Will a motor with a higher CR have more engine braking effects?

noel

 

theoretically yes. but the difference will be unnoticeable if the change in ratio is minimal.

 

im not a fan of engine braking. i'll use it occasionally yes, but not when i really heat up the motor.

these are my opinions regarding engine braking, nothing more.

if you are racing or just running the motor hard and hot, and then you are constantly engine braking you'll be closer to detonation. when you run in 2nd gear to vtec and then let off and let her engine brake from 7.8k, as soon as you let off she goes lean. going fully lean at 7.8k and falling in a HOT motor makes your chances of detonating greater IMO. when i look at my a/f guage during engine braking i can't even see a red led that its so lean.

in a motor with higher compression, i'd think that the leaning out would have more of an effect on the heat factor. i just wouldn't and don't do it. i'll just pop the clutch, or pull out of gear completely.

of course, this is all speculation and you hardly EVER hear of a honda dying from detonation unless it was tuned by a monkey or someone was trying to blow it up by fully advancing, running 87 octane, and pushing a 100+ shot or something of the like.

just my thoughts, but i do believe there to be some validity to them
v

 

Turbo with stock injectors and no fuel management running 100+ PSI fuel pressure with their FPR? That's the big one.

In theory, engine braking should increase, but there's so many other factors involved when switching pistons. Weight in particular.

 

Detonation only occurs when there is cylinder pressure and fuel in the chamber. when you let off the throttle there is verylittle air going into the engine and NO gas going in so detonation will not occur. air by itself will not combust even when its compressed with out the cumbustable element like fuel. When the engine decels the injectors shut off and the mixture goes lean to avoid detonation.

 

Carburetors do the same thing. Detonation will occur when the throttle plates are OPEN and the engine is under load, not when you're cutting the amount of air [and fuel] going in short.

 

good thing i checked this post again. good **** to know. like i said...they were my opinions and nothing more.

v

 

I've also read that with Honda engines, becuz the combustions chambers are so small, you can run a lot higher compression ratio, becuz there's a more compact flame motion. Is this true? Or is EnDyn just fulla sh11t?

 

Dude... don't quote endyne... anything they can't prove they make up... and some things they could prove with some $$, they make up. If endyne was all that and a bag of chips, don't you think you'd see a lot more sponsorship and impressive stuff at the strip from them?