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spark plug recommendations !!

56K views 30 replies 22 participants last post by  Alain Serhal 
#1 · (Edited)
what do yall recommend. going with another plug or staying with the stock ones? my mods are in sig , the others mods i have done is vetteair and higflow cats . thanks
 
#3 · (Edited)
NGK TR55's are OK for street applications.

If you are going to track the car and want better reliability and performance switch to a Silver electrode plug. Silver has the best thermal and elecrical conductivity specs. Forget about Platinum, Iridium and Copper. and other mullti electrode gimmicks.

I recommend Nology Silver Racing Plugs, Part # G4YS or Brisk Silver Racing, Part # DR 17 YS. OR Beru Silverstones if you can find them (no longer made).

Note that the above NGK's, Nology's & Brisk need to be indexed for maximum performance.

The best racing sparkplug available is the Silver electrode Brisk LGS Premium Racing plug. This is used by Lamborghini and Ferrari. Part # DOR 17 LGS. This plug has a center Silver electrode and 4 recessed grounds. It does NOT need to be indexed. This plug offers the best 360* flame spread. I recommend this plug for maximum effort competition.

I recommend Magnecor KV85 Race Wires for non-Capacitive Discharge applications. These are the most reliable and low impedence wires available.

If you want to go with a higher performance CD wire I recommend Nology "Hot Wires". These must be grounded correctly. You may also want to consider installing Nology HD engine ground straps with this application.
 
#4 ·
well i put ngk tr55s and the car didnt like it. the car would start bulking under part acceleration i guess running lean since its a hot plug. i then looked up ngk and it recommends the TR6s for the ls7, i then switched to tr6s and car runs awesome now. i have always used tr55s on my ls cars but i guess the ls7 likes a colder plug.
 
#6 ·
I dance with who brung me.
Stay with the Sparkplug the factory engineers deemed good.

Beware, Splitfire has resurected itself from bankruptcy and is selling their garbage again.
 
#7 ·
Just finished putting some NGK Iridium plugs in mine an hour ago...TR-5IX with GM high performance red wires...not that it makes much difference or increases performance..but looks nice since they are red, and affordable. The drivers side rear plug was a real joy!:mah:

But purrs nicely now. had the original AC/Delco's...they looked horrible when i pulled them out.
 
#10 ·
TR6 is the plug to run , I have used them on Turbo LS1/LS2s , The LS7 is a high compression pumpgas motor , i think the TR55 is a little to hot for the crapy gas we have at the pump !
 
#13 · (Edited)
Yes, single electrode plugs should be indexed with the "open" gap toward the exhaust valve.

This aids in correct flame front travel and orientation, fast burn and more complete burn with increased HP and less emisions.

Caution: When marking the plug to indicate the gap you must use a special dielectric marker, so as not to short the plug. Most normal markers have ink that will conduct electricity.

Both tapered and flat indexing washer kits are available, usually in 3 size ranges. Try Powerhouse products.
 
#14 ·
DJ,

this might seem like a dumb question, but for indexing purposes, the open gap goes towards the exhaust valve, but is the open gap pointing up at the valve or down towards the piston. Basically, if you were looking at a clock and the exhaust vlave was on the upper right....would the gap point at 1 to 2 o'clock or 4 to 5 o'clock?
 
#15 · (Edited)
The sweet spot varies due to combustion chamber shape, quench area, Intake to Exhaust size ratio, Exhaust valve positioning and flow characteristics. it also determines how much efficiency can be gained.

GRofT is: The gap should be positioned somewhere between the center (horizontal axsis) of the combustion chamber and the exhaust valve center axsis. The objective is to position it in the lowest flow area to get the best ignition and largest flame front.

In the LS6 it can be anywhere between the 1:30 to 3:00 position in the example you provided.

In the LS7 the larger Intake to Exhaust valve size ratio dictates a more critical positioning and a 2:30 position works best tending more toward 3:00.
 
#17 ·
Getting some sputtering and missfire with my TR5 Iridiums with only 7k miles on them...a little dissapointing...i pulled out the plugs, all are pre-gapped at .035. I wonder if i should put the TR55's in..or would anyone recommend the TR6's?

Im pretty much running stock.

THanks!
 
#19 ·
My LS7 o6 Z06 started cutting out slightly at the strip last year after sitting all Spring from 6000-7000 RPM. It wasn't flat like a plug but a surge.

Voltmeter showed normal across the posts. I had good plugs so I did a battery cell test and found one cell dead. These newer cars computer needs X amount of amps/volts to operate correctly. Changed out bad celled battery which was under warranty, AC Delco. Problem solved. These cars shouldn't be eating plugs like the cars of the 60's did. They eat more battery's then plugs. I've never pulled a bad plug yet with over 150 passes on a few Z06's unless I had a mech/issue. Knock on wood I haven't had any mechanical issues that would cause me to check my plugs. Remember we are still using a 12 volt system changed from 6 volt in 1955 to 12v when the V8 was first introduced to the corvette. In 1956 they added a higher CCA battery but from the 1950's on these cars have had a ton more electonic/electrical demanded on that battery. Check your battery cells if plugs are good.
 
#20 ·
the car would start bulking under part acceleration i guess running lean since its a hot plug. i then looked up ngk and it recommends the TR6s for the ls7, i then switched to tr6s and car runs awesome now. i have always used tr55s on my ls cars but i guess the ls7 likes a colder plug.
 
#26 · (Edited by Moderator)
TR 6 installed and with the new wires from gmpartshouse
Now to wait for spring to take the car out to test through the rpm levels and see if these plugs will act responsive.
I was wondering why the original plugs when check were all gapped at .060" what would the reason be the difference ? The new ones i check at .040" before installing as suggested.
 

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#29 · (Edited)
Just use NGK R spark plugs for Z06. You awake your Beast in ur corvette.
Pay attention while choosing your spark the electrode metal head should be thick enough, simple cylindric that has height and bold. Because it sparks electrecity in a bold way all around the upper metal and hard exchanging faster electrons so your gas will be directly fired.
If you use a thin metal head electrode spark plug and pointy you feel that your car speed enhacement is lazy that is because one way electrons sparks in a thin line movement.
 

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#30 ·
Just use NGK R spark plugs for Z06. You awake your Beast in ur corvette.
Pay attention while choosing your spark the electrode metal head should be thick enough, simple cylindric have height and bold. Because it spark electrecity in a bold way all around the upper metal and hard exchanging faster electrons so your gas will be directly fired.
If you use a thin metal head electrode spark plug and pointy you feel that your car speed enhacement is lazy that is because one way electrons sparks in a thin line movement.
You do realize this is an 11 year old thread.
 
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