I remember a while back when this board was first born, we had a great thread about turbos and superchargers. I thought that we all came to the conclusion that SC's rocked and were the best solution. Now we have like 3k more members, and the new blood is only raving about twin turbos.

So whats the deal? I stick to my original conclusion that I hate turbos!

[edit: sorry mods, you can move this to performance]

 

There were some of us here from way back that already said turbos were better. People just think SC's are better b/c somehow they are magically more reliable.

 

Turbos are way more efficient then superchargers but take more money to do right. IMO for the Z, PE's twin turbo setup is the best, left 3 cyls run a turbo. right 3 cyls run another. Each bank runs its own turbo. Also, regulating boost is way easier in a turbo setup, that way you can have a street tune, and a race tune with the touch of a button.

 

If the turbo set up is gonna be like the 300's, then I'll gladly pay more for less hp w/ a supercharger, especially if it replaces the intake manifold.

Michael.

 

turbocharger = more piping, new exhaust manifold, external wastegate, front mount intercooler, two air filters, oil feeding line and oil return line, etc.

supercharger = new supercharger with pulley, less piping, no external wastegate or internal wastegate, one air filter, no oil feeding line or return line, less hassle to install, etc..

I have played with turbo car before, and it's a headache to keep them maintain... I have seen supercharger cars, less headache..

If supercharger can give me 50-80hp gain for $3000, then that's what I'll get..

 

Generally...

turbocharger = more money and parts.
supercharger = less money and parts.

I repeat, GENERALLY.

However, a turbocharger should give you better performance because they normally give a larger area under the curve. Boost comes in faster and earlier, therefore, giving the car more power on the bottom end.

The power curve from a supercharger is very linear, therefore, it won't give you the push a turbo does at lower RPMs.

 

what the hell are you talking about??? a supercharger gives u instant power because its belt driven directly from the crank. therefore an s/c gives u instant power at low rpms in relation to crank speed.

turbos (depending on specs) are what gives u the low rpm lags. get it straight

 

Obviously it depends on the turbo specs...but I said generally.

Here's a dyno sheet for reference. It's a comparison between a Turbo and Supercharged S2000. Now, look at how much torque the turbo has before VTEC, compared to the supercharged one. Both have same peak RWHP. The turbo'd S2000 even has more rwhp through out the whole curve, although they both have the same PEAK rwhp.




Do you know why people with supercharged S2000s have such a hard time launching their cars? And do you know why people with turbo S2000s are able to launch their cars so much easier?

 

Dyno chart of Turbo S2000 by itself

 

if you're going to use an s2k as an example, then yeah, its got some lag to it because it uses a centrifugal blower that acts kinda like a big turbo (obvious on the graph). but every s/c that i've seen/had experience with uses a roots blower, which gives more power in the low rpms; not an advantage on the streets 'cause of traction problems. why dont u enlighten me on s2k launches for s/c and turbo. i know how a roots type s/c and turbo car launches, but apparently an s2k is different 'cause of its centrifugal s/c.

 

A centrifugal blower does not act like a big turbo, the boost on a centrifugal blower is directly proprtional to the rpm on the engine. However fast the belt is spinning at the time is how fast the s/c is spinning (regulated by pulley size of course). That does not cause huge lag like the turbo does, but instead produces a linear hp/tq curve.

The reason the turbo is better on that application is because with 153ft/lbs of torque, you can't launch the S2K without bogging unless you launch in VTEC, with the turbo, you can spool the turbo and launch from ~4500rpm and get a much better result.

With the centifrugal s/c not only do you start with 153ft/lbs but now you have that minus whatever amount is needed to run the s/c. This doesn't solve the problem that the S2K has which is low end hp/tq, and only reinforces its strong point (high rpm power).

With the Z however we want the power to come after the wheels have gripped and have no problem getting out of the hole. So IMO turbo or turbos will benefit the Z. I don't really see many gains to be had with the roots type Stillen setup.

 

Personally i would like to staick with an all motor set-up. Squeeze every last bit of power out of the engine without forced induction. But if i had to choose one or the other, i would probably prefer a twin turbo set up. I say so to keep up the Z car legacy seeing that past models had turbo options......

On teh other hand, if a supercharger was to prove more efficient and more power for the dollar, i would switch my opinion very quickly.

 

IIRC, a centrifugal supercharger has a compressor wheel much like a turbocharger and boost increases as RPM increases. I believe there is supercharger design where boost remains the same at all RPM.

Furthermore, turbo lag can be tuned by selecting the right compressor housing, compressor wheel, exhaust housing, and exhaust wheel. My 300 has virtually no lag, but the boost is peaky.

That holds true if you're brake boosting. Otherwise, revving the engine w/ the clutch dis-engaged will build 0 boost. Turbos are engine-load driven and if there is no engine-load, then there is no boost.

Superchargers are RPM driven so you can rev to xxx rpm and it will generate boost. As opposed to turbochargers described above.

I'll have to disagree. That's not necessarily the case. I, personally, have a severe traction impediment in my 300. If I launch soft, then I'll bog down. If I launch hard, then I'll just spin the tires. On the other hand, Supras have a sequential turbo setup which is more forgiving.

Michael.

 

I'm not sure I follow you on this one, what does the clutch being engaged have to do with exhaust gasses flowing throw the turbo header/exhaust housing on the turbo, and creating boost?


A centrifugal s/c is basically a belt driven turbo, but the difference is that boost builds and decreases with engine RPM, unlike a turbo where it is delayed in buildup and doesn't decrease when you take your foot off the gas. No turbocharger (turbo or super) ever remains at equal boost, the roots or screw type s/c are the only ones that come close. Air takes time to compress regardless of what kind of pump you use.

Notice you say "virtually"....my point was that a turbo will always take more time to build boost then a s/c. Also it is a compromise between the amount of boost you can put out and the ability to spool faster. With an S/C you do not have to make that compromise.

 

This argument is pretty much irrelevant. If Nissan makes a FI 350z, it will be twin turbo. No, they have not officialy announced this but I would bet money on it.

We know this because:
1) Nissan is all about sharing as many parts as possible between cars
2) Nissan is already developing a twin turbo VQ (for the GT-R)

So all they have to do is detune it a bit and drop it into the Z. Simple.

 

but you also can't tune the boost (well, maybe to a very minor extent, but it would be a hassle).

 

Didn't one of the lead designers of the Z go on record as saying he thought Nismo should concentrate on a SC for the Z and not a Turbo?

 

I'd love to stay true to the Turbo heritage that is the Z, but if the Supercharger proves better for the car then I'll get it.

I'm going to be driving this baby for QUITE some time.

Speaking of, has anyone heard of the hood modification for the Super Charger?

 

i don't see how it'll be better.

 

My last car (Civic SI) was Supercharged and Turbocharged (Not at the same time read story). I started with a Jackson Racing supercharger. Now, I had an engine management (Standalone unit) and can monitor my engine vitals. Now, while datalog I was monitoring everything, one thing that I was in shock was the intake temperature. This bad boy was exceding over 180 Degrees!! People don't understand how HOT! a roots supercharger gets. Do you know how hot that is? That is extremelly hot air going into your engine and causing detonation in hot days. (which I did experience a lot even with a fully tuned motor). The belt kept slipping and I just hated the damn thing. Its funny how their is a lot of PRO Supercharger than Turbo. Quite frankly if you haven't had both at all, your opinion isnt really valid because you havent experienced either or. So I ditched the damn Jackson and bought a Greddy Turbo kit. WOW! Night and Day difference. Better Power, LAG? What Lag? When a turbo is properly setup their shouldn't be lag unless you go OVERSIZE, thats where people misunderstand and just go by what people say. Not only did I run 1 second faster with the turbo, I made way more horsepower and more torque! The air temp from the Hondata was reading at a steedy 75 degrees as opposed to 180+!! Keep in mind this is with a front mount intercooler. I was so much happy with the turbo and maintance is just as easy as 1-2-3. Sure, you have to change your oil every 2k miles but who said Forced Induction was cheap? I can go on forever as I have a list of things why I will never buy a "roots" supercharger. Now, Vortech Supercharger is a different story, its pretty much a Turbo on a stick. Which I would consider... A turbo is a lot more fun, with the push of a button (Boost Controller) you can adjust the boost level unlike a supercharger which you have pulleys to mess with. A turbo will make more power than a supercharger can PERIOD! The blow off valve sounds cool on a turbo And I just had excellent experience with turbo! I had it for over 1 year and all I can say is great things! Sure their is more to it than bolting it on like proper cooling off (Turbo Timer) and what not other little things but overall a true enthusiast who loves to go fast wont spare to settle for less.

Turbo =Living on the Edge
Supercharger = PUSSIES!

By the way, here are pics of my Civic SI...(Which I also had Nitrous w/ STOCK BOTTOM END!)