best Turbo n Supercharger out?

[ArthurKing]

I dont know any 700HP turbos either...

[j_greene]

Originally Posted by ArthurKing

I dont know any 700HP turbos either...

Well then check this out
http://www.superstreetonline.com/fea...130_0406_350z/

again this is the extreme end of the tuning spectrum and they are using turbos.

[LancasterWannaBe]

and on that site it says,

"Well, for starters, the engine's not even a VQ35; it's a VQ30 out of a Nissan Gloria"

That motor also turns 8000 RPM, so a lot of the HP is revs, not torque.

IMO, the best turbo or S/C out there for my street car would also be street legal.

[longlivetheZ]

Guys...go the the "forced induction" forum and read the "supercharger vs. turbo" thread. A properly tuned, well thought out turbo system will easily out perform a supercharger system. If you read the drawbacks of a S/C system vs a turbo system, you wouldn't even think twice. It takes ~30 hp to turn a S/C and you have to pop the hood and change pullies to change the boost, amongst other things...no thanks. With turbos, all you have to do is turn a knob from your driver's seat. The best boost controller out right now (that I know of, at least) is the Greddy Profec B Spec II and it can be had for ~300 bucks or less off ebay. And turbo timers...really cheap in the grand scheme of things.

Turbo...the only way to go.

Here's a link to the "Forced induction - Turbo vs. Supercharger " thread. Thought I'd save you guys the trouble of finding it. READ IT ALL!! IT'S VERY informative and you'll NEVER think about putting a belt/gear driven S/C on ANYTHING EVER AGAIN!

[LancasterWannaBe]

it takes 30 plus hp to turn a roots type blower, not a centrifugal s/c.

I don't disagree that turbo is better for max power, but how much boost are you really going to give a brand new car? Common people, the Z runs a 10.3 C/R, you can't just turn up the boost unless you're running some high octane fuels, water injection, or using CO2 by the Kg on a regular basis. If you're going to race your Z all the time, then by all means, lower the c/r, run methanol, and boost the hell out of it . But for everyone else, you'll just have to live with low boost.

Now it was also said that the centrifugal s/c will not make "instant power". No Sh*t folks, power increases with RPM so nothing will make "instant power," it's the torque curve we're concerned with.
Looking at the charts that we were given earlier (thnx j_greene ), It looks like the greddy kit will produce more torque at low to mid RPM, but it rolls off a lot, further in the RPM band. Take a look at it, it just wimps out after 5k!

Also, while the low end torque is good, you will not benefit from it much while "sportily driving with fellow cars" (AKA street racing) since you'll be reving high most of the time. I personally would prefer the s/c's torque curve for the occasional sporty drive over the turbo kits (that I've seen) any day.

If I had a race car, I would rather have some good turbos any day, but for a street daily driver car, I'd go s/c. Besides - like I said before - if you blow your engine, you can quickly take the s/c kit off and tow your car back to Nissan to take advantage of that good old warranty...
I really don't think you'd be able to do that with any turbo kit.

About the EBCs and turbo timers on ebay. If you want to trust your car to the "word" of a fellow ebay seller, go right ahead man whatever floats your boat. But used or not, you will NOT be able to simply "turn a knob from your driver's seat" and make a lot more power.

[longlivetheZ]

Originally Posted by LancasterWannaBe

it takes 30 plus hp to turn a roots type blower, not a centrifugal s/c.

Sorry...let me clarify that statement a bit. I left something out before. It takes 30 hp PER EVERY 100 HP to turn a roots S/C. That means you're losing 90 HORSEPOWER just to the S/C on a 300hp engine. That sucks, man...to hell with that.

Originally Posted by LancasterWannaBe

I don't disagree that turbo is better for max power, but how much boost are you really going to give a brand new car? Common people, the Z runs a 10.3 C/R, you can't just turn up the boost unless you're running some high octane fuels, water injection, or using CO2 by the Kg on a regular basis. If you're going to race your Z all the time, then by all means, lower the c/r, run methanol, and boost the hell out of it . But for everyone else, you'll just have to live with low boost.

Turbos make S/Cs obsolete because a turbo system can be tailored to the car, track (if applicable), weather conditions, current mods, competition, etc. and can be made to make any kind of torque curve you want at any rpm you want. You want low end power, change out the turbine or compressor wheels and viola...you want insane power at high rpm, get the biggest turbo you can find and shove that under your hood...there ya go...now you're like this 358ci small-block Chevy running 10.0:1 compression, a single large-frame Innovative GTB88 turbo and making over 1,400 hp on C-16 race gas. Weren't you just complaining about how little boost you could run with a 10.3 comp ratio? So much for that. And even if you don't wanna run C-16, I'm sure it does juuuuuuuust fine with regular high octane if you back off the boost, which is as easy as turning a knob inside the car if you have the right kind of B/C. Sure, it probably won't run 1,400 hp on pump gas, but it'd still be painful.



ANYTHING is possible with turbos. They're far more versatile, practical, and have infinate potential when used properly...S/Cs just....well....aren't.

Originally Posted by LancasterWannaBe

Now it was also said that the centrifugal s/c will not make "instant power". No Sh*t folks, power increases with RPM so nothing will make "instant power," it's the torque curve we're concerned with.

That's another thing that sucks about S/Cs...they're only RPM dependant. Turbos are RPM and load dependant. I'm going to post a long quote about this from that thread I posted a link to regarding this. I'll shorten it as much as possible. READ IT!

Finally, turbos run proportional to demand. What I’m getting at is that compressor speed is dependent on airflow, which comes from two main variables: engine rpm and throttle position, if you will. Now, a belt-driven blower car’s compressor speed is dependent on only one variable: rpm. So why care? Because when you’re just maintaining speed on flat and level ground, trying to make some mileage, a turbo car’s compressors are going very slowly and hence don’t increase pressure before the throttle body. But a belt-driven blower car has no idea what the throttle position is; the compressor is simply geared to the crankshaft, so it’s spinning much faster and making, say 2 psi in our example here. (And if it’s a Roots-type blower, it’s making 6, 8, or even 10 psi!)

So what do you do? You have to back out of the throttle even more. That means throttling losses are up (bad for mileage), and you’re pumping hot compressed air through your intercooler all day if you have one, and you’re using crankshaft horsepower to compress the air—then throttling it back anyway!

What a waste.

Originally Posted by LancasterWannaBe

But used or not, you will NOT be able to simply "turn a knob from your driver's seat" and make a lot more power.

Eh...how do you figure? You're in the car, you reach over to your boost controller, flip it to your high boost setting, more boost = more power...

[LancasterWannaBe]

Atmospheric pressure is 14.7 PSI (101.33 KPa). When boosting 7 PSI (0.478 atm), a centrifugal setup shows gains of 55%-60% HP on the Z. So with a 47.8% increase in manifold pressure - meaning ~47.8% increase in fuel combustion, the car gains 55%-60% percent power.

So now I'm going to do some math.
I want to figure the approximate power lost in rotating the S/C turbine.

In theory, the crank power levels are as follows:

Turbo: ([14.7 + 5.5]/14.7)*287HP = 394.38 HP
S/C: ([14.7 + 7]/14.7)*287 = 423.67 HP

Now for the difference of percent power sent to the wheels:

([347/394.38] - [367/423.67])*100% = 1.36%

The centrifugal supercharger setup loses 1.36% additional power before the wheels.

So: 0.0136*423.67HP = 5.77HP.
This is the power required to turn the S/C turbine.
(yeah that would be a little less than 90HP)


As for the rest....

You just restated what I had already posted.

Higher compression + High Boost needs higher octane fuels.
I think everyone here knows this already. I'm also sure you're all aware that a centrifugal s/c turbine can also be changed...

As I said before, "I don't disagree that turbo is better for max power." In fact if I had the money to void my warranty (and to own a Z ) I would totally go with turbos. They're not just more advanced, they're more thermally efficient. Hell, some cars have even shown increases in gas mileage when going with turbocharger setups that weren't meant for racing.

The whole reason turbochargers have advanced so much is because of the studies of turbine engines. If I were to mention the Garrett JFS100 or a Gnome T58, what would you all have assumed I was talking about? Trust me, I am quite aware that turbos are more advanced.

But, back to the voiding a warranty issue. I would want to have the option of easily removing my kit if something went wrong. Procharger kit means:

* no oil line
* no exhaust mods
* no cutting anything to make the ducting fit
* no electronics to wire
* no need drill holes for boost gauges or gauge wireing

Now since this has gotten to be such a big discussion, why doesn't someone ask about the AF Z? There's a s/c in that.

I guess my whole point is that the "best Turbo n Supercharger out" might not be the best because it makes the most power. I might just be the most driveable.

Now all said and done, I really DO wish the Z had come turbocharged from the factory. All I can say is the 05 supra better!

[longlivetheZ]

Originally Posted by LancasterWannaBe

Atmospheric pressure is 14.7 PSI (101.33 KPa). When boosting 7 PSI (0.478 atm), a centrifugal setup shows gains of 55%-60% HP on the Z. So with a 47.8% increase in manifold pressure - meaning ~47.8% increase in fuel combustion, the car gains 55%-60% percent power.

So now I'm going to do some math.
I want to figure the approximate power lost in rotating the S/C turbine.

In theory, the crank power levels are as follows:

Turbo: ([14.7 + 5.5]/14.7)*287HP = 394.38 HP
S/C: ([14.7 + 7]/14.7)*287 = 423.67 HP

Now for the difference of percent power sent to the wheels:

([347/394.38] - [367/423.67])*100% = 1.36%

The centrifugal supercharger setup loses 1.36% additional power before the wheels.

So: 0.0136*423.67HP = 5.77HP.
This is the power required to turn the S/C turbine.
(yeah that would be a little less than 90HP)

I give you props for the math approach. I like that. I'm not even going to ATTEMPT to go through it all right now cuz I've been drinking all day and I'm leaving soon, but I will later.

Originally Posted by LancasterWannaBe

I'm also sure you're all aware that a centrifugal s/c turbine can also be changed...

You mean compressor...there is no turbine on a belt or gear driven S/C. That's true, but you have more size and variation options (many more when you start playing with the turbine side as well as the compressor side) with turbos. Due to this versatility, turbos can be set up MANY different ways and can match and exceed a S/C efficiency and/or power out put under any circumstances or conditions. Plus, a turbo'd car will usually get better milage than a S/C due to the turbos being load dependant...not only RPM dependant.

As for the warranty issue. That's kinda up to whoever comes across this dilemma. I wouldn't really consider it because I couln't imagine the techs at the dealership NOT being able to tell there was a S/C on there...if nothing else, they'd probably be able to tell where bolts and screws were removed and turned and so on.

[LancasterWannaBe]

Originally Posted by longlivetheZ

You mean compressor...

Yeah my bad.

Originally Posted by longlivetheZ

As for the warranty issue. That's kinda up to whoever comes across this dilemma. I wouldn't really consider it because I couln't imagine the techs at the dealership NOT being able to tell there was a S/C on there...if nothing else, they'd probably be able to tell where bolts and screws were removed and turned and so on.

I know a guy with a 01 dodge 5.9 R/T. He bolted a supercharger onto it and sure enough - due in part to dodge's amaizing engineering abilities *sarcasm* - he blew the engine. I don't recall what went wrong, but it was one of those small things that wrecks everything - you know, a dodge thing ...

Anyway, he removed the entire kit carefully and took the truck back to dodge. The techs didn't notice anything, so he got a new motor.

I'm sure you could do the same thing with a turbo kit, but it would be so much harder. I dunno, if I end up getting a Z, maybe I'll turbo it also since Nissan are built better than dodge.

Does anyone on this board have a turbo'd 350Z? If so, I'd like to hear what they have to say, especially if they did the work installing it.

[LancasterWannaBe]

How much boost are the twin TD05H 18G turbo's capable of when used with the VQ35?

Assuming you ran with some 104+ octane boosters or something (assume detonation is not a problem), how hard could you push them?

Also, how is the mileage affected with the piggy back comp controlling the car?

[chippowzer]

whats better a 5 speed or 6 speed for drag

[longlivetheZ]

Yo lancaster...look up the Greddy 350ZTT...friggin awesome. Running mid 4 seconds to 60mph on VERY low boost...that should give you some idea of what a TT'd VQ35 is capable of.

Originally Posted by chippowzer

whats better a 5 speed or 6 speed for drag

Depends on the car's power output and the gear ratios being used. A race designed auto trans is better in some ways...look at the Buick Grand National...

Originally Posted by lancasterwannabe

How much boost are the twin TD05H 18G turbo's capable of when used with the VQ35?

I'm not sure...I'll try to find out.

Originally Posted by lancasterwannabe

Assuming you ran with some 104+ octane boosters or something (assume detonation is not a problem), how hard could you push them?

Depends on how much boost the turbos are capable of.

Originally Posted by lancasterwannabe

Also, how is the mileage affected with the piggy back comp controlling the car?

Turbos have the potential to increase a car's mileage if the driver stays out of the throttle. Again...it depends on the driver.

[Shabbyflamingo]

Undoubtly APS TT kit and intracooler are the most powerful TT for a Z. They posted something like 432HP from stock Z. Thats nuts! I plan on saving up for a good little bit to get that 7,000 bone kit but the first time I hit 3,000 RPMs I just know Im gunna have to re-apolster my seats..lol