Recommendations on Spark Plugs to Use
#1
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Recommendations on Spark Plugs to Use
I have a 1988 Mazda RX7 Turbo 2 running a T66@10psi/15psi. At either boost level the car has started to misfire above 5000rpm when under load in either 3rd/4th/5th gear. I'm running stock ignition and this originally wasn't a problem, but started happening when we dyno'd the car after installing a new Aeromotive FPR. (Car on the dyno made one clean pass and had 11.8:1 afr's under boost)
Would new plugs solve my problem? If so should I go with B10EGV's or is there a better plug for my application?
-Rob-
Would new plugs solve my problem? If so should I go with B10EGV's or is there a better plug for my application?
-Rob-
#2
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Originally Posted by Hi_Im_Rob
I have a 1988 Mazda RX7 Turbo 2 running a T66@10psi/15psi. At either boost level the car has started to misfire above 5000rpm when under load in either 3rd/4th/5th gear. I'm running stock ignition and this originally wasn't a problem, but started happening when we dyno'd the car after installing a new Aeromotive FPR. (Car on the dyno made one clean pass and had 11.8:1 afr's under boost)
Would new plugs solve my problem? If so should I go with B10EGV's or is there a better plug for my application?
-Rob-
Would new plugs solve my problem? If so should I go with B10EGV's or is there a better plug for my application?
-Rob-
#3
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Already did it...
EDIT: I know theres other guys that have to be making 400whp+. What plugs do they use?
I'm planning on 500whp soon. What plugs would that require?
EDIT: I know theres other guys that have to be making 400whp+. What plugs do they use?
I'm planning on 500whp soon. What plugs would that require?
#4
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Originally Posted by Hi_Im_Rob
Already did it...
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Possibly, I would use the NGK Racing Spark plugs.
http://www.rx7.com/store/rx7/fcignition.html
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http://www.rx7.com/store/rx7/fcignition.html
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#8
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Did you check the plugs to see if they are fouling or misfiring?
If it is the spark plugs, go one step colder.
The B10EV's are the cheap option.
NGK does make a rotary specific 10.5 heat range plug, but it's big bucks - like $30 / each.
Another (expensive) option is to use the Denso Iridiums - $30 / each.
I think the CDI box will probably fix your problem though.
-Ted
If it is the spark plugs, go one step colder.
The B10EV's are the cheap option.
NGK does make a rotary specific 10.5 heat range plug, but it's big bucks - like $30 / each.
Another (expensive) option is to use the Denso Iridiums - $30 / each.
I think the CDI box will probably fix your problem though.
-Ted
#11
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Originally Posted by Hi_Im_Rob
If I fouled the plugs I would think it was too much heat.
I'm gonna try the 10.5 range plugs and the 6A and see if that fixes my problem
Thanks guys
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I'm gonna try the 10.5 range plugs and the 6A and see if that fixes my problem
Thanks guys
![Smilie](https://www.rx7club.com/images/smilies/smile.gif)
#12
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Check your plugs if they're colored bluish/purplish on the threads. If it is, you need colder plugs. The NGK 10EGV's are great plugs for high output engines. Your problem *could* be just weak spark that may need a boost from a CDI box.
I had ignition break up near redline when I dyno'd with comp. upgrade/ turbo. The CDI box solved that. The plugs were fine which were the BUR9EQ in all 4.
I'm using the B10EGV now which require thin walled sockets to install them.
When choosing those "motorbike "plugs, you need to use the "B" which are 14mm plugs. The last 2, 3 letters designate plat. or iridium .
I had ignition break up near redline when I dyno'd with comp. upgrade/ turbo. The CDI box solved that. The plugs were fine which were the BUR9EQ in all 4.
I'm using the B10EGV now which require thin walled sockets to install them.
When choosing those "motorbike "plugs, you need to use the "B" which are 14mm plugs. The last 2, 3 letters designate plat. or iridium .
#13
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Originally Posted by Innovation
How did you plan on getting 500whp?
I dyno'd 352whp in 2nd gear with the misfire. We shut down at 6k because the breakup was pretty severe.
![Frown](https://www.rx7club.com/images/smilies/frown.gif)
EDIT: We did a pull in 3rd gear and shut down around 5000rpm with ~380whp because the breakup was bad again.
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I'll buy the special NGK rotary plugs if they'll solve my problems.
RETed, do you know the part number for the NGK rotary plugs? Should I use those or just go with the Denso's?
RETed, do you know the part number for the NGK rotary plugs? Should I use those or just go with the Denso's?
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