Archives for : September2015

370Z Forced Induction: Boost is not created equal

Many times a week I’ve been getting this question asked. What is the difference between a supercharger and turbo kit for the VQ37VHR? For starters most people get the misconception that a supercharger will produce boost faster than a turbocharger. There is much more to that answer. It all starts with properly piecing together a kit and its intended purposes. Turbochargers of today are much more reliable, use more advanced materials, and are manufactured in such a way that all improve the turbo’s quality\reliability and performance. This is why you see more auto manufacturer’s producing their vehicles with more turbos and the fact that gas mileage can be improved without sacrificing power.

The goal of this post is not to give you all the in’s and out’s of how a turbo or supercharger work but to clear up the biggest misconceptions and present to you the visual difference of what a supercharged and turbocharged engine in this case the VQ37VHR look like with two very popular kits out in the market.

TTvsSC

This dyno graph comparison plots both a SC’ed and TT’ed VQ37VHR against each other on 91 octane fuel. Red is supercharged and blue is turbocharged. This will definitely clear up the misconception that a supercharger can out spool a turbocharger. This particular supercharger is a centrifugal style which is known for its “lag” although people are unaware of it and differences between it and other supercharger styles. At 3500 RPMs you can see our plot. Boost on the SC’ed engine is 1.66 psi. Boost for the TT’ed engine is 8.5 psi. This correlates directly into power and torque of course! Let’s look at the differences there. We’re producing 274 torque on the SC’ed engine and 403 torque on the TT’ed engine. That’s a difference of 129 torque. I bet you can probably tell me which car would be funner to drive. Horsepower for the supercharged engine is 182 whp and 269 whp for the turbocharged engine. You can also see that peak power is also higher on the turbocharged engine.

A supercharger kit is cost effective to produce and install. There are less parts and much less labor involved to install it. The opposite is true for a turbocharger kit. However you can reap the benefits of turbocharging when you’re all done! It WILL put a bigger smile on your face, this is fact.