I can't seem to make up my mind between them. Anyone know the pro's / con's between the two.

I'm looking for a nice deep sound that sounds great at WOT, and Vtec, but minimal to no drone and nice and quiet for normal driving so I when I'm listening to my tunes it sounds as good as possible.

HP gains are a plus, but not critcal. I have no plans on tracking or racing it...street or otherwise.

I'd appreciate any help you guys & gals might have for me on this.

Oh...one other thing I've noticed from the pics, is that the larger TP they show on the 70mm one doesn't appear to have the mounting tabs for the heatshield....if I get a TP that would be a must since the police in my area are brutal. I certainly wouldn't put it past 'em to check under the car with a mirror.

 

I have the 63mm and love it. No drone, quiet while crusing around but sounds like a beast at WOT

 

Your preference sounds like you need 63mm.
But i would go for 70mm without a doubt if im going for sparrow

 

either one will be loud, but 70mm will be louder for sure.

 

unless you are FI stick with the 63

 

The 63 Sparrow is not loud and I think that will be your best bet for better performance and little more sound.

 

can u guys tell me the diffrence between 70mm and 63mm ? which is better for NA??

 

From what little I know, they've changed the piping on the 70mm now so that the latest version provides enough backpressure for NA. Horsepower gains are claimed at somewhere around 10-12hp, IIRC. (although I haven't seen a dyno to back that up) vs. 6-8hp gains with the 63mm. The larger piping and hp gains come at the cost of the exhaust being louder, and with apparantly some degree of drone. This is the reason for my dilemna.

Although when it comes to drone, other than the notoriously bad Invidia's, drone seems to be subjective with most of the other exhaust systems. Some claim they drone while others don't, and so how much of an annoyance it is will apparantly have to be heard for ones self.

BTW...If cap1's description is accurate, that's exactly what I'm looking for!

 

Subscribing to thread

 

Not trying to be a jackass, but just want to clear up that backpressure doesn't help anyone. (This is a very common misconception)

Smaller diameter piping (relatively speaking) is sometimes better because of increased exhaust VELOCITY.

The most efficient exhaust system will have the least backpressure AND maximum velocity.

I've seen the dyno graph of a TR1 63 V1 with 63mm testpipe making 8whp and 8wtq on an AP2.

I've also heard that it's pretty quiet without drone at cruise and pretty mean at wot.

These attributes make it my favorite choice for my '04.

I believe the 70mm would be too loud and sacrifice exhaust velocity, usually manifesting itself as a lower-end torque deficit. Something I def. don't want on this car.