First off, I'm curious, I just got the invidia exhaust and yes it's very loud.
First question, if I were to get silencers would it not be the same as the stock exhaust because don't silencers imped airflow?

Second question is about getting 4.57 gears. If you put the gears in, it will increase your operating rpms by 500 or so. Basically the question is if you were driving at 5k in rpms vs 4.5k, won't that increase your fuel consumption? Or does rpms don't affect it unless I'm at WOT?

 

I hope this didin't come as a surprise to you.
You got this exhaust because of some or all of the following:
1. You wanted it loud.
2. You wanted better flow.
3. You wanted to lose a bit of weight.
4. You wanted a different look.
5. You wanted a different sound.
Now you want it to be not so loud. Silencers will do this. Yes, silencers will reduce flow. With your present exhaust, you can't have both flow and reduced sound. No, I highly doubt that an Invidia, even with silencers, will be anywhere as quiet as stock, unless you are prepared to get a silencer that is custom made to plug that thing right up.

4.57 gears are an 11.5% increase in ratio, therefore, at any given rpm, you will be 11.5% higher than you were with stock gears, so yeah, when you used to go 4.5K rpm, you would then be going 5017rpm.
Only if you continue to drive in the same gear at the same speeds as you did before. On the highway, you won't have much choice is you normally cruise in 6th. In the city, many people choose to drive in 1 gear higher than they did before at the same road speed, thereby reducing their rpm and actually getting a bit better fuel economy. What you do and how you drive will determine your fuel consumption.

 

I like the exhaust and knew what I was getting. (just not the interior noise....lol). I just can't have a conversation when accelerating. I was just curious to know if I put silencers on, would that cancel my hp (what little I gain) because of the air impedence.

 

Say what??
Cant hear you.. sorry

 

Anytime you plug up an existing design, it will perform to a lesser standard (in respect to performance). You are right in saying that you gain little with this exhaust, but the big question will be, if you plug it up enough to make the noise tolerable, will you then actually lose more than what you had before? Chances are yes.

It is not the volume of noise that is bothering you in the interior. It is the drone. This is a resonance frequency of sound that possesses characteristics beyond simple volume. Eliminating the volume in a given exhaust may not eliminate the drone. I believe, in the end, you got what you got and now you have what you have. It might be time to sell it to someone who can tolerate the drone and get something that doesn't. If you do what it will take to achieve what you want, you will no longer have an Invidia exhaust anyway.

 

I've found that with my 4.77 gears, I get slightly better city mileage but much worse highway. I'm about even at 24-25 mpg for both city and hwy.

 

FWIW I only use the silencers on long trips.

you get used to the sound within a week, and it's fine after that. but with the silencers in, the car is extremely quiet.