I ordered a NB headerback a couple months ago, a few weeks later I decided to go ahead and add the downpipe as well. It was a bit of a wait, but Abe was upfront about that before I placed the order. The exhaust arrived and, I'm sure you've heard the story; everything looks great, it fits like a glove.

I'm running a BEGI/FM cast manifold that Abe was able to build my exhaust around. I was previously running a BEGI 2.5 inch separated gasses downpipe (that I had dumped the wastegate rather that returning it back into the exhaust, and a racing beat headerback. The car is much quieter now, so much so that it feels "slow" by comparison (loud = fast, lol). Luckily I did some before and after logs so I could compare.

4th gear pull, both pulls starting at 1700rpms, stopping at 7000rpms. I used the MS log to compare time between 2000rpms and 6900rpms to eliminate any slight variances in beginning RPM. The results:

BEGI/RB
9.585 sec
3000rpms = 143kpa
3500rpms = 163kpa
3750rpms = 185kpa
4000rpms = 210kpa

ARTech:
8.731 sec
3000rpms = 147kpa
3500rpms = 173kpa
3750rpms = 189kpa
4000rpms = 212kpa

So my 4th gear pull picked up almost a complete second and spool is a good bit quicker. Obviously the RB exhaust was choaking the car, but I'm very happy with the results. I just wish I was baller enough to have done a manifold as well.

 

Did you touch the tune at all? did it lean out at all?

 

I did a couple 5-10 minute logs to adjust the tune before doing the 2nd pull. I was actually very surprised by the lack of change in the tune. The car looked to be running a little more boost with the ARTech which may have skewed the results a bit (I'm wondering if that was a result of increased backpressure on the wastegate since it was dumped previously).

 

Attached the spreadsheet if anyone wants to look at the numbers a little closer. Beginning MAT and CLT were about 10 degrees warmer today as well, it's hot down here today.