rxseven07

i saw somewhere where you could put rx-8 spark plugs in our cars? whats the point? for the 13b or 12a?

Brianhsval

Couldn't say don't know what an 8 runs. Personaly I run BUR9EQ-14 in the trail and BUR7EQ in the lead.

Jeff20B

iTrader: (13)

You should run the plugs that were designed to match your ignition system. If you run newer plugs that were designed for direct fire, they'll tend to misfire in a cap'n rotor setup.

rxseven07

okay cool thanks

Narfle

iTrader: (16)

the FD's are seeing enhanced streetability and plug live with the 7AL plugs from the 8. the problem is they are $20 and relatively unreknown. i dont know if theyd fit the 12a. but im fairly certain they would work in the 13b with no detrimental effects. probably gains.

JoseReyes

They should fit, If you can fit 2nd and 3rd gen plugs on a 12A then why will the 8 plugs not fit.. except $$$$$.....per plug...

Rotor13B

Now wait a minute, The plugs from my SA would not fit in my 13B.

mcnannay

^ are you sure? I've interchanged br8eq-14's and bur9eq/bur7eq's between a few of mine and family members rx-7s

so i don't see why you couldn't use br8eq-14's in a 13b, actually my 13b is supposed to use them (74-78). I thought they all had same thread and reach.

BadAssRX-7

yea the dealer is the only place i could find plugs for a clients 8 and DAM they are PROUD

Rotor13B

I'm positive, When I first got my 83 i was diagnosing an ignition problem and was going to use the plugs in my SA since they were brand new. When I pulled the plugs and checked them against the ones in the 83, The head (threaded part) was smaller than than the head on the plug i pulled out of the 83.

Mr BiG G

newer plugs designed for direct fire shouldn't misfire in a cap n rotor setup as long as the new plugs aren't hotter plugs

mcnannay

were you using ngks? im sure autolites look different, dont know about reach, but yes the br8eq-14's (pre 86 plugs)look completely different because they dont use the semi surface discharge style that the bur9eq/bur7eq use (btw thats what the extra U in the part number designates). But you're not going to run into any clearance issues.

mcnannay

i was trying to think and get all my facts straight here, and this is what i remember for sure:

I have used both bur9eq/bur7eq's in my 74-78 13b block, as well as br8eq-14.
I have used br8eq-14's in both my brother old 82, and his current 84 gsl.
So id have to say there is no difference in the plugs, they both are interchangeable, although it is reccomended you use the correct plugs for your ignition system, and that the only drawback i see in using an rx-8 plug, but without experience i can't say. I don't notice any difference running the pre 86 plugs and the ssd's in my 13b.

Sorry for the semi-hijack

Rotor13B

It wasn't that the plug was going to be to long or to short, The actual diameter of the threaded part was smaller on the SA. Btw, they were nippon denso plugs.

kenn_chan

I think that maybe you bought the wrong plugs then, The only difference that might casue a problem with them physically fitting would be tht they used a special thin walled socket for a couple of years, other than that they should all thread in and the length of the threads themselves should be the same also.

kenn

Kentetsu

Jeff

What plugs should I be using then, if I have the 2nd Gen coil setup (12a)? Got me curious now....

Brianhsval

I have the 2nd direct fire on my '85 SE and run BUR7EQ in the lead with it. BUR9EQ in the trail.

vipernicus42

iTrader: (4)

Makes sense.. if you're using a 2nd gen coil for direct fire, you should run a 2nd gen plug setup..

But what I'm curious about is :

- Is there a difference between the type of plug you need in a 2nd gen direct fire vs. an Rx8 Direct Fire? If not... then as long as your car is running direct fire ignition (DLIDFIS, 2nd Gen coil, anything) then the Rx8 plugs might be worth a try.

Jon

Jeff20B

iTrader: (13)

vipernicus' logic is unflawed. Yes, it's worth a try.

There are surface discharge plugs, such as the 2nd gen and later, and the 'other' kind. Surface discharge typically is only found on direct fire ignition systems because it supposedly takes more voltage to jump the gap reliably. I've always followed the simple rule of matching plugs to the ignition system. You can try, for example, BUR9EQ in trailing on a cap and rotor system and it will work, but if it misfires, you'll never notice it. Trailing adds so little power anyway, that you'd not even notice it on a dyno since it'd have to misfire many, many times in a row to show up as a power loss. Infact, if you don't run trailing at all, the loss is still within a typical chassis dyno's margin of error.

Blah! Tell you what, if you don't have emissions testing in your area, can't find BR8EQ-14 in any autoparts stores anymore, and have some sort of leading direct fire ignition system, just get two BUR7EQ for leading and two BUR9EQ for trailing and be done with it. Call it the 2nd gen spark plug upgrade, or something. Let's make an acronym out of it. 2GSPU Wow, that looks official. One easy way to remember is L7 (remember the girl band?) and 9T (the 2nd gen cars were brand new in 1990)

By the way, the reason why I said that thing about not having emissions testing in your area and going with BUR9EQ in trailing was because if they do misfire, it could increase HC a little. Then again, there's nothing stopping you from trying it.

krew

OK I'm running a 12 a Bridgeport with 2 MSDa,s, which woulld be the best plug?

rxseven07

ive created a monster