The Definitive S2 Spark Plug Thread

[JP]

Denso Iridium have only one place in this world from personal experience and that is the bin.

[bad8008]

i was thinkin of using denso iridium power platinum any thoughts anybody?

What's the status of you using the Denso Iridium?
Anyone heard of Volker Iridium?

[bad8008]

Check those plugs!

I did mine the other day and was quite surprised
One thing I'd like to add is make sure the spark plug socket is very secure, it can take some time trying to get it out of the hole.

I also found it easier to remove the cover with the throttle damper removed.

Good one Steve

Matt.

Mate, how do I remove the Throttle damper?

[audiman]

snap on do a v good diamond coated tool that grips the plugs without a rubber insert (they always fall out) - expensive, but the best.

[bad8008]

guys, what's a good spark plug tool?

[JP]

If the car is mapped safely then you shouldnt be getting any det in the first place. Is it worth pushing an engine that hard for an extra 5-10 bhp at the redline???

Went from 525 to 591 on 4 degree of timing on the 1.8t last night then backed it of by 2 degree to 17 and it dropped to 562 running Vpower @ 1.5bar. The guy mapping couldn't detect any knock on the det cans whatsoever at 591 but the ECU was detecting 1 small spike at 8300rpm on 1 cyl, so as it is a road driven car we played safe and detuned it.

So the change of plugs with a safe map gained 37hp at surrey rolling roads. £120 vs £40 on plugs = 37hp for £80 which I consider a cheap mod.

[audiman]

Been playing with sparkplugs after repeated failures of the F5DPOR's from GSF and main dealer ended up settling with BKR-8EIX from NGK.

I wouldn't touch denso Iridium's with a barge pole, I have seen too many heads written of because of them breaking up on FI cars.

BKR -7E's and 8E's copper electrodes are fine but need regular replacing and don't like high boost application unless you close the gap to smaller than factory 0.6mm. The benefit though if you are getting det, the electrode will deteriorate and cause missing under load before you melt your pistons.

Looking at trying a set of plugs soon that will hopefully allow for more ignition timing that we tried on a 1.8T last night on the rollers were we managed to get to 19 degree advance instead of 15 without det. only downfall is they are £38 per plug.

If the car is mapped safely then you shouldnt be getting any det in the first place. Is it worth pushing an engine that hard for an extra 5-10 bhp at the redline???

0.6mm is fine for high boost, but limits the amount of flame and can be the cause of det iin the first place. Suprised you get the stock plugs giving issues. Ran my S2 with 2.5-2.7 bar peak holding 2.4ish boost for 20k with no misfires ever. But it was a safe map.

[S2Phil]

To stop plugs coming loose try installing the plug, nip it down then back it off and then retighten to desired setting. The crush washer obviously compresses when you first install the plug, when the engine runs then everything expands and the crush washer gets squeezed a touch more, when all cools the tension from the washer may relax allowing the plug to come loose.
I also find on plugs that are not pre-gapped that closing the gap will ensure that the spark isnt blown away under higher boost loadings. So if your gap is normaly .025" set it to .020".

[JP]

Been playing with sparkplugs after repeated failures of the F5DPOR's from GSF and main dealer ended up settling with BKR-8EIX from NGK.

I wouldn't touch denso Iridium's with a barge pole, I have seen too many heads written of because of them breaking up on FI cars.

BKR -7E's and 8E's copper electrodes are fine but need regular replacing and don't like high boost application unless you close the gap to smaller than factory 0.6mm. The benefit though if you are getting det, the electrode will deteriorate and cause missing under load before you melt your pistons.

Looking at trying a set of plugs soon that will hopefully allow for more ignition timing that we tried on a 1.8T last night on the rollers were we managed to get to 19 degree advance instead of 15 without det. only downfall is they are £38 per plug.

[audiman]

NGK plug is NOT pre gapped like the Bosch plugs.

If you cant buy Bosch, just order genuine (they are Bosch anyway)

[bad8008]

how they burn...

Thanks.

correction... meant to say "burnt off"...
excuse me english.

[bad8008]

yea. look fine.
engine well maintained
btw, wouldn't the spark plug for the ADU / ABY must be the same gap regardless its brand name? and also same screw thread pattern?
I know Bosch is a well known spark plug, but i think its also difficult to grab one of those recommended Bosch plugs from my area.
Anyone that doesn't use Bosch, please share your experiences and also some pics of the plugs after replacing them to see how they burn...

Thanks.

[audiman]

look fine

[CoCaine]

Do they look ok?

[audiman]

BK7re is what im running.

found the standard plug a little to hot in modded engine.

also the bk7re are about 12 quid a set delivered from sparkplugs.co.uk

Stock plug is the same heat range as the bk7re, NGK orig number is PFR7B, if you must use NGK plugs then you want an 8 range.

Bosch plugs work best all round, the stock s2 plug is used as a performance plug on many cars, VR6T,1.8T's,RS4's,RS6's, Porsche etc etc.