[jblough99]

Thats what I was hoping for. Does the piping drop back down to 2.5" inside the muffler for each side?

[Tiago@VRSF]

Drops down to 2.75" on each side.

[1chanc3]

Any sound clips of the v2 with stock downpipes? I'm very interested but i'm not sure how it will sound....

[jblough99]

Any dyno charts with before and after exhaust? If not do you any numbers for gains with your system over stock exhaust on a tuned car?

[jblough99]

So no one has a dyno of the VRSF exhaust vs stock? I really like the idea of this exhaust with the huge weight savings and simplification of one large pipe, but if there isnt any performance gains over stock I dont want to throw money away. Yes I know most of the gains from an exhaust come from removing the secondary cats, regardless of brand, but if the muffler on the VRSF is restrictive enough to cancel out those gains then why bother. Judging by sound alone, it is definately quieter than other exhaust, even with catless DP's, which leads me to believe its more restrictive.

[Tiago@VRSF]

So it's quite a few DB louder than the stock exhaust with no internal baffling, unlike the stock exhaust. How does that make it more restrictive?

[ajsalida]

Originally Posted by jblough99

So no one has a dyno of the VRSF exhaust vs stock? I really like the idea of this exhaust with the huge weight savings and simplification of one large pipe, but if there isnt any performance gains over stock I dont want to throw money away. Yes I know most of the gains from an exhaust come from removing the secondary cats, regardless of brand, but if the muffler on the VRSF is restrictive enough to cancel out those gains then why bother. Judging by sound alone, it is definately quieter than other exhaust, even with catless DP's, which leads me to believe its more restrictive.

Quiet is an acoustic phenomenon, not related to flow. Plenty of really loud exhausts flow poorly. A single pipe on a N54 will mix the acoustics up of the two banks, with a lot of cancellation. That is why they are quieter than other catless duals. Eliminating the secondary cats and having a combined cross sectional area equal or greater than stock will make it flow better.

[danielg69]

Originally Posted by ajsalida

Quiet is an acoustic phenomenon, not related to flow. Plenty of really loud exhausts flow poorly. A single pipe on a N54 will mix the acoustics up of the two banks, with a lot of cancellation. That is why they are quieter than other catless duals. Eliminating the secondary cats and having a combined cross sectional area equal or greater than stock will make it flow better.

Yes I agree. Although I have never owned a VSRF product I would be hard pressed to believe it is more restrictive. Here's a good video of a tiny exhaust that is well, quite loud.

[3000GT MR]

No back pressure /restricted exhaust problems here

[gunda]

there appears to be something attached to the end of that exhaust :s lol

[jblough99]

Originally Posted by Tiago@VRSF

So it's quite a few DB louder than the stock exhaust with no internal baffling, unlike the stock exhaust. How does that make it more restrictive?

I wasnt saying it is more restrictive, just based on sound alone I was thinking it might be more restrictive than other aftermarket options. Like I said the VRSF is #1 on my list of options, I just like getting all the data I can before making a final decision.

[jblough99]

Originally Posted by 3000GT MR

No back pressure /restricted exhaust problems here

The fact that your running this exhaust with a big single turbo, it sets my mind at ease about its ability to flow

[bantam]

Originally Posted by Dr. G

Two perfectly straight 2.5" pipes technically flow a bit better than a single perfectly straight 3.5" pipe of the same length.

This is likely incorrect. While the two 2.5" pipes have a slightly greater cross-sectional area, you have ignored the frictional effects present within the pipe.

As I recall, the rule of thumb is that the flow rate is proportional to the cube of the radius of the pipe, so the 3.5" pipe would flow about 35% more than the 2 x 2.5" diameter pipes given the same boundary conditions.

[Electric]

I am pretty sure the VRSF catback mirrors the AMS exhaust. Would you be saying this about AMS? BTW I dont have either but I know that a lot of "shops" are complete clowns when it comes to their opinions on things like this. I dont know if VRSF is the best, but from looking at it, its definitely an improvement over stock.