Hey! My buddy has a question, he has b18c jdm with rebuild, cr increase up to 12,5:1, everything is oem, so with this base map of hondata , How many degrees do you think the ignition should be delayed?

Regars

 

GSR or Type-R based engine? Is the compression ratio calculated value (all volumes measured) or some estimation from piston box (I assume you are talking static compression)? What fuel? Is intake and exhaust side also completely stock? Typical driving enviroment? Even if knowing variables like these, quite hard to say exact numbers.

For example, my previous builded B18C6 with +12:1, dynamic 10-10.5:1 depending camshaft adjustment, (fuel RE85) worked fine with quite stock ignition map (no ping, detonation or anything else) but it made best torque and power at ~25-26 degrees.

So my answer is put knockphones on and listen. If there isn’t knock, especially mid to high engine load, then it will be fine until dynorun where find out the best perfomance.

 

Its b18c6 complety stock , only ycp 12,5:1 static

 

Someone please? Hes run in p28 and not has knock sensor. For safety 4-5 degrees less all the map?

 

If you don't want to pay $$$ for one, you will have to build it yourself. Quality base maps aren't free... so you have to decide what level of quality you want in a basemap.

 

Well base maps, like the name says, are just where the engine tune up starts. It is just canvas where engine tuner start to paint, not the final work of art.

 

I thought previously that I was clear enough, but again, anyone who understand how internal combustion engine works and how those few listed variables affect, don’t want to say and even can’t. After all it is just educated quess. Four to five degrees less in mid-to-high load area can be more than enough, or maybe not. So I am sorry, it’s need concrete work. There is no any other way than real life test, in safe road conditions (closed area) or dynamometer. Acoustic ”knockphones” are easy to made and cost efective way to monitor uneven rattling or pinging noises. Start increasing load from bottom little by little and listen. If heard something, stop, take couple degrees back from that area and do another carefull pull. In dynamometer it is much easier, just find out where torque stop rising and you have found your maximal needed timing. It usually occurs way before knocking limit, because these type engines (pentroof chamber, sparkplug at middle of it) doesn’t need ridicilous amount of ignition advance anyway for burning mixture effienctly.