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Hussein's 1998 V70 Xr : The Force Awakens


lookforjoe

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I've put about 50 miles on my LS2 coils so far. I need to clean up the wiring but this is the setup as of now:

LS2%20Coils.jpg?dl=0

Using the dwell settings from a Silverado I had a dwell of 4.6ms at my average operation voltage of 13.4 volts. With this amount of dwell I had lots of knock and spark blowout at 10psi with a spark gap of .032".

I lowered the dwell to 3.5ms and was able to run 20psi at .032" without breakup. 

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I've put about 50 miles on my LS2 coils so far. I need to clean up the wiring but this is the setup as of now:

 

Using the dwell settings from a Silverado I had a dwell of 4.6ms at my average operation voltage of 13.4 volts. With this amount of dwell I had lots of knock and spark blowout at 10psi with a spark gap of .032".

I lowered the dwell to 3.5ms and was able to run 20psi at .032" without breakup. 

 

That's odd ....at 13.5 volt I measured a charge time of 4.3 ms with these LS2 coil.

3.5 ms seems a bit low, they will not be fully charged.

 

At 14 volt and 4 ms charge time:

http://www.meditekst.nl/cop/LS2_14v_4ms.wmv

 

Volt - ms

6 - 12,5

8 - 8,7

10 - 6.8

11 - 6

11,5 - 5,6

12 - 5,3

12,5 - 4,9

13 - 4,6

13,5 - 4,3

14 - 4

 

 

Edited by Piet
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 This is what I measured on the LS9 coils:

http://www.meditekst.nl/cop_hussein.mov  (14 volt - 3 ms)

at 10   volt : 4.5 ms

at 11   volt: 4 ms

at 11.5 volt 3.7 ms

at 12    volt:  3.5 ms

at 12.5 volt : 3.3 ms

at 13   volt:  3.2 ms

at 14   volt   3.0 ms

 

These charge times  are shorter then the charge times of the LS2 coils

 

Edited by Piet
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These aren't the dwell times you are using for the LS2 coils, are they?

No, the GM coil dwell table is quite different. Piet figured out the ideal dwell times by empirical testing of an Ls2 coil pack I sent him.

GMDwell1_zps7723021a.png

Runs very well with the GM coils, but only up to about 20psi (on my turbo). After that, it breaks up. I tried many variations of dwell reduction & that does not seem to be the issue, or at least only part of the picture.

Screenshot%202015-05-13%2020.29.11_zpsbg

 

Edited by lookforjoe
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Have you guys tested NGK BCR8ES sparkplug with lowered sparkplug gap to 0.5mm (0.02"). This works fine on stock T5 coils on my friends 850 T5 with 1000hp on E85. ;)

I've tried various NGK plugs in the past, not that specific plug. I tried the 'race' plugs in the 8 (colder) range. Overall, I've had better luck with the stock DPP+ fine wire Bosch plugs. I've been able to run higher boost at wider gaps. This is all since using COP, even back with the TurboTuner COP. Cap & rotor setups are a different story.

In my case though, it's not the plugs that fail, it's always been the coil packs. When the breakup does occur, swapping the coil packs resolves it. I haven't always touched the plugs when this has happened, except to look at them.

I still have a stack of 15 Bosch regular & Motorsport coil packs I need to swap in one at a time to see which of them fail at high load.

I'm going to try the LS9 coils next, now that I have good dwell times to work with (thanks Piet!).

Right now I have the wagon coming apart to do the clutch replacement. Bloody hot working outside.

 

Edited by lookforjoe
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To avoid misunderstandings...:)

These are charge times not dwell times. 

Dwell times have to calculated out off the charge times for each RPM to get the values for the dwell table.

Edited by Piet
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Between 4.1ms and 4.6ms of dwell (at 13V) I couldn't run more than 10psi of boost. When reduced to 3.5ms I could run 20psi without problems. I'm still above 70% efficiency at 20psi on the EFR7064, so this isn't much different than 20psi on your turbo.

I understand that this isn't the full saturation time that the coils are spec'd at requiring, but these coils have a known problem with pre-firing when over charged:

http://rennlist.com/forums/944-turbo-and-turbo-s-forum/740107-tech-the-944-951-ignition-system-9.html#post10237916

Even at only 3.5ms of dwell I'm sure these coils will be putting out a lot more spark than the stock coils. I could never maintain .032" gap at 20psi with the stock coils before, so for now, I am happy.

Have you guys tested NGK BCR8ES sparkplug with lowered sparkplug gap to 0.5mm (0.02"). This works fine on stock T5 coils on my friends 850 T5 with 1000hp on E85. ;)

A tiny spark plug gap is what I'm trying to avoid. 

 

 

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