Jon's Hellcat

[jonx96]

I have never checked my plugs yet, 10,500 miles, maybe I should ?
I wonder at what point is it good to go with colder plugs ?...I'm at 15 > 16 lbs. on the 2.85 & my tuner said when I need to change to go with stock.

I'm thinking setting gap at .028, does that sound ok ?

I don’t think you will go wrong with one step colder. I think that would be a perfect gap for you. We went ngk. But I don’t drive the car a ton I would have been fine with a silver plug instead of iridium. You’ll have to see what you want. Iridium just last longer but silver or copper does better with heat but don’t expect them to last. NGK seems to do good tho with this plug for it being iridium and dealing with the heat issue of iridium

 

[Speedy!]

Couple things...normally a burned strap doesn't happen as a result of knock, although knock can be a side effect of a lean condition, which would induce knock. Hopefully that makes sense. The cars I've seen that had knock the strap wasn't burned but crushed into the electrode. Obviously there are exceptions but that's what I've typically seen.

As for plugs and heat range, when I was replacing my engine I checked the plugs in the RE motor and they were Bosch R6 Iridium P/N 9748 heat range 7. NGK 2309 are heat range 7 as well I believe. I left the stock plugs in place since the RE motor is designed for 14.5psi stock.

 

[Mean Cat]

Much cheaper then some other places selling them as a set. They were like $6 a plug

View attachment 62358

So you said these are 1 step colder plugs ?
I do like the iridium for longevity.

 

[Mean Cat]

Couple things...normally a burned strap doesn't happen as a result of knock, although knock can be a side effect of a lean condition, which would induce knock. Hopefully that makes sense. The cars I've seen that had knock the strap wasn't burned but crushed into the electrode. Obviously there are exceptions but that's what I've typically seen.

As for plugs and heat range, when I was replacing my engine I checked the plugs in the RE motor and they were Bosch R6 Iridium P/N 9748 heat range 7. NGK 2309 are heat range 7 as well I believe. I left the stock plugs in place since the RE motor is designed for 14.5psi stock.

View attachment 62519

Same plug as Hellcats.
And the stock plug is double iridium

 

[vortecd]

A base supercharger kit making 6 lbs you would go 1 step colder. Our cars are around 10 then going more on top of that should be going a step colder. Can you run stock heat range with more boost, yes. Just more insurance with more boost to go colder.

 

[vortecd]

So you said these are 1 step colder plugs ?
I do like the iridium for longevity.

I read stock heat range is a 6, that bosch number does show a 7 heat range

 

[Mean Cat]

stock plug heat range is a 6, these are a 7

ok so higher the # the colder the plug

Have not brushed up on my plug knowledge lately

 

[Mean Cat]

Stock plug that @Speedy! showed is $16 a plug at Auto Zone.

 

[vortecd]

well somewhere I got wrong info. Being stock is a 7 then they should be fine. The NGK also is a 7. My bad

 

[vortecd]

I

Stock plug that @Speedy! showed is $16 a plug at Auto Zone.

f you want to stay with stock Bosch plugs they will be cheaper going rock auto

 

[Mean Cat]

I read stock heat range is a 6, that bosch number does show a 7 heat range

So maybe 8 heat range ?

 

[Mean Cat]

I

f you want to stay with stock Bosch plugs they will be cheaper going rock auto

I like the cost of the NGK & iridium

 

[Speedy!]

Don't change heat range just because, do it based on how your current plugs look. Too cold and they get sooty. I ran heat range 7 in the old car as well (2309 NGK) and it was also around 16psi. I'd expect that to be good to close to 1000hp.

 

[vortecd]

So maybe 8 heat range ?

I thought stock was a 6 being it is a 7 then stay with. I ran 20 lbs of boost with a 7

 

[vortecd]

Don't change heat range just because, do it based on how your current plugs look. Too cold and they get sooty. I ran heat range 7 in the old car as well (2309 NGK) and it was also around 16psi. I'd expect that to be good to close to 1000hp.

I hate spreading bad info and I don't know where I read stock was 6

 

[vortecd]

The NGK are a $1 cheaper per plug then the Bosch at rockauto

 

[Mean Cat]

I hate spreading bad info and I don't know where I read stock was 6

It happens

 

[Speedy!]

I hate spreading bad info and I don't know where I read stock was 6

It's actually more difficult than it should be to find specs on the stock plugs. I had to do about 3 cross references to eventually figure it out.

 

[jonx96]

I started the car and let it idle and gave it a few revs. Tested again and the cylinder tested much better than last night. I’ve been talking with @16GoManGoHC2 and he thinks there’s a chance it will recover to the proper range of 10 percent or less. He has seen them recover before. So I don’t think I’m going to just through an engine in yet.

 

[Speedy!]

I'd scope it to see if you can see anything.