arc_55

I am fairly new at rotary engines although not new to tuning. I am working with a car that is going to be a sub 300whp car and am wondering what plug options are best to begin with for trailing and leading.

I would like to start with fairly inexpensive plugs to begin with so i can accuratly read the plugs ground strap, heat range markings, and signs of detonation ect. I see alot of talk about plugs when researching but i was hoping i would get some consitent answers by making a post.

I will probably be putting in an iridium or platnium plug once my plug reading is done. So the more suggestions the better!

Thank you.

rx7brandon

iTrader: (1)

ngk stock trailing all around. until you get an amped ignition or go above 14 psi(400+hp). any other plug will not give you any better results for the extra cost.

arc_55

so you are suggesting ngk sd11a for leading and trailing? Just confirming the ngk number.

thanks for the input

edit: turns out the sd11a is not a ngk number i can go by when i call/research under copper core i get BUR9EQ for t2 trailing plugs.

As i did more research i realize theses are the plugs i am looking for and also found a nice article from mazada trix

http://www.mazdatrix.com/ign-2.htm


thanks for the help

redwkw

used stock spark plug if u need 300rwhp for ur 7's ...

swif

iTrader: (4)

Interesting. So the highter the number the colder the plug.

I myself was looking at what plug heat range to run on my car. and had asked for input as well. I am looking to hit low to mid 400s at the wheels with my single set up. I was told to run 10 all around. What are your guys thoughts?

Dudemaaanownsanrx7

iTrader: (23)

10's all around yes. Especially if you're running an amp. My 9's were burned to hell after a couple months of weekend driving. This could be attributed to either the temp or just the cheaper plug design in general. I'm now running greddy race plugs 10's all around. Much better plug.

To the OP the stock plugs would work fine for that power goal. NGK b9egv's all around are a little cheaper and a better plug IMO, but they require a special thin wall socket or a regular socket turned down on a lathe.

Brent

swif

iTrader: (4)

I illbe running HKS twin power on the car. What NGK plugs in 10s would be best? I plain on driving the car on weekends with a day or two during the week to and from work.

Thanks for your input. Why do you beleive the NGKs are better then the gredd plugs?

Dudemaaanownsanrx7

iTrader: (23)

No the greddy plugs are much better. They are supposed to last much longer as well. I used to run b9egvs. B10egv's would have been better. If the greddy plugs last i plan to run them exclusively. Stick to 10's, 9's are too hot with the twin power.

swif

iTrader: (4)

Who has the best price on these? What is the part number I should be looking for?

zaridar

iTrader: (3)

I have always heard NGK all the way! I heard that the 4 ground helps the spark go outward from the tip of the plug and not stay in between the electrode and ground like on a conventional one ground plug... also it has to ignite through that little hole in the housing... I was planning on running br9eq but you all say 10.... they dont make a br10eq i dont think so i might go with the br10eix iridium 1 ground.... any thoughts?

Dudemaaanownsanrx7

iTrader: (23)

GRD_SP-13000150 is the greddy part number o22-3989 is another number you can use to look them up. The cheapest I found was $116 shipped for 4, but they have since gone up where I first got them.

All the plugs I've mentioned so far are NGK plugs. Some people have run the stock plugs on pretty high HP rotaries. In my experience I have found that they have a greater tendency to foul. The bg9egvs made my car run better, and when I had a flooding issue they made the car start better.

The twin power isn't supposed to be run on a non resistor plug as it can apparently damage the box. (egv's are non resistor) I never had a problem with this, but have now switched to the greddy race plug. This is the same race plug by ngk just re-badged.

All 10's is what I recommend for a car running an ignition amp, or any car running 400-550 hp. The br10eix have been successfully run by many people as well, and are a resistor type plug. Meaning they are safe for the twin power. I've never run this plug but it should be another low cost alternative. In the long run the greddy race plugs are supposed to come out cheaper because they outlast other plugs by so much. My bg9egvs only survived like 2 months and the greddy plugs made the car run and idle so much better. So far they have outlasted the b9egv's, and as mentioned before not sure if this is completely due to the plug materials or the fact that I stepped down to a cooler plug, but I plan to stick with this plug.

If you're on the stock ignition system and low HP then stock plugs, or 9's all around would be fine.

zaridar

iTrader: (3)

ok thanks! ill have to keep that in mind... just curious about what anyone else on here is running for ignition for 12a carby. Im turboing mine like i said and am going to be pushing around 400rwhp.

swif

iTrader: (4)

Thanks for the info. I will start to seach out who has a desent price for the Greddy plugs. I will also stay with 10s.

swif

iTrader: (4)

How are the greedy plugs doing from that last time you posted?

Veryspeedy

Gday All,
I have a question about some plugs.
I have a s1 Rx7 with a 13B PP, it is a dedicated race car have asked many people about plugs and get different answers.
This is a track car only what is the best plug to use and how long should they last ?

TrentO

I've used the NGK R6725-105 (10.5 heat range) for my road race turbo for years. I've never had a problem. After a season of running rich I usually foul them up and wind up buying another set. I've run the NGK BR10EIX as well, with the same rough life, but I think the Race plugs were a little better for power.

-Trent

swif

iTrader: (4)

Thanks for the input.

What is the engine set up that you have?

the_saint

Trent,

Where did you get your plus from?

Which turbo are you running?

Which of the 2 do you prefer? Are you running a Twin Power?

Mike

GoodfellaFD3S

iTrader: (213)

^^What are your power/boost levels?

Reading through this thread, I don't see a problem with running 9s with a twinpower, especially at power levels around 300 rwhp. If they wear down, just replace them. They're not pricey, unlike the Greddy/NGK race plugs I've been running for years now......

the_saint

Rich,

Aiming for around 400 rwhp with a GT35 on a street port.

Current plugs need replacing, coincident with the install of the single turbo / power fc / and HKS Twin Power, etc.

I was running 9's all around successfully for years on my stock twins (14 psi) on a street port, and was wondering if they would suffice for the current setup.

I don't mind replacing spark plugs, although if there is a better option that would 'last' a longer and be driveable then I would be interested.

Thanks for the input.

Mike

GoodfellaFD3S

iTrader: (213)

Hey Mike,

you're at the level where I'd recommend the Greddy or NGK heat range 10s. I have found running 10 leading and 10.5 trailing works great for me at 15 psi low boost and 21 psi high boost.... around 430 and 500 rwhp respectively.

Note that if your tune is off these plugs can foul pretty easily, but once you have the AFRs dialed in they last for quite some time.

HTH--

the_saint

Thanks for the advice.

Any point tuning with the 9s before installing the colder plugs, i.e. not wanting to trash the colder more $$$ plugs.

For the NGK 10s, have a part number you can recommend? Any preference for either maker (HKS or NGK)?

Definitely helps.

Mike

AlexG13B

iTrader: (7)

Ima be running 10s with gredddy race plugs on my td61. Will be tuned shortly by BDC, hopefully be around 400rwhp with water injection and maybe a twin power.

GoodfellaFD3S

iTrader: (213)

Changing plugs can throw off your tune, I'd recommend get tuned with the plugs you're going to run. I use the race plugs all the time and they've proven to be streetable.

Make sure you pick up the Greddy (not HKS) brand or the NGK. Years ago I remember failures with the HKS iridium tips coming loose and fragging motors.

NGK part #s are R6725-10 (for 10 heat range) and R6725-105 (for 10.5 heat range).

the_saint

Rich,

Thanks.

Will try out the NGK plugs. Do they need a thin wall socket, if so will order that at the same time.

Mike