Max. allowed Coil Charge Time (Dwell)

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EMS
Posts: 41
Joined: Tue Oct 12, 2010 1:24 pm

Max. allowed Coil Charge Time (Dwell)

Post by EMS » Wed Apr 25, 2012 1:42 pm

I have some trouble with a MY99 car running a Syvecs S6PNP on E85. I have some slight misfire from about 1.5 bar of boost (GTX3076 turbo). I am running PFR7B plugs gapped to 0.6 mm. Changing Dwell time from 3.5 ms to 4.5 ms made it better, but I don't have the experience up to which level I can increase the Coil Charge Time.

Can someone shine a light on this?

Thanks in advance,

Mark.

Charlie
Syvecs Staff- Tea Boy
Posts: 114
Joined: Thu May 22, 2008 12:28 pm

Re: Max. allowed Coil Charge Time (Dwell)

Post by Charlie » Wed Apr 25, 2012 3:41 pm

Mark is it on the orig coil pack or has it been converted to coil packs?

EMS
Posts: 41
Joined: Tue Oct 12, 2010 1:24 pm

Re: Max. allowed Coil Charge Time (Dwell)

Post by EMS » Wed Apr 25, 2012 6:49 pm

Original coil pack on top of the manifold.

Charlie
Syvecs Staff- Tea Boy
Posts: 114
Joined: Thu May 22, 2008 12:28 pm

Re: Max. allowed Coil Charge Time (Dwell)

Post by Charlie » Thu Apr 26, 2012 5:47 pm

Have you tried a different one? Most people switch to coil on plug at that power level over here

EMS
Posts: 41
Joined: Tue Oct 12, 2010 1:24 pm

Re: Max. allowed Coil Charge Time (Dwell)

Post by EMS » Thu Apr 26, 2012 8:53 pm

I've not tried another coil and I am not intending to do, as the car "only" runs 1.6 bar of boost. At the moment there is hardly any misfire, only every now and than. I just want to know how far I can increase the Coil Charge Time without frying the coil. (as increasing it from the 3.5 ms from the Syvecs "basefile" did help)

EMS
Posts: 41
Joined: Tue Oct 12, 2010 1:24 pm

Re: Max. allowed Coil Charge Time (Dwell)

Post by EMS » Tue May 01, 2012 10:14 pm

Anyone?

Jasper K
Posts: 56
Joined: Fri Aug 15, 2008 1:38 pm
Location: Taiwan

Re: Max. allowed Coil Charge Time (Dwell)

Post by Jasper K » Sat May 05, 2012 5:35 am

Hi Mark,

Ultimately you would need to use an oscilloscope and monitor the dwell curve. You should perhaps use a wideband current clamp to measure the current from the 12V Power feed to the coil pack. You should see a charging current when the coils are charged. You can slowly increase Dwell time until you see current starts flatlining (some ignitors are current limited) or a sudden rise in current indicating saturation has started. Then back off the dwell time a bit and you're done provided the coil pack can handle the heat. At least electrically speaking this would be the approach.

Another problem is that these coilpacks are wasted spark. They will be firing twice as fast as later COP solutions which is also means that there might even not be enough time to charge them fully at high revs.

Have you tried gapping the plugs as small as 0.55 or 0.5mm? Are your HT leads in good condition? Too much parasitic losses are not helping the already not so good '99 coilpacks. Alcohol based fuels are more difficult to ignite. Straight Methanol would be the worst.

Cheers,

Jasper.

pavlo
Zen Performance
Posts: 406
Joined: Mon Aug 04, 2008 9:18 am

Re: Max. allowed Coil Charge Time (Dwell)

Post by pavlo » Sun May 06, 2012 2:19 pm

You could certainly go to 4ms, I will check some maps for more info.

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