The End all Turbo Spark plug Thread
06-19-2014, 09:57 PM
#27
well I don't see how the electrode can fall off that anymore than any other plug, certainly more robust than the rotary race plug electrode you just installed, which I remember someone (was it you?) fretting about this previously. The R6725 is pretty much the racing rotary standard the world over as long as you can afford them.
any way, this jumped out at me;
not sure why they imply it's not for turbo rotary engines
any way, this jumped out at me;
not sure why they imply it's not for turbo rotary engines
06-20-2014, 12:53 AM
#28
Maybe iridium electrodes don't stick to the plug body as well as platinum ones do
Last edited by Brettus; 06-20-2014 at 12:57 AM.
06-20-2014, 07:24 AM
#29
R7420 & R7440 are iridium tip, platinum electrode
R6725 is platinum tip & electrode
BR10EIX is iridium tip, with a platinum disc welded to a ? electrode
Note that there are two different BR10EIX plugs
Part# 6957 is a solid end terminal nut and probably the preferred choice, called BR10EIX SOLID
Part# 6801 is a loose end terminal nut (threaded), called BR10EIX
R6725 is platinum tip & electrode
BR10EIX is iridium tip, with a platinum disc welded to a ? electrode
Note that there are two different BR10EIX plugs
Part# 6957 is a solid end terminal nut and probably the preferred choice, called BR10EIX SOLID
Part# 6801 is a loose end terminal nut (threaded), called BR10EIX
06-20-2014, 05:58 PM
#32
I am currently going back and forth on the spark plugs, leaning towards the denso's because of cost and availability 26.79, and I like the 9, 10 heat range,
or the r6725's 10.5 and 11.5 but I think those will be too cool for my application.
or the r6725's 10.5 and 11.5 but I think those will be too cool for my application.
06-20-2014, 08:25 PM
#33
No, I just happened to stumble across it in the NGK Racing catalog. The RX8 plug is much more open/exposed than the 13B plug, but it looks like the RX8 electrode is angled out to about the same OAL depth despite the shorter reach. I'd suspect that it lights off easier. That said, most of the more knowledgable people I have access to seem to prefer the R6725 over the R7440. Not sure if it's for cost or some other reason. There's plenty that I don't get told about.
07-18-2014, 09:33 PM
#34
1000 odd kms down the road . Just pulled these after a 200km road trip cruising at 3200 rpms most of the way .
left side is trailing 11.5s right side leading 10.5s Was expecting the trailings to be black but they look pretty good to my untrained eye .
And for reference ...... here are the recently replaced BUR9EQPs next to the new plugs
Trailings on right . Leadings on left
left side is trailing 11.5s right side leading 10.5s Was expecting the trailings to be black but they look pretty good to my untrained eye .
And for reference ...... here are the recently replaced BUR9EQPs next to the new plugs
Trailings on right . Leadings on left
Last edited by Brettus; 07-18-2014 at 09:55 PM.
01-21-2015, 07:04 PM
#42
Great info! Was reading this and the rx7 post regarding the Autolite AR3932 plugs as I was interested in a lower cost alternative that is readily available locally. I found it interesting that a month after this thread was started the rx7 guy Howard posted that he was going away from the Autolites. Appears one of his plugs lost some ceramic in the motor after a detonation when he blew his fuel pump fuse while boosting at 25psi. A bit extreme circumstances, but thought it was worth mentioning. I still plan on trying them, as I don't plan on being in the 500rwhp realm. Of course, plans change now and then
FD Spark Plug Tech 2013 - Page 4 - RX7Club.com
FD Spark Plug Tech 2013 - Page 4 - RX7Club.com
07-21-2015, 05:05 PM
#44
LOL... I also posted in my thread. Update on the AR3932 plugs I installed back in January. I have been getting a few occasional misfires so I checked the plugs last night. They were pretty well worn so I replaced them. Much better They lasted 6 months running 10psi boost. Started out gapped at 0.025" and ended up worn to about 0.040". Not sure how many miles it has been, but unless there is bad weather this is my daily driver. At $3.99/ea I don't mind changing them a couple times a year.
Left to right = FL/FT/RL/RT
They lasted 6 months running 10psi boost. Started out gapped at 0.025" and ended up worn to about 0.040". Not sure how many miles it has been, but unless there is bad weather this is my daily driver. At $3.99/ea I don't mind changing them a couple times a year.Left to right = FL/FT/RL/RT
07-21-2015, 05:23 PM
#45
LOL... I also posted in my thread. Update on the AR3932 plugs I installed back in January. I have been getting a few occasional misfires so I checked the plugs last night. They were pretty well worn so I replaced them. Much better They lasted 6 months running 10psi boost. Started out gapped at 0.025" and ended up worn to about 0.040". Not sure how many miles it has been, but unless there is bad weather this is my daily driver. At $3.99/ea I don't mind changing them a couple times a year.
Left to right = FL/FT/RL/RT
They lasted 6 months running 10psi boost. Started out gapped at 0.025" and ended up worn to about 0.040". Not sure how many miles it has been, but unless there is bad weather this is my daily driver. At $3.99/ea I don't mind changing them a couple times a year.Left to right = FL/FT/RL/RT