Dyno testing: NGK BKR7E vs Denso IK27

[fast_a2_20v]

I've been running these Denso Iridium plugs for years in our spec miata and knew from our engine blueprinter that they were worth a smidge even in those anemic little 1.6L Miata motors. Curiousity got the best of me and I knew that was only one way to know if these are worth the cash was to get a 1.8t on the rollers.

We strapped up our mk4 test car, and left it on medium boost and 91 octane pump fuel (Utah....). A couple of pulls were performed to make sure everything was up to temp, then we let the car sit for ~15 minutes and did a pull with the bkr7e's. We hurried and threw in the Denso's, waited another 5-10 minutes or so, so that the downtime between pulls was about even for both, and then did a pull on the Denso's. This is what we got:



As you can see there is a consistant gain throughout nearly the entire powerband.  Combine that with the fact that much colder heat ranges are available, and the WAY longer lifespan, and these plugs clearly blow the copper NGK's out of the water. We went on to make over 400whp on the denso's.

We went ahead and stocked up on hundreds of these denso plugs after we put these thing through their paces, and we are proud to bring them to you at some of the best pricing on the net. Our price is better then sparkplugs.com. 

Click here for our full selection of Denso Iridium Plugs

[Iceman]

Any long term testing in the plans?   They may dyno better, but how are they after 1000-2000, 5000 miles?  My car runs great with the bkr7e's.  All the misfires I previously had pretty much disappeared.   I'd be willing to give the Densos a try, but if the misfires come back then that would suck. 
What's the typical lifespan of them?  I usually swap out the NGK's at every oil change, (3000-4000).  The price would be worth if it I could go 2 or 3 oil changes between changing the plugs, and the car runs just as good or better.

 

[fast_a2_20v]

Just to give you an idea, denso recommends changing them at 30.000 miles. From the research I have done on other forums and such, trying to find anybody running these that long- I see guys changing them after 20-25k to be common in higher output turbo cars.

I'd love to say we ran them out as far as we could and this is what happened but honestly- I don't think you want to wait till 2015 for us to rack up that many miles. In the spec miata nobody ever changes them. You change them if a piston smashes it. 

[Iceman]

I've got nothing but time on my hands 
Seriously though, I'd be willing to give them a rip.
Are the IK27's the same heat range as the bkr7e's? 
The heat range recommendations on your site said I should use the IK22's, but I just want to make sure if I switch, I'm doing it apples to apples.

[CO AVANT]

IK24's are about = to NGK 8E.  IK27's are one step colder.

A platinum/iridium plug in a colder heat range usually runs as hot as a copper in the standard heat range when under high stress. Many will use a platinum/iridium plug one to two steps colder to counter that.

How many miles were on the copper plugs during this dyno before they were swapped out for the Denso's?

[fast_a2_20v]

They had about- 30-40 miles on them. Put them in that morning and drove around and bought race fuel and a piece of hose, spare fuel jug, etc.

I had IK24's on hand as well, but I put the 27's in because we were shooting for 400+ whp. So far, the "cold" start, idle, everything is perfect with the 27's, but we'll see about that when winter comes. For pump gas I would recommend the 24's for a big turbo car. I have boatloads of 22's, 24's, and 27's in stock, I didn't bother with any 20's or 29's/31's, although I may fool with a set of 29's when I get our other shop car togheter and on the dyno- its a bit bigger turbo and a bit higher compression so it may be worthwhile.

So just to be clear, if your running a BKR7E now, I would probably switch over to a IK24 

[CO AVANT]

I've been testing many different plugs and basing what I've liked and disliked best by: plug life, if the plug if fouling, how my timing logs look, etc...

I stopped using BKR7E's a couple years ago because of fouling issues at high elevation in the winter months.  Sometimes my car wouldn't even want to start.  I still have a box of them sitting around that I will never use, lol.  I've been having some good luck with the NGK BKR8EIX's. I also tried the Bosch F5DPOR's and DTC's as well as many others...  Logs are showing that the car likes the NGK 8EIX's best so far.  I've had some IK22's sitting around for years that I haven't used but they are not cold enough for me with the power I'm going to push now.  I might just need to try some IK24's or 27's here in the future.....once I have an engine in my car again.  Nice comparison BTW 

[Iceman]

I see they come pregapped to .024. I run the NGKs at .028.  If I get the ungapped Densos, is it ok to run at .028?

[fast_a2_20v]

.028 gap will work great on a stock turbo car, we just close them down for big turbo work. You should definantly still check the gap they aren't always spot on right out of the box.

[screwball]

i just threw a set of these in my car earlier and they were pregapped at .028.  i ran the bosch F7LTCR plugs before these although, i think they've been discontinued.

[Bastard]

hate to break it to ya, but the densos are made on the same production line as NGK. Aside from their habit of putting non functioning grooves in things, they are pretty much the same as the NGK iridiums.

In other words, the equivalent heat range NGK IX plug should outperform their nickel tip in the same way. Especially considering the needed drop in heat range that the dyno makes clear.

Plus NGK sells em cheaper.

[fast_a2_20v]

I'm not sure about the assembly line thing, but the denso is a finer electrode then the NGK as well, by quite a bit. 

[35Rgtimitch]

I'm not sure about the assembly line thing, but the denso is a finer electrode then the NGK as well, by quite a bit. 

This is excellent information. Are the plugs currently offered at a sale price and what engine combination was being used for the test on the MKIV? Additionally, what was the heat range of the plugs?
Thanks...