Harrop Owners Chime In!

[DrFerry]

Originally Posted by drwankel

Thanks! Good to hear. I should probably give these a shot. Regarding prices, these are for the R2556G-9, which apparently is the successor to the R2556B-9 as someone mentioned above. Prices are pretty reasonable.

30 bucks from Summit:

https://www.summitracing.com/parts/ngk-93253

$25.12 from NGK directly:

https://www.ngk.com/ngk-93253-r2556g-9-racing-plug

Even in today's inflationary environment prices have come down from 2017 - at least on these plugs.
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[DrFerry]

Originally Posted by drwankel

Thanks! Good to hear. I should probably give these a shot. Regarding prices, these are for the R2556G-9, which apparently is the successor to the R2556B-9 as someone mentioned above. Prices are pretty reasonable.

30 bucks from Summit:

https://www.summitracing.com/parts/ngk-93253

$25.12 from NGK directly:

https://www.ngk.com/ngk-93253-r2556g-9-racing-plug

I forgot to say... Try to figure what changed between the R2556B-9 and the R2556G-9 versions. The difference between the "B"and the "G" version means something. The specs for each are in the images below. Can always call NGK too.
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[DrFerry]

drwankel
Looks like I found the difference between the "B" and the "G" versions. The electrode in the R2556B-9 that I use is "non-projected" but the "G" version says "recessed". I have no idea what that will do. They still make the R2556B-8 as mentioned earlier which is the OEM heat range but all else is the same as I use. See image attached.
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[DrFerry]

Originally Posted by Davisca455

Just a little detail about the NGK R2556B-9. They aren't just a colder version of the OEM style plug, they have a significant difference in the design. (I'm a G-Power kit, and if you were to try these plugs in a stock engine, it will barely start, pops and farts, cranks out codes like a vending machine.) NGK has a new part number (R2556G-9) that supersedes the R2556B-9, and is MUCH less expensive.

OEM on the Left
NGK R2556G-9 on the Right (looks exactly the same as the "B" version)

Chris,
Can you post a photo of the difference between the R2556B-9 and the R2556G-9 center electrode? The NGK specs show the "B"means "non-projected" whereas the "G" means "recessed".. See specs in image below.
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[Davisca455]

Originally Posted by DrFerry

Chris,
Can you post a photo of the difference between the R2556B-9 and the R2556G-9 center electrode? The NGK specs show the "B"means "non-projected" whereas the "G" means "recessed".. See specs in image below.
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Here you go.

The "B" is on the left (55,000miles)
The "G" is on the right (10,000miles)

[Davisca455]

Originally Posted by DrFerry

Chris,
Can you post a photo of the difference between the R2556B-9 and the R2556G-9 center electrode? The NGK specs show the "B"means "non-projected" whereas the "G" means "recessed".. See specs in image below.
.

…additionally, I ended up looking for the "G" version, because the NGK website said the the "B" was discontinued and that the "G" was the replacement.

https://www.ngk.com/ngk-4962-r2556b-9-racing-plug

[DrFerry]

Originally Posted by Davisca455

…additionally, I ended up looking for the "G" version, because the NGK website said the the "B" was discontinued and that the "G" was the replacement.

https://www.ngk.com/ngk-4962-r2556b-9-racing-plug

Thanks Chris. I cobbled together a side by side image from NGK's website pages showing the difference in center electrode "non-projected" vs. "recessed" protrusion and it's attached below. Yes, I also saw the R2556B-9 was discontinued although the R2556B-8 in the OEM heat range is still available.

It's great to know the E9X M3 Forum community is still alive and well at M3Post - at least among the Harrop folks. I had signed off back in early April and recently took a look again in early July. Thanks for all your help with the photos, and your input regarding the NGK R2556B-9 and R2556G-9 plugs.

It turns out not only did G-Power Superchargers supply the plugs with their blower kits but also VF-Engineering based on an old post I found and included earlier (perhaps on another Harrop thread). Thanks again.
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[Davisca455]

Originally Posted by DrFerry

Thanks Chris. I cobbled together a side by side image from NGK's website pages and it's attached below. Yes, I also saw the R2556B-9 was discontinued although the R2556B-8 in the OEM heat range is still available.

It's great to know the E9X M3 Forum community is still alive and well at M3Post - at least among the Harrop folks. I had signed off back in early April and recently took a look again in early July. Thanks for all your help with the photos, and your input regarding the NGK R2556B-9 and R2556G-9 plugs.

It turns out not only did G-Power Superchargers supply the plugs with their blower kits but also MF Engineering based on an old post I found and included earlier (perhaps on another Harrop thread). Thanks again.
.

Glad to help (or learn).

I just added a side by side picture in my first reply to your request for a photo.

I suppose "Recessed" is NGK's updated way of saying "Non-Projected"?

[Davisca455]

Originally Posted by drwankel

DrFerry How many miles do you have on those plugs? You mentioned they were installed in 2017, so I'd imagine quite a bit.

Haven't done plugs yet with the supercharger, but I've got about 5k on the kit now so its probably close to time. The really short spark plug change interval with supercharging isn't something I was thrilled about. Would be great if I could get back to a 30K interval.

Are these plugs fine to run for a street only car, and one that is not always in hot weather? It gets cold here in the winter, usually likes to hang around slightly above freezing for a few months.

Also- hows your idle with these plugs?

I'm not DrFerry, and my blower kit isn't a Harrop, but I do have some mileage data to to share about the NGK R2556B-9 plugs.

My blower kit was installed in 2009, and since then the car went 55,xxx miles on the original set of NGK R2556B-9 plugs.
The car never gave me any indication that the plugs should be changed, it ran perfectly at all times, even the average fuel use was at 20.6mpg.
But reading the forum and seeing that some other folks were stating that their blower kit manufacturers were recommending 10k mile plug changes, I thought "Fine, what could it hurt?"
I didn't really expect that I'd notice anything different, but my throttle response after the initial install of the new plugs was very noticeably improved.
I'm a "spark plug" guy now.

[drwankel]

Originally Posted by Davisca455

I suppose "Recessed" is NGK's updated way of saying "Non-Projected"?

I have a wild guess on this. On the top of the NGK site it says this:

"NGK.com specializes in hard to find NGK products. We are not NGK Spark Plugs USA. To contact them, click here."

So this site is actually a reseller. Given the age difference between the listings, its possible that someone different entered the specs on the newer plug and just picked a different word, or maybe it was the same person and they just picked a slightly different word.

In a more far fetched possibility, NGK is a Japanese company, and the specs might have originally been in Japanese. Its possible that the end result here is two slightly different translations of the same Japanese word.

[DrFerry]

Originally Posted by drwankel

I have a wild guess on this. On the top of the NGK site it says this:

"NGK.com specializes in hard to find NGK products. We are not NGK Spark Plugs USA. To contact them, click here."

So this site is actually a reseller. Given the age difference between the listings, its possible that someone different entered the specs on the newer plug and just picked a different word, or maybe it was the same person and they just picked a slightly different word.

In a more far fetched possibility, NGK is a Japanese company, and the specs might have originally been in Japanese. Its possible that the end result here is two slightly different translations of the same Japanese word.

Perhaps so, but when I look very careful at this side by side of both plugs I can see the "B" non-recessed center electrode version does protrude very slightly more than the "G" version perhaps by 0.5mm or less. The plugs come pre-gapped so functional performance "maybe" the same. Davisca455 is currently running the "G" version. If there's a difference in performance I'm sure he'll let us know. See image below.
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[SilverSlug]

Did Harrop re-continue producing their super chargers??

Last I heard, Harrop discontinued production, and the last kit they made sold to one of our members (a few months ago).

Did something change??

[ygoz]

Originally Posted by SilverSlug

Did Harrop re-continue producing their super chargers??

Last I heard, Harrop discontinued production, and the last kit they made sold to one of our members (a few months ago).

Did something change??

They never did, they stopped selling it in the US due to CARB compliance.

[Davisca455]

Originally Posted by DrFerry

Perhaps so, but when I look very careful at this side by side of both plugs I can see the "B" non-recessed center electrode version does protrude very slightly more than the "G" version perhaps by 0.5mm or less. The plugs come pre-gapped so functional performance "maybe" the same. Davisca455 is currently running the "G" version. If there's a difference in performance I'm sure he'll let us know. See image below.
.

It looks to me that in your side by side picture of the NGK's, the plug on the left is tilted away from the camera and their picture of the plug on the right is tilted toward the camera.
If I'm seeing it correctly, then that would explain why their picture on the right makes it look as if that electrode is further out of the body.

Here's a picture of my old "B" (left) and "G" plugs side by side.
The electrodes protrude the same amount.

(The gap on the "B" measured .030", the gap on the "G" measured .026")

(No performance drop with the "G". In fact I experienced snappier throttle response, but attributed that to fresh plugs.)

[tbuck]

Originally Posted by gozmanyoni

They never did, they stopped selling it in the US due to CARB compliance.

Mike managed to get a final consignment of like 11 kits from Harrop, but as of now these are not available. That may change and Mike is undoubtedly trying to get more.

[DrFerry]

Originally Posted by Davisca455

It looks to me that in your side by side picture of the NGK's, the plug on the left is tilted away from the camera and their picture of the plug on the right is tilted toward the camera.
If I'm seeing it correctly, then that would explain why their picture on the right makes it look as if that electrode is further out of the body.

Here's a picture of my old "B" (left) and "G" plugs side by side.
The electrodes protrude the same amount.

(The gap on the "B" measured .030", the gap on the "G" measured .026")

(No performance drop with the "G". In fact I experienced snappier throttle response, but attributed that to fresh plugs.)

Thanks for the information and photos. I called NGK USA and spoke to their Technical Support (Lela). NGK USA told me the R2556B-9 and the R2556G-9 versions are identical. The center electrode protrudes 0.5mm on both of them.

[DrFerry]

Originally Posted by Davisca455

It looks to me that in your side by side picture of the NGK's, the plug on the left is tilted away from the camera and their picture of the plug on the right is tilted toward the camera.
If I'm seeing it correctly, then that would explain why their picture on the right makes it look as if that electrode is further out of the body.

Here's a picture of my old "B" (left) and "G" plugs side by side.
The electrodes protrude the same amount.

(The gap on the "B" measured .030", the gap on the "G" measured .026")

(No performance drop with the "G". In fact I experienced snappier throttle response, but attributed that to fresh plugs.)

Oh look, G-Power is selling them too. And for a pretty penny I might add.

PLUGS
https://www.g-power.com/en/configura...ugs-m3-e9x-b82

G-Power E9X M3 Goodies
https://www.g-power.com/en/configura...3-2007-2013-39
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[tom @ eas]

Originally Posted by DrFerry

Thanks Chris. I cobbled together a side by side image from NGK's website pages showing the difference in center electrode "non-projected" vs. "recessed" protrusion and it's attached below. Yes, I also saw the R2556B-9 was discontinued although the R2556B-8 in the OEM heat range is still available.

It's great to know the E9X M3 Forum community is still alive and well at M3Post - at least among the Harrop folks. I had signed off back in early April and recently took a look again in early July. Thanks for all your help with the photos, and your input regarding the NGK R2556B-9 and R2556G-9 plugs.

It turns out not only did G-Power Superchargers supply the plugs with their blower kits but also VF-Engineering based on an old post I found and included earlier (perhaps on another Harrop thread). Thanks again.
.

Normally referred to as NGK #9, these have hand-installed electrodes. Believe these were also used on the R35 GTR.

[Davisca455]

Originally Posted by DrFerry

Oh look, G-Power is selling them too. And for a pretty penny I might add.

PLUGS
https://www.g-power.com/en/configura...ugs-m3-e9x-b82

G-Power E9X M3 Goodies
https://www.g-power.com/en/configurator/bmw-1/3-series-38/m3-e90-e92-e93-2007-2013-39
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Barf!

Ya, I'm in Northern California so I'm not having them shipped from Germany if at all possible.
Whatever GP-Infinitas spares that I can get locally, that's the route I take, but it usually takes some investigation to figure out if that's even an option.

Summit has a large facility in Reno Nevada, and they usually have them in stock there.
Reno is just 2-1/2 hours away from my place, so I typically get my Summit orders next day for the regular shipping price.


https://www.summitracing.com/parts/ngk-93253

[DrFerry]

Originally Posted by Davisca455

Summit has a large facility in Reno Nevada, and they usually have them in stock there. Reno is just 2-1/2 hours away from my place, so I typically get my Summit orders next day for the regular shipping price.

https://www.summitracing.com/parts/ngk-93253

Thanks for the alternative and domestic parts source.

[DRLane]

I ordered a set, I'll report back upon install and upcoming track event.

[DrFerry]

Originally Posted by DRLane

I ordered a set, I'll report back upon install and upcoming track event.

Any news?