Originally Posted by Stu @ M Developments

Lairy cams do of course make a difference as they not only create charge dilution at low piston speeds but they also drop the intake velocity down drastically which greatly affects mixture distribution. The affect on mixture distribution often needs to be offset somewhat by an excellent quality plug with a bigger gap. I am sure you have all noticed a quality Iridium plug with run a CVH and a YB better at 15:1 that some iron girder like 071 or C57 plug that make them sound like they are hunting at idle and cruise? You wouldn't be mapping too rich to save fitting good spark plugs and ignition systems obviously... LOL

The interesting thing I note from all the mappers on this topic talking about the engine likes this AFR, and it dislikes that AFR, etc, is that nobody has mentioned they adjust the fuelling tables and then the spark lead tables?

You guys do know the combustion initiation and burn speed at 13:1 is different to 14.x and 15.x:1 don't you? You cant just dial fuel in and say.. "Ah, thats better" what you probably did, was correct an incorrect advance map by changing the burn speed to something more suited to your spark map so of course it sounds better.

I am sure the missing spark advance discussion was just an oversight of course...

Originally Posted by Karlos G

Thanks James, do you guys sell them?

Originally Posted by SiZT

Are the IK27's a good upgrade from BCR8ES's? As I run the NGK's in my mini and they cause it to miss at low rpm, high load

Originally Posted by Karlos G

Just to add my input on this topic, my CVH idles at 14.0 and cruises around 14.7 with no problems, but it didnt used to until I increased my cruise advance to high 30's (FYI idle adv is 12).

Originally Posted by scotty4130

reference the afr gauges, any recommendations/advice? Aem seems to be the only one getting some positive feedback.

Originally Posted by scotty4130

reference the afr gauges, any recommendations/advice? Aem seems to be the only one getting some positive feedback.

Originally Posted by Stu @ M Developments

Good man, sounds about right mate, if your going to do it, do it properly.

Originally Posted by scotty4130

reference the afr gauges, any recommendations/advice? Aem seems to be the only one getting some positive feedback.

Originally Posted by James @ M Developments.

IK27s suit the CVH very well we use them alot and have good resuts with them.

Originally Posted by Karlos G

Just ordered a set of these from you guys, be interesting to see the difference to my NGK's