Chad, what is the reasoning with you guys using the non protruding... just trying to pick your brain...

 

I am also wondering. Maybe because they are supposedly a tad colder than the protruding which would be better for higher cylinder pressures? Have u guys backed to back them?

 

The projected tip has better drivability due to the spark starting closer to the middle of the chamber. On the track this isn't an issue so run non protuding to keep the heat out.

 

Here's my take on the NGK bp series....in the EVO 8 series

Replaced the copper plugs in my car with 3K on them with NGK BPR8eix gapped at .030 stock boost etc car completely stock 4500 miles on her. Copper plugs were not worn out at all. gap was measured at .032 on the coppers as they came out. ( stock gap is .030-.032)

Idle improved a very little bit, but the top end improved quite a bit. I had set the limit at 8K on top and the coppers broke up at 7500. BPR8eix fixed that ..no issues. Subjectively the car pulled smoother in the middle of the rev range

Longevity wise the BPR8eix's last very well I usually change them out on a yearly basis ( 15-20k miles /year ) First change out set was measured at .035 gap as they came out. Prolly could have been in another 3 months.

After tuning and upping boost to 25-tapering to 22 ( along with other mods like exhaust , fuel pump, 3 port ECu boost etc ) the second set with an initial gap of .025 lasted 15 months. Car started breaking up in the winter at 7200 so I changed them out...measured gaps were .034 -.036.. note that much higher boost and getting the AFR's right is harder on the plugs

I just did the plugs again 3 weeks ago as the car was missing at high rpm again....stuck with the BPR8eix and measured the old ones as they came out these were in there 20 months this time as I got lazy ....smallest gap was .042 and the largest was .047 Yikes !!! Car was missing at high rpm again and the idle was not as smooth as it normally is


The new set went in at .025 and it is back to being very smooth.

In all this, i would not say the BPR8EIX have made a significant improvement to the idle or starting, never really found that to be an issue on my car. it idles very smoothly with the stock cams. I have found simply that the BPR8eix work better at high rpm and last much longer than the coppers. I would say that having the 1 step colder plug allows the heat to escape to the head faster and will help when you are adding boost. Plugs will last longer

I have not tried the non protruding versions as the stock iridium Evo8plugs are the protruding versions..i figure Mitsubishi did that for a reason. In fact if you put the BPR8eix side to side with the Mitsubishi IGR iridium plugs they look identical from the electrode, and the amount of ceramic protruding into the chamber.

Lastly, I always use high dielectric spark plug boot release compound on the plugs ceramic body to a) help reduce flashover down the ceramic causing a hesitation or miss and b) help get the plug wires off easily. I also use a little antiseize on the plug threads to prevent galling and seizure.

My .05c

CBRD I concur with you

 

On my last set-up I had coppers that would foul out on the regular due to stock coils, tall cams, and rich tune. After my second set I got the iridiums and never had another problem. Current build is ditching the stock coils for spoolin-up btw

 

the combination of spoolnup non CDI and the IR plugs is killer-

I have seen no reason to run a CDI based setup--

If we run the NON protruded- we tend to run NGK race plugs-- which feel much better on track yet foul kind of easily in the pits lol-

cb

 

now that you guys are talking about plugs, what would be the best option for a full race/road racing application?


Thanks.

 

what mods? full race application with high boost and big turbo you would probably want an NGK BR9EIX. Hope that helps. If you need 1.5 colder you would want the BR8EIX.

 

for most people the BPR7EIX or BPR8EIX works fine-
cb

 

Do these same plug ranges apply to straight E85 use?
Or do you go for the stock heat range of 7 due to the cooler/slower burning properties of the ethanol?

 

Whats the difference between BR9EIX and R7376-9? Looks like its the same plug but the race has a platinum ground strap and 4x the price.

 

we tend to run the 7 range most of the time--- i've never seen a measurable difference in dropping heat ranges--

the E85 car that made 750 something on our dyno used 7's--

---

jc- id have to check the NGK race part numbers, I dont know them off hand-

cb

 

Cheers Chad.

 

Just ordered some BPR8EIX plugs to try after reading this, been using BPR8ES for the last 6 months, prior to that BPR7ES.

 

Switched mine from BPR7ES today, was having break-up at higher boost levels. Didn't have any problems on the BPR8ES I ran over the winter, I put the 7s back in because I had a set on hand when the 8s started to miss.

Completely cleared up issues I was having with the car, including start-up and idle. Looks like I've found my plug.