Quote (FMX_89 @ Oct 7 2014 07:39pm)

It's not even an answer. It's a tangent.  A cai and catback WILL increase power if either of the stock pieces they replace are a restriction.

No need for 47 paragraphs of ITT tech educated rambling.

Quote (AXIS @ Oct 7 2014 07:41pm)

Exactly. There are plenty of cars with dyno results proving gains over 20 RWHP.
And his "educated" argument leaves out some pretty big portions of physics.

Quote (CarsAndKush @ Oct 7 2014 07:22pm)

That's his point isn't it? That those 2 "mods" are no better than the ones dodge equipped the viper with.



We aren't talking any cars. We are talking the srt viper.

Quote (Sopranos @ Oct 7 2014 03:01am)

tl;dr poopshit

Quote (TURBO_DODGE @ Oct 6 2014 10:40pm)

umm no? i bought the challenger cuz i like the car; its bone stock cept a diablosport tune, intake, bigger tb and exhaust, so less then 750 in mods.

i have over 12k into my spirit r/t, that car is built and kicks the shit out of my challenger all day and night, which kinda happens when it puts down more than 200 more hp to the wheels, shit traction or not.




the viper was stock. CAI? is stock, just aftermarket filter, woopty fucking do. doesnt do shit. Cat back exhaust? stock, just different muffler styles for sound. There is no performance gain there.. The cat is going to be the biggest restriction and leaving that in /modding thereafter, really does nothing for performance at all.

unless the motor is opened up and something is done like forced induction, nitrous, motor work etc, its pretty much stock.

What do you really expect to gain on a cat back and CIA? I really hope you dont believe the claims made by cai and catback systems that claim to add 20 hp... which isnt exactly false but they dont exactly give you all the information either.. sure you may see a miniscule increase at a specific and irrelevant rpm using said cai, but your peak will never be more then like 1-3hp over stock andin most cases, null, same with cat back exhaust systems.

Also note that that "cold air" isnt cold anymore by the time it mixes with existing air and radiant heat from the intake manifold and cylinder head. Forced induction doesnt get away with it either because when you compress any substance to x amount of psi or subject to x amount of force, it will generate heat at a deterministic value based on the force being applies.. FMIC's try to work around it by cooling the air, but you loose pressure doing so because of my above statement. Less compression/pressure, less heat and vice versa. But if you want to reach a x psi setting, there is nothing you can do about the heat unless other substances influence it; like methanol injection.

Both should be done because you want a different sound, because there is zero performance to gain from such systems unless you open the motor and give it more induction capabilities by porting the head and stroking/boring the motor or adding forced induction and supporting mods.


Assume no throttle body for the following. When a piston is on the intake stroke, it creates a vacuum, ok, got that? ok, that void, unless compressed, can and will only be filled by that exact amount (fluid dynamics 101, and yes, air is considered fluid). Putting a cai on, does not magically make the engines cylinder heads allow for more cfm, give you a longer bore or bigger stroke to pull more air into the cylinder. It doesnt work that way. Sure, filters are restrictive, but i tell you one thing, if that was ever an issue, the amount of suction created by an engine would rip the filter apart and swallow it. ie-put a metal screen over the end of your vaccum cleaner, nothing happens, now put a piece of paper over it..and gulp lol. same shit. Which is why you can run massive turbos with filters on them and be fine because there isnt much restriction to begin with no matter what filter you run.

i mean, its simple really if you understand fluid dynamics.. when there is a bottleneck/restriction in a air system (venturi to be technical) all thats happening at the bottleneck point is that the air is being accelerated in that linear direction from that point on unless it comes upon another venturi etc etc. The faster fluid/air moves, the less pressure there is; and vice-versa. It evens itself out in the end because in a non forced induction system, the baro pressure is forcing the air in at x amount of bar psi, and the engine is creating a vaccum pulling air in with the assistance of atmospheric down force. No matter what you do, you will always get the same amount of oxygen in the engine regardless of stock or aftermarket intake. There is more air being pushed into the motor via atmosphere then the engine will ever be able to induct on its own.

Which is why if you put a boost gauge on a n/a motor, dont be surprised if you see up to a 3-4psi reading spike when driving it; usually from cruise to wot scenarios. Because the atmospheric pressure is greater then the vacuum created by the engine; and that sudden gulp surges the intake manifold ever so slightly which is where you read boost from(after throttle body/before cylinder head). Your engine will still only induct x amount to burn based on your cylinder heads intake runner capabilities and above mention shit.

With all that said; thats the reason for a throttle body. It is a direct and absolute restriction of air flow, unlike a filter; to regulate how much air is allowed into the motor for combustion.// in ending, if there was such restriction by the stock filter/intake pipes that actually effected the flow of oxygen to the motor in any significant manner, the engine would fail or just not run at all. CAI is for looks and sound. It does jack shit unless you do physical work to the motor to and increase physical dimension to allow for more air; ie- cylinder bore/stroke/throttlebody bore/intake runner porting, etc etc.

Air is considered a fluid when it comes to physics,, dont mistake that for liquid as liquids only take the shape of somthing vs fluids do that plus expand to fill that space...Physics 101, All liquids are fluids but not all fluids are liquids. Which is the whole basis of one of my first paragraphs. The benefit of air being a fluid vs a liquid is that air is compressible and liquid is not. push your hand through the air and nothing significant happens, vs do it in water and there is a significant amount of resistance vs in air because the water doesnt compress... Which is the reason for a compressor for forced induction vs like, lets say, a fan which just accelerates air (like a boat prop, and is the basis of its function. It pushes on water and because water/liquid doesnt compress, it forces the boat forward )


so unless you go forced induction, cai on an n/a motor is pointless unless you are going for engin*** aesthetics or sound. and please dont equate that sound for power, its just the result of resonance in the solid intake pipe vs a stock plastic plex pipe. That little crunched section in your stock intake pipe is to eliminate that sound specifically, and the secondary reason is to make it easier for filter changes allowing for maneuverability of the intake pipe.


i could go on an on but i gotta get to bed for work in the morning.., but fucks sake i hope you get it by now, cai doesnt do jack shit and the above paragraphs is why i consider it aesthetic and stock in terms of performance.