I am still debating on Turbo/TT or SC.

I understand that a roots SC will give HP/TQ gain from idle to redline. Turbos have a lag period when they spin up. Both SC and Turbos have a PSI that determines how much air they force into the engine. Now for the question...

Other then what I have mentioned, whats the difference between running a Single Turbo, Twin Turbo or Supercharger?

All of them can have boost increased to raise the HP/TQ of the engine. I know theres different types of turbos (Bigger/smaller) that can be used to create more PSI. Is there only one size SC? Dose the TT (G18 for example from Greddy kit) effect the engine differently then a single (T88 for example) large turbo?

I guess it's a couple questions, but I really want to get a firm understanding of FI before I get FI. As a Network Administrator I believe in efficiancy. If a single turbo can do the same job of a twin turbo wouldnt that be more efficient? Less moveing parts = less to break IMO. Wouldnt it make more sence to always go with a Supercharger since it provides power throughout, rather then requireing "spinning up"? Or is there some hidden gain I cannot find in Turbos over Superchargers?

Ejimacate muh pweese

 

I will give you as much as I believe I know.... I am not at all a guru and I am fairly new at understanding turbos and SC. But here is what I know......some of which (please correct) could be outright wrong.. I would try to get some more info from some more experienced members.

All 3 systems are great....anyone who says one is better than the other....only drives thier car a certain way... Each system is meant to do different things.

From my understanding the SC will give instant boost, which in a drag app. might be better with just a bolt on and go. Unfortunatley from what I have seen to change boost on a SC you need to change pullies.....to go back and forth between track mode and street mode could be a pain.... But, sc is probably the most responsive and reliable form of FI... the only other downside I can think of is theres been a lot of complaints about worn belts, and the noise could possibly get irritating.

For single vs. twin turbo... Im not sure, i can only speculate..
As far as I know if you can fit a single big turbo on the Z then please let everyone else know...

I have seen arguments about this over and over again... I really dont know which one is better....there are so many good points to both sides... I do believe that many cars with high HP have single turbos....but it supposedly takes longer to get that boost level since the rotational mass of the turbo...which is a lot when you spin it so fast... is much harder to turn on one turbine than on two smaller ones.

SC vs. TT ... the point is.... you'll never get anywhere with this debate.... SC provide power quickly without the lag....and are much more reliable.... but how many 1000hp SC cars have you seen? It seems to me that on the high end of things, turbos can just put out more boost.... i have seen 3bar gauges for turbos, thats like 40+ lbs of boost right?

Once again take my info with a grain of salt.....I have only recently FI'd my car with the Greddy TT, and have much more to learn about the whole concept....anyone who can tell me I said something wrong please do.... Bottom line in my opinion.. GET FI...either SC or TT, definatley get an intercooler, and like I tell everyone else.... get a diaper....... The whole debate wont matter once you get in your car

 

Thanks for your input brushijr. For the reason you mentioned, I am trying to find out. Is a single large turbo better then 2 small turbos?

I didnt really recognize that SCs require changing a pully to up the boost. Thats some good info!

I know theres some turbo gurus out there. Please help me fill in these gaps of information I am missing. I want to make an educated choice on my FI, not just a popular choice.

 

for the setup on the 350z a tt setup is more beneficial. it is after all a v shaped motor. If it were even possible to fabricate all the piping necessary for a single setup you would still have tremendous lag waiting for the turbo to spool. the sc is good for a car to have more power but as for racing it would be too much trouble dealing with belts and pullies. With a turbo you can up the boost with the turn of a ****, add fuel and timing and your set to go. This is coming from a former built ls/vtec turbo civic owner.

 

Starting to sound like the SC is a "set it and leave it" FI Solution. It's safe, easy and final. Unless you want to go through the trouble of pullies and belts parts changing anytime you want more power.

Single turbos require alot more pipeing? and take even longer to build boost? So a high reving engine would benefit the single turbo more then a TT setup, correcT?

Double121 you mention that the TT is a more beneficial setup for a V type motor, why? It's these little questions I want to understand. I mean, I know the difference between a straight/inline motor and a V type motor. But there is still only one path for air intake isn't there? Thats kind of where the difference between Twin Turbo and Single Turbo start looseing sence to me. Other then I can understand a single big turbo might simply have more lag to build boost.

 

The '84-'89 300ZX's could come turbo'ed from the factory. They had single turbos (albeit small ones). The trick with a single turbo is that both sides of the engine have to feed it or you will only be driving your "bigger" single turbo with 3 cylinders worth of exhaust.

While the twin turbo setup takes more intake piping than the single, the single needs more exhaust piping to get the exhaust gases to the turbine. Other than the earlier 300zx, I personally don't know of any V engines that come single turbo'ed from the factory. The twin turbo setup streamlines the exhaust more.

Now, a single larger turbo to be driven by 6 cylinders can flow a lot of boost and has half the parts of a twin setup, but to properly use a huge turbo, the engine "usually" makes the big horsepower at the top end. This is great for dynos, sometimes the 1/4 mile, and certainly for the highway... but, it doesn't have the same torque as a smaller single or twins would have around town for more casual driving.

Hope that helps some, please keep the questions coming
-Joe

 

I think I am starting to "get it".

So the turbos actually get there spool up from the exhaust? Then the spooler sucks in the air from the outside, through the intake system. Hence the "lag" of turbos in general.

Ok I think I understand the basics of a turbo system, twin and single. I think I understand how the S/C works aswell. Same basic consept as the turbo except the S/C runs off pullies (Correct?).

Soo... If both turbines require "spinning up" to achieve the air pressure for the engine, why not use an electric motor to spin up the turbos in advance? Wouldnt that eliminate the need for half the piping? And it would reduce the "lag" from both applications, TT/T and S/C.

I design my networks to be efficient and use the minimul amount of hardware needed. The less things to break the less overtime I have to put in. So wouldnt an electric variable speed blower motor to spin the turbo/SC be more efficient then relying on the engine? Variable speed with a dial of some kind to change boost on the fly.

Did that make any sence? hehhe

 

There are motor driven turbo and blowers out there. Things such as a water pump for a centrifugal chilller for example is similar. As far as reliablitly and less things to break, seems you would have more to break like that expensive electrical motor, not to mention the load it would put on a simple 12 volt system. Turbos are about as simple a creature as you can get. wheel shaft and wheel sandwiched in a couple of housings, bolt it on and go. Also you would still need piping from the housing to the intercooler and then to the intake. Bascially cost is what seems to be the factor here. Can you imagine what an aftermarket company would charge for an motor driven turbo seeing as how much they charge for the ones we buy now?

 

www.howstuffworks.com

Go to the top right and type in TURBO.

You will get EVERYTHING you need to know about turbo's and superchargers there. They even have a SWEET turbo diagram that moves and everything. Its how I got started in understanding all this FI stuff.

I started a little over 2 years ago and now I am VERY informed about FI and tuning cars.

 

Thats exactly the info I was looking for!

Thanks a ton for everyons input!!