Originally Posted by Red__Zed (Post 1440655)

same principle applies to posting numbers that don't show losses.


FWIW, the IP dyno showed losses with that exhaust on both FG2s I saw run it, but that is not really relevant here.


For the curious, the 370z substantially benefits from running a crossover of some sort. Almost every aftermarket exhaust that shows gains has one, and that is honestly where they get most of their gains.

cylinder banks on the VHR look like:
135
246

with a 123456 firing order. The alternating pulses are ideal for a crossover exhaust, and can get funky flow characteristics if routed to a single pipe. These of course can be minimized by bring the join point farther back.






The backpressure issue is a little misunderstood by most. The engine doesn't so much need backpressure, at the risk of low end torque, as it experiences bad flow characteristics generated by the exhaust gases cooling en route.

You basically want zero backpressure from the collector back, coupled with maximum flow(not actually implementable, but not hard to get close). The header design does need to generate backpressure, as well as provide sufficient velocity that the system does not back up under overlap (won't ever happen at high rpms, will happen at low)


dual 3" is either going to create an eddy at the header output/cat/tp output, or require running a non-optimal header design (at best, a staged header diameter)


Vizard's numbers say the Z with full boltons needs about 720CFM of exhaust flow to prevent restriction. A single 3" pipe flows over 1000CFM, which means that it is in no way contributing to increased restriction, and any issues are in your muffler. 2x2.5 offers over 2000CFM of flow....

Any gains that come from different exhaust designs are mostly due to removing restrictions (cats, muffler), or tuning of exhaust pulses, not from increasing pipe diameter. Increasing pipe diameter is mostly likely to create funky flow characteristics due to either messing with the header piping, or creating eddies...as well as allowing exhaust gas to cool and back up.

Originally Posted by awkwardturtle (Post 1440688)

It's called using common sense... something that is clearly in short supply these days. If you think Go-Power, a reputable company, is falsifying a 4 whp gain, suit yourself bud.

Originally Posted by corbin09 (Post 1439766)

I dont have a video.. I may be able to post up a dyno chart however... Let me e-mail my tuner and see what he has on file. With non-res tp and the topspeed y pipe into a muffler that was pretty much a straight pipe was very loud. I think with HFC's you will be happy. It will be loud but shouldnt drone as much.

Originally Posted by edub370 (Post 1439200)

dual 3" WILL lose you low end torque. back ressure creates torque. sure u might gain slight hp up top but the butt dyno will feel like there is less power because of the torque loss.

and before anyone asks "how do u know if a 3" will lose power? have u tried it?"... well no i havent, but i understand how cars work...


"Horsepower sells cars, torque wins races".

-Enzo Ferrari-

Originally Posted by FPenvy (Post 3396644)

ZOMBIE THREAD!

5 year old revive lol

Originally Posted by JARblue (Post 3396649)

:icon17:

http://i971.photobucket.com/albums/a...psbjo4kp8y.jpg

Originally Posted by Chuck33079 (Post 3398995)

Yeah, he comes in, drops some "knowledge" like the above, and disappears again. He should stay and play. We haven't had someone this aggressively stupid in a while.

Originally Posted by cv129 (Post 3399013)

His post history says this:

Joined and made 1 post on 2013.

In February 2015, his car makes almost 400 ft lbs wheel torque and gps verified vmax at 175mph.

In October 2015, his car is the faster/fastest n/a 370z in Boston.

In this thread he claims 330whp and 270tq at some point.

His parents let him out of his timeout to play forza and use internet, and he got too excited. I forgive him