Hi guys.

First of all about my RX7 and my problem. On high RPM and the time of changing
gear not happend full ignition in rotary housing, some ignite in exhaust,
comming fire from muffler and have a sound like this " butk..butk.." .
I think prime cause is spark plugs and I am going to change them.
What do you think about it?

Second, which spark plugs is better? RX7 TT type R 1993. No modify on my car, only after market full exhaust.
I am going to use NKG spark plugs, and interesting which combination is better:
1. leading both - BUR7EQP, trailing both - BUR9EQP.
2. all - BUR9EQP.
3. all - BUR7EQP.
4. or which other?

thanks.

 

all bur9eqp

 

Unless your car is fairly modified, just use the stock setup of 7's and 9's. Also, go ahead and replace your O2 sensor and run a bottle of fuel system cleaner in your next tank. A little backfiring is normal with a rotary but it shouldn't be too excessive.

 

given your mods,unless you run on the track all the time,use bur9eqp trailing and bur7eqp leading.
your problem is likely to be an air leak into the exhaust

 

i had this problem with shooting from the exhaust, in my case it was - dirty/used spark plugs(causing missfire) and leaking exhaust(needed to reeplace the gasket)

spark plugs
all 9s or bur9eqp trailing and bur7eqp leading

(me for example i have 11.5 plugs - really cold- for a drag car or something really modified , but because of the way i drive it - proper ragging :] they work ok for me (so far )

 

you need to list your modifications. The car will backfire if you have removed any pollution equipment.

 

Which spark plug holes are leading and what ones are trailing is there a chart or is it as simple as top hole on both sides are leading ?

 

I bought my car with all 9s in it . I dont think it is heavily modifided , and it fouls plugs once in awhile. The engine has been rebuilt has a down pipe and Race beat muffler. What mods would call for this set up what is the theory behind it?

 

The theory is the colder the plug, the better protection against pre-ignition. However, the downside is that using a plug too cold will cause pre-mature plug fouling and worse gas mileage.

You mainly only need to move to a colder plug when you are running higher levels of boost. If you are running stock boost, there is no real reason to run anything other than stock plugs.

 

T=Top=Trailing
L=Lower=Leading

The stock spark plugs also have T and L on them to indicate where you should place them

 

Thanks a lot guys.
Everything clear.

And which wires are better for me?
Think, I should replace them too.
Give me advise.

 

just check if you need to change them, have a look inside there is no point changing the leads if they in good working condition..

 

If by full exhaust you mean downpipe, midpipe and a cat back, you may have a problem. These cars start to behave kind of strange with a downpipe, exhaust and no cat. You may be in a situation soon where you need an ecu. If you are shooting fire that would indicate a rich condition which is good, well better than lean at least. Stock plug configuration is fine. It would also be fine if you ran 9's all around. As far as plug wires are concerned, i would recommend ngk or magnecore. I had magnecores and switched to ngk. I like the material that the ngk wires use better. Good luck!

--Hank