3T GTE - Wasted spark??

[Hen]

If you are running a single coil for each cylinder there is absolutely no point to setting it up to fire on the exhaust stroke. Just set it to fire only on compression.

The only reason waste spark is used is because it is cheaper. Two twin post coils is cheaper than 4 individual coils, and can do the same job. The sparking during exhaust is a useless, though harmless, byproduct.

Hen

[TA22 GT]

OK, looks like I will go for one coil per cylinder and not fire on the exhaust stroke.

Thanks for the feedback.

Cheers,
Simon

[rob1]

If you are running a single coil for each cylinder there is absolutely no point to setting it up to fire on the exhaust stroke. Just set it to fire only on compression.

The only reason waste spark is used is because it is cheaper. Two twin post coils is cheaper than 4 individual coils, and can do the same job. The sparking during exhaust is a useless, though harmless, byproduct.

Hen

spot on. because it's cheaper. 4 spark plugs and you only need 2 twin post coils. to run wasted spark on the twin plug head and you would be looking at 2 4post coils (if there's succh a thing!)

[TA22 GT]

I've done a bit more research and now it seems that running one coil per cylinder will cause damage to the coil as both plugs are on the compression stroke.

Looks like I have to run wasted spark as I mentioned earlier. Eg So both plugs fire on the compression stroke as well as firing both on the exhaust stroke.

I've been looking at the Haltech twin psot coils, anyone know if these are the same as the twin post M&W coils?

Cheers,
Simon

[3t-RA40]

I run this setup on my 3t with a Haltech. I will take some photos tonight when I get home and post them up. Haltech sugguested per twin post coil that one runs to the firing cylinder and one to the exhaust cylinder eg coil one runs a lead to cyl one and a lead to cyl four. Leads can look neat if you take the time.
Cheers,
Neil.

[BeRad]

id say the haltech coils are just bosch coils... but yes they work fine. surely you dont NEED to run wasted spark , look at how toyota has done it with the standard system and make it work with the microtech.

[TA22 GT]

I run this setup on my 3t with a Haltech. I will take some photos tonight when I get home and post them up. Haltech sugguested per twin post coil that one runs to the firing cylinder and one to the exhaust cylinder eg coil one runs a lead to cyl one and a lead to cyl four. Leads can look neat if you take the time.
Cheers,
Neil.

Neil,
Pics would be great. I think your set up is the way to go.

Cheers,
Simon

[TA22 GT]

id say the haltech coils are just bosch coils... but yes they work fine. surely you dont NEED to run wasted spark , look at how toyota has done it with the standard system and make it work with the microtech.

The stock system fires both plugs at the same time on the compression stroke. With an aftermarket ECU I can't see how this can be done unless you have 8 output signals from the ECU. My ECU only has 4 outputs so wasted spark is the only option.

Let me know if you think otherwise as I can't work out how to achieve what I want without going for a wasted spark set up as Neil has done.

Cheers,
Simon

[3t-RA40]

The stock system fires both plugs at the same time on the compression stroke. With an aftermarket ECU I can't see how this can be done unless you have 8 output signals from the ECU. My ECU only has 4 outputs so wasted spark is the only option.

Let me know if you think otherwise as I can't work out how to achieve what I want without going for a wasted spark set up as Neil has done.

Cheers,
Simon

That was the reason that I ran wasted spark, the next step up in computer was about $500ish to allow me to run true direct fire and sequential injection. I opted for wasted and sequential.
Cheers,
Neil.

[TA22 GT]

Neil,
I'm no expert on sequential injection. How does this work and what are the advantages?

I assume my system currently fires all injectors at the same time and with sequential they fire in line with the crank position?

Cheers,
Simon

[rob1]

Seq. inj. fires the right injector at the right time. You're right. I have a haltech e8 which has sequential inj. i think the e6x (next model down) didn't have this.

[thechuckster]

sequential only benefits you at idle and if you have very large injectors , e.g. when at low pulse-widths requirements you simply can't open the injectors long enough for the 2 or 3 times per 720 degrees of rotation that a factory setup (pairs injectors, batch fired) would run at.

Sequential tries to open the jinjector just before the inlet valve starts to open, the faster the rpms or the airflow, the earlier ahead of this moment the injector has to start to open (and it usually takes an injector about 1ms to open). There's also the timing issue (cam position) to deal with and any errors from that sensor require the ECU to drop back to a batch mode until the cam position is correctly identified.

Once you're on revs or up on boost it (sequential injection) is of little or no consequence.

fwiw: 1J & 2J turbos run injectors in 3 batches and the spark (despite individual coils) is waste-spark. Likewise the 7mgte.

[TA22 GT]

OK thanks. Somehow I don't think I'll get much value out of sequential injection as it currently idles well without it.

Cheers,
Simon

[3t-RA40]

Seq. inj. fires the right injector at the right time. You're right. I have a haltech e8 which has sequential inj. i think the e6x (next model down) didn't have this.

Yeah I have E6X. It does have sequential inj, but you can't run true direct fire and seq inj at the same time.

sequential only benefits you at idle and if you have very large injectors

Yes, I'm running sard 750cc inj. That's why I went seq inj and wasted spark.

Some photos of the engine bay. Excuse the engine bay at the moment, currently doing a top mount turbo manifold and have to redo the intake manifold.
Coils run 1 through 4 from left to right. The lead on the left post of the coil runs to front spark plug 1 through 4 and the lead on the right post runs to it's opposite 4 through 1.
Coil 1 - front 1, rear 4 -- Coil 2 - front 2, rear 3 etc




shot of the trigger, haltech hall effect sensor and rare earth magnets

[NAJJE]

3t-RA40,

You have done exactly what I have been hoping would work for ages!!! Legend

I am in the process of purchasing a Haltech E6X and was hoping I could setup the Hall effect sensor the way you have in the existing dizzy housing.

Was this hard to setup, or a matter of bolt on the trigger wheel and sensor and way it goes?

BTW are you running Haltech Coils with this setup?

Rob