sailor777

I have been told to go to a hotter spark plug for better performance and also to go to platinum.
Any choises here? Number of plug to use? etc?????


Gerald

chucksu

I could be wrong in thinking of this logic but lets see here.

Stock Plug Amount = 4 (4 cylinders, 1 plug per cylinder)
Replace Stock Plug Amount = 4 ^Same logic.

Needing a "hotter" spark = wasting your money unless your boosted.

Spending money on new plugs when stock are still good = Waste of money, best gains from aftermarket plugs have only been about 1 dyno hp & thats because stock plugs had over 25,000 miles on them.

So unless your getting into high milage numbers on your RS2, you dont need new plugs & it would just be a waste of money. Thats my view on things & I cant really force you not to buy something you dont need.

hotbox05

iridium will be my choice in about 7 thousand more miles.

sexyscionlover

moved

SciFly

Basics about spark plugs. Fact, not opinion

-a "hot" plug is merely one that resists carbon fouling of its insulator by having a longer insulator nose. This makes the heat-sink path longer and so the white porcelain tends to run at a higher temperature. The "self cleaning" temperature of anything is 800F.

Hard working little buzz engines hardly need an especially hot plug.

The spark -quality- is the very same in all brands of plugs BUT there is a slight difference in spark quality between conventional plugs and platinum plugs.

You need to know the appearance difference for the following statements to make full sense.

The spark is an ionization path between the two electrodes. It is hot enough to initiate ignition of the a/f mixture of course.

The voltage (electrical pressure) builds up over a span of time and nothing happens until the moment when ionization threshold is passed.

In a conventional plug the large, rounded center electrode is slightly variable in it's firing characteristics. And as the sharp edge of the center rod wears away by spark erosion the plug need higher voltage before it fires. And it also gets more and more variable about when and how well it will fire during the quiescent period of rising voltage gradient.

Sparks like to fly off best and fly at lower voltage from a sharp or well defined -point-

Hence, the platinum tipped plug, invented nearly a century ago (surprise!). The center electrode is like the cross section of a sewing needle and it is flush flat with the end of the porcelain nose. This protects the point from burning away in time.

A pinpoint tip fires at the same instant along the gradient, every time, and for a very long term of severe service.

And, too, that it needs less voltage to ionize across a platinum type tip, then we can generally profitably open up the gap somewhat more than the specification calls for with the conventional blunderbus-tipped spark plug.

DO NOT waste your money on "multiple tip" Platinum plugs or any other. They don't work any better. And in fact, simply shield and quench the spark kernel from the mixture it's trying to ignite.

Get cheap, single-side electrode Bosch or other brand regular platinum plugs and you'll be happy.

At this moment my xB engine cover is off for painting and lettering. I think this is a good afternoon to go upgrade to basic platinum plugs for the "feel good" aspect.

I don't expect any real increase in anything wonderful to result, but only personal satisfaction felt by spending money on the toy car.

SciFly

Ah, cool, so just now I am looking up to learn about iridium. Here she is and -it looks neat and desirable to me-



Read the clear-cut text at this place
http://www.spark-plugs.co.uk/pages/t...park_plugs.htm
its the source of the picture above

----
Neat and desirable because it moves the spark kernel further into the combustion chamber (depending on other factors allowing)

Found: supplementary technical info
heat ranges why and how
http://www.densoiridium.com/heatranges.php

=====
FOUND: correct part numbers for Denso Iridium and Denso Platinum plugs for xA,XB,Echo

Autozone -should- have them in stock.
Iridium: IK16 if the counterman looks blank at you, say "stock number 5303". That is Denso's stock number for this plug labled IK16
The heat index is 16.

The Denso single platinum version is called PK16R11 and its stock number is 3134

I just got this info direct from Denso Sales by telephone. Their website plug selector is not working anyway. So this is good info and its all straight.

thanks have fun,
reid

HaVoK

Just for reference:

The NGKs should be (04-05):
G-Power Platinum P/N: BKR5EGP Stock#:7090
Iridium IX P/N: BKR5EIX Stock#:6341

If I'm not mistaken.

SciFly

production sample in my hand. I'll install these IK16 Densos today.

Sciond

wellllllll.....how are they???

aychse7en

just buy some copper NGKs. i've run them for years with nothing but great results in NA and FI cars. they don't cost much, you can pick them up and almost any auto parts store, and they perform just as good as anything on the market. plus copper plugs cool themselves quicker and are great for avoiding knock in high heat applications.

bblhed

I have found that the best thing to do when swaping plugs is to stick with the brand and number that came with the car stock. When the car starts to get on in miles you might want to step up to the next heat range to prevent fouling but that is about it. Most cars come with the higest heat range possable from the factory now anyway so you are kind of stuck.

This is one of those strange things about autimibles that I have never truly understood, but I do accept. If your car came with cheep plugs like Mopars come with Champions and you replace them with the same plugs it will be fine, but if you change to a diffrent brand they will foul out on you. The only exception to this is with Ford where you can swap the Motorcraft plugs for Autolites and that is only because they are made by the same company.

Just be glad that Toyota hasn't switched to Bosh Platnum plugs. $ouch$

firesquare

i ended up replacing my plugs with platnum tiped plugs and some di electric grease.

i would have gotten iridiumn (sp?) pligs but i didnt want to wait 2 days for them.

so maybe at 90,000 miles ill throw in some iridiumn plugs and some "sporty" wires

SciFly

I was at the parts counter the other day when this poor working class black guy was about to pop for Bossh Platinum +4 plugs for his eight cylinder crappy Lincoln and I said "BuDDY don't waste your money. If you want platium get the SINGLE gap Bosch.

He just saved $20 by taking my advice. I "discovered" the incredible performance increase the Bosch 4203 single gap platinum plug gave to my Model T Coupe. This was about three years ago now. We in the T hobby have been plagued for decades with garbage-running plugs that foul too easily. We'd learned that the best working plug was the old, OEM Champion X plug.

However, nowadays that Champ X plug (a HOT plug) cost about $25 a copy because it's a low-volume production. And what you'd get was an inferior imitation of the original kind.

So what I did: Look for the HOTTEST plug design around. What I found was the Bosch single platinum wiht a nosecone projecting far into the combustion space. It proved to be just the ticket for our smokey, low temp. Model T engines. This particular plug, the 4203 actually made more power than the X plug. No more fouling. Better flame launch. Best of all: it cost a buck fifty a few years ago.

I'll go price that plug today and see if its gone up in price.

NB: Thes multiple side electrode plugs are all snake oil imo. A single gap plug is all a spark needs. Spark only jumps from point a to point b. There's no need for multiple gap plugs except sometimes in avaiation for superior long term life in the event of gap erosion or loss of a gap; another would take over.

The pin-point take-off of a platinum tip or iridium tip does seem to make a hotter spark. The hotter the spark (and a pin point spark is dense-ified), the faster the flame kernel may start off and the -more alike is every ignition-

If I get a scanner I can show off the blurb on the Denso box illustrating this hotter, pin point spark principle.

BTW, using a modern conventional single coil ignition in the T, I ran a plug gap of .090" !!! and this worked gangbusters and did not ruin a thing.... but did make it a challenge to not leak out the spark plug wires or dist. cap.

Later I gapped down a bit. But now in the Scion I'm trying .055" gap as a reasonable in-between.

The larger the gap, the higher the initiating voltage and longer the physical size of the spark and this bigger spark may tend to maximize fuel economy by a percent or two and may indeed increase apparent throttle response.

We'll see. Evaluating wide gapped iridium Densos now...
thanks,
reid

Sciond

ok I just got them..what do you think of the gap your at .055???

Sciond

there in seem to work nicely...I will drive ti some more tomorrow can't really tell if there is a butt dyno difference but I would prolly say not much.....

TheScionicMan

Don't forget to take into account the amount of use the old ones had on them, so even replacing them with the same type may provide more on the butt dyno.

Personally, I don't think there's much to be gained except for the supposed length of service. When you factor in the cost of the iridiums and such, it doesn't add up, IMO. I'd rather change the cheap ones a few more times.

Sciond

naah I would rather change it less since I do abaout 33,000 miles a year.....like I said I wasn't saying there was a great gain in performance... I am more curious about gas mileage

UncivilizedRacer

Spark plugs arnt that pricey. I change mine every 3rd oil change. Well worth the time and effort.Mantienance is the best thing to keep the car running at its best.

In my turbo SRT I change them every oil change.

turboxB

Dude you dont use hotter plugs on any F/I motor. You gotta go colder.

OldYeller

Read this thread for a "hot" discussion of plugs...........

https://www.scionlife.com/forums/vie...ht=spark+plugs