With regard to the SES light using a gutted cat....
When the PCM randomly checks catalyst efficiency, it momentarily commands full rich then full lean, then back to a normal pulse width on the injectors. Then it watches the downstream oxygen sensor for the mixture change to show up. If the oxygen sensor reacts too quickly, the PCM turns on the SES light. How a spark plug anti-fouler fools the PCM is beyond me, but apparently it does.

 

from what ive read, the CAI improves throttle response, but thats it. is this true? im lookin at the cheaper ($35) CAI on eBay, and can fit a K&N on it. if it doesnt help with power, then im not gonna spend the $150+ to get a GOOD one. ill just use it for the sound and looks.

ive now changed my mind on the High Flow. ill not waste the money. i have a 24in glasspack in the place where the stock muffler was. sounds good all the way from 700-4500 rpms. i havent pushed it past that.

 

this is true. but with the cold air bein denser, it can increase compression. which is part of the reason performance diesel engines run open systems like a CAI. the denser air, increases compression. so when the combustion happens, it pushes down on the piston even harder.

its like a turbo, it pushes more air in, and increases compression. in a diesel, this increases HP

 

maybe im on the wrong forum to talk about diesel. arguing my diesel knowledge against gasoline will get us nowhere HAHA. thanks for the info guys!

 

If all you want is quicker throttle response, mash the pedal down faster Save your money on the CAI, spend it on gas

 

Diesel is a whole different ballgame. Fuel vaporization takes place in the cylinder due to waaaaay more compression than a gasser. Ram air works great on a diesel, not so much on gassers.

 

the fuel/air mixin (which is the same as your fuel vaporization) does happen in the combustion chamber due to compression, as well as the fact that diesels create very little vacuum. so on the intake stroke, the tiny bit of vacuum isnt enough to pull a fuel/air premixture into the cylinder. and the compression isnt really a whole lost higher.

a stock chevy 350 has anywhere from 8.2:1 to 11:1 compression ratio, dependin on the year and generation. whereas, the 5.9L Cummins straight 6 has a 16.3:1 ratio. the 14.0L Cummins 855 (though it is a 14L) only has a ratio of 14:1. Many gassers will go this high, but must run high octane fuels..

 

I was thinking of doing a CAI because my stock airbox is cracked. My blazer was wrecked before I bought it. They did a decent job on the body repair but never replaced the air box. I might just get a junkyard airbox.

 

The only reason I did a K&N Is because I grabbed it for 100.00

 

A better solution is to buy an aftermarket catalytic converter made by Magnaflow. Magnaflow Catalytic Converters, Catalytic Converter Cost sells them at the lowest prices online and they offer free shipping.