2010 370Z NISMO Twin Turbo build courtesy of GTM

RCZ

Hmm, 3" was recommended for bigger turbo setups on the STI (2.5l F4). Much smaller engine, granted target boost was 23psi for me then, but I would imagine the 3.7TT flows a lot more than the 2.5T did. Freer is better for FI apps. .02

JB-370z

no 3" really is not a must have for all applications and ecspecially if you are not pushing too much power.

I would stick to what the pros at GTM say you can do and what is safe.

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GTM Stage 2 Twin Turboed 370z (First in Texas, Thanks To Baker Tuning)

hide187

Single piping vs dual maybe?? Dual 2.5 would be 5 inches of total piping.

twotonezed

That is not an accurate statement to my knowledge. A 3" single flows more than a dual 2.5" setup. Someone told me once that the single 3 flowed more. Dual 2.5 doesn't equal 5 in this case. The other great thing is that a single 3 weighs less. I loved the JIC Ti I had on my 350z.

stormcrow

Single vs. dual is apples to oranges. Bigger is not always better, even when speaking of FI applications. If it were, why not go 4" or 5"? The reason is that exhaust flows in pulses and if it gets too cool due to a slower rate of flow (bigger exhaust will flow more slowly..especially if oversized for the application) the fluid dynamics change as well as the weight of the air mass. This can cause the exhaust to "back up" in the exhaust sytem and the motor to work harder to expel it.

In truth, with the bends, length, resonators and such in place in different exhausts, it is hard to truly say what diameter exhaust will flow the best. Only flow rate tests can determine this. Who has time for that?

EDIT - BTW, the most restrictive portion of the exhaust system is the manifold(s).

Mike

troof!

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NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z
Porsche: 93 968 / 23 Macan GTS / 93 968

wishihadnav

yeah i think 2.5 is fine for this setup..i believe the greddy kit is externally gated with a dump pipes..

Mike

definitely 2x2.5 does not equal 5

a 2.5" exhaust has an area of 4.91" to flow the air
a 3" has 7.07, so dual 2.5 > single 3"
and a 5" would have 19.64 square inches, huge!

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NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z
Porsche: 93 968 / 23 Macan GTS / 93 968

wishihadnav

yeah i would have to agree that two 2.5 setups will flow better than a single 3...the single 3 is less weight but the weight is relatively low to the ground so it really wont affect handling much..also the merging of two pipes into a single collector does create some extra turbulance as opposed to two separate exits..

wishihadnav

however i believe the Greddy kit uses disco potatos which are known to push 3 inch piping without any trouble..

LiquidZ

Actually, TD06SH-20g's.

Disco potato is a Garrett GT2860RS.

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wishihadnav

^oh 20g's aren't too bad..id probably ditch those however n run 28r's..haha

FuszNissan

Well, to play devils advocate, I am running a 3" catted down pipe, into a 2.5" true dual exhaust. I am tuned at 470RWHP and locked at 6.5 psi.

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LouFuszNissan
ZDAYZ 2012

tao168

Just wondering you guys install a turbo timer? If so how was the wiring done. Looking at installing 1 but been working at the wiring for sometime.now

stormcrow

Hmmm...I understand now. I didn't know you had the Touring. Ok, so if I had actual switches there and didn't want to give up my cubby, I would probably mount the EVC 6 in the headliner just behind the dome lights. And thank you for your gracious offer of opening your home and offer of a meal. A lot of people won't understand what a kind offer that is, but I do. Thank you.


No turbo timer for me. Water cooled turbos do not really call for one. Though, just out of habit I do sit and idle for a minute or so before shutting down if I have banged on the car just before coming to a stop.