: Another Spark Plug Question for the LS6



LS6-CTS-V
09-05-05, 09:29 AM
I know we have talked about this before, but I could not find the thread.

What is the best plug to run in the LS6???????

OuTLAw
09-05-05, 01:25 PM
I installed a set of Bosch +4 Platinum along with a set of Magnecors and by far one of the best cheap installs that I have done to date. Doubt if I gained horsepower but I definately felt improved throttle response.

lasstss
09-05-05, 02:38 PM
Im very partial to the NGK V power plugs. Work especially well with a blower..:D

heavymetals
09-05-05, 04:04 PM
I installed a set of Bosch +4 Platinum along with a set of Magnecors and by far one of the best cheap installs that I have done to date. Doubt if I gained horsepower but I definately felt improved throttle response.

Ditto for me plus I covered the cables with Koolsox.

HDMLNIUM
09-05-05, 08:05 PM
NGK V TR55's for me gapped at .045 and you will gain a few hp by doing this..:yup:

Bill

LS6-CTS-V
09-10-05, 11:56 AM
Did you feel a gain in HP or mileage? What advantage do they serve?

ntechnic
09-10-05, 04:54 PM
I've seen half a dozen dyno results were the bosch +4's lost power compared to stock plugs. The problem seems to be shrouding. The combustion chamber at TDC, where the plug is basically firing, has a cross section like a lens from a magnifying glass. Sort of like a shallow dinner plate with an identical plate place on it upside down. The important part of the chamber is to the sides of the spark, not below it. The +4's appear to actually slow and inhibit the flame front, and effectively retard the timing. And as I said, I've seen six times where they lost power on the dyno, and none where they gained power.

My personal favorite's are the NGK platinum. These are top notch, and I've never seen them lose power compared to stock plugs.

I've also always seen power gains from simply unshrouding the stock plugs. You use a dremel or small air grinder with a very small stone wheel. Carefully grind the end of the ground electrode back to where you see half of the center electrode when you look dead end on at the plug. Round the corners back, and round all four edges to eliminate hot spots. On high horsepower cars, this trick is usually good for 4-5 free horsepower, and I've seen 8-9 in supercharged cars.

Barak
09-11-05, 02:50 PM
I've seen half a dozen dyno results were the bosch +4's lost power compared to stock plugs. The problem seems to be shrouding. The combustion chamber at TDC, where the plug is basically firing, has a cross section like a lens from a magnifying glass. Sort of like a shallow dinner plate with an identical plate place on it upside down. The important part of the chamber is to the sides of the spark, not below it. The +4's appear to actually slow and inhibit the flame front, and effectively retard the timing. And as I said, I've seen six times where they lost power on the dyno, and none where they gained power.

Bosch ran out of engineers, so they decided to have their marketing department design a new spark plug. May sound crazy, but how else do you explain one of the biggest automotive suppliers in the world designing a spark plug that ignores the principles of flame propagation.:hmm:

ntechnic
09-11-05, 03:32 PM
Bosch ran out of engineers, so they decided to have their marketing department design a new spark plug. May sound crazy, but how else do you explain one of the biggest automotive suppliers in the world designing a spark plug that ignores the principles of flame propagation Agreed! In general aviation, piston powerplants have multi-electrode plugs, but the engines are actually low performance, they built for max reliability, not max peformance. And they're willing to design around the problems of the multi-electrode because in extreme conditions, the plug can foul three electrodes and still fir on the fourth as the pilot looks for an emergency field.

We don't foul plugs, so these are pointless, expensive way to lose power.

And don't even get me started on all those extra potential hotspots to start pre-ignition problems!!!

CTSV05
09-11-05, 07:30 PM
Hmmm, I have used the +4 in several vehicles, and actually noticed an increase in mileage in the two trucks.

They are in the V and to be honest, I noticed no change in power. They are less than our factory platinum patch plugs, but it seems they have some drawbacks as well.

a64pilot
09-12-05, 07:38 AM
If you are running LOT'S of N2O or really high boost on a blower then the NGK's running a heat range or two cooler are the way to go. The reason is resistance to detonation. If you don't fall in the above catagory then stock is actually quite good until they need changing due to age.