If I'm not mistaken, all of Vortech's hp figures for their sc kits on their website are at the flywheel.

so this thread has now turned into a bunch of bla bla bla.... flux capasitor...... bla bla bla..... highspepd muffler bearing.....bla bla .bla



lets keep this to GTM and wait for their final numbers if you want to fight about what makes what and what temp //psi something should make start a new thread.

Considering how well the older VQ engines with aftermarket exhaust responded to centrifugal sc's at the top end, the stock system is most likely hurting peak power a lot.

Yeah we should just buy everything without understanding what it does first. That sounds pretty logical. We aren't fighting, everything we are talking about is directly related to the GTM supercharger and the results that have been given so far. Its just a discussion about their results, but to be able to make sense of the results you have to understand the mechanical aspect of how they arrive at those results. Things aren't lining up technically and that makes a big difference to those people who buy things with their eyes open.

Don't forget you are in the tech area, not the classifieds.

I say this with the best intentions and humbly because I dont pretend to know everything, I know there are folks in here that know a lot more than I do. Maybe you should make an effort to understand what all that bla bla is? You would enjoy this thread quite a bit more. Nothing personal you know me by now, no need to get defensive.

I don't know how much compressor maps will tell us, but maybe with the information given we can determine the mass flowrate of the supercharger in this application and see how its lining up with the known pressure ratio?

I completely agree here. This is good info.

The only thing we all need to understand is, there is alot of info thats incomplete that only GTM can provide/explain at this point.

I'm sure the tune around the exhaust system + higher octane will make alot of people (east coast :tup:) happy.

I didn't mean to make any assumptions on the supercharger, I just wanted to point out that your "5 psi is 5 psi" statement and your conclusion regarding how everything that puts out 5 psi should be making the same power is simply wrong.

Because I am lazy (and the fact that I am not a native english speaker) I will "lend" a good explaination of efficiency I found in another forum:

yes good info in the wrong thread. get a clue guys

Yes, temperature is a factor too, but I was assuming a system with an adequately sized intercooler and boost measured post-IC, which is usually is, as it is in the GTM system.

Exactly (with the exception that we're not talking about turbos or backpressure here). Volumetric efficiency of the compressor wheel. More efficient = less energy wasted = more power for the whole system. That much is very obvious. But it's not what I was talking about. I was talking about the amount of air entering through the throttle body into the combustion chamber at 5psi (at a fixed temperature). Small picture, not big picture.

Nah, I don't see a problem with those guys discussing this. It's interesting info, related to the topic of GTM's SC, and being discussed reasonably (no bashing, name-calling, etc).

Could you point me to where you saw that thread Silo? I'd like to read more on the subject.

If it is a matter of intake charge density and backpressure, then that makes sense. I'm glad I learned something today. So there must be a sweet spot for volumetric efficiency that will squeeze the absolute most out of a turbo.

The quantity of air that flows through the engine at a given boost pressure, temperature and rpm is detemined by the flow characteristics of the engine(port size, valve size, cam, displacement) and not by the characteristics of the compressor that creates the boost. Other than minor differences in parasitic losses from bearings and belts, boost is boost regardless of how the engine created it.
Silo's chart indicated a larger turbo could flow more air than a small turbo at a given pressure, which is not true if they were both used on identical engines. It would be true if the larger turbo was used on a larger engine.

I would think the intake piping would have more influence on how much power the engine makes at a given psi. A 3 inch pipe supplying 5 psi to the engine would result in more power than say a 1/2 inch pipe supplying 5 psi.

This is why I love super chargers. Everyone wants a turbo with 500+ power. Thats great and all but unless your a track junkie all that highend HP is wasted and not utilized. These power curves will create a more fun daily driver then any high HP turbo setup.

Not bad... 360+RWHP is C5 Z06 territory. Not bad at all.

8PSI would probably get you over 400RW. But even at 5PSI you've got a pretty fast car.

Intake piping size will affect efficiency. 5psi at the intake manifold will produce the same power when delivered through a 1/2 inch pipe as it would with a three inch pipe. The system using the 1/2 inch pipe would waste a lot of the power produced in forcing enough air through the pipe to yield 5psi at the manifold. Pressure inside the 1/2 inch pipe would be about 36 times higher than the pressure in the 3 inch pipe to deliver the same 5psi at the manifold.

Sounds like someone did not forget what they learned in physics.:tup:

Can someone help me read this tq curve.

How do I read this dyno sheet.

HP rating on the left side.. TQ rating on the right side


The line that rises from low to high is the HP

The flatter line is the TQ

So what's the Tq curve? And what makes it a good thing? Thanks for the response

The TQ curve is how the TQ is applied to the wheels.. is it smooth, does it spike, is it harsh, etc..

Thats the TQ curve or measurement
http://www.the370z.com/attachment.ph...1&d=1266542155

A better shot of before and after.. so a noticeable gain in TQ from start to finish. It's flat so that makes it predictable, smooooooth.

http://www.the370z.com/attachment.ph...1&d=1266542246

oh oh ok...Thanks I get it now...Do you notice the wave in there...I wonder what caused that.

prolly this guy....




:wtf2:

That I really wouldn't know anything about but maybe someone else in this thread might be able to answer what might cause that

:bowrofl::roflpuke2::inoutroflpuke::roflpuke2:

If he's mentally challenged I wouldn't think its funny....but that sure is a big *** set of papmers...god damn...

nah, its a staged photo--still funny though.

ahh boy good old friday nights....gotta love it..

Then again, check out the torque curve of Greddy's 370Z TT kit at less than 6.5 psi.
Welcome to the official GReddy USA blog: 450whp Tuner Turbo Kit for 370Z coming soon!

Bingo! There you go, this guy speaks the truth. The boost pressure you are seeing is measured at the intake manifold. It doesn't matter if it got their through a turbo or supercharger, nor if it was through 10" piping or a 1" garden hose. Two completely different FI setup's with equal manifold pressure and temperature (assming they are both effectively intercooled) will yield the same engine output. If it didn't, it would violate the laws of thermodynamics.

What happens most often in the case of a turbo that is too small for its application is that it reaches a point that it can't maintain sufficient cfm for a given engine rpm, and the measured manifold boost pressure will drop accordingly. I know several folks have experienced this with small gt25's on their sr20det's.

Question: On the various 350Z forced induction systems, why was there such a wide variation in peak hp numbers from roots SCs, centrifugal SCs, and TT kits even when at similar boost levels?

has nothing to do with the car but the different FI options. They all create boost differently. Roots having boost the quickest, then Centrifugal SC, then TT. Sometimes Centrifugal SC and TT produce boost at around the same time though.

What's even funnier is that huge safety pin...haha. Where do you find that?

But if boost is boost, then they should all have similar peak numbers at the same boost level on the same engine, right?

The internet is a wondrous machine isn't it. I actually just went to google images and just searched 'fat guy'. It comes up on the first page, first row.

http://images.google.com/images?clie...-8&sa=N&tab=wi

I definitely don't know all the reasons why boost doesn't actually translate that way but I do know that TT is the efficient boost option. It is essentially free energy because it is using the actually exhaust of the engine to spin the turbine. The only problem is you have to wait for the exhaust pressure to build for the TT to spool. SC on the other hand uses engine HP because the turbine is spun by the engines belt system which, while creates boost, also takes HP to do. Typically the main benefit of SC over TT is earlier boost times. The disadvantages is that you will typically not have as high gains from SC then you would a TT. Main reason being is becuase the engine itself it working harder just to spin SC.

Like i said above, sometimes Centrifugal SC and TT produce boost at around the same time though.

There is no free energy. All of the power required to spin a turbine and compress inlet air comes from the engine. Belt driven off of the crank or back pressure on the exhaust stroke, the power requirement is the same.

This is caused by the friction and drag from the supercharger and belt, some have more then others which will result in HP loss to the rear wheels.