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Holden202T wrote:I was under the impression the end of the ceramic is more cruisy ranges and right in the plug at the top of the ceramic is where you'll find WOT readings .... and you usually need a torch or good light for this!

as for the brown, im not sure that's from additives, I get the same results with methanol ?!?!

If you use an additive in the methanol it gives a tan colour on the insulator, raw methanol should be a clean insulator like new out of the box but not as shiny.

I never use additives!

seems I found my issue. yep bloody bosch plugs once again.

The heat range was way out after speaking to my local mechanic about it. I forgot that I even had the bosch ones in there, I was testing something and must of forgot to put GM ones back.

dont mind the eroded electrodes, these are 2nd plugs which have likely 200k on them lol. but strap discoloration is to the bend and dry clean. no speckley deposits.



install some brand spaking new GM ones just before lol comparison showed 1/3 of the electrode gone in the old ones.

Different plug manufacturers use different numbers to show the heat range. NGK the larger the number the colder the plug but some other manufacturers are the opposite.

I've mostly used NGK and the odd set of champion plugs.

I had that with bosch once. I ran there's in a V8. For example NGK heat 6 was BOSCH heat 7 i think. One of the big manufacturers has a comparison chart.
I ran the Bosch super 4's in a 5 litre and they were fantastic. That engine used to kill a normal set in 1 tank it was that badly tuned. I got a long time out of the 4's.
Way before i knew about tuning, and that was after a pro dyno tuned it. Idle must of been aroun 10:1 AFR.

Pink additives?
After fixing it, around 15k on these platinum plugs...

whats the pink coolant leak ?

a lot of octane boosters makes them bright orange and you see it sneaking into gas at the pump now in some places around the globe

heres a couple from the Gemini, previously I was running NGK race plugs, basically a BPR6EFS but an 8, since going turbo I was fouling plugs more often so went to a BPR7EFS and its been much better.

this first one is the current plugs out of the Gemini, these are the plugs I had in it for my 10 second pass, and have been in it ever since (put them in that day at the track) and that was pure methanol, and recently I've had it running on E85 .... so might not be real accurate = .030 gap. and this one is a new set of plugs I had when I was trying different gaps at the dyno I basically put these in after finishing tuning/testing and tested the larger plug gaps .... .050 roughly.

delcowizzid wrote:a lot of octane boosters makes them bright orange and you see it sneaking into gas at the pump now in some places around the globe

BP for one. 95 in particular.