I have 3 questions I would like to ask. I think I know the answers already but a moron on a local Honda site came to our local maxima site (not this one)and started to bash. So it's time to make one of us look like an idiot.

Question 1, is AFR affected by timing? IE, if you tune your car on the dyno, then add or subtract timing, will the AFR change? or will it remain the same.

Question 2. is AFR affected by the loss if a catalytic converter? I know if you are dumb enough to put your wideband after the cat the reading will change if it is removed, but is AFR affected by the removal?

Question 3. He thinks that if a car is put on a dynapac, it can force the car to run at a specific rpm, (which I have heard before) and that it can be tuned at that rpm. Now on my car at least, if i am going down a very steep hill and I let off the gas, the car goes lean (leaner than 21 according to my wideband) so how on earth does the car get fuel when the dynapac is forcing the wheels to spin the engine at X rpm?

Flame away!!

 

if you already know the answers why are you starting a thread? Or do you just want a thread full of answers backing you up so that you can send him a link and really shut him up

1. Someone correct me if I'm wrong but yes timing changes can affect AFR. If you can adjust both then tune both for optimal results.

2.the reading of your a/f isnt affected whether you have a cat or not. it will read accurately where ever you place it. Naturally you'll get a less acurate reading if you put it after the cat than if you put it before it.

3. so I'll leave that for someone else to answer

 

this should help you some also
http://forums.maxima.org/all-motor/5...questions.html

 

1. No. The ignition timing just affects how completely the a/f mixture gets burned, not how much fuel ends up in the cylinder.

2. Indirectly, maybe. To a certain extent, more gas out = more gas in. If the MAF senses this, the ECU might add more fuel. Other than this scenario, don't really see how it would.

3. On a dynapack or mustang dyno, the car will be at WOT or partial throttle and a brake will be applied to the drums to keep the wheels turning at that speed. The dyno isn't what's making the wheels turn, it's just applying a load.

 

something like that

but I could be wrong

 

Any reason I shouldn't delete my post?

 

Totally agree with all his answers. Was going to comment on the dyno question last night but forgot to lol.