What is a safe internal compression number to go with? What can
a stock b18c1 engine take?

I've tuned my car to good a/f numbers, and will be tuning
ignition timing.. Anyone know what compression numbers
I should be shooting for? (using some machine with altered
spark plugs)

 

I dont understand what you are doing, maybe I am reading this wrong?

And how did you tune good A/F numbers without altering your ignition timing in the first place?

 

are you referring to cylinder pressure?

 

Sounds like cylinder pressure. Are there pressure sensors built into the plugs, or is it some form of ion sense setup where it reads plug resistance?

I wouldn't go for any cylinder pressure figure so much as I would try to avoid the pressure spikes that start occurring right before detonation. AFAIK, any tuner with actual cylinder pressure readings applicable to Hondas is probably sitting on them. That sort of thing isn't very fluent yet.

 

Yes.. cylinder pressure.

My tuner tunes mostly supras and hondas. He swears
by the cylinder pressure analyzer to determine the best ignition timing (safe) to
run.

I guess I just haven't heard of anyone ever talking about using this machine
when it comes to dyno tuning.

 

I went looking through my notes and I cant find the sheet that had safe numbers on it, If I remember correctly 800-1200psi is safe. The best way to tell is to slowly increase your timing and watch the peaks, as you advance in 2 degree increments the pressure should start to climb, if you see a big jump in pressure with a small increase in timing advance then you have reached the threshold for detonation. You can do the same thing watching the dyno graph, when you stop making fairly large jumps in power by increasing the timing by 2-3 degrees then you have reached your threshold.

works for me anyway

good luck

BTW is your tuner's name todd king?


jason

 

That's pretty cool. I remember reading about using a cylinder pressure analyzer in Maxium Boost when they were tuning that GSR motor with the old school DFI. They would slowly increase timing until the cylinder pressures got to a "safe" level or to right below the point where it started detonating since the cylinder pressures would immediately spike.

 

Sweet info, st00pid.