I have decided that i will either get the stillen or the injen exhaust and was just wondering if one was "better" than the other?

 

Welcome to the board!

Both are dual exhausts, injen shows slightly higher hp gains with a raspier "buzzy" sound associated to tuned import cars. Stillen has a more mellow tune. Also the tailpipes look completely different so its really depends on your taste.

Just so you know, a lot of information as already been posted. Do a search using the brand names and you'll find enough info to last you a whole week of reading.

 

I have the injen ses w/ helix test pipes, if you dont care about how loud you car is and you juts want HP gains you can go with this setup otherwise you should look into another system...My pipes are really LOUD at WOT........

 

I vote for Stillen. I love the deep smooth sound. I just think its over priced.

 

If I were you, go with Nismo. Performance Nissan is selling them for less than $900. Save yourself $250.00 and get intake or something else with that money.

 

Go with the Borla if you like the stock sound of you z, with a little deeper note and slighlty louder. Go with the Injen if you want your z to sound like a Honda. Injen has built their second exhaust system, since they screwed up on the first. BORLA, guaranteed for 1 million miles. Great sound. 13 hp gain.

 

I've heard many people say the injen sound raspy like a honda civic online, but amazing in person. Idk, I personally find that hard to believe. Sound clips are usually atleast a little accurate. I have a question about dual exhaust for when I start to mod my car. Since dual exhuast hasn't shown big gains on our car....why even bother with a dual exhuast system?

 

Borla is the only true dual exhaust... Best hp/tq gains over Stillen, Injen, HKS, 5Zigen, Veilside, etc.

 

Going by the Sport Z dyno curves, Stillen and Injen came out #1 and #2 respectively. Borla had little torque gains. I'm having a hard time choosing between Injen and Stillen, Stillen had slightly better gains but is heavier than stock... it's a toss up to me

 

I was kinda wondering the same thing myself. I used to own an FD3S (gen 3, rx7) and i remember that for a stock car if you got too big of an exhaust it would reduce back pressure and might rob the engine of some power, but the combination of the bigger exhaust with headers and cats would actually yield more power overall because when combined with other mods the bigger exhaust was beneficial. Could it be that an exhaust that doesnt make the biggest HP change on a stock car, may yield more HP on a car with other mods?

 

Jeez Maserom, ur a lil harsh on the injen hm? I honestly don't think my injen sounds like a honda fart can. To me it's more like a deep grumbled roar, and yes i was very scared fo the honda fart can. As for as power, I couldn't be any happier with the gains and well I just love the angled look. I guess you can say it's all in the eye of the beholder. The only thing I didn't like about the stillen system is the fact that it weighs more than the stock exhaust. Tough choices but I say listen to sound clips and choose for yourself.

 

I need to find someone near Augusta, GA with an Injen exhaust... I'm leaning towards Injen, but I'm worried about test pipes and headers making it sound nasty.

 

Yep. Backpressure is still needed in a stock car, so you can get away without having a true dual. The more heavily modded the car is, the more the added breathing of a true dual is needed cause you will need to get rid of the excess air. Things that add alot of air to the engine, ie. cams, SC, turbo, benefit most with the added breathing of a true dual.

 

How much more than stock does the Stillen exhaust weigh?

 

The most important info to find on a search on the topic would be this.

Real world numbers from the 350Z sports magizine dyno shoot out. Look at torque and where the power is delivered and over what range. Injen TD does not out power the Stillen TD, look at delivery.

Borla (car 2) = 8.2 Hp - 2.7 ft/lbs torque (peak values)
HP increase from 5500 rpm to 6500 rpm range. Lost HP & torque below 1800 rpm. 60mm pipe. Weighs 52lbs.

Stillen (car 1) = 8.1 Hp - 7.3 ft/lbs torque (peak values)
Hp and torque increase starting around 3000 rpm to redline. Lost a little Hp & torque below 1800 rpm. 60mm pipe. 74lbs - 10 lbs heavier than the stock system.

Injen (car 1) = 7.6 Hp - 5.1 ft/lbs torque (peak values)
Small torque loss at 2800 rpm. Torque gain starts at 3300 rpm. Small Hp increase starts at 3300 rpm, maxing out from 5800 rpm to redline. Major loss in Hp and torque below 2200 rpm. 49lbs.

Nismo (car 1) = 6.3 Hp - 4.5 ft/lbs torque (peak values)
Developed torque and Hp over wide rpm range. Torque increase starting at 3000 rpm. Most HP increase from 4800 rpm to redline. No power losses below 1800 rpm. 54lbs.

5Zigen (car 2) = (-3.4) Hp - .02 ft/lbs torque (peak values) Lost Hp, no real torque gain. Most expensive. Loudest. 58mm pipe. Lightest @ 25lbs.

 

If this is the case, then how come David hasn't provided a cutout view of the muffler where it's claimed to be separate piping. Thus, confirming it as a "true" dual system. There was a thread on this subject matter that went dead.

 

Im not sure how that matters even MGV. how can you call borla the only true dual?

injen has 2 pipes from the cats all the way straight back with no crossover and 2 mufflers. borla has a single muffler(claimed seperate piping inside) and an Hpipe.

stilling also has completely seperate mufflers and pipes with a xpipe I think.

 

How about the Stillen with high flow cats to save weight? But I'm not sure how much lighter the high flows are.

 

Ares,
I didn't call the Borla a "true" dual. To my understanding, a "true" dual is separate piping for each cylinder bank. Separate piping would have it's own cats and muffler, right? The Borla design incorporates both piping into 1 muffler. My question is, and disregarding the crossover at the H pipe, is the piping independent inside the muffler? Therein lies the accuracy of "true dual."

Yes, you're correct about the Stillen.

 

INJEN did not mess up on the 1st time . infact, they only changed the style of the tips on the 2nd time. I personally hate borla because it makes the Z sounds like an american muscle. Why would you make an import sound like an american car. lol
Thats only my opinion. Borla has also lied to us that the car with the borla dynos 20 hp to the wheels. Injen actually dynoed their car afront of their customers with proof of the actual gains.