A little more than 1/2 a HP when NA.
In all of the research I've done, I've found a collection of various small increases. 1/2 a HP here, 1/2 a HP here, 1-2 HP there, a little more TQ boost on another part of the curve and so forth.
With several small increases available, why not utilize them?

Note: where the diffuser is used also makes a difference. I'll go more into this later.

I also found areas of trade. For example, the primary tubes on the collector... I experimented with 2", 2.25" and 2.5" while holding all other variables constant.

Each different diameter had its strong points, it took a little bit of a judgement call to decide the optimum here, but 2.5" primaries had the best overall curve.

2.25" was good too, but it lost 2 HP up top. 2.25" didn't really seem like an acceptable trade.

 

i was going to switch out my nismo y pipe for the XYZ pipe but im gathering from this response that i shouldnt even bother with it? No sound difference?

in your first post it said that the resonator should improve the sound? But should i not bother with it if i was just gonna get the XYZ with resonator?

 

Thanks Tony. I don't know how much hp you need to consider "very high", but I'm willing to set the PSI to whatever meets your requirement! (Either that or I'm sure I can bribe you).

Honestly, I'm tired of the loud exhaust drone while cruising around town (2k rpms) and want something quiet that still flows. No fumes + no noise + turbo power = 0 exhausts to choose from. I'm hoping someone on this planet comes up with a product to fill this empty niche...

 

hmm good point. But again if I can get a more exoctic sound like a ferrari over my Nismo F it im in. unless its alot of money

 

Tony, correct me if im wrong, but i think him adding the XYZ pipe with resonator will get rid of the rasp/rattle that people experience with nismo exhaust and HFC/test pipes combo... (i know i experienced this when i had my nismo exhaust and Berk HFCs)

i think this is what tony meant when he said it will improve the sound.. to me, no rasp, is the best sound improvement there is.

 

I have the nismo catback with the Berk metallic HFC. As of right now, I get slight rasp and some popping, which I assume the resonator will fix. If you have a stock cats with the nismo exhaust, keep it that way...it sounds like sex.

I really liked the stock cats plus nismo catback sound, but after I added HFC, the exhaust note I was trying to keep kind of disappeared. I'm hoping this resonator will cure the slight rasp and popping.

 

yeah the rasp is terrible... although i think the nismo with Berks (minus the rasp) sounds better than nismo with stock cats... the HFCs really wake it up..

i would be EXTREMELY interested in hearing the XYZ pipe w/ resonator, nismo muffler and HFCs or test pipes... according to tony, the resonator might just get rid of the rasp thats experienced even with test pipes!!

 

I'll be doing some of the testing. I have a setup that rasps, and I'll compare sounds and post data and videos when its all done with a resonator.. Just wait and see!

 

Yeah I noticed the popping with this setup too! It sounds pretty cool to me. HA!

There is a slight rasp, but it's there for a few hundred rpm's and then it dissappears. You guys must mean serious business for getting the exact tone you desire. I don't blame you, it's addicting.

I do however wonder if I can get rid of the hissing I hear everytime I drive the car with the windows down.

 

I've made a lot of posts, but I believe that quote was a response to a question relative to the XYZ pipe on a fully stock exhaust system.
I wouldn't bother putting it on an otherwise stock system.
The stock Mid pipe is 2.5". And sudden contractions in the system tend to add rasp. So connecting a resonated XYZ to a stock midpipe would be pointless.

That's a very different situation from what you have.

In your case, you have a 3" midpipe so yes, it will certaintly improve the sound.
If you have test pipes or HFC's on the Nismo exhaust, yes, the resonated XYZ will make a clear reduction in rasp.

 

have any of the independent dynos been completed yet?

 

No. I still need to get more parts from production to send out.

Dynos will be posted probably within hours of their completion.

...With sound and video too.

 

Can't wait I really want to hear the shockwave I am looking into single exhausts right now.

 

tony, taking over the world one car part at a time.

 

Tony

Let me know once the Dual 3" with X pipe is released or if you need someone.
I might not be high HP(425WHP) but definitely like the way the exhaust comes apart with the V-Clamps.

Current setup:
APS TT
Fast Intentions 300cell HFC
Greddy EvoTT true dual 2.75"

Also I see your saying that with the Y pipe that you offer you can
have the cat at that location and use test pipes further up where the
stock cats go but wouldn't that in turn set off O2 CEL's since the O2
sensors would not be relocated.

 

No. I'll have a fix for that once the MD test pipes come out.

 

motordyne is coming out with test pipes also? and is this the first part of that secret product your coming out with, with the supposed 40rwtq gain? looking forward for that piece

 

thats the other one, and that wont come out for awhile, so might as well forget about it, and just be suprised when it comes out.

he said, the gains are better than the orignal protoype. they are so great posting the gains might get flamed because they are so good.

 

well i hope i could amuse some people one here, but i guess not.
i should have known the type of people who drive Z's
anyway.
i guess it will just be like all the other exhaust in performance,
some people look for sound
some people look for looks
I look for power, even if its just a bit more than other exhaust systems.

hey tony, would there be any chance to throw up a dyno comparasion of stock exhaust and then yours, im pretty sure everyone on here, will believe you, mrev and spacer is gold.

 

Yes there will by dynos against stock. Even though I have many dynos of my own, I do prefer to let them be independant.