your igniter modual

IB3 is where your paired up trigger wires for cylinders 1 and 6 go

IB2 is for cylinder trigger wires 2 and 5

IB1 is for cylinder trigger wires 3 and 4

**The IB numbers are seemingly backwards because the wires that run to the coils from the igniter from the OC1,OC2 and OC3 wires change colours when they go through the plug on the coil mounting bracket **

THIS COULD BE WHY SOME CONVERSIONS DON'T WORK.

VB Plug Needs the posative that used to run to the coil packs posative plugs.

GND Needs the earth wire that used to run to the coils negative.

TACHO wire is not needed dont connect to anything tacho will still work properly.

I did this conversion about 8 months ago when i had my fourth coil pack die and it wasn't under warranty anymore

It cost me about $60 for 2nd hand coils and Ignighter from Pick a Part,Solder Wire,length of heat shrink,6 diodes from Dick smiths.

I used some wire that i already had to extend the wires as nessisary and some Insulation tape

Car hasn't missed a beat since I did this and actually runs better than it ever did on the coil packs has a lot more down low torque.

And because I diagnosed the dead coil before I converted I have 5 good coils that I can sell off.

I dont know if these coils are any good on Turbo RB's though these coil setups were also used on GTO's

Here's a pic of the Mitsi Ignighter

[pure_methamphetamachine]

Rather than using the little white wire to power the VT coil, why not run a decent sized wire/cable directly from the battery?

[shadybeaverguy]

Hey guys I just installed a waste spark setup today on a S1 RB25DET

On the small plug, I ran the black to ground, and the white to 3 terminals on the buick coil.

My igniter has E1 E2 E3 E4 E5 E6

I bridged 1 6 / 2 5 / 3 4

It started and ran with a miss.

I pulled the HT leads off one by one, and 4 and 6 made no diff.

I swapped them, and it ran much better.

I took it for a test drive, and it broke down when it boosted.

How is this possible? I rechecked all connections, and they are all 100%.

The only thing i'm not sure about is the ground... I don't need another ground besides the small plug do i?

[mad082]

what condition was the coil and ignitor that you were using? also what condition were your plugs and leads? could be that there is a fault there, especially if something is second hand from the wreckers

[shadybeaverguy]

Everything is brand new, except for the ignitor which is from my car, and working with coil packs...

[shadybeaverguy]

I think I found the issue... My small plug only has 1 black, 1 white, so I think I have a messed up ground...

Not too sure how to ground it now!

I'm sure my car was a prototype or something - I have plugs and stuff that are different to everyone elses...