zer0

So, a 2.5 inch DP and a 3 inch catback has less overall restriction than a complete 2.5 inch system. You keep taking away restrictions an you will add power. So Stock sucks, complete 2.5" is good, 2.5" DP with 3" catback is better?

MIAPLAYA

Exactly...I mean at some point if you start TOO small you are going to have issues. If it was lets say a 2" downpipe and a 3" exhaust you might not see the same gains. But the 2.5" downpipe is MORE then sufficient for this turbine and amount of exhaust gas discharge. Adding the 3" after it reduces the backpressure which increases turbine efficiency and allows for expansion of exhaust gas as it cools.

zer0

Feel free to add your input here:
https://www.scionlife.com/forums/viewtopic.php?t=125753

They have a different opinion on exhaust..

MIAPLAYA

Well I will respect their thread and not puke all over it with what I think but I think the dyno charts speak for themselves. Theory and conjecture are all well and good but lets look at what happens in the real world. Its pretty clear based on the charts above. The 2.5" exhaust tested was downpipe back (same as 3") 100% mandrel bent and tig welded with no resonator and only a 3" in Thermal muffler. The Mossy is 3" downpipe back mandrel bent, tig welded, 3" in Stromung muffler. Clearly the dyno doesn't lie. These runs were on the same Turbonetics dyno, on the same day, same boost pressure, same fuel, no tuning changes. Is a 2.5" exhaust good sure. The out of box Spec V kit makes just shy of 240 on the bone stock exhaust. Clearly a gain of 13 hp with the 2.5" is good. But nothing like the 35 HP of the 3"

zer0

Yes, I am a firm believer of the 3" exhaust. Ive ran it on my DSM without problems..thought about going 3.5" but they stopped making it..lol

I was just merely asking this question, because I know people are pondering...hmmm how is that efficient.

I just hope Mossy can make the Spipe not be the lowest point of the car...

MIAPLAYA

Mossy looked at Turbonetics' black Tc on the lift on Scion Day there and they think they can fit their exhaust in there without being too low including the S pipe and using 3" piping. John will have more for us when he gets up to Stromung for the R&D work.

jam0321

the s-pipe will be the biggest of our concerns. Looking at some other companies designs of a 3" s-pipe has caused some clearance issues. It will definitely be a concern but we will let you know...

DTRUONG_112

if you make it 3in all the way back from the downpipe with no fitment problems, count me in as one of the six.

MIAPLAYA

Will do...

datrickster24

I hope the R&D on this has already been started.

-Dan

MIAPLAYA

I'll call Greg tomorrow and see where we're at.

datrickster24

Sounds good.

-Dan

jam0321

Okay so here is the latest. My car will be going to get the prototype 3" done in 2 weeks. I'll have pics, vids, and of course price very soon there after. I'll also have a thorough report done for you guys. But if it anything like the 3" Mossy Performance makes for the Sentra Spec V this thing should kick a$$!!! Stay tuned!

datrickster24

Sounds good!! I hope they do a group buy for the first buyers...I want this not sure if i can get it... if its in the 500 or less range i could go for it! Cant wait for the update.

-Dan

jam0321

we'll definitely look into a group buy option. Thanks for the idea.

PghtC

sounds interesting. If it fits well I might be game...maybe.

They could always use oval pipe for the s-pipe to keep it more low profile.

jam0321

so the project is still forthcoming but I want to have your opinions:
do you prefer
1) OEM style muffler ie. ZPI and Dezod
2) Straight through Muffler ie. Megan Drift Spec (angled tip w/o the bumper melting)

Again, 3" downpipe back but which style is preferred and who would be interested in a group buy? Roughly (now don't hold me to this) $700

Nu_ERA

Count me in as one of the six if they do a 3" ... I prefer the Drift-spec look also like the Megan one

jam0321

me too which is why i'm asking. I don't want to be the only one and not have this group buy sell.

datrickster24

Id prefer normal oem tip..

-Dan