Turbo tail/flares and their aerodynamic disadvantage

[nkotselas]

Hello everyone ,

I have a 78 sc converted turbo look by Kremer in Germany. It has the turbo tail, front spoiler, flares, 205/55 16 and 225 50 16 tires. I am curious how this would affect the aerodynamics. I have seen that switching to a front and back spoiler can increase the top speed by a few mph, but I have also read that the turbo look car out of the factory went 12 mph slower than the standard carrera. (Mind you my car is turbo look visually, so it does not have the extra weight like the factory.)

My car is being pushed by a euro spec 3.2 with low miles, a pre muffler and a muffler from m&k soon to come + a SW chip, I'm hoping to get around 250bhp. Also when the turbo conversion was done, it was lowered more than any porsche I've seen so far. I raised it to protect my new paint, front spoiler, and engine. Does this also have a significany effect on a car's top speed?

On a side note, does anyone know the weight of the tail, front spoiler and flares together?

Thanks in advance
Nick

[nkotselas]

After raising the car to spec

[Flieger]

The tail should reduce lift and therefore drag but the bigger frontal area of the fenders would likely more than compensate for that.

What do you care about top speed? You wont access it unless you are on the Autobahn or a track. Is it fuel milage?

The tail is heavy. The steel flares are heavy.

[Noah930]

Weight has little effect on top speed.

The turbo bodywork will present a larger cross-sectional diameter to the oncoming air. That will hinder top speed (compared to a narrow-body car), unless the bodywork somehow lowers the car's coefficient of drag by a similar (but opposite) amount to compensate.

Raising the car's ride height will allow more air to flow under the car, thereby generating more lift. That'll likely impact the car's handling at high speeds, possibly enough to lower top speed, too.

Of course, the biggest impediment to high top speed will be the lack of HP with your normally-aspirated motor, compared to what you could get if you actually had a turbocharged motor (with mods ) to go with the car's turbo looks.

IIRC, the coefficient of drag on a turbo body is something embarrassingly horrible like 0.49.

[nkotselas]

If money was not an issue it would definitely be turbocharged by now.

Top speed wasn't my only concern, just a general question that I could use to understand other such as acceleration at higher speeds, fuel economy, etc.

[CRNT918]

If I remember correctly, RUF used a narrowbody on the Yellowbird because it was 10mph faster than the Turbo widebody.