Best Spark Plugs?
Safety Car
Joined: Sep 2001
Posts: 4,411
Likes: 1
From: Wilmington NC
Originally Posted by BlownV6
The C5 has alittle rocky idle so i figure i'll go ahead and change the plugs and wires and see if that's the cause. What NGK plug is everyone using?
I don't think you can do better than iridium. A very tough material that allows a very small profile plug. This means less stuff in the combustion chamber.
Either the NGK TR55IX or the Delco version which is now OEM.
From Road and Track Technical Correspondence September 2004:
Sparkplug electrode material does not play a direct role in spark intensity. However, platinum and iridium electrodes can be much smaller, notably reducing misfiring because they result in more robust flame kernels. This is because the smaller electrodes are less of a shroud, exposing more mixture to the flame front.
An unusually dramatic illustration of this is with aftermarket supercharged engines running high boost. Such engines often falter terribly at high boost and high rpm due to ignition failure. Simply screwing in iridium-tipped sparkplugs typically eliminates the misfiring and allows the engine to rev to its power peak. In practice, this means a simple plug change is worth 30 bhp simply because the new plugs allow the engine to reach its designed redline.
Le Mans Master
Joined: Nov 2000
Posts: 6,266
Likes: 156
From: Galloway Twp. NJ
Cruise-In VII Veteran
Originally Posted by Mike Mercury
yep; I have heard the Bosch +4's are fine ... but not for smaller plug wires.
I tried the +4's in my '85 corvette and they sucked.
from now on I'm buying the TR-55's.
for $1.20 ea you can't beat 'em!
Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
Originally Posted by Richin Chicago
I don't think you can do better than iridium. A very tough material that allows a very small profile plug. This means less stuff in the combustion chamber.
Either the NGK TR55IX or the Delco version which is now OEM.
From Road and Track Technical Correspondence September 2004:
Sparkplug electrode material does not play a direct role in spark intensity. However, platinum and iridium electrodes can be much smaller, notably reducing misfiring because they result in more robust flame kernels. This is because the smaller electrodes are less of a shroud, exposing more mixture to the flame front.
An unusually dramatic illustration of this is with aftermarket supercharged engines running high boost. Such engines often falter terribly at high boost and high rpm due to ignition failure. Simply screwing in iridium-tipped sparkplugs typically eliminates the misfiring and allows the engine to rev to its power peak. In practice, this means a simple plug change is worth 30 bhp simply because the new plugs allow the engine to reach its designed redline.
Either the NGK TR55IX or the Delco version which is now OEM.
From Road and Track Technical Correspondence September 2004:
Sparkplug electrode material does not play a direct role in spark intensity. However, platinum and iridium electrodes can be much smaller, notably reducing misfiring because they result in more robust flame kernels. This is because the smaller electrodes are less of a shroud, exposing more mixture to the flame front.
An unusually dramatic illustration of this is with aftermarket supercharged engines running high boost. Such engines often falter terribly at high boost and high rpm due to ignition failure. Simply screwing in iridium-tipped sparkplugs typically eliminates the misfiring and allows the engine to rev to its power peak. In practice, this means a simple plug change is worth 30 bhp simply because the new plugs allow the engine to reach its designed redline.
but I have all the rest. indexing gets rid of the spark shrouding.
out of the box the plus 4 are better, without indexing.
indexing is a measurable improvement. on a dyno up
to 1 and 1/2 horse per cly. My car is faster and starts
better with the new plugs and wires. tr-55's, champion,
and the iriium's, and all standard hook electrode plugs, will run better indexed. the plus 4's are
easier. and run well.
Safety Car
Joined: Oct 2000
Posts: 4,949
Likes: 10
From: Monticello MN
Originally Posted by Rock'en Silver 02
The Bosch plus 4's and Jacob's wire's,Installed, Huge improvement.
Does anyone know?
Ed
Safety Car
Joined: Sep 2001
Posts: 4,411
Likes: 1
From: Wilmington NC
Originally Posted by Rock'en Silver 02
that where the plus 4's come in, Have not indexed them yet.
but I have all the rest. indexing gets rid of the spark shrouding.
out of the box the plus 4 are better, without indexing.
indexing is a measurable improvement. on a dyno up
to 1 and 1/2 horse per cly. My car is faster and starts
better with the new plugs and wires. tr-55's, champion,
and the iriium's, and all standard hook electrode plugs, will run better indexed. the plus 4's are
easier. and run well.
but I have all the rest. indexing gets rid of the spark shrouding.
out of the box the plus 4 are better, without indexing.
indexing is a measurable improvement. on a dyno up
to 1 and 1/2 horse per cly. My car is faster and starts
better with the new plugs and wires. tr-55's, champion,
and the iriium's, and all standard hook electrode plugs, will run better indexed. the plus 4's are
easier. and run well.
Team Owner
Joined: Mar 2005
Posts: 20,933
Likes: 905
From: salem OR
Originally Posted by Richin Chicago
But aren't the plus 4s quite a bit more intrusive? i.e. there is just a whole amount of more material in the middle of the combustion chamberwith the plus 4s? Iridiums are tiny.
What Happens when they,the electrodes.
Point directly away from the fuel mix, straight to the side.
That is your shrouding. Iridums are no doubt better, but when
3-4 who knows are shrouded. NO combustion cannot be equal
unless u index or go Plus 2 or 4. I know a car with indexed
plugs will gain a tenth. every time.
Don't take my word Call Accell or Jacobs
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Drifting
Joined: Sep 2002
Posts: 1,947
Likes: 0
From: Howell MI.
Originally Posted by y2k02c5
NGK TR 55 IX Iridums and Magnecor Wires. Best Wires hands down!!!
I have the TR55 NGK'S
www.Magnecor.com
Drifting
Joined: May 2003
Posts: 1,715
Likes: 1
From: cAshburn VA
Originally Posted by Mike Mercury
not necessarily. The Bosch +4 are known to not like LS1's with stock wires or "next better" sized wires.
In-Other-Words the Bosch +4's can fool one into believing he has defective wires; when it's not the case.
They are very cold plugs to be using in the LS1; and they need as much voltage as they can get.
In-Other-Words the Bosch +4's can fool one into believing he has defective wires; when it's not the case.
They are very cold plugs to be using in the LS1; and they need as much voltage as they can get.
Drifting
Joined: May 2003
Posts: 1,715
Likes: 1
From: cAshburn VA
I am running 02 LS6 heads, agian, great improvement, no issues.
Originally Posted by C5XTASY
I'm also currently running +4s in my 2000 LS1 and they run great. However, I'm going to be installing 2003 LS6 heads soon and will be switching to the Delco 41-985 Iridiums. Bosch does not make a recommended +4 for LS6 heads. I found that interesting and I wonder why these plugs would be recommended for my LS1 but not for the LS6.
Does anyone know?
Ed
Does anyone know?
Ed
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TR 55's.
