spark plugs - HKS irridium
#4
Former Moderator. RIP Icemark.
Originally Posted by swiftfc
I hear Iridiums isnt good for normal street use. im just saying what i've hear not what i kno
With a CDI system, using Iridiums is probably worth an additional 5 HP peak
And I only use them on street driven vehicles.
#5
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Originally Posted by Brody8877
I kno the RX-7 manual and other RX-7 owners advise to use NGK Spark plug, has anyone use HKS irridium spark (rotary heat range) ? do anyone advise it?
-Ted
#7
southern style
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there not really made by HKS, they just buy em and slap their name on em. good plug tho i have used them i go through a lot less of those than normal ngk's from the parts store
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#8
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I use NGK Iridiums on my car. They are about 7 or 8 a piece at O'reilly's (sp). The only problem is that you have to use a special thin walled spark plug socket (only available at racing beat and mazdatrix for about 60 bucks) to get them in due to the lip aound the spark plug holes. The part number I use is BR9-EIX, I believe.
#10
Former Moderator. RIP Icemark.
Originally Posted by Sideways7
I use NGK Iridiums on my car. They are about 7 or 8 a piece at O'reilly's (sp). The only problem is that you have to use a special thin walled spark plug socket (only available at racing beat and mazdatrix for about 60 bucks) to get them in due to the lip aound the spark plug holes. The part number I use is BR9-EIX, I believe.
They are not designed to be a multi electrode plug for a rotary engine and the center electrode is rather limited in size (reducing the available spark size) and as I recall is a single side electrode plug further reducing plug life and limiting spark. Toss in that the BR9EIX is also about 2mm short so you have a minor decrease in compression and bring the actual spark further away from the mixture. BR9EIX are plugs that fit, but are hardly a good choice. And really if you wanted to go the Brix way, Ideally you would want the BR7EIX which was commonly used in some mid/late 60's Porsche 911 product.
If you look at the Denso IRE01-27 (the grown up version of the Brix9) the spark is moved more than 2.5mm into the mixture over the Brix).
The only NGK Iridium plug for the rotary engine that I am aware of is the RE7CL (leading) and the RE9BT (trailing), but the problem is that the gap is .048 radically bigger than the stock gap (stock on the FC is .028) and basically requiring a CDI system to prevent the spark from being extinguished prematurely.
Last edited by Icemark; 01-20-06 at 11:59 AM.
#11
I R SAD PANDA W/O BAW
I have HKS iridiums and love them. No problems driving on the street. Dont buy them if you dont need them. I needed colder plugs and decided to go this route.
#14
Originally Posted by arghx
Who can truly benefit from these irridium plugs? I'm talking about actual hp gain here. I mean that's not cheap... I've gone through 3 sets of plugs in 10k miles due to various problems that have since been fixed. $30 is really expensive.
#15
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Originally Posted by arghx
Who can truly benefit from these irridium plugs? I'm talking about actual hp gain here. I mean that's not cheap... I've gone through 3 sets of plugs in 10k miles due to various problems that have since been fixed. $30 is really expensive.
-Ted
#16
I'm a boost creep...
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Iridium and platinum plugs simply last longer. They don't increase performance. Manufacturers fit them to pretty much all modern engines to increase service intervals.
I plan to use platinum leading plugs next time like the FD's do, just for longevity. Currenly I replace leading plugs twice as often as the trailing plugs.
The only thing HKS add to those plugs is cost, so don't waste your money on them.
I plan to use platinum leading plugs next time like the FD's do, just for longevity. Currenly I replace leading plugs twice as often as the trailing plugs.
The only thing HKS add to those plugs is cost, so don't waste your money on them.
#17
Former Moderator. RIP Icemark.
Originally Posted by RETed
Spark plugs do not increase performance or power if your original spark plugs were working fine in the first place.
-Ted
-Ted
It has been shown that Fine Wire sparkplugs (.5mm and smaller) do increase the power slightly (typically 1%) over a conventional (2.5mm) spark plugs, due to the more direct arc and reduced combustion influence pattern (quenching) in piston motors (of course I am not sure convinced you can index a plug in a rotory motor to gain anything there or I would mention that as well).
The other advantage with fine wire plugs is that they typically have a lower resistance to firing in the first place. Meaning lower voltage will be required to fire the plug. The is an advantage in aging systems that the coils do have reduced output. This is much more apparent on modifed engines, where additional boost or mixture have pushed past the factory design. This article on a mustang and Irdiums shows there are some gains on these type systems: http://www.sparkplugs.com/pdfs/muscle.pdf
But as you pointed out, with a stock engine, perfectly firing system, no wear on the coils, wires, or the plugs and with the proper plugs, there should be no performance increase when switching between plugs. But unfortantly the inherent design limitations and increased misfires are what fine line spark plugs help cure...
So, in conclusion there are two reasons that Iridiums do actually increase HP, first is because a smaller center electrode requires less voltage to jump the gap. This means fewer misfires, which should be seen in higher mileage and more horsepower. The second reason is smaller center electrodes reduce quenching.
Last edited by Icemark; 01-22-06 at 09:32 AM.
#20
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Originally Posted by Icemark
That is not exactly correct.
But without getting into a lengthy discussion into flame kernel and flame front propogation, how many FC guys are willing to spend over $100 for a 1 - 2hp gain (NA of course )?
(of course I am not sure convinced you can index a plug in a rotory motor to gain anything there or I would mention that as well).
-Ted
#21
Former Moderator. RIP Icemark.
Originally Posted by RETed
I want to know how to index the NGK BUR7EQ / BUR9EQ spark plugs?
-Ted
-Ted
#24
Caramelldansen
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Originally Posted by Icemark
well I spend around $30-$35 retail each for the Densos
#25
Rotary Freak
Originally Posted by MHopkins
Where can you get 'em for $30? sparkplugs.com has them for $35.30
Bottom line, if you're N/A or turbo making less than 250hp you really shouldn't be spending that much on spark plugs.
That said, HKS spark plugs are great, they didn't foul, or fail in any way through 5,000 miles of supercharged retardation.