Champion Spark Plugs

[e21Mark]

I've recently been looking at competition spark plugs as a friends rally spec BMW E30 M3 has been getting through them at quite a rate.

BMW actually do a Grp A competition grade plug but they're £400+ a set of four.

http://www.ebay.co.uk/p/Genuine-BMW-CMSP-Saloon-Ig...

Champion do the QA55V, which is also listed as a competition plug for the EvoIII but I used to hear bad things about Champion.

http://www.ebay.co.uk/itm/4X-CHAMPION-RACING-SPARK...

Are concerns justified or is it just a case of people having their favourites?

[GreenV8S]

What do you mean by 'getting through them'? Are they being fouled, overheated, physically damaged? Unless you know what sort of problem you're trying to cure, it's impossible to say whether changing the plug brand/type/grade will cure it.

[stevieturbo]

Unless it's an absolutely extreme setup....spending that sort of money on plugs is mental.

And even if it is....it's still mental lol.

And I'd sooner use NGK or Denso long before Champion

[e21Mark]

By all accounts the plugs are fouling to the point of misfire. I know it's quite common to use a set of plugs to start and warm an s14, before swapping for a fresh set, but I'm unsure you wouldn't still need to do this even if you were running ridiculously expensive "because M car" plugs at £100+ each?

The engine in question is a full rally spec s14/ 2.5 with suitable cams, flowed/ported head, dual injectors etc. It a bit of a beast and combined with a Drenth sequential box, is a pretty awesome thing to see. Actually make that hear!

[Mignon]

[quote=e21Mark]By all accounts the plugs are fouling to the point of misfire./quote]

Then there's something wrong with the engine. Fueling, oil consumption or ignition system voltage. It could be as simple as some twonk trying to run the plugs with too big a gap for the ignition system.

[e21Mark]

The engine is fresh from a rebuild and certainly not consuming any oil. It's on DTA and running 'wasted spark' with mapping by Sandy Brown. It's certainly making the sort of power one might expect from an s14 of this kind of spec' but I don't know whether there might be an issue with plug gap?

Can the gap be altered on the plugs linked above?

Is there any formula to gapping plugs or is it a case of just seeing what works?

[Mignon]

That's hardly an unusual engine spec and the plugs have no idea it's a BMW and could care less even if they did so it shouldn't be any harder to ignite than any other similar N/A engine. Platinum electrode plugs, 0.75mm gap, gets the job done on most things.

[e21Mark]

I wasn't trying to suggest plugs would no the difference, but that there's no fault or obvious reason for fouling. As I said, it's quite common for s14 to be started with one set of plugs before swapping to another. I know even stock engines can foul their plugs if you have to start, stop and re start in quick succession.

I'll mention the gap but I'm also thinking this might have been a common issue for BMW to have their own race plugs?

[stevieturbo]

the pictures on those links are very hard to see, but if it's like the NGK or Denso race plugs, there would be very little gap adjustment.

But as others say, it should not be fouling plugs in the first place almost regardless of spec.

It suggests either an engine problem, tuning issue, spark issue or using too cold a plug.

And if it is fouling plugs, the sensible thing to do would be use cheap plugs and change often until you fix the underlying problem.

£100 for mega expensive plugs...or £400 for unobtanium coated plugs, will cover one hell of a lot of cheap plugs !

[Krikkit]

I would speak to Sandy again and see if he has any ideas... He mapped it after all, I've not seen his other race builds (admittedly not an S14) use plugs at that rate.

[stevesingo]

My S14 makes 280hp ish at WOT lambda 0.88 (AFR 12.94:1) and I use Denso IX27B without any overheating and certainly no fouling. This is a step colder in heat range that the recommended IX24B.

The issue with S14 engines running stock ECU, with or without piggyback A/N systems, is that the cranking enrichment and cold start enrichment is really quite coarse and if it fails to start quickly or it is ran for a short period of time, switched off and attempted to restart, they will foul the plugs.

With your DTA, your tuner should be able to tune the cranking and cold start enrichment much more accurately than stock.

[e21Mark]

I had that exact cold start issue with my first M3, when the seller had moved it prior to collection but never warmed it through. I had to call the RAC to remove the plugs etc.

I'll check and see what exact plug he's using Steve. (This isn't my engine) I spoke to a couple of other people racing M3 and they all use one set to warm their engines and another set to run with. None use these Group A plugs though, which it turns out have no adjustment. Do you run 4 or 8 injectors?

[stevesingo]

Four injectors, Bosch 0 280 158 123 627cc/min 25deg split cone running sequential injection.

Edited by stevesingo on Wednesday 15th March 20:54

[stevieturbo]

Sounds like either poor tuning, plugs are too cold, or needs a stronger ignition system.

We're well into the 21st century now, fking about changing different sets of plugs for hot and cold ??? WTF ?

[PeterBurgess]

Blimey Stevie, 21st Century? A few years ago I worked on a 19th Century 1898 De Dion engine, this January I cut seats on a 20th Century 1915 AJS V twin.......I'm getting there I'm trying to encourage the guy who owns the AJS to put it on my rollers, flat cap worn backwards an absolute must!

Peter

[stevieturbo]

PeterBurgess said:

Blimey Stevie, 21st Century? A few years ago I worked on a 19th Century 1898 De Dion engine, this January I cut seats on a 20th Century 1915 AJS V twin.......I'm getting there I'm trying to encourage the guy who owns the AJS to put it on my rollers, flat cap worn backwards an absolute must!

Peter

Did you need to change plugs in it for hot and cold ? lol

[Boosted LS1]

^ It doesn't have plugs Stevie.

It has a flint on top of the piston and a stone wedged in the head chamber.

[PeterBurgess]

Aye, but it runs a full race MegaFlint tm spark enhancer with a Neanderthal++ tm ox yoke ex manifold system

I don't think plug heat range worries obtain Stevie, just happy if they start!!!!

Peter

[99hjhm]

Any numbers off the plugs he is using? EDIT: Guess they are BMW branded.

Edited by 99hjhm on Sunday 19th March 14:09