Spark plugs for supercharged engine
Turbo Mini Forums

Previously when my engine was an N/A SPI I was running BPR6ES spark plugs and it ran fine. Now that I have supercharged it, should I run something different? I have it up and running and no issues with spark or miss firing but it is going onto the dyno next week to be thoroughly tuned and I want to ensure it has the correct plugs.
When doing a search on here most are using BPR7ES.

Specs are:
1275 supercharged with standard pulley. Not sure of boost figures
Comp - 8.45:1
Turbo head with 35mm inlet valves
LCB manifold, ceramic coated
Custom inlet manifold with twin injection.

Looking for a good drive car with some low end torque. Not looking to break records on the dyno.

Opinions on plugs?

I used to run BPR7ES plugs on mine I never had any probs with them but once they started to foul up it was game over with them.

You will def hav to go the bpr7 for everyday driving and maybe bpr8 if you r running the boost really high. with ngk the higher the number the colder the plug and yhats what you need wit any boosted application. I run the bpr8 in mines. hope this helps.

OOPS I meant that's lol

+1

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

some other brands dont seem as prone to this, I think its the ceramic that NGK uses.

Thanks guys for your info. So the 7 or 8 is the go but preferably in another brand. I have never had any trouble with NGK but I also haven't had a S/C mini.

I've never had any problems with the NGKs and I've had them dripping with fuel. A quick flash off in the gas burner and they went right back in.

We killed a set today, tried burning them off but no luck,

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

I did get mine pretty black when I first started the car with the S/C on it but they still fired ok.

They were friggin awful on mine, twas a nightmare when trying to get the idle and no load fueling right. Its s pain in the arse to keep having to clean em up as well. That said the easiest way to clean them was to give it a good blasting.

Going cooler than a 7 is not necessary. 6 should be fine.

It all comes down to the age old way of looking at the colour of the plugs to determine burn condition and plug temperature. This seems to be a lost art but is one thst is still used by test and development outfits

if you are continuously fouling plugs you have one or two problems or both. First would be a poor fueling set up ( easy to avoid with fuel injection) or too cold a plug. You'screwed if you suffer both at the same time.

Edited by Sprocket on 1st Dec, 2013.

Good call.
With all the technology in cars these days people forget to start with the basics. I see it every day at work. First thing the mechanical does is plug it up to the diagnostic machine.

I will buy a set of the 7's just in case but see how the 6's go.

Cause you haven't got an intercooler wouldn't too cold plugs cause problems?

on new minis they up to the BCR8ES when running reduced pullies

No intercooler. Like I said. The 6's are running fine although it is not properly tuned yet. I can't even take it round the block as the fuel table isn't set up for all loads and rpm's.
So even though it runs it may not when pushing it a bit.
I am probably over complicating it. We'll see how it goes