Vaillant

Something about the way you post is a little odd...very matter of fact but it often sounds like cut and paste.

Anyway, there are plenty of "fastest" cars out there that are turbo charged (great example: Bugatti). And plenty that aren't. This turbo vs. supercharger vs. naturally aspirated debate is one that is eternally argued on message boards everywhere, but the best conclusion I've heard is it all comes down to driver preference. Do you want low end torque? Do you want an increasing rush of power to the top? Do you want the simplicity of NA or the added complexity and tunability (is that a word?) of boost?

Plus, there are great engines from each of the three groups (super, turbo, NA) and there are crappy ones. And, depending on an engine's characteristics, often one thing makes sense more than another.

I think many racing formats keep it NA to keep costs down, but there are plenty that have turbos, such as WRC (which is quickly becoming my favorite). I can't think of any racing, except maybe drag racing, where the cars are supercharged, but that's probably due to ignorance on my part rather than them not existing.

As far as Corky Bell goes, he's a proponent of BOTH supercharging and turbocharging. In fact, the link you provided has a picture of both his books on the matter. I think that says a lot about both systems being viable.

Okay, I should get back to work....

zoom44

i've guessed at this before but i think i haveit this time- Supercharger are you perhaps a technical writer? that would explain how you have access to all of the info and diagrams and such.

wakeech

...that's because it often is.

:D sure, whatever, close enough :D


...and for Super, i'll just say that turbocharging is a KIND of supercharging ('cause it is)...

Efini 8

who cares ... as long as the car is fast, and can make the cool sounds the turbo does :DROOL

ProtoConVert

Why turbocharging is the way to go:

1 - NA mods will only get you so much HP. Turbos are absolutely necessary to get a 1.3 liter motor to high HP - the only place where the RX-8 is lacking.

2 - There is no turbo lag if you keep the motor at higher rpm's, as with track situations.

3 - The only real inconvenience of turbo lag is to off-the-line performance for maybe 20 yards... if you want stoplight performance then maybe turbos are bad for you, but even for drag racing I'd say turbo will get you more power than NA mods. Furthermore, modern turbos are somewhat undeserving of the laggy reputation.

4 - The sound of a turbo is aesthetically pleasing. (granted to some)

5 - I am willing to sacrifice minimal response (if there is any to sacrifice) and maybe .5-1k rpms from the top end range (again if that is even necessary) for 1 atmospheric equivalent boost.

6 - RX-8's strong point is not only the RENESIS, you also get a great chassis, essentially with old school Lotus design. In this area does the RX-8 outshine its competitors. While I do not have access to this kind of chassis structural data, I would venture to say that the numbers support it

Also, yes, in a perfect world the power could be there by a stroker kit or a crate motor (which is available for 10k for the 350z, but I digress) but neither of those provide relatively high HP.

wakeech

ummm... well, okay.

making power is pretty simple in theory: there are two dependants on power... just look at the equation.

torqueXrpm (and then devided by some unit conversion ratio) = power

so, it's a pretty simple picture. to make more power, you need more torque at a given rpm, or more rpm at a given torque.

to make more power with any engine, you either need more rpm whilst maintaining some level of torque, or just more torque.
in general, it's simpler to just make more force at a given rpm than to try and struggle with maintaining torque at sky-high rpm (ie: holding the engine together).
to make more torque, you just need to increase the amount of pop-per-turn, which is force, which is generated by pressure in the IC engine. pressureXarea (divided by a unit conversion ratio) = force, so you can either increase the pressure generated on an area (like forced induction: more fuel combusted = more pressure, or in NA application increasing the compression ratio), or you can maintain the same amount of pressure on a larger area (increasing the displacement = about the same amount of pressure on a larger piston, or on the same piston through a longer stroke that has more leverage on the output shaft)...

anyways, it all does the same thing: more power, and that is the goal.

*cough*goturbo*cough*

RacingDynamcs

turbo!!! unlike suprcharing u get a boost controller and if u dont need the boost u turn it down....SC's u need to walk out of the car, pop the hood ajust that **** ur self....meh!

Supercharger

Why turbo is not the way to go (part 4)

Formula 1 Qualifying Lap Time Comparison:

________________ 650 hp NA F1 ________ 1100 hp Turbo F1

Estoril, Portugal
(4.35 km) _______ 1:15.468 (1989) _______ 1:16.673 (1986)

Monza, Italy
(5.8 km) ________ 1:23.720 (1989) _______ 1:23.460 (1987)

Suzuka, Japan
(5.86 km) _______ 1:38.041 (1989) _______ 1:40.042 (1987)

Spa, Belgium
(6.94 km) ________1:50.867 (1989) _______ 1:52.026 (1987)


http://www.f1db.com/grandprix

wakeech

ahaha... look, seriously man, there's a LOT more to a Grand Prix car than the engine.

look at the trap speeds over those laps, and i guarantee that on the tracks unmodified (the straight coming into Parabolica at Monza, the straight with the 120R or whatever at Suzuka, the straight into Bus Stop at Spa-Francochamps) and you'll see that the turbos obviously motivate the cars more effectively.
the single largest difference between the cars is aerodynamics, and structural design: modern F1 cars make nearly as much grip, with much nicer tyres ( so much so that a 3 stop race is now not uncommon, usually reserved only for Monaco in the past), slicker skins, lower Cg's, inertial-moments, etc, as they did back in the big-*** tyre turbo days, without flat bottoms and without the skid-panels on the bottom...

because the mass of the cars is about the same, and the dimensions haven't changed extraordinarily, it's all about the chassis... how does Ferrari, probably the 3rd or 4th most powerful engine on the grid (behind BMW, Mercedes, and maybe Honda or Ford) set blistering trap speeds and set obviously faster lap times?? the same way that the grossly under-powerd Renault team does: with a better overall car.
that's the whole thing about F1, is that the entire car improves, constantly. those blocky old up-right-seated bricks can't hold a candle to the coffin-esque razor blades of today, as is evident in your numbers.

but trust me, you can't say that turbos are a bad idea because of this :p ahahaha... nice try.

Sputnik

Yeah man, a real racing fan would know that the removal of the turbo was not the reason why those lap times fell.

---jps

Supercharger

Why turbo is not the way to go (part 5)

Engine throttle response affects a car's cornering performance.
That's one of the reasons why a NA car is faster than a turbo car on a road course.

Group C Sportscar Qualifying Lap Time Comparison:

______________ 750 hp NA Peugeot _____ 1200 hp Turbo Nissan

Le Mans, France
(13.6 km) _______ 3:21.200 (1992) ________ 3:27.020 (1990)


http://user.tninet.se/~aiq291w/index.htm

wakeech

in two years, tyres (and the regulations on them) can change quite a bit... this also doesn't tell us the mass of the two cars, their class, or anything, just the horsepower, who made them, and what year.

aero, and tyres could easily make that difference... btw, cornering ability isn't affected by throttle response, it doesnt' give you more grip, it'd just be easier to control at part throttle, which is condusive to lower lap times, but you can't argue with 550hp...

and as for why the Nissan is slower, everyone knows that Nissan never built a very good Le Mans car ever anyways ... Peugot's the home team!!

kidmarc

This post is late due to not reading this forum for a few months.

One pioneer in the turbocharging field is Allan Nimmo of Performance Techniques. He has demonstrated the hidden capabilities of the turbo many times. His work is well known in the world land speed records at Bonneville.

He was in Turbo and High Performance magazine in 1990 with a feature article on his turbocharged V-8 driven Mazda Rx-7 of 936 hp that posted 9.63 quarter mile times; 0-60 in 3.6; top speed 232 mph; lays scratch in all three gears; is an automatic; and all of this while the A/C is on. It is unnoticeable that the car is modified except for the low profile.

To note, Allan is a fan of the rotary.

To address whether to turbocharge, supercharge, or naturally aspirate... The choice comes down to the pluses and minuses. Contrary to Supercharger's comments, these are the issues as to turbochargers vs. superchargers/blowers

The minuses can be reduced once you understand some basics outside of automotive design.

Peace
marcus