spark plugs
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Joined: May 2005
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spark plugs
need to replace the spark plugs pretty soon in my car. (99.5 a4 1.8t) I want the NGKs but not sure which ones. You guys always say to go with copper, right? So just a ngk standard plug or ngk platninum or what? thanks
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Joined: Aug 2005
Posts: 167
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RE: spark plugs
I'm currently using NGK BKR6E, changed from NGK BKR7E. Car is very happy, specially during cold morning starts... I found this post rather informative:
Hope this helps...
D
ORIGINAL: Daft [/i]
The factory plug for our cars is the Bosch F7LTCR.
The NGK equivalent part (as a single ground type plug) is the BKR6E.
Bosch and NGK have different heat range indexes and this is why one plug is a "7" and the other is a "6".
If you wanted to get an NGK plug that was 100% identical to the F7LTCR, you would buy the BKUR6ET. Denso makes a similar multi-ground plug called: K20PBR-S10.
The problem with the F7LTCR, BKUR6ET and K20PBR-S10 is that they are all multi-ground plugs
http://www.sparkplugs.com/productIma...6437%2D2%2Ejpg
Multi-ground plugs have several ground paths so that when one spark path wears out, the spark can use another path that has a shorter gap (electricity takes the path of least resistance...). This allows the plug to maintain it's stock 0.032" gap for a very long interval (30,000 miles).
For people who are going to chip their car, a multi-ground plug is going to have a gap that will be too big for the added 8-10Psi of boost that a chip yields. This results in misfires and rough operation under full boost. To prevent this, you would want a plug with an adjustable gap. This means that you will need a single-ground plug.
http://www.sparkplugs.com/productImages/2/792%2Ejpg
Although this seems like a lower quality part, it will allow you to tighten the gap enough to prevent misfires and acheive better timing throughout the entire rpm range.
The rule of thumb is to close the gap 0.004" for every extra 50HP you extract from the engine via forced induction or compression changes. This means that the stock gap of 0.032" should be reduced to 0.028" for best operation.
Platinum and Iridium plugs are not a viable solution becuase they have a very narrow center electrode which is far more prone to misfires even if you tighten the gap. A copper single-ground plug like the NGK BKR6E is the best plug for this application due to it's price and availability. Most people can get this plug for less than $1.50 per plug.
The factory plug for our cars is the Bosch F7LTCR.
The NGK equivalent part (as a single ground type plug) is the BKR6E.
Bosch and NGK have different heat range indexes and this is why one plug is a "7" and the other is a "6".
If you wanted to get an NGK plug that was 100% identical to the F7LTCR, you would buy the BKUR6ET. Denso makes a similar multi-ground plug called: K20PBR-S10.
The problem with the F7LTCR, BKUR6ET and K20PBR-S10 is that they are all multi-ground plugs
http://www.sparkplugs.com/productIma...6437%2D2%2Ejpg
Multi-ground plugs have several ground paths so that when one spark path wears out, the spark can use another path that has a shorter gap (electricity takes the path of least resistance...). This allows the plug to maintain it's stock 0.032" gap for a very long interval (30,000 miles).
For people who are going to chip their car, a multi-ground plug is going to have a gap that will be too big for the added 8-10Psi of boost that a chip yields. This results in misfires and rough operation under full boost. To prevent this, you would want a plug with an adjustable gap. This means that you will need a single-ground plug.
http://www.sparkplugs.com/productImages/2/792%2Ejpg
Although this seems like a lower quality part, it will allow you to tighten the gap enough to prevent misfires and acheive better timing throughout the entire rpm range.
The rule of thumb is to close the gap 0.004" for every extra 50HP you extract from the engine via forced induction or compression changes. This means that the stock gap of 0.032" should be reduced to 0.028" for best operation.
Platinum and Iridium plugs are not a viable solution becuase they have a very narrow center electrode which is far more prone to misfires even if you tighten the gap. A copper single-ground plug like the NGK BKR6E is the best plug for this application due to it's price and availability. Most people can get this plug for less than $1.50 per plug.
D
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Joined: Dec 2005
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