Can Spark plugs make a noticeable difference....r400

[Reiver]

Doing online searching I found numerous references to plug recommendations for the r400 Duratec...they mostly led back to NGK BR7EFS plugs...the regular copper off the shelf not special plugs.  

The Caterham provided NGK TR6AP 13 is a more expensive laser platinum plug.

So, I tried the BR7's gapped at the recommended r400 mentioned .9mm.

Man, I've never really felt a difference in a plug before but this was really noticeable. Nice to have others experiences noted and saved on line. 

That copper old school was much smoother at lower rpm (especially when fully warm) and great at wot. 

[KnifeySpoony]

I've tried both and not felt a difference in my car.  I know on blatchat some people really favor the BR7. 

Edited 19 hours ago by KnifeySpoony

[Reiver]

I noted quite a difference.  Going thru the work done on the car the injectors were upgraded and a few other things.... prior guy tracked I suppose.  Not sure if that would make a dif but the TR6ap's were not consistent throughout the rpm range.  Especially when the lump was up to fully warm (never gets hot), sat for a bit, and was restarted.  Slight hesitation at low rpm's for just a short period of time, then fine, like clearing your throat....they only had 3k on them btw.  That issue is now gone.

Seems stronger thru the rpm scale but that is seat of the pants and could be me.

 

The other issue for me was our gas.... 91 is the highest locally available and I get that 95 RON is our 91.... but we have hot summers and a cooler plug couldn't hurt given the compression figures.  I use ACES 4 to raise the numbers and it is a good injector cleaner too.

[MV8]

The TR6 is a colder heat range with a wider gap. If the ignition coils are not up to firing under all conditions, a smaller gap will improve running. A hotter plug can help as long as the tips are not melting. In general, boosted typically take a colder plug and smaller gap to prevent plug failure/overheat.

[Reiver]

Thanks... the gap on the TR6 is wide ..., so is the BR7 and I took my info from numerous 7 websites and a builder that recommended the set up I described above for the r400D... it is a wider gap than normal but appears to work very well.  Very smooth at idle and just right thru the rpm range.

They noted the TR6 having issues at wot.  

I like a colder plug in Az due to the 91 octane and ambient temps.... I could try a BR6 in the winter (60's and 70's) and the 7's come summer... regardless it does run fine and better than it did with the TR6's for whatever reason..

[MV8]

BR7 come with a 0.9mm (about .035") gap. TR6-13 is a 1.3mm gap.

[Reiver]

1 minute ago, MV8 said:

BR7 come with a 0.9mm (about .035") gap. TR6-13 is a 1.3mm gap.

 

Mine came with a much tighter gap, I had to open them up to .9... I didn't measure what they were tho.