Gen 2 Spar Plug Ground Strap Mods J Bend Cut Back Cornered

[MrCreosote]

Has anyone done this AND measured any HP increase OR reduction of knock/detonation? It is possible that some shrouding is necessary if lots of swirl is present otherwise the spark could be blown out.

I've done this on a lot of engines mostly out of principle, quantitative testing - the theory sounds good - especially when other premium plugs are doing the same thing. The Denso Iridium Twin Tip incorporates basically everything that follows:

SHROUDING:

The original was to cut back the strap so the end was at the CL of the electrode. A better method "should" be to end the strap away from the electrode to achieve the same strap end position. This method unshrouds the plug more.

Final though is to totally unshroud the electrode with a big re-work of the strap: straighten the strap and make a "J" bend so the center axis of the strap is coincident with the electrode axis.

ELIMINATING HOT SPOTS - The sharper the corner, the hotter it runs. HOT SPOTS BAD!

Next was to cut the corners off the end of the strap. By cutting the corner off the 90*, you get a pair of 45*'s which will run cooler. Call these the SIDE CORNERS. You can get crazy and do the ultimate job of a full 180* radius. Depends how good you are with a die grinder.

You can knock the TOP CORNER off the end with a file. Harder to do since this is the thin dimension of the strap. Could do a full 90* radius which I think is overkill.

[SRT_BluByU]

different spark plug gimmicks have been around for decades.. I've never been convinced they do much. Same goes for indexing plugs.

[dave6666]

I use these on my Gen 2. Seemed like a good deal with free shipping. Gonna dyno next week.

Untitled2.jpg

[ViperTony]

I use these on my Gen 2. Seemed like a good deal with free shipping. Gonna dyno next week.

I installed those in my dash vents, I believe they help facilitate a venturi effect when the AC is blasted causing the blower motor to suck in more air for less wind resistance. Jet streaming. I think this is good for 2/10ths in the quarter mile.

[Krazy-knuck]

I added them to my exhaust.

[MrCreosote]

I think it may have been Steve Schmidt talking at the Superflow Advanced Engine Technology Conference at Colorado Springs years ago back when Bill Jenkins used to show up, made it clear that he wasn't going to give away any secrets, but he did say a few things:

*) Ultra light weight pistons are not dimensionally stable and don't allow rings to seal completely. Heavier, stronger pistons are required.

*) They had a throttle body on the front face of a large plenum and moved it about an inch upward and picked up 100 HP. I don't think he said why but I think it was due to the introduction of tumble in the plenum which is sped up when the flow transitions into significantly smaller runners.

*) The only time he saw any HP increase through plugs, it was that in come cases, a projected tip picked up some HP.

My memory is horrific. I am 100% sure he mention the piston thing. The other two I clearly remember in someone's presentation, I think it was Steve but I'm not sure.

_________________

EDIT: If you ever get a chance, you must go to the PRI trade show. It turns out that the Superflow AETC was not held in 2019 but had seminars at PRI - so I guess AETC may be cancelled for good. PRI is amazing - it takes 1/2 a day just to walk the aisles. SEMA is similar, but probably twice as big - 1/2 being wheels! There is also a automotive machinery area that was part of SEMA back when I went. While SEMA is impressive, PRI is where the action was at.