View Full Version : RX7 plugs in RX8??
Herblenny
06-26-2008, 10:41 AM
Can someone post some information about this??
Herblenny
06-27-2008, 11:19 AM
OK.. I guess NO ONE.. LOL!
I'll post some comparison pics this weekend!
Herblenny
06-27-2008, 11:43 AM
after a bit of research, only the RX7 plugs for the trailing will affect the housing.
I'm curious since leading is the main fire, Can I use the leading from RX7 and trailing from OE RX8 plug?? Lets have a short debate:)
Herblenny
06-27-2008, 11:45 AM
From the other forum
If you are talking about RX-7 plugs (BUR9EQP [NGK-5255], IRE01-31 [NGK-5720]), DO NOT run those in your trailing position. They will bottom out and distort your housings.
If you are talking about OEM RX-8 plugs (RE7CL, RE9BT), do not run trailing plugs in your leading position. They are too short and the electrode design will induce shrapnel.
Either run correct OEM plugs in their proper positions or run RX-7 trailing plugs (BUR9EQP [NGK-5255])in the leading position for turbo applications if so desired.
The trailing plug on the FD is 21mm. The trailing on the RX-8 is 19.
When you tighten an FD trailing plug into the Renesis trailing plug hole, it bottoms out before the gasket hits the mating surface.
This means the base of the electrode is pushing against the housing.
I've seen the damage. Don't do it.
Phoenix7
06-27-2008, 12:07 PM
:dunno: I heard you CAN use 8 plugs on the 7 but they must be gapped properly, don't know much other than that though.
WE3RX7
06-27-2008, 04:18 PM
I dont mess w/ the plugs on the 8 unless serious boost is introduced. I ran the last 8 on 8.5 psi on stock plugs all day with no issues... OE should be fine for most if not all NA applications on a renesis...
Herblenny
06-27-2008, 11:07 PM
I put some new FD leading plugs (7s) on the 8. Measurements are the same and after installation, car started right up! It actually idled perfect. But didn't have a chance to drive it around. But I think its ok? I guess I'll find out tomorrow....
Herblenny
06-28-2008, 07:11 AM
Plugs..
Comparison between FD plug vs. Renesis..
As you could see, trailing plugs have different thread length..
http://rotarycarclub.com/attachment.php?attachmentid=1866&stc=1&d=1214654817
But the leading length is VERY similar..
http://rotarycarclub.com/attachment.php?attachmentid=1867&stc=1&d=1214654835
http://rotarycarclub.com/attachment.php?attachmentid=1868&stc=1&d=1214654863
And here is the reason why I wanted to use FD plugs... because I have like 70-80 new plugs:)
http://rotarycarclub.com/attachment.php?attachmentid=1869&stc=1&d=1214654918
Herblenny
06-28-2008, 06:08 PM
My impression on the FD leading plugs....
When first cranked, it started it right up and felt smooth.
I was on the interstate and engine felt really smooth... but lacked slight pull that I had previous. After about 120 miles today, I noticed it really lacked power. I also noticed that when rev'd up, it had slight break up.
I just put my old plugs (less than 5k miles) back in after removing some carb build up. Immediately I noticed noticeable power and when rev'd up, no hesitation or break up.
Thats my impression with FD plugs.
Nexcis
06-30-2008, 08:22 AM
I know this is in the wrong forum but... it's relaited to the conversation...
Okay, given your recent findings Phil, what is your impression on using the 8 plugs on the 7?
Herblenny
06-30-2008, 08:38 AM
Well, I know a lot of FD owners running 300+ HP prefers to use all 9s instead of 9s and 7s.
That being said, Trailing 9s from 8 will not work on FDs. So, that only leaves with 7s for the leading.
Now I think its not much to do with FD 7s but could be something majorly wrong with my 8. Last night, I did all the resets and crank the car up and let it idle for 10 mins. This morning, I got it started and the car idled quite badly. RPM will hike up to 2k and then drop backed to 750 and idled like ass. I'm going to swap both leading and trailing with my older plugs this afternoon and see if its any better... I8U stated that it could be the PCM... I'm taking the car into the dealership in the morning and see what they could tell me.. I'm quite fed up the the 8!!! I know a lot of you think its a great car, but I'm starting to think differ.. I've literally tried everything I could do but now I'm hitting the wall on this damn car!! And its worth less than my FD:) The headache isn't worth it!! We'll see what the dealership says... If its going to cost me more than a grand, I'm NEVER buying another fucking Mazda Rotary for daily!
Nexcis
06-30-2008, 12:25 PM
You know how some FDs were / are cursed? I think you got one of those 8s that are. I've yet to have any problems with my 8.
Herblenny
06-30-2008, 01:26 PM
Maybe so... I'm taking the car into the dealership tomorrow at 9. I've been collecting ton of extra parts just in case they tell me its the PCM, Engine, TB, coils, sparks, wires, wiring harness, UIM, LIM, injectors, etc... Only think I haven't bought is the fuel pump:)
rx8man
08-25-2008, 05:48 PM
My rx8 had, RE6C plugs in it, which no company where I live can find anyhing on these plugs, but I did get giving on the RE8CL plugs--$85 EACH.
I'm running BUR7EQ's (costs $14) in the leading at the moment, could be a little down in power? No problems yet-- but these haven't been in there very long.
rx8man
08-26-2008, 11:26 PM
btw, the re6 plugs are the early plugs that came stock in the cars, and the re7 plugs are the updated versions, supposedly to combat flooding. You can get the re7 and 9 plugs on sparkplugs.com.
Cheers, No one here knew what I was talking about, when I rang around for Re6 plugs.
One Qustion, that someone may be able to help with?? Coils, when I did the 20b transplant, I used Bosch Coils with the LTX (mircotech) -- has bosch done a set for the rx8 -- yet??? Coz the Mazda Dealer here want $115 plus tax per coil.
rx8man
08-27-2008, 03:27 AM
Mazsport in florida (not the mazsport in aus) offers an ignition upgrade but I have not heard anything definite as to how good it is (and for $600US it should be damned good). Black Halo Racing is about to offer a conversion kit using GM LS1/truck coils which are proven to be strong and reliable and have heat sinks for long life. That is the route I plan to go with my car.
I'll give the Mazsport ones a miss, but I've had dealings with Ray from Black Halo Racing before:)
Cheers for the info, I'm E-mail him now, cheers
rx8man
08-27-2008, 04:55 AM
Mazsport in florida (not the mazsport in aus) offers an ignition upgrade but I have not heard anything definite as to how good it is (and for $600US it should be damned good). Black Halo Racing is about to offer a conversion kit using GM LS1/truck coils which are proven to be strong and reliable and have heat sinks for long life. That is the route I plan to go with my car.
Ray has just got back to me , and his prices are just over Half the Mazsport ones, Which is good:)
rx8man
08-27-2008, 11:25 PM
Yes, and you will get the product in less than 6 months after you pay for it, unlike what I am told about mazsport. :rofl:
Yip, and theres a big price difference, which means a far bit to people like me-- at the wrong end of the food chain....lol
:beatdeadhorse5:
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