Does this look like spark blowout?
06-10-2017, 12:45 PM
#1
Does this look like spark blowout? LS3
16psi
15 degrees timing
11.0A/F based on my wideband on the DP
BRE7F @ 0.028"
93 + meth #10 and #5 nozzles.
Clucth was slipping some on the dyno (thats why torque was low), but boost was very lazy and it was breaking up near peak power (up top).
The smooth curves were 16psi @ .032 with less airflow (more restriction). I havev added about 20% more airflow with some tweaks to the turbo setup.
*****EDIT: I had some screen shots of the log of run #68 on the dyno.*********
16psi
15 degrees timing
11.0A/F based on my wideband on the DP
BRE7F @ 0.028"
93 + meth #10 and #5 nozzles.
Clucth was slipping some on the dyno (thats why torque was low), but boost was very lazy and it was breaking up near peak power (up top).
The smooth curves were 16psi @ .032 with less airflow (more restriction). I havev added about 20% more airflow with some tweaks to the turbo setup.
*****EDIT: I had some screen shots of the log of run #68 on the dyno.*********
Last edited by RealQuick; 06-15-2017 at 08:09 AM.
06-11-2017, 11:48 AM
#4
LS3
16psi
15 degrees timing
11.0A/F based on my wideband on the DP
BRE7F @ 0.028"
93 + meth #10 and #5 nozzles.
Clucth was slipping some on the dyno (thats why torque was low), but boost was very lazy and it was breaking up near peak power (up top).
The smooth curves were 16psi @ .032 with less airflow (more restriction). I havev added about 20% more airflow with some tweaks to the turbo setup.
16psi
15 degrees timing
11.0A/F based on my wideband on the DP
BRE7F @ 0.028"
93 + meth #10 and #5 nozzles.
Clucth was slipping some on the dyno (thats why torque was low), but boost was very lazy and it was breaking up near peak power (up top).
The smooth curves were 16psi @ .032 with less airflow (more restriction). I havev added about 20% more airflow with some tweaks to the turbo setup.
06-11-2017, 12:53 PM
#7
it makes sense from 4900 to 5000 torque drops and you get a lean spike. Look at a log of the exact dyno pass from 4900 to 5000 and verify the injector DC is still increasing. If you can also verify fuel pressure at that exact moment it would give you the most confidence of losing spark. It is worth noting that if the a/f increased first and then the torque drops due to it, we will not able to tell due to the transient delay of the exhaust driven O2 sensor. It may also be worth noting that in the past when I have dealt with spark blowout it felt more like hitting a rev-limiter, The stop was sudden and obvious.
The gap is already very tight, it would be an enormous hassle to lower it even more just to re-dyno the car to find out that the spark really is blowing out. That is because you wouldn't want to leave the gap that small in my opinion. Prefer gaps around 0.032"+ in most applications. This leaves you adjusting dwell or improving ignition character somehow. In other words, the larger the gap, the better the performance and economy of the engine, any engine, as long as the spark actually makes it. So instead of reducing gap to 'band-aid' the issue, I would rather improve my ignition output somehow and increase the gap.
The gap is already very tight, it would be an enormous hassle to lower it even more just to re-dyno the car to find out that the spark really is blowing out. That is because you wouldn't want to leave the gap that small in my opinion. Prefer gaps around 0.032"+ in most applications. This leaves you adjusting dwell or improving ignition character somehow. In other words, the larger the gap, the better the performance and economy of the engine, any engine, as long as the spark actually makes it. So instead of reducing gap to 'band-aid' the issue, I would rather improve my ignition output somehow and increase the gap.
Last edited by kingtal0n; 06-11-2017 at 12:59 PM.
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06-11-2017, 02:07 PM
#8
it makes sense from 4900 to 5000 torque drops and you get a lean spike. Look at a log of the exact dyno pass from 4900 to 5000 and verify the injector DC is still increasing. If you can also verify fuel pressure at that exact moment it would give you the most confidence of losing spark. It is worth noting that if the a/f increased first and then the torque drops due to it, we will not able to tell due to the transient delay of the exhaust driven O2 sensor. It may also be worth noting that in the past when I have dealt with spark blowout it felt more like hitting a rev-limiter, The stop was sudden and obvious.
The gap is already very tight, it would be an enormous hassle to lower it even more just to re-dyno the car to find out that the spark really is blowing out. That is because you wouldn't want to leave the gap that small in my opinion. Prefer gaps around 0.032"+ in most applications. This leaves you adjusting dwell or improving ignition character somehow. In other words, the larger the gap, the better the performance and economy of the engine, any engine, as long as the spark actually makes it. So instead of reducing gap to 'band-aid' the issue, I would rather improve my ignition output somehow and increase the gap.
The gap is already very tight, it would be an enormous hassle to lower it even more just to re-dyno the car to find out that the spark really is blowing out. That is because you wouldn't want to leave the gap that small in my opinion. Prefer gaps around 0.032"+ in most applications. This leaves you adjusting dwell or improving ignition character somehow. In other words, the larger the gap, the better the performance and economy of the engine, any engine, as long as the spark actually makes it. So instead of reducing gap to 'band-aid' the issue, I would rather improve my ignition output somehow and increase the gap.
After the changes this winter (plugs gapped down to 0.028 from 0.032, turbo screen, cutoutS, wastegate dumped to atmosphere, and clutch/driveshaft) I did start getting a p0300 random misfire. When I logged this misfires they would be random jumping around from cylinder to cylinder. I had done some research and apparently a lighter clutch/flywheel assay could trigger this. Maybe it was the plugs gapped down too tight. Some guys have recommended gapping 0.018-0.022 with #8's.
As far as ignition goes, I have the granatelli coils that put out some serious spark... so maybe my car was fine at a bigger gap? Seems like I could go up or down on the gap, but it isn't easy getting to the plugs on the drivers side. I need to drop the DP and remove the exhaust manifold. I'd prefer to do it once. Maybe I should open the gap on the 4 pass side plugs, and log misfires to see they remain on the drivers side?
06-11-2017, 06:26 PM
#10
9 Second Club
What dwell are you running the coils at ?
And can you try a set of OEM coils ? Just how well proven are those Granatelli's ?
You're at fairly low boost, spark should not be a problem with any OEM coils.
And can you try a set of OEM coils ? Just how well proven are those Granatelli's ?
You're at fairly low boost, spark should not be a problem with any OEM coils.
06-11-2017, 07:10 PM
#11
Steve - dwell is same as stock. I should email them about the dwell, didn't think of it until you mentioned it.
Not sure how proven the Granatelli's are, but they were used on the other 16# run (the smooth curves on the sheet).
i could try the stock coils again, but the granatelli's were unchanged from previous sessions.
06-11-2017, 07:42 PM
#12
lots of guys have made well over 1k whp with stock ignition and lot of guys have had issues with aftermarket stuff so I'd probably swap on some new msd wires and the stock coils and see how it looks. doesn't hurt to check the grounds also?
with good amount of methanol (hard to ignite) and stock 2005 igntion stuff I'm making 900whp easily using same gap and plugs as you
with good amount of methanol (hard to ignite) and stock 2005 igntion stuff I'm making 900whp easily using same gap and plugs as you
06-12-2017, 09:55 AM
#14
can you clarify, I just realized, your smooth curve was a previous dyno session when the car ran "fine"?
Look at the smooth curve at 4900-5000. Notice torque drops significantly. a/f gradually follows but does not precede by much. I think there is something in that particular region causing the drop in torque, perhaps a timing reduction is taking place.
the second curve with all the loopy lines is not very useful for diagnostics. the SOLID line that runs to the end is very heavy with important clues that something is/was causing a drop in torque.
Look at the smooth curve at 4900-5000. Notice torque drops significantly. a/f gradually follows but does not precede by much. I think there is something in that particular region causing the drop in torque, perhaps a timing reduction is taking place.
the second curve with all the loopy lines is not very useful for diagnostics. the SOLID line that runs to the end is very heavy with important clues that something is/was causing a drop in torque.
06-12-2017, 12:26 PM
#15
FormerVendor
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Ignition Coils = 10 AMP Hi, OK first I have found "mixed" reports with your fitted coils.
The coil you have AND the LS coils are 10 amp coils at best.
I agree they should work fine at your 1 Bar Boost, not sure with Meth Injection.
I would do a "run" with Race Fuel.
I would ALSO like the dwell report ?
I would do a "run" with OEM coils and Race Fuel
I would like to know the SPW brand ?
I would like to know if you used Silicon Grease ?
I "read" you Spark Plugs as good.
Lance
The coil you have AND the LS coils are 10 amp coils at best.
I agree they should work fine at your 1 Bar Boost, not sure with Meth Injection.
I would do a "run" with Race Fuel.
I would ALSO like the dwell report ?
I would do a "run" with OEM coils and Race Fuel
I would like to know the SPW brand ?
I would like to know if you used Silicon Grease ?
I "read" you Spark Plugs as good.
Lance
06-12-2017, 01:36 PM
#16
How does one see spark blow-out looking at a plug? Those plugs look like they have too much run time on them to see anything to me? Is that a new plug with one pull on it and immediate shut down?
Do you run any water in your "meth"? If so, how much? What kind of pressure is the "meth" kit running? I found running much water in the mix can cause spark issues.
Most of the issues people have with OEM coils seem to be linked to the Holley ECU. Either way as suggested gap them down and see if the issue goes away. .015 is what I'd suggest to see if it clears up. Then bump them up slowly form there.
Do you run any water in your "meth"? If so, how much? What kind of pressure is the "meth" kit running? I found running much water in the mix can cause spark issues.
Most of the issues people have with OEM coils seem to be linked to the Holley ECU. Either way as suggested gap them down and see if the issue goes away. .015 is what I'd suggest to see if it clears up. Then bump them up slowly form there.
06-12-2017, 06:36 PM
#19
This x2. I threw in a new set of BR7 over winter and never bothered checking the gap, high revs and could feel it blowing out similar to how it had on the dyno when I first experienced it. I think out of the box they were all 028, closed them up to around 020 and no issues at all.
06-13-2017, 11:28 AM
#20
can you clarify, I just realized, your smooth curve was a previous dyno session when the car ran "fine"?
Look at the smooth curve at 4900-5000. Notice torque drops significantly. a/f gradually follows but does not precede by much. I think there is something in that particular region causing the drop in torque, perhaps a timing reduction is taking place.
the second curve with all the loopy lines is not very useful for diagnostics. the SOLID line that runs to the end is very heavy with important clues that something is/was causing a drop in torque.
Look at the smooth curve at 4900-5000. Notice torque drops significantly. a/f gradually follows but does not precede by much. I think there is something in that particular region causing the drop in torque, perhaps a timing reduction is taking place.
the second curve with all the loopy lines is not very useful for diagnostics. the SOLID line that runs to the end is very heavy with important clues that something is/was causing a drop in torque.
The wired lines are the hp/tq after the changes (coils have not changed, just plag gap went down from 0.032 to 0.028).
Now, boost does not fall off anymore, but I got something funky happening in the upper rpms.