Dholly, I have heard the exhaust, actually on Gurgen's car. I went as far as bringing a digital sound meter that I use for Home Theater setups and calibrations. I will post the results if anyone is interested, but the 4db louder is about right. We did inside the cabin and an outside pass by. For my taste, I think it's a bit loud when passing by. It was hard to be objective about the inside cabin sound because Gurgen's engine has it's own rumble to it, but I would say it's the same as stock at idle and a bit louder when you punch it. I am just curious how this will change over time, will it settle down or just change tone? I thought about adding some dynomat to trunk, but that still will do nothing for the exhaust sound outside. I realize that this is a performance mod, and exhaust sound is part of the reason most people get it, but I still want the gains without the significant increase in sound outside the cabin. I am told that the Borla Dual Exhaust is not as loud, if anyone has one or has heard one please chime in (i'll even come out and measure db's if your in so cal). I also talked to my local muffler guy, and he suggested that he may be able to add a resonator or something to quiet it up without affecting performance, of course he needs to have it in the shop first.

 

Sound is so difficult to quantify I think posting results of a controlled test of both systems with a meter is a great idea. I have a Rat Shack meter for HT as well and can test the Borla if anyone in western or upstate NY wants to meet up. Maybe windows up, down and pass by readings at 1k rpm increments in various gears for the 6mt. Now that Gurgen has the RT cats on, using his 5at might be a tad misleading!

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

Newbie question... To reset stock ECU after exhaust mod, I disconnect battery cable overnight?

2004 5AT Premium/Sport/Aero Garnet Fire/Willow

 

Yes. CAUTION: To avoid an accidental short circuit and potentially explosive sparks at the battery, always disconnect the negative (-) battery cable first and move its end terminal away from the battery before disconnecting the positive (+) cable. Reconnect the positive (+) battery cable first and the negative (-) cable second.

Alternatively, if you prefer not to disconnect the battery, the quick ECU reset procedures can be found in the www.G35driver.com FAQs and DIY forum.

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

Gotchaa...

I am in SoCal (Rowland Heights to Irvine)... I've got the Stillen Hi-Flow and 350z duct (no plenum).

Gurgen has the Injen and Plenum + RT Cats.

If you'd like to do a sound check on mine before I throw on the Crawford Cats, PM me and I'll shoot you my cell # so we can talk.

Cheers, Ted


'03 Sedan 5a: BS/G, Prem, Aero/Body, Sport, Nav
Click for MODS or Vote at Online Showoff

 

rear view

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

162561-stillen.jpg

 

rear view closeup

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

162567-stillen3.jpg

 

side view

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

162578-stillen4.jpg

 

i posted DaveO about the production borla dual exh. sys. for
sedan's,also photo's on 12/24/93 , in review, great quality(if
you are paying for show quality polished exh. don't go borla.
for me i intend to "keep the rubber on the road" not wheels up!
the performance is super, interior sound under acceleration
is ok for me ,but my wife thinks it's bit loud, outside sound is
very pleasant to all comers. sounds like a europan GT car.
price is a bonos also. borla rep. told me H and/or X pipes
creates / slight turbulance and a bit of back pressure. the same
as reduceing pipe I.D.. I TRUST MY VENDOR, and
would purchase borla again. i have raced at a national level
in several classes(scca and shifter karts) it ain't my first exhaust.
happy new year
bob

old road rat

 

Bob,

Real happy you like your Borla exhaust. Don't necessarily agree with your expert or believing everthing that he or anyone else says (including me). H-pipes and properly designed X-pipes don't necessarily work in the same way. Please chekout this site --- http://www.carcraft.com/techarticles/69238/ --- You probably remember the V-8 tyi-y headers and what they did for torque.


DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / Stillen Exhaust System

 

Interesting article. So which exhaust performs better the Borla or Stillen?

 

On Wed. 7th, I'll know exactly what my sedan with the Stillen X-pipe catback exhaust, Stillen cold air box and 350z upper intake tube is good for. Haven't seen any comparable Borla dynos yet.

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY

 

dholly,

Too bad you don't have a baseline dyno. I REALLY wish I had done one before making mods. The reason is that with (1) the Crawford plenum, (2) an Injen CAI, and (3) the premuffler removed, the dyno for my 2004 6MT sedan showed only 217 HP.

Frankly, 217 HP is about (or maybe even less than) what I would have expected from a *stock* 6MT sedan, not one with several hundred dollars of performance mods. Maybe the dyno machine was one that reads low... or maybe the fact that they did the dyno in 4th instead of 5th was a factor... or maybe the weather (it was really cold that day) had some affect. Or--and this is why I wish I had a stock dyno from that same dyno machine--my mods had ABSOLUTELY NO AFFECT. The problem is... I DONT KNOW.

Regardless, if I were you I would be very pleased with any number above 230.

--Steve

 

Gotchaa,

Which exhaust system has the x-pipe?


DaveO
2003 G35 Sedan - DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TechnoSquare ECU
Street Edge TC / B&M Cooler / Stillen Exhaust

 

Steve, yeah originally I was hoping to do before baseline/after install dynos at the same time. Unfortunately its a PITA to do (several hour r/t out-of-town, work conflicts, etc.) but, after hearing enough "maybe that's not such a good idea", I felt better with some ECU learning time. There is some speculation that immediate before/after pulls could be more accurate than many believe, based on the fact that dynos are done at W.O.T. with the ECU in full open loop mode, i.e., not closed or learning. I'm gonna try and get the details behind this statement from the dyno owner to see if/how it applies to a/f and timing with our learning ECU. I'm taking the mini DV cam and digi cam to record it all. At least I'll know for certain where I stand now.

2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY