I posted this on another thread but I thought it was worth a new one.

"What I want to know is why hasn't anyone went retarded with a supercharger? People that have tt and run 650hp spend what? $25,000 to make everything perfect? Why hasn't anyone got a built supercharger? Keep in mind how many 5000hp dragsters use turbos? How many use superchargers? I am just tired of seeing everyone post how the only way to make power is with a turbo. When you look at the picture build your engine find a fat supercharger and fit it, tune it, etc. and you would have spent roughly the same as the turbo guy did and you would have the same amount of power without lag. I have just been curious why it hasn't even been whispered yet."

Is there no company that will build a supercharger for you? If not there should be a bigger one you can fit. No?

 

Go read my reply to your post

 

I would like to know also. "booger" what info did you have. I see you have vortech SC on your screen. My friend has vortech also.

 

blowers can definitely make good power... my first project car ever was a vortech supercharged vehicle... i went "nuts" with it and turned it from a 275hp, 14.3 sec 1/4 mile car into a 900hp monster that ran 9.56 @ 143 (via $35k in mods)... so before we get into this, understand that I'm not just some biased blower hating turbo evangelist...

BUT, the centrifugals have nowhere near the HP potential of a similarly sized turbo... here are some facts:

on my 900hp car, it took about 200hp to drive the blower... that means the fuel system was using 1100hp worth of fuel, the motor was under 1100hp worth of stress, but the net horsepower making it to the flywheel was only 900hp... Imagine the strain that this puts on the snout of the crankshaft when it has to drive a 200hp accessory... a smaller blower takes less power, but it still produces far more parasitic losses than a turbo... the bottom line is, all motors are capable of withstanding a certain amount of cylinder pressure and strains before they reach their "limit"... with a turbo setup, you will get a larger percentage of this power to the flywheel and out to the wheels than you will with a supercharger, period.

the previous facts refer to peak power, which will occur near redline... when it comes to low and midrange power the turbo has even more of an advantage... the turbo's ability to make full boost from 3000 - 7000, vs. the supercharger's linearly increasing boot that only peaks at redline, is a clear win... think about it: if the turbo makes more power at 10psi than the blower does at 10psi, then obviously the turbo at 10psi will completely dominate the blower at 5psi... this would be precisely the situation at around 3500rpms when both cars are configured to run "10psi"...

Internal combustion engines follow this general thermodynamic breakdown:

1/3 of the energy from combustion is lost as heat transfers to the cooling system

1/3 of the engery from combustion is lost as hot air goes out the exhaust port

1/3 of the energy from combustion translates into useful work and pushes the piston down

The turbocharger is the closest thing in the internal combustion world to a "free lunch" because it actually reclaims some of that lost 1/3 heat energy going out the exhaust and uses it to build boost...


As far as top fuel cars only running superchargers, in reality the turbos OEM's don't make turbos that would work in this application... the largest turbo suitable for an automotive application is good for about 2400hp... so to make 7000+hp like top fuel does, you'd need 3 of them... with only 500ci, you couldn't spool 3 of these things in a reasonable time period to make the car quick reacting... bottom line, the power potential would be superior to the blower, but the drag racing elapsed time potential would suffer... This could possibly be changed with years and years of R&D and additional OEM development, but since the rules don't allow turbos, this development has never occurred...

 

There's just one answer to this question, turbochargers have been banned from top fuel racing in the US since adam was a boy (many, many years ago now) so it's not been possible to run turbocharging for this exact reason.

In fact about the same time period (about mid 80's from memory) that turbocharged formula 1 engines were making 1200 Horsepower from 90 cubic inch engines for a 2 hour race, not 4.5 seconds like a top fuel supercharged engine.

Imagine the power that Formula 1 engines would be producing today if the governing body had not banned turbocharging from this catergory of motor racing as well!

Peter

 

good info!
turbo all the way!

 

My car makes full boost as soon as I mash the gas. The only time it doesnt is when I am in lets say 6th gear at 65 mph and stand on the gas. It will goto 5psi and slowly increase as my motor lugs along.

Turbos worst enemy is turbo lag. If I want to race a supra from a roll he would have to brake boost to build psi otherwise in any gear from any roll I would kill him. Turbos still have lag in roll races too.

 

Yes but you don't have a centrifugal supercharger now do you? TRUST me, a Vortech, Procharger, Paxton, etc. will only make 50% of max boost at 50% of redline... the roots style blowers like they put on the Cobras make a much flatter boost curve, the problem is that they are even worse for efficiency than the centrifugal supercharger... so fine, you get Xpsi across the whole RPM range, but you are WAY below the power you'd have with Xpsi from the turbo...

As far as your comment on Supras, all the Cobras I've beaten the snot out of with my Supra didn't seem to think I was too laggy Turbo sizing is an art, and many people are only concerned about peak HP numbers and are frankly running way too large of a turbo...

And let's compare apples to apples... When we put a 1000hp turbo on a V8, it spools before the gas is to the floor... You can't really compare the power/lag scenario between a roots supercharged V8 and a big turbo'd 3.0L... If the roots blower was the end-all-be-all, we probably wouldn't have so many customers with the new Cobras that enquire about us building turbo kits for them when they see our 1500hp Turbo Mustang STREET CAR do over 170mph in the 1/4 on radial tires.

Like I said before, blowers are neat, they make "decent" power, and for some people they are more than enough (in my early years of performance work, I was one of those people too)... but it is a mathematically proveable fact that they are inferior in terms of power production to the turbo. This really is not open for debate!

Jeff

 

"STOP THAT" Jeff.....your making me want to get rid of my blower

 

Sorry booger, I mean no offense to anyone with a blower!

That is why I pointed out that I had a very powerful blower car myself at one point, I wasn't just born a "blower hater" or anything...

But when you've been down both roads and have seen the results of the turbo firsthand, it's pretty hard to ever go back

 

It was a joke....got to much $ in it now...maybe down the road

 

I figured you were only halfway serious at most, but I just wanted to make it clear to other people that I wasn't trying to bash them... I wouldn't jump into a "I just supercharged my car and love it" thread and try to burst the guy's bubble, but this thread did basically ask "why do people think turbos are better?"... Just so happens I have a few answers to that question

In reality, anybody with boost is so far ahead of those trying to "do it" with nitrous or cubic inches, that all of us FI guys should consider ourselves "on the same team"... the blower guys are just the second-stringers, that's all

LOL!

 

I look at it this way . A SC is a great way to get into the forced induction world . Like you did ,and Im doing . This the first car Ive tried to build up . It maybe the only one [ I dont know ] I may go TT down the road . But I have to learn things one step at a time , to be able to understand how every thing works together . The only thing I need to do is do more research so I dont make so many mistakes . The mistakes can get costly.

Its starting to get warm enough to get the Supra out Jeff . When you do...I want a ride in it

 

No replacement for displacement? As many of the new F/I guys are finding out now, to make a Z go faster, one doesn't necessarily need more cubic inches. More cubic dollar$ seems to work fine, too...

 

2JZ your right about psi. What do you have done to your supra? Are you on stock turbos or single. Oh, and I could care less about peak hp. Your only there for a sec.

I forgot about the differences in blowers. What do you mean by efficiency (sp?)? I cant imagine any more power this car is so fast. Hell in second gear when I get to 5500 and up my car starts spinning.

pics
https://my350z.com/forum/media-share/114480-test-new-car.html

 

Pressurizing air generates heat, different types of compressors will have different efficiencies in doing this... Even two different turbos will heat the air differently and consume different amounts of hp to make the same amount of boost...

The family of roots style blowers is less efficient that the family of centrifugal blowers... the roots style draw more parasitic HP from the crank to turn them and they heat the air more... both of those points amount to the roots making less HP at the same PSI than the centrifugal would... the upside of the roots is the boost curve is very flat... so there are pros and cons to each style of blower...


Supra: single 63mm turbo, custom turbo kit, custom fuel system, AEM standalone ems, Greddy FMIC, ACT clutch... 640rwhp... with 285mm wide tires, at full boost I will spin the tires up to 80mph... because of this "cool but not useful" excess of power, I use the AEM to dial in a boost curve based on road speed... for example, at 0mph I run 12psi, by 25mph it's up to 15psi, by 40mph it's up to 20psi, by 60mph it's up to 25psi and so on... max boost is around 28psi... let this sink in for a minute -- the turbo is not laggy, the computer is continuing to electronically raise the boost limit as the roadspeed (and therefore traction) increases... it's like traction control via boost control and it makes for the most incredible feeling street car you can imagine... you know how basically all cars feel faster in the lower gears than they do in the higher gears? with a given amout of HP, you will accelerate much faster from 30-40mph then you do from 80-90mph... not this one! from 30-40mph it's making 400rwhp, but from 80-90mph, it's making 640rwhp... so from 0 - 100 you are continually pushed back in the seat harder and harder and it gives the feeling that the car's power is limitless... might sound kind of corny, but it's the most addictive feeling this side of heroin (or so I hear )

Unbelievable flexibility in boost control is yet another area where turbos dominate blowers... no need to change pullies or belts, just have the ECU send a few electrons down the wire and WEEEEEE, more horsepower!

Jeff

 

Why is the turbo banned in Top Fuel racing?

 

and why is EFI banned in NASCAR? face it, most of these "race" organizations aren't exactly riding the cutting edge of technology... why? there are various political and historical reasons that don't really matter in this discussion, but suffice it to say that there aren't many (or any) racing classes that really encourage all out, max technology, no limitations on money spent, power made, let's just "see how fast you can go"...

F1 is the perfect example.. they are championed as being the epitomy of high tech, high budget racing, and yet they banned turbos years ago... these guys were running over 60psi, and making over 800hp per liter on methanol... even on nitromethane, top fuel only does about 850hp per liter, and they are LUCKY if they can keep it running for 5 seconds... driver's from that era of F1 have been quoted as saying that if you didn't just have perfect natural instincts, you would die, the cars were so fast there was no time to think... tirespin at over 200mph from sheer power, the cars simply had to be slowed down... in short, the turbos were too good at doing their job...