Man I almost forgot with the hesitation issue. But when we were installing my HFC's I noticed that I had two Honda Civic's exhaust pipes on my car .. What in the hech are these two straws doing on my car???
This is probally why me exhaust tips sound like there are gong to rattle of when my wife drives away in the moring..

 

becuase it's a naturally aspirated car. 3.5 liters/two banks = 1.75 liters....you don't need large diameter piping for that displacement.

 

You arn't making a whole ton of power (relatively), and you're not FI.

Thus, you don't need huge exhausts.

Don't you think it's rather impressive that the two pencil's create that much power?

 

I accully do think that Nissan did a GREAT job making power with those toothpicks bowdown: by why not use something a little bigger.

 

not in all cases this is true

 

Large diameter pipe doesn't make the car go faster, 2 1/2" pipe is large enough
up to somewhere around 400 RWHP. Almost every exhaust system that
company's like Magnaflow sells doesn't exceed that 2 1/2" figure! Unless you
have a Twin Turbo motor putting out major HP is there any need to move up
to a 3" system. Our cars will lose HP if you installed headers, test pipes and
a lager diameter system!
Gary

 

I know that but there is now way our exhauts is 2-1/2. 2 if its lucky. I was not expecting 3 inch dual exhaust like I had on my Monte( 650hp) but Civic exhaust just looks funny. We lose power from headers, Test pipes. That I don't agree with. I have HFC's and the car is pulling harder. Power still equals how fast the exhaust gas can leave the engine, to allow the pistons to move faster. I do agree that to large you will lose power..

 

They don't NEED anything bigger.

In their eyes, it's a 1% power loss for a 90% NVH decrease. That's a compromise I'm willing to take.

 

plus if the pipes get larger, more rasp right? That's my understanding.

 

it's more of a drone with larger pipes. The cats and can are what change the rasp the most

 

Larger pipes create more noise.

Resonators and restrictions will eliminate drones.

Rasp comes from having 'straight pipes' and not enough expansion chambers (resonaters and again, restrictions such as cats).

 

My STi had one 3" pipe and smoothly pushed the 300HP & 300ft*lbs...

The G has 2 2.5" pipes. So total cross sectional for the G is about 10sq in., and the STi was about 7sq. in. Looks like the G has plenty of volume to flow the power, I trust the designers on most of thier set-up. Only thing I scratch my head on is the "Y" design into the one 2.5" pipe (cross sectional area here is about 5sq. in). To "solve" this I was thinking of trying the "H" I have seen on here a bit. Only posts showed butt dyno results. If anyone has more on NVH loss and performance gain please PM me (I dont want to hijack the post).

 

I too am interested in the y to h mod

 

the STI being a turbo car, benefits from a larger exhaust. The G does not. It lacks the displacement to do so.

 

Larger diameter piping = less torque in N/A form.