Spark plug mod
 

I've had some really good number on my last tank(considering it was mostly city) and lately on my commute.:) The only thing different besides removing the WAI (which was for about 100 miles) is a spark plug mod found here.https://fueleconomytips.com/index.php...id=31&Itemid=2
I just used the standard NGK plugs regapped at .035 instead of .044 and indexed. These plugs replace the side gapped and index one that were in there. I've got about 350 miles on them. Don't really know how to test this but it sure is not hurting anything and only took about 35 minutes to.

so wait, all you did was get off the shelf plugs and close the gap?

No you drill a 1/16" hole in the bonding strap above the electrode and then dish the electrode a little so that when it fires the spark will go through the hole in the bonding strap for more spark front. There's pictures in the link. It an interesting idea, granted that there is only 2-3% to be gained in this area but every bit helps.

I'm planning on doing extensive plug testing somewhere down the road, it'll be expensive, but whatev, it'll be nice to know also, I say, so yeah.

Anyone know who has the indexing washers now?

I still have them. Just tell me where to send them.

I guess you dun got my address no mores. I'll pm you with your fancy instant messaging client.

Got your address via gassavers IM! I know... I am living on the edge.:p

Will send them out tomorrow. Still waiting for my MID and ECU chips? Should I IM you my address?

Yeah, I guess you should, I lost it in the swap of sites and the whole falling asleep instead of burning you a new chip, :p

I'll cut your advance in half, just for kicks, shouldn't ping then, but what do I know, I'm pretty worthless.

Spark Plus Socket Size
 

My 2005 Prius mileage had been as high as 61.3 mpg for a tank of gas over the summer. In the past month, my gas mileage dropped to 57.5 mpg, and the Prius, on occasion, wanted to stall when I accelerated or decelerated - although it never actually did.

I bought a set of Autolite platinum spark plugs to see if maybe the plugs are fouling. Can someone tell my what size spark plug socket I need to use to get the spark plugs out?

Why not use plugs with open electrodes.

I have used Magneti Marelli 4 electrode splugs extensively in performance applications.

Or you can use these..

https://www.sianghin.com/products/ign..._plugs_big.jpg

But I have not seen an ounce of FE improvement.

Mainly because the NGK are 1.98 for each plug.:D

I think Ill try this trick. The engine has been missing once in a great while, so it looks like Im going to replace all that fun stuff, and I might as well try modding the plugs. :)

c8089923: the new spark plugs should take the same size wrench as the old ones.

I've tried the open electrode spark plugs, and noticed little to no positive affects in any of my japanise designed engines, altho I hear they work great in amarican made engines.

The race plugs I used were about 7$ each but this was quite sum time ago.
The cost didnt bother me , I didnt pay the bills out of my pocket.
We used normal plugs after that.

Diamondlarry did a spark plug comparison test a while back (but i can't click to zoom in on the results):

https://www.gassavers.org/showthread....park+plug+test

Yeah , same opinion as mine.

For the same money you could buy some corplast sheet and do some aero-mods and see a real benefit.

It's in kind of an odd format but here it is.

The link no longer works. I have heard of people doing this before, but never knew exactly how it was done. Does the hole go directly above the electrode? What do you use to dish out the electrode?

The web archive caught a copy of the article, but not the pix...
https://web.archive.org/web/200603150...id=31&Itemid=2

Lowering your gap from stock is like advancing your timing because of the lower voltage requirement.

Drilling a hole in the ground strap only serves to give a better 90 degree angle for the spark to jump to, lowering required voltage to fire the plug, and, again, advancing your timing. The spark won't fire through the hole either, it'll fire to the point of least resistance (closest point), the bottom near the electrode.

Increasing the voltage(or gap) will give you better ignitabillity when you go into lean burn. What you really want though is more current to the plug. Automotive ignition systems are grossly inefficient.

cut back the ground trap

Does anybody have a line on some indexing washers?

Any FE gains to be had by changing the heat range of your plugs?

The Z1 calls for a heat range of '4'.
I wonder of a '5' or '6' (with correct gap) would show any FE gains?

Low number = cooler plug
High number = hotter plug

For FE gains = cool or hot?

The heat range all depends on the company. In the NGK scale a 4 is hotter than a 5 or 6. The only reason you would see gains from going to a 5 and maybe a 6 would be because you are getting pre-ignition from a plug running too hot. I'd be weary about running a 6 in a car meant to have a 4. The colder you get the more likely the plug will foul and/or get buildup on it that will cause misfiring.

Champion and Bosch have a lower number for a colder plug. NGK and Denso go higher.

Your engine uses the following and if it has stock compression you only want to go up one step from that at the most. With Champion and Bosch they have a couple of heat ranges that are so close to each other that you can pretty much select from a small group of heat ranges.

NGK 4 -> 5
Denso 14 -> 16
Champion 11,12 -> 9,10
Bosch 8 -> 6,7

where the hell do you get the washer to index plugs??

Summit:
https://store.summitracing.com/egnsea...115+4294854256
(Not sure of the correct size/style).

I may pick up a set (for me and a few friends).

I just wonder which direction the electrode should point in a Z1.
I was thinking towards the timing belt... but who knows.

I have a set of 6's in my Z1 (with a 4 wire 02 and chipped P-28) (there is no issue that I can tell).

I was wondering if a set of 5's (or back to the OE 4's) would give any FE gain.

I will be back on the dyno (loading) in a few weeks and want to pick them up before then.

The ground strap should be on the exhaust side of the chamber.

Where can you buy the indexing washers? I need to get some too. Disregaurd this post I posted before reading everything.

I heard about this a long time ago. so how would you firgure out which washer to use?? keep trying them until you find the washer that indexs correctly??

You have to keep trying until you get it right.

You can get indexing washers from Summit Racing Equipment. www.summitracing.com

ZPILOTO, did you ever index your plugs? How did it go?

I tried almost every plug on the market over the last 15 yrs or so. I haven't found anything that comes close to the performance of Halo spark plugs. I've used them in all my cars for the last 3 years.

Where do you even find those?

The Doctors Step-By-Step Guide To
OPTIMIZING YOUR IGNITION

By Dr. Christopher A Jacobs, PhD., E.E.
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Here is a basic explaination:
https://www.fordmuscle.com/archives/2.../goodangle.JPG
1. The ideal position of the plug is such that the gap is facing towards the valves, preferably the exhaust valve.

https://www.fordmuscle.com/archives/2...adangle_tp.JPG
2. The object of indexing is to avoid this problem: when this plug fires the spark is directed towards the chamber wall, rather than the center of the combustion chamber.

yes to the exaust is the best for performance ,,,MPG ,,i'm learning

I'm not so sure about that positioning for Wile-E, since the plug comes in closer to the horizontal, it seems like it will "trap" the spark against the top of the head... whereas turned the "wrong" way it points more to the center of the combustion space (bearing in mind the piston is still coming up when it fires.)

i try to index to the ex. valve

Have any of ya tried Pulstar plugs? They're ridiculously expensive.

One of my friends bought them at full price for his 96? Explorer... just talked to him and he said his trip computer didn't report any gain in MPG, but he noticed a lot more low-end torque.

Right now I have Bosch Platinum+2 plugs in my car. It seemed to revive it's performance some, comparable to 4 years ago... not much as far as gas mileage tho. I'm definitely satisfied with these, but am just ever-so curious about those pulstar plugs.

Edit: Also... could you somehow increase gas mileage by upgrading/changing the Ignition Coil pack?... There's "performance" ones... didn't know if there's something that'd work to save gas too.

Before everyone goes out and buys indexing washers, make sure your car uses gasket seat plugs. You can't index tapered seat!

Tapered seat engines include most Fords, late model Mazdas, pretty much every GM engine made since the mid 60s, and some Chrysler vehicles after 1990(most after 2000).

If it is an import you are usually safe in assuming gasket seat.