I bought 4 of these today and gave them a try, seemed to work really well. No breakup, lots of power. These are a heat range 9. Equivilant to NGK R5671A9. I have been running the NGK B9egv and they have been fouling pretty quickly. Gap is .022. I am running a to4s single and 15# on the PFC. Still pretty rich at 11.2ish. I am also running a MSD dig 6 on the leads only. Anyone else tried these ? Good thing about them is they take a 5/8" sockets like the stockers.

 

The stockers are 13/16", but I get your meaning -- you don't need a special socket to install these plugs.

I recently tried the BR10EIX plugs and while they seemed to work fine when on power (including a dyno tuning session), they misfired a bit on light cruise and (annoyingly) at idle. I wasn't sure of the cause of these troubles until someone else posted that they had issues with the BR*EIX and switched back to B*EGV. I switched my leading plugs back to some B10EGV and my issues went away. I'm happy with the B*EGV plugs for my car, but it is nice to have more options.

I'm surprised that you've had trouble with the B9EGV plugs fouling. My car runs very rich at idle and I don't seem to have any fouling issues with my B10EGVs. I did foul a BUR9EQP when I first got the car back, but it cleared up after some revving.

-Max

 

theres so much talk of spark plugs that im confused, i have a mostly stock FD with K&N filter, downpipe and exhaust, im not sure what plugs i have (ive never changed them) how often should i need to change them and what kind of plugs would be good for me?

 

Bob:

You are running a close to stock setup much like my own. As a result, standard plugs are all you need. The boys at the top of this thread are running PFC's and most likely elevated boost and a/f settings. Hence, the need for a performance plug. Standard plugs are BUR7EQP for the leading plugs and BUR9EQP trailing plugs. The "P" stands for platinum. These are believed to give your plugs a longer performance life. The word is mixed on that, however. NGK is the most recognized mfr. of such plugs, but Autolite and others have rotary suitable plugs.

I just changed plugs and went with Autolites. They eliminated some break-up I was having with the old/worn plugs. You can expect to change plugs about every 25,000 miles or so.

 

Yes, 13/16 you are corrrect Max, what I meant to say was the stockers can be reached with a socket properly - no more cut down 13/16" socket.

Thanks

 

I just checked sparkplugs.com , these puppies are nice and cheap compared to the NGK iridium's. Also, the 5/8" head on the Autolite would be nicer than messing with a ground-down 13/16" socket.

-s-

 

My latest findings are they work great. I drove on them for an hour yesterday and at times under 14# boost - no breakup, no miss, no bad idle. Pulling them today for plug reading.

Im bought the 3933 ( heat range 9 ) and the 3932 ( heat range 10 ). Trying the 9's out now. I'll report back.


tom

 

Some conversions:

AR3935 = NGK 7 heat range,
AR3934 = NGK 8 heat range,
AR3933 = NGK 9 heat range,
AR3932 = NGK 10 heat range,
AR3931 = NGK 11 heat range

I ordered some AR3934 and AR3932 today . They are copper and not iridium, so it will be interesting to see how long they last compared to the BR*EIX's.

-s-

 

Here are some Champions that should also work.

C59A = NGK 9 heat range
C55A = 10
C53A = 10.5


http://www.sparkplugs.com/results_cr...=c55a&x=49&y=5

 

My concern isn't so much how the plugs will perform but moreso how they will last and handle the heat. I saw a comparison a while back that showed that the electrode on other plugs tends to round out and wear faster on most non NGK OEM style plugs. It's a major hassle but I'd say pull them at 500 mile intervals and post pics so the wear characteristics can be seen.

 

TRUE! Non "iridium and gold/palladium" will wear out faster.

But then I also wonder if Autolite or Champions can take the total heat/pressure abuse of our engines which is twice as often as normal 4 cycle engines.

 

I'd do this, on a 1000 mile interval, if you find me a link to this info:


-s-

 

I'll let you all know, but for now I like the power, performance and especially the $2.50 price for each of them.

Tom

 

what car/ motorcycle are these for?

 

thanks for the plug tip. i love autolites... where did you find them for 2.50 per?

howard coleman

 

Wow, took forever to dig this up. The original thread I found this info on is all but non existant anymore. Infact when searching for silverbulletrx7 only one thread shows up (well maybe this one also now). Its only one of the 2 pages I was looking over from that thread but mind you I found this info late 2003 early 2004 so finding them both is definately proving to be a challenge. When I find the other page I'll post a link to that as well.

http://www.silverbulletrx7.com/plugs/index.html

 

Just to let everyone know advanceautoparts.com has them (autolite) and they are cheaper than sparkplugs.com and it's the same amount for shipping. they cant get them at the store but you can order them off of their website. they also have the B10egv cheaper than sparkplugs.com

 

oh and the b10egv you can have ordered at the store and they dont charge anything and it usually only takes 1 day to get them

 

Plugs are working great. I pulled them today and may go to a colder
plug - AR3932.

Cheers,Tom

 

I read a couple things on sparkplugs.com about heat range....

"The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug. For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.... When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage."

SO my question is, would running Autolite AR3933 (9 heat range) actually be too hot of a plug assuming sparkplugs.com info is correct??

 

I posted photos of mine after ~1300 miles. They work fine, but the electrodes are wearing more quickly than I'd like.

https://www.rx7club.com/showthread.p...85#post4766985