You cant tell people anything these days : (

 

Hmmmmmm.............



Interesting.....

 

Maybe so but you're talking about in a moderate case and things change much more when you're messing with high density air than naturally aspirated engines and things change when you're raising the pressure from vacuum to above atmospheric.

There are degrees of everything. Honestly, 12:1 is fine and from the injector duty cycle you gave earlier, that is perfect. Like zinner said, it's a weigh between safety and power. If you're safer at 12:1 ratio but you're losing say 12 HP, it's worth it in the end cause you could be making 0 HP when your engine detonates (this is in an extreme case but just something you should think about).

Now when you say too much fuel and too much air, I think you're thinking in the wrong state of mind. You need to think of the effects of both and how they weigh as far as possible outcome between having too much fuel and not enough fuel. Too much fuel will lead you to run richer and in worse case scenario you'll flood your engine. Damage with flooding engine: Damaging catalytic converter, ruining your 1st O2 sensor, replacing fuel injectors (to a better size if the case was that they are too big) and replacing spark plugs. Hundreds of dollars in changes. Damage from detonating: Possibly causing your head or piston to crack, melting of the pistons, damaging spark plugs, possibly damaging your valves and the list goes on. This will result in possibly thousands of dollars in replacing or upgrading parts and not even including labor if you're sending the engine to a professional.

These are the things you have to weigh. Is it worth it just to gain a mesley few more HP?

Judges? *Buzzer*

 

Jim the pistons don't fly out of the engine, they just crack and stay neatly inside the cylinder wall, so no messy clean up.

 

well, from what i gather, several people who have been tuned are dropping #4 cyl. probably because that particular cylinder gets less fuel flow, so it runs leaner...

you have to remember, that wbo2 in your bung hole is just an average of all 4 cyl, not just one.

 

im not looking for a flame here...just an opinion from a person who actually knows the difference between their ass and a hole in the ground...such as zinner or NJHK.....i got my car dynoed a few weeks ago and the AF reading was at approx 15 until about 4krpm then fell to approx 12....i have a 2.2 and know that i cant tune that yet, but what should i try to achieve once HPT gives me support?

 

If you're naturally aspirated, running 12 isn't necessary. The boosted guys do it for safety reasons because when you're boosted Combustion chamber temperatures raise higher than an n/a 4 cylinder would. Fuel in their case is not only for ignition purposes but for a "cooling" purpose. Fuel helps lower the temperatures in the combustion chamber and keeping things at a good temperature and from overheating from this process.

Why do the temps raise much higher than an n/a engine? Simple. They are using either compressed air or "stacked" air that is highly pressurized...compressed air is hotter than the air that your engine would naturally vacuum in.

So what a/f should you aim for? You could run 14s and be alright N/A.

 

thank you....that actually cleared up some stuff that i read on other threads too

 

Good. If you have anymore questions, feel free to ask. If I don't know, I can atleast point you in the right direction.