Has anyone installed the Stillen True Dual Exhuast on the HR yet? Are there any mods you have to do for install or is it still "bolt-in"? One person told me something about the flanges.
Thanks
-E
PS - Sorry if this is a repost.

Merry Christmas!

 

the flange issue is where the headers meets the cats.

you should be fine with any catback exhaust.

 

it will fit, get it and do a before and after dyno

 

A tech at one of the speed shops here installed a Stillen true dual on someone's Z. He told me when they did the dyno before and after, it actually "lost" horsepower with the Stillen exhaust. I thought it very strange that a company who claims one of the highest horsepower gains on that exhaust would sell something that ended up losing power. Other than that, I haven't heard from anyone or read anything in a forum about gains or losses on the Stillen exhaust. From Youtube posts, I thought that it sounds good, but a lot of people mentioned it's very quiet compared to other exhausts in the market, and it's also one of the heaviest, even compared to the factory exhaust system. If you get it, please let us know your before and after dyno results. Good luck.

 

I highly doubt that stillen "lost" power. It is way less restrictive than OEM.. Possible dyno error.

 

I was kinda thinking the true duel is engineered towards FI? Which if so, it can cause a NA car to loose power due to no back pressure. Right?

Mike

 

False. The vq responds actually better to a true dual setup vs. a single path. Even gains have been shown on a FI dual exhaust like the EVOTT.

 

Back pressure is not important unless you're on two wheels... True dual is the way... but shouldn't be too large of a diameter for N/A.

 

That's what I thought as well, but I can't seem to find out from anyone else what their experiences were with the Stillen exhaust.

As far as going too big, I read somewhere that the Greddy Evo TT exhaust still made 10 peak horsepower on the NA 07 Z, which I think is pretty good. Not sure if that was with the stock cats or not, but I was wondering... If I went with the Greddy Evo TT vs. the Greddy Evo2 while still NA, does anyone think my overall power curve will drop too much? I'm just thinking it would be a cost efective way to get an exhaust for now until I possibley switch to FI. But the FI part might be quite a bit of ways down the road from now.

I think more power is always good, but I like Mine's Co. from Japan way of tuning, and would like to base my gains on how they tune cars. It seems they don't go all out on horsepower, but they really change the response of the engine. In turn, those profesional drivers feel the car is putting out a lot more power than is listed from Mine's Co. I just wish I could afford those Mine's Co. parts though, lol.

Sorry to go of the original subject of this post, but thanks in advance for any ideas.

 

^^ Regardless of which exhaust you get, the gains will be unnoticeable. It doesn't matter if you put a 2.36", 2.5", or 2.75" (EVOTT) they will all be left unnoticed by the driver. Why would you get a 2.36" for now while you're NA, and then later on down the road when you go FI, you would have to go through the hassle of purchasing another exhaust suitable for FI like the EVOTT? If you do that, consider yourself a ******* idiot.

My advice, get the EVOTT now. It makes power NA, and if you decide to go FI later, it'll work then too.

 

Which is exactly what I meant. I guess I didn't make it clear in my last post. Exactly as you said, it would make more sense to get the bigger exhaust now so I wouldn't have to change it later. That's what I meant by "cost effective." I never said I would buy and change to another exhaust down the line, as I don't have that kind of money to do so.

Anyhow, thanks for the advice on the exhaust. I just wanted to make sure, whether it was noticable by seat of the pants or not, that I wouldn't be "losing" any acceleration or response from the engine by going to a bigger exhaust NA, and if it would make my 0-60 or quarter mile times worse, or if it would stay relatively the same.

 

Judging by the EVO TT's dyno graphs, the power seems about the same as stock exhaust but at the top end it makes more.

 

Losing low end power due to a larger diameter exhaust has nothing to do with back pressure, and everything to do with exhaust gas velocity and scavenging.

TK

 

got ya. It was just diff on my sentra. I didnt know if it was a universal thing, bc RSX type s's for ex gained whp from a 3" N/A. While my sentra lost double digits with the 3'' till FI.

Mike

PS someone should get a before and after of the stillen duals, I like the way they sound but would like results.

 

Ya depends on the car I guess. But the HR is really choked down by the stock exhaust / cats.. (based upon before/after graphs)

 

go with Evo TT you wont be dissapointed.. heres mine

http://www.youtube.com/watch?v=7WckUDUu52M
http://www.youtube.com/watch?v=Gu_2oWU2HBc

 

What about using HFCs with the dual 3" Greddy TT? Wouldn't that be too much for NA? Keep in mind that it's not a certain that I will go FI any time soon.

 

^^
The GReddy EVOTT has 2.75" piping.

Search for the thread where Shariff installed the evott onto an 07. You will find all your info there.

BTW, when Sharriff installed the evott, he gained 10whp. When he installed the test pipes in addition to the evott, he gained 20whp. So to answer your question, no you will not lose any power if you decide to get test pipes or hfc's.