In that case I would estimate the Stillen to be a little higher. Maybe 55-60%. Does anyone know the pipe size on the Stillen? I would guess 2 1/2" I believe the Borla is 2 1/4".

 

^^^+1, Stillen pipes is 2 1/2" all the way.

Has anyone look inside the Borla first muffler/resonnator? Is it a straight through with perforation, or does it has a crossover (H-pipe)? Crossover help equalize the exhaust pressure, improving flow. Kinda like scavanging effect.

Off topic, but on the Z32 w/o crossover, it sound like two 3 cylinder engine. Kinda like first gen Viper w/side pipe, two 5 cylinder. Both sound like @ss. This doesn't apply to the Borla as much because the two banks share the same muffler.

 

I think that's right, Borla is 2 1/4" & Stillen is 2 1/2". I would assume that the Borla is also straight through since their gains are similar to Stillen's.

 

The stillen uses an X pipe while the borla uses an H pipe.

 

Well, I found out that the borla exhaust will not fit on 05/06. So for know my only options are the Stillen or HRK Muffler w/coupe mid pipe.

 

Borla will hit just fine. All you need is the muffler bracket sold my most G35 Vendors

 

kewl...I really like the way the Borla sounds.

 

Perhaps you already have an answer. The Stillen true dual exhaust weighs 13 lbs. It will increase horse power 21-23 and torque 21-23 foot pounds. The Stillen exhaust that I have for sale is stainless steel, a true dual with an X pipe to balance pressure.

 

I think a lot of this information is false. No way the whole stillen catback only weighs 13 lbs. And those rwhp and torque increases are a bit inflated.

 

Wow 13lbs and 21-23 hp and ftlb gains!

So that's why you are selling yours?
https://g35driver.com/forums/showthr...01#post1498301

 

13lbs - BS!
HP gains - also BS!

I love stillen stuff but there is no way that exhaust weighs 13lbs and I have never seen proof of their claimed #'s but have seen ~12hp.

 

I believe the facts of the matter is that Stillen weighs 13 pounds less than stock and Borla weighs 20 pounds less than stock for the sedan cat back.

 

I will be honest with you, but STILLEN can not even be compared to Borla!
As far as I know, STILLEN is WAY better!!!!!!!!!!!!!!!!!

 

Actually the Stillen exhaust weights a little more than the factory exhaust. It only gains at the most around 10 hp or so. Not 20+.

 

I say neither. Wait another month or so for the Fast Intentions sedan system to come out. Its going to be bomb! Be patient. FI is a kick-*** company with great customer support and sweet systems