Nissan 350Z / 370Z Tech Forums banner

Turbo VS SC.. stock internals question..

2374 Views 6 Replies 5 Participants Last post by  LuKsEaZy
Just wondering.. why is it required to drop compression for turbo (ie, change internals) and not required or even advantageous for SC? What makes a SC a simple bolt on, and a turbo so complicated?

I know how each operates, which is what confuses me even further... shouldnt you have to drop compression for both to operate?
1 - 7 of 7 Posts
Well you need to drop the compression for both if you really want to see higher gains that 400rwhp. 8psi is 8psi either way you look at it. The difference is with turbos you are at 8psi throughout the powerband, whereas with a supercharger you dont hit 8psi until redline.

(i just randomly picked 8spsi)

Turbocharging is no more complex than Supercharging, both require a thoroughly engineered fuel system, full ignition timing control, and efficient intercooling to produce reliable high Horsepower.

If you tune the engine safely for the fuel octane utilized there's no need to alter the stock static comp ratio unless you intend to run a very high boost strategy, over 8 PSI of positive pressure. :cheers:

Hmm thanks guys, that clears up a bit.. However, anyone know why domestic cars and larger displacement motors (typically V8's) seem to favor superchargers?? Why does a SC work better on a big displacement engine.. why not turbo that same engine?

There are a number of reasons though cost being the main reason, a quality Twin Turbo system is more expensive to purchase than a single centrifugal Supercharger, cost is always a factor particularly in the lower price end of the car market.

If you look at the more expensive end of the local US car market (Corvette and Viper) you will find that Twin Turbo Systems do very well at this end of the market, where lower cost is not the primary consideration.

Another reason is drag racing rules, many classes state that only 1 power adder can be utilized, a supercharger is considered to be 1 power adder whereas Twin Turbos are considered to be 2 power adders, obviously this impacts on peoples choice of FI in they wish to race in a certain drag racing class. :cheers:

Why does a SC work better on a big displacement engine..  why not turbo that same engine?
They don't, and many large displacement engines do utilize turbocharging over supercharging, if for instance if you look at the mustang in drag racing I'm sure you will find that single turbo engines dominate this class as the preferred form of FI. :shiftdrive:


See less See more
^^^ very true peter...i totally agree. I prefer Turbos just like most of the market does in racing.....Look at the Tractor pulls with the big rigs doing those pulls....Quad turbos and they dominate especially with the deisels motors, the big blocks go for the holds true to Drag racing...I rather a turbo.

Also the massive deisel motors that are in plants and dams...most have a MONSTER turbo....I have seen one the size of a house before!!!!

Anyway that is my 2 cents
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.