Colder plugs on stock motor?
#1
Colder plugs on stock motor?
Just changed my plugs, used the NGK iridium motorcycle BR*IEX plugs, but they didn't have any 7's in stock, so I'm running BR8IEX leading and BR9IEX trailing.
My motor is completely stock, but I will be installing a downpipe within a week or two. Colder plugs should be less likely to detonate, but foul more easily, but Iridium should make a better spark and last longer. I'm hoping the hot summer weather will play a factor and prevent fouling. It was 100+ degrees yesterday while I was changing them.
The BR-IEX's were $7.00 each at my local motorcycle shop
, and they had a thin-wall wrench to use for installing them. I had to grind the walls even thinner.
I just wanted some feedback, has anyone tried this? Is there anything I'm missing?
-scott-
My motor is completely stock, but I will be installing a downpipe within a week or two. Colder plugs should be less likely to detonate, but foul more easily, but Iridium should make a better spark and last longer. I'm hoping the hot summer weather will play a factor and prevent fouling. It was 100+ degrees yesterday while I was changing them.
The BR-IEX's were $7.00 each at my local motorcycle shop
![Big Grin](https://www.rx7club.com/images/smilies/biggrin.gif)
I just wanted some feedback, has anyone tried this? Is there anything I'm missing?
-scott-
#2
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Here are photos of the old plugs, I've never seen any as bad as these. I was under the impression that the dealership I bought the car from had changed them out, but obviously they hadn't. I wonder how long it was since the previous owner changed them... ![eek](https://www.rx7club.com/images/smilies/eek.gif)
Also I mis-typed the part number for the plugs I installed. It's BR8EIX leading and BR9EIX trailing.
I'm thinking the colder leading plugs might be a bad idea, these leadings were pretty dark. The rear rotor wasn't quite as bad, but same basic thing, lighter trailing, darker & more gunk on the leading. Everything feels fine so far, but I'm planning on checking these ones in a thousand miles or so, will post an update then...
-s-
![eek](https://www.rx7club.com/images/smilies/eek.gif)
Also I mis-typed the part number for the plugs I installed. It's BR8EIX leading and BR9EIX trailing.
I'm thinking the colder leading plugs might be a bad idea, these leadings were pretty dark. The rear rotor wasn't quite as bad, but same basic thing, lighter trailing, darker & more gunk on the leading. Everything feels fine so far, but I'm planning on checking these ones in a thousand miles or so, will post an update then...
-s-
#5
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Also from my understanding Iridium plugs just last longer but copper still gives the best spark. Platinum and Iridium ive heard is just so they last longer.
#6
That photo shows the plugs as if you were looking at the motor from the drivers' (left) side of the motor:
The idle with the BR*IEX's (w/ 3k miles on them) was fine, there was a bit of that 'puffing' sound that seems to come as the plugs get older, and go away right after you switch to new ones, but it was plenty smooth. I was mostly curious to see how they held up, being non-stock plugs and in different heat ranges than I had planned on using. It looks like 8's were good to use, I might try 9's next time, because to me the leading's look like they were getting too hot, or at the very least could afford to be dissipating more heat.
I do have a slight exhaust leak at the downpipe >> cat junction, and it's causing the car to overboost a bit (+1-2psi at full throttle). That could be causing the apparent hot/lean condition, though I'm not sure.
I switched back to stock copper plugs, BUR7EQ and BUR9EQ, mostly because I want to get a feel for what the car's like with fresh stock plugs in it. The wires are old and I'm looking into either buying a set of NGK's or making a custom set of MSD's, if I can find some that will match with the BR*EIX's threaded end.
-s-
Code:
Front Trailing . Rear Trailing Front Leading . Rear Leading
I do have a slight exhaust leak at the downpipe >> cat junction, and it's causing the car to overboost a bit (+1-2psi at full throttle). That could be causing the apparent hot/lean condition, though I'm not sure.
I switched back to stock copper plugs, BUR7EQ and BUR9EQ, mostly because I want to get a feel for what the car's like with fresh stock plugs in it. The wires are old and I'm looking into either buying a set of NGK's or making a custom set of MSD's, if I can find some that will match with the BR*EIX's threaded end.
-s-
#7
www.silverbulletrx7.com
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When your idle gets "puffy" as you say you are probably losing power and the plugs need changed. It's a gray area though as to how lumpy the idle is. I normally notice this after 3K or so on stock plugs.
As for the exhaust leak that shouldn't make any difference in boost or a hot/lean condition. I have recently developed a super bad exhaust leak and other than sound it has no impact.
dis1
As for the exhaust leak that shouldn't make any difference in boost or a hot/lean condition. I have recently developed a super bad exhaust leak and other than sound it has no impact.
dis1
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