Bosch spark plug extensions

[tvr4ever]

My local indy wants to know the part number for the Bosch spark plug extensions i ordered. It seems that there are three different versions.

Does anybody know what the Bosch part number is ???

[sumoone]

i have an extension that will not stay on the plug and the part no is as follows

0 356 351 047

i have a pre serp 5.0 ltr RV8 (94)


mark

[GJR]

Not sure about the Bosch pt.No. but both these websites are using the same code/pt.No. :- E0142

http://www.racetechdirect.co.uk/product-subsection...

http://www.clever-trevor.net/part/29/plug-suppress...

HTH

G

[GreenV8S]

To add to the confusion, it's also common to use a Vauxhall part.

[tvr4ever]

GreenV8S said:

To add to the confusion, it's also common to use a Vauxhall part.

I know Peter, that's what I said to my indy. When he tried to order them, they at first wanted to send him Beru extensions, not nearly as good as Bosch. When he insisted (well I did...) on Bosch ones, they informed him that there were three different versions. I also tried to order them at an Opel (Vauxhall for you guys) dealership, but they could only order through their Opel dealer computer system the Beru ones.
So that's why I need the Bosch part number.

GJR, when you look closely at the photo of the first link you mentioned, you can see that the make of the extension is Beru, thanks anyway for the effort.

sumoone, I will try that number with my indy, thanks

[The AJP Griff]

The original ones have 5kohm resistance,if thats any help.Personally i wouldn't use the ones which look identical but have no resistance,even though they are significantly cheaper.

[tvr4ever]

The AJP Griff said:

The original ones have 5kohm resistance,if thats any help.Personally i wouldn't use the ones which look identical but have no resistance,even though they are significantly cheaper.

That might do the trick, i'll relay this info to my indy, thanks.

[GreenV8S]

If you have resistive leads then you want non-resistive extenders, so it depends which leads you have.

[The AJP Griff]

GreenV8S said:

If you have resistive leads then you want non-resistive extenders, so it depends which leads you have.

Is that true?I was advised that as the plugs are non resistive,then the leads and extenders should be reistive,ideally.This is what was std from new on my griff.

[tvr4ever]

GreenV8S said:

If you have resistive leads then you want non-resistive extenders, so it depends which leads you have.

OK, my leads say they are "supressed" (?)
So I should get extenders with the lowest resistence or non possible, right ?

[Griffit]

The AJP Griff said:

GreenV8S said:

If you have resistive leads then you want non-resistive extenders, so it depends which leads you have.

Is that true?I was advised that as the plugs are non resistive,then the leads and extenders should be reistive,ideally.This is what was std from new on my griff.

I think I read what GreenV8S said somewhere, be it on here or in the bible. I thought there was only one type of plug suited to the RV8 TVR's, which is non resistive. I've got resistive leads and swapped from resistive extenders to non-resistive extenders (from ACT) without any problems with either performance of the engine or radio interference - cured my misfire though!

[The AJP Griff]

Griffit said:

The AJP Griff said:

GreenV8S said:

If you have resistive leads then you want non-resistive extenders, so it depends which leads you have.

Is that true?I was advised that as the plugs are non resistive,then the leads and extenders should be reistive,ideally.This is what was std from new on my griff.

I think I read what GreenV8S said somewhere, be it on here or in the bible. I thought there was only one type of plug suited to the RV8 TVR's, which is non resistive. I've got resistive leads and swapped from resistive extenders to non-resistive extenders (from ACT) without any problems with either performance of the engine or radio interference - cured my misfire though!

To be honest it can all get a bit confusing once you start comparing possibilities with different plugs,leads and extenders.The more resistance you can keep in your HT circuit the better is what i was advised.This helps prevent backfed emf going back to your ignition module on dizzy equipped cars,or the ecu itself if you run wasted spark Omex/Emerald set ups.The plugs used by TVR are,as far as i'm aware,only used by TVR,and many of the best RV8 tuners just use BP ES type plugs rather than the B7ECS type.This also gives you a choice of either resistive or non resistive,ie BPR OR BP type.
These cars left the factory with both resistive leads and extenders,the non resistive extenders were only bought about as a cheaper alternative some years ago now,and not by TVR .I'd fit what TVR did myself,they knew what they were doing.
One thing i do find is that if i use resistive plugs,leads and extenders it seems a little too much,and the car sounds a bit 'fluffy',even though no loss of performance is present.I've used NGK BP7ES plugs in my car for years now,without any problem

Edited by The AJP Griff on Sunday 20th January 17:38

[GreenV8S]

The AJP Griff said:

GreenV8S said:

If you have resistive leads then you want non-resistive extenders, so it depends which leads you have.

Is that true?I was advised that as the plugs are non resistive,then the leads and extenders should be reistive,ideally.This is what was std from new on my griff.

That's what I mean. You want non-resistive leads with resistive extenders, or resistive leads with non-resistive extenders. So you need to get the right extenders to suit your leads.

Or you can fit resistive plugs, and non-resistive leads and non-resistive extenders.

Basically, you want to ensure that you have exactly one resistive component in the HT circuit.

[The AJP Griff]

GreenV8S said:

The AJP Griff said:

GreenV8S said:

If you have resistive leads then you want non-resistive extenders, so it depends which leads you have.

Is that true?I was advised that as the plugs are non resistive,then the leads and extenders should be reistive,ideally.This is what was std from new on my griff.

That's what I mean. You want non-resistive leads with resistive extenders, or resistive leads with non-resistive extenders. So you need to get the right extenders to suit your leads.

Or you can fit resistive plugs, and non-resistive leads and non-resistive extenders.

Basically, you want to ensure that you have exactly one resistive component in the HT circuit.

Sorry Peter,i'm confused by your reply there('thats what i mean'). What TVR fitted,and what i was advised was to have both leads and extenders of resistive type,as plugs are not resistive.IE two components need to be resistive.

[tvr4ever]

GreenV8S said:

Basically, you want to ensure that you have exactly one resistive component in the HT circuit.

OK, it's starting to make sense now, so with NGK B7ECS plugs I can use non-resistive components for the rest of the circuit. (did I get that right ...?)

[spend]

Sounds to me like Mike is simply suggesting use 2/3 resistive components. My logic dictates that the resistive components are most likely to deteriorate so the cheapest 2 of the three components should be the resistive ones. Since plugs are replaced frequently Mikes suggestion to use resistive versions seems eminently sensible. Expensive non-resistive leads and cheap resistive extensions would then seem the most cost effective.

Still confused?

Dave

[dwgriffith]

tvr4ever said:

GreenV8S said:

Basically, you want to ensure that you have exactly one resistive component in the HT circuit.

OK, it's starting to make sense now, so with NGK B7ECS plugs I can use non-resistive components for the rest of the circuit. (did I get that right ...?)

NGK B7ECS plugs are non-resistive types (no R in the code)?

[GreenV8S]

spend said:

Sounds to me like Mike is simply suggesting use 2/3 resistive components. My logic dictates that the resistive components are most likely to deteriorate so the cheapest 2 of the three components should be the resistive ones. Since plugs are replaced frequently Mikes suggestion to use resistive versions seems eminently sensible. Expensive non-resistive leads and cheap resistive extensions would then seem the most cost effective.

Still confused?

Dave

Don't see why the resistive versions should be noticeably less reliable than the non-resistive ones?

If you have a wasted spark you will have a much more powerful spark available and can afford to run a higher HT resistance. If you're driving the coils directly from the ECU you may well find that the ECU suffers resets from the back EMF spikes and increasing the HT resistance can reduce this problem. But with a standard dizzy/coil setup you want to be wary of having too much HT resistance. If you have resistive leads that are probably giving you 5K-10K resistance, that's pretty much all you want so everything else should be low resistance.

[griffter]

I always understood that the higher the resistance in the HT circuit, the higher the voltage BUT the lower the current. This gives a different spark characteristic to low voltage but high current. I think high voltage allows a bigger plug gap, but a lower current gives a shorter (and possibly less intense) spark.
So it's important to the get the resistive nature of the HT circuit right, and it affects (and is affected by) coil, plugs and plug gap (among, doubtless, other things).
With all due respect to Mike I suspect TVR used resistive extenders because Vauxhall did, and these were cheaply, easily and plentirfully available.
Non resistive leads will be copper - virtually unobtainable nowadays. Almost all leads are carbon - resistive - e.g. Magnacors.
Standard plugs are B7ECS but I've used Range Rover BP6RES in an emergency and not noticed a difference (in fact if anything they ran cleaner). BP6RES are widely available and cheap - they are fitted to RR, Morgans and Marcos V8s, so...

I suspect TVR decided they needed extenders to reduce heat at the leads, used carbon leads as these are virtually de rigeur, and accordingly had to use a non-resistive plug - which happens to have a heat rating and non-extended nose suited to prolonged heavy use (ie car being driven hard). Good sales pitch to charge £4 a plug.

The suppression (radio / LT ignition amp etc interference) issue is also an HT resistive thing - more resistance = less interference. I think as long as one component is at least 5k ohm resistive you should be OK on that score though.

Finally, I thought Bosch and Beru were one and the same or at least related. They're both German anyway.

Edited by griffter on Monday 21st January 08:59

[Griffit]

Just been reading the "Old dog, new tricks" article in this month's Sprint magazine and there is an excellent article on RV8 tuning options by the acknowledged guru, Mark Adams.

Reading between the lines he seems to be suggesting the coil lead and plug lead give the optimum level of resistance for an RV8 in a TVR application and thus no further resistance (e.g. plug extenders / plugs) is required. He goes on to recommend Magnecor leads... Page 18 is the page you'll be after if you're interested in the physics behind it all.

BTW: I mentioned previously that I'm running non-resistive plug extenders that I bought from ACT, from memory these are Beru but I'm willing to be corrected. Beru do not appear to be a budget brand as such if you check out their website and company history!