Colder plug issues
07-18-2013, 11:12 AM
#1
Colder plug issues Based on some recommendations, I switched from TR6's to BR7EF's, both gapped at 0.028". Now with the BR7EF's it is cutting out in boost. I can feel the power drop for a split second, then it picks back up, kind of like it's surging. It will do this a dozen times or so before redline. Seems like it might be blowing out spark? It is worse with the cutout open. And then in normal light throttle driving it will surge as well. I didn't have these issues with the TR6's. When I pulled the TR6's they looked to be in great shape.
I'm running a Turbonetics 7668 up to 13psi, 0.76-0.78 lambda on 91 octane (8% methanol), and spraying a 50/50 mix of water/meth at 15gph. Current timing is about 10* and IAT's are ~60F. The tune is conservative at the moment but I plan on adding more timing once my progressive injection controller shows up.
I'm running a Turbonetics 7668 up to 13psi, 0.76-0.78 lambda on 91 octane (8% methanol), and spraying a 50/50 mix of water/meth at 15gph. Current timing is about 10* and IAT's are ~60F. The tune is conservative at the moment but I plan on adding more timing once my progressive injection controller shows up.
07-18-2013, 01:47 PM
#3
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That behavior sounds like it's either knocking bc bad fuel, or blowing the spark, although 13 psi is really not a lot of boost to blow. Is the fuel good from a good source?
Try Champion 9405 plugs.
Try Champion 9405 plugs.
07-18-2013, 02:16 PM
#5
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I've had similar experience this weekend at the track. I'm on e85 and ran br7ef plugs on 10lbs of boost without issue gapped to .028. I upped the boost to 13-14lbs and that is where I started breaking up a little more up top and ran slower. I pulled the plugs and replaced them with b8efs's gapped to .023 as I've heard those plugs being a little colder would potentially fair better. I'm hoping it was just that the gap was too wide but heard that there isn't much if any lose of power going with the b8efs plugs. FWIW my best runs on 10psi with e85 were with the br7ef plugs. You may want to try those and gap them a little tighter, but i'm no expert and would rather lean on the experience of some of the more seasoned folks in this section.
07-18-2013, 02:35 PM
#8
Nope. Only good things come from gapping them smaller in your case. You might lose .5WHP down low or something, but you won't be blowing it out anymore. Put em at .022 and see what that does. I'll bet money it solves your problem.
07-18-2013, 03:38 PM
#14
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And with such low boost, do you really need to be injecting so much water/meth ?
Do you actually have pump duty set to full at 13psi ?
What compression ratio ?
Throwing lots of water into the engine when it isnt needed is never going to help matters.
Do you actually have pump duty set to full at 13psi ?
What compression ratio ?
Throwing lots of water into the engine when it isnt needed is never going to help matters.
07-18-2013, 03:46 PM
#15
Pump comes on full at 4.5psi, hence why I'm waiting on my progressive controller. But it doesn't start breaking up until 8-9psi.
Stock SCR, 9.5.
07-18-2013, 04:01 PM
#16
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Other people do spray a lot. I spray a lot.
But you need to consider that most of the people spraying lots, do not use such a high percentage of water.
There will come a point when there is simply too much water, and that water will put out the fire to to speak.
And also those spraying lots, are also pushing harder. The amount you spray needs to be relative to the power or fuel flow the engine is using. And this is even more important when you use water.
With straight meth, you could dump almost as much as you wanted and it will always burn. It's just another fuel after all.
I'm certainly not saying to stop using water, but you just need to bare in mind you can only use so much water before it actually starts to cause problems.
But you need to consider that most of the people spraying lots, do not use such a high percentage of water.
There will come a point when there is simply too much water, and that water will put out the fire to to speak.
And also those spraying lots, are also pushing harder. The amount you spray needs to be relative to the power or fuel flow the engine is using. And this is even more important when you use water.
With straight meth, you could dump almost as much as you wanted and it will always burn. It's just another fuel after all.
I'm certainly not saying to stop using water, but you just need to bare in mind you can only use so much water before it actually starts to cause problems.
07-18-2013, 04:25 PM
#17
Other people do spray a lot. I spray a lot.
But you need to consider that most of the people spraying lots, do not use such a high percentage of water.
There will come a point when there is simply too much water, and that water will put out the fire to to speak.
And also those spraying lots, are also pushing harder. The amount you spray needs to be relative to the power or fuel flow the engine is using. And this is even more important when you use water.
With straight meth, you could dump almost as much as you wanted and it will always burn. It's just another fuel after all.
I'm certainly not saying to stop using water, but you just need to bare in mind you can only use so much water before it actually starts to cause problems.
But you need to consider that most of the people spraying lots, do not use such a high percentage of water.
There will come a point when there is simply too much water, and that water will put out the fire to to speak.
And also those spraying lots, are also pushing harder. The amount you spray needs to be relative to the power or fuel flow the engine is using. And this is even more important when you use water.
With straight meth, you could dump almost as much as you wanted and it will always burn. It's just another fuel after all.
I'm certainly not saying to stop using water, but you just need to bare in mind you can only use so much water before it actually starts to cause problems.
Can someone explain why projected tips are not as desirable?
07-18-2013, 04:29 PM
#18
9 Second Club
But yes you are correct. With just a plug change you should not be experiencing this problem.
I would doubt that a colder plug could cause your problem. Ive run 7's and 8's and had no problems and noticed no difference between them.
I'm back on 7's again with a normal projected tip.
Although I'm using BKR7EIX's at the minute. ( For no other reason than...because lol )
Prior to that I was using a cheap BCR8ES which is a 8, retracted nose. I just didnt like the retracted nose. Not sure if that number would be readily available in the US though. It's just a cheap plug found in some older turbocharged cars here.
I would doubt that a colder plug could cause your problem. Ive run 7's and 8's and had no problems and noticed no difference between them.
I'm back on 7's again with a normal projected tip.
Although I'm using BKR7EIX's at the minute. ( For no other reason than...because lol )
Prior to that I was using a cheap BCR8ES which is a 8, retracted nose. I just didnt like the retracted nose. Not sure if that number would be readily available in the US though. It's just a cheap plug found in some older turbocharged cars here.
07-18-2013, 10:55 PM
#20
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Run a 70/30 mix if you are going to have it spraying full tilt at such a low psi and throw a another 2-4 degrees at it.
If you are set on keeping the 50/50 and full blast at that boost level, tighten the gap down to .025 or .022. If it were mine, I'd bring the meth in on full closer to 10psi also. When I had the stock engine and making 13-16 psi boost it tried to cut out bringing a full meth(70/30 mix) spray under 8-10psi..
If you are set on keeping the 50/50 and full blast at that boost level, tighten the gap down to .025 or .022. If it were mine, I'd bring the meth in on full closer to 10psi also. When I had the stock engine and making 13-16 psi boost it tried to cut out bringing a full meth(70/30 mix) spray under 8-10psi..