GT Motorsports: 370Z Supercharger system development

Buddy Revell

400 to the flywheel is about 344 to the rear wheels.

rackley

I don't really know anyone who quotes flywheel HP except perhaps the manufacturer... It's rather misleading.

But yes you're right. Thanks for the "flowing" debunk. Assuming you don't have a closed throttle plate in one of the I/C tubes and you're pumping into the same engine, 5psi is 5psi is 5psi. It's putting the same number of oxygen molecules into the chamber.

With regards to sizing, a smaller SC or turbo has to work harder (spin faster) to make it, which would cause more parasitic losses, but the same amount of air is going past the intake valves into the combustion chamber. The whole "flowing more" is really misleading because the air isn't "flowing" any faster or harder.

Z eliminator

Now that we see how much power the sc made at 5 lbs boost was a bit of a let down.
at 2 lbs boost it made 18.5 rwhp / 1 lb of boost/ When we look at the the SC at 5 lb's we see that its makeing 11.8 rwhp/ 1 lb of boost.
6 lbs = 70.8 rwhp = 355.8
7 lbs = 82.6 rwhp = 367.6
8 lbs = 94.4 rwhp = 379.5
9 lbs = 106.2 rwhp = 391.2
10 lb = 118 rwhp = 403.0

Now that standard rwhp. the SAE number will be lower. I now estimate tha on a my 7 AT. it will make 353 @ 8lb. and 368 @ 10 lbs. SAE. A 6 mt will make about 5% more than a 7 AT. To compare RWHP of my ported stillen M-62 on my 2003 350z 5 AT. it made 11.78 rwhp to 1 lb of boost. Base line 218 to 313 with the stillen SC on the 350.
When I added headers to the 350 it lost 10 hp. when i put the high flow cats on it lost 6 more hp.
The numbers on the GTM are lower than i first estimated to be But Sam is working on it and im sure that he will make it better. No matter what it makes i have bought it and Sam has assured me that it will run well. Once he has fine tuned the maps, there could be a lot more power.

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12.343 @114.14 . 4.5 stroker motor is now being built. Dec 1 2015.

Silo

No, it's NOT dude... 5 psi might be harder to imagine, so lets go to 20 psi. A GT25 at 20 psi is far less "efficient" then a GT35 at the same psi. Efficient means, that on the same engine the GT25 has too spin a lot faster then the GT35 to produce 20psi of pressure causing the compressed air produced by the GT25 to be much hotter compared to that of the GT35, which in turn means that there will NOT be the same number of oxygen molecules in that chamber!

RCZ

^ a change in temperature might make a 20whp difference. No one is saying the supercharger is blowing hot air either. I am assuming charge temperatures are hotter with the sc, but not enough to justify that much variation in hp. Remember that there is an intercooler between the turbos and the engine as well as between the sc and the engine. That cooler should be able to bring the air temps down to similar levels.

5psi is not harder to imagine than 20psi. Its the same thing.

Are we to assume that this supercharger is blowing hot air by your logic? I certainly hope not. We know charge air temp makes a difference, but their tt kit made like 400 at 5psi. How is the sc making 400 at 10psi.

I think I'm going to ease up on asking any questions here until the official numbers are released, there is not enough real finished kit data, so we are all just making assumptions... and you know what happens when you assume.

Also, Z Eliminator, either you are really talking worst case scenario or the kit has a long way to go because 10psi on a high compression motor like ours should net more than 70hp.

Buddy Revell

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

shumby

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.

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Originally Posted by SAM@GTM
Engine detonation is not normal and it should never never happen, and whoever told that need to do something else for living .
Sam

Buddy Revell

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.

RCZ

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.

LiquidZ

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?

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DannyGT

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 ) happy.

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Performance GTM Stage 1 SC, GTM Res.Test Pipes, Invidia Gemini Exhaust, GTM HD Oil Cooler
Wheels & Suspension AME Tracer TM02's 19x9.5F 19x10.5R w/ 265x35F & 305x30R, Hotchkis Sways, BC (BR) Racing Coilovers (Car Sold)

Silo

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:

shumby

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

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Originally Posted by SAM@GTM
Engine detonation is not normal and it should never never happen, and whoever told that need to do something else for living .
Sam

rackley

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.

Buddy Revell

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).