GTM 370z supercharger 550bhp/400 ft of Torque: The Masterpiece
 

Firstly let me just say that from what I have seen on here for the past 18 months, I'm a big fan of GTM.

Just 2 questions out of curiosity in relation to the car in these videos.

1. Why was there no build thread for this car?
2. Why have these figures not been repeated on other stage 1 builds?

YouTube - GTM 370Z SUPERCHARGER 550BHP/400 FT OF TORQUE 460 RWHP 360 RWTQ.THE MASTERPIECE

YouTube - GTM 370Z SUPERCHARGER STG1 8PSI 550BHP/400 FT OF TORQUE 460 RWHP 360 RWTQ. TEST DRIVE

I would be happy to address your questions.

1) There is in fact a build thread for that exact car: http://www.the370z.com/forced-induct...s-release.html

2) This was part of the R&D process. Those numbers were made with a one-off race intake, GTM 2.5" cat-back exhaust and STOCK CATS. It is also an extremely aggressive tune on 93 octane gas. Mainly this was to demonstrate the supercharger's capability. Our off the shelf tune is conservative to ensure that everyone that buys and installs it will be able to achieve the advertised 500bhp (or very close to it depending on many variables) without undue risk to their engines.

The other main reason why we are showing such a graph is because we were able to achieve those numbers with this supercharger unit. Also, this is a strong validation that the supercharger unit is capable of more power with a better tuned VVEL tuning solution.

Here is the same supercharger unit making 490whp on a 350Z (VQ35HR with tuned dual CVVT) with 100 octane gas:


This shows very clearly how VVEL adversely affects power output with a supercharger. I cannot overstate that enough.

Again, we were able to make 460whp on the 370Z with STOCK CATS. The reason for that is because, quite simply, the back pressure generated by the stock cats keeps air from blowing through the engine. This means more air stays in the cylinder to be combusted. Once we are able to tune VVEL, we will be able to reduce the overlap and thus make more power on supercharged cars.

Thanks for the quick and detailed answer, much appreciated.

:bowrofl:

i need one :)
is there a kit ready for shipping :D

And probably NA too.

How is the progress coming on this project? Any updates? :tiphat:

We are making great progress so far, Also we are applying everything we have learned from stage 1 to the stage 2 so we can utilize all the 91 potential. The 91 supercharger has been on and off the car hundred times do far. It is a very time consuming process ...

Sam

Any estimate on a release date for stage II?

I've got the money just burning a hole in my pocket!!

We should be done by the end of this month, FYI we could have been done much sooner if we stuck to just fitting the bigger charger instead we are focusing on maximizing the potential of the 91 with this engine .

Sam

Thanks for the update. If I recall correctly that's about when you said it would be done when I spoke to you a few weeks ago.
I have no doubt that you are going to make sure it is the best it can be.
I wouldn't want it any other way.

Once it is released, how long will it take to ship from when the order is placed?

We are hoping right away, We already have a good size list of people that have prepaid and have been waiting for a while for the stage 2, so those order will be shipped out first.

Sam

:yum:

Reading this thread makes me want that Stg.2 even more than I already did :yum:

Waiting for the stage 2. " by the end of the month ?" Thats the best news i have heard yet. Can not wait to take it down the 1/4 mile.

Can someone with engineering knowledge give a layman's explanation of how the VVEL hinders the power output and how "tuning" it will benefit both NA and SC cars? I have a vague understanding of it but I know VVEL tuning and "cracking" the ecu has been a hot topic

I've posted an explanation on another thread, can't find it... here's a brief copied and pasted explanation.

The VVEL system in our cars and extremely aggressive at about a 300 cam duration;

Valve Overlap

"The portion of the operating cycle of a reciprocating engine in which, when the piston is passing TDC (top dead center) on the exhaust stroke, both the intake and exhaust valves are open. Valve overlap increases the efficiency of the engine operation by allowing the low pressure caused by the exhaust gases leaving the cylinder to help the fresh charge of fuel-air mixture in the induction system to start moving into the engine."

When you're pushing so much air into a car (forced induction) with an aggressive cam - there's air that isn't going to be used and is just going to pushed out of the motor and wasted because both the intake / exhaust valves are open at the same-time. Drop the cam duration, you'll have more time between the valve overlap process so when the air enters the head it will give the bottom end enough time to use that air for the combustion process, building more psi, creating more power.

Let me know if there's anything I'm incorrect about, but that's what I've gathered.