Naturally Aspirated vs. Forced Induction: which is best

user7

Member
Joined
Jun 2, 2006
Messages
66
Location
Vancouver, Canada
Car(s)
2011 Ford Mustang (v6)
The great debate!

I should clarify that 'best' refers to the best daily drive car. The type car you would like to live with; think something with decent power, acceptable maintainance/reliability, acceptable running cost.

I ask this because I'm planning to buy a used car, and I've been mulling over what kind of engine I want. The way I see it there are three categories: Manufacturer forced induction (think supra and colbalt ss), typical naturally aspirated, and aftermarket force induction.

I find myself leaning toward naturally aspirated, I don't want to worry that my engine will explode while I take the next corner. I feel that I should spend my money on a larger engine/displacement rather than a super/turbocharged car. Plus I would always have the option to install an aftermarket one.

But I'm most wary of aftermarket turbos/superchargers. I always wonder if a skilled mechanic installed it, was it installed propperly, has it been maintained properly. The way I see it, if the owner was looking for cheap power, what else has he skimped on the car.

it's not a pole thread, I'd rather hear opinions and experience.
 
Oh, that is a tricky one.

Turbos and superchargers used to be a way to get even more power out of already powerful motors, but in these days of ecomentalism the Turbo has been coupled with smaller motors to match the power of larger, more thirsty motors.

Also, we have the introduction of variable-impeller turbos that reduce turbo lag by taking a bigger bite of the air at low speeds. While these are still fairly exotic, I would expect to see them become more main stream soon.

Then there's the part of me that has no use for a turbo or supercharger. When I'm rock crawling I want max torque at low rpms and linear, predictable power delivery. There's a reason I'm looking at the 4.0L X-Terra and not the 3.3 supercharged. I also like simplicity and there's a part of me that distrusts increased complexity. A turbo is just that, and I just hope that the motor that's attached to it is designed and tuned for a turbo and it's not a bolted-on afterthought that will cause problems down the road.
 
Really it depends on what you like, both have their pros and cons, and what you will be reading from responses are personal opinions, not concrete, proven facts. I suggest you try all three and see what fits you best. :)

Myself, I think the best of both worlds is high revving, low torque engine with a supercharger or turbo for the low end revs. So, an S2000 or Civic Si (1998-2000) with a blower.
 
There is no replacement for displacement.
 
I drive a spec v sentra used to be N/A and it was a great car quiet-ish, fast-ish, smooth and a reasonable place to be for cruising, recently I added a turbo to it and well it's about a million times better. Driving is always fun now and it still keeps all the other good characteristics.

So my vote goes turbo, as long as it been done right.
 
I love the responsiveness of an N/A engine, but the rush from a force-induction engine is spectacular as well.
 
I think that depends on what sort of person you are. If you want to spend a little extra time and money keeping up a forced induction engine, go for it, but if you don't then you're better of NA. I have one of both, the Mustang is naturally aspirated, and Grand Prix supercharged. One thing I like about the Grand Prix, I have two different modes- standard and performance. Standard mode the car drives like normal, the SC kicks in on heavy throttle. In performance, the engine revs more (more supercharged goodness) and the shifting changes.

If you go aftermarket for your forced induction, as long as you build up the bottom end of the engine properly there will be no problems. Unless it's a very common add-on for the car, you may have trouble getting service and support for it if something does go wrong since it will be hard to find someone who knows what's going on with the added-on system. With factory forced induction, the engine comes beefed up from the factory, so it's stronger than a NA counterpart. Keep in mind though, factory FI systems are typically very low boost compared to aftermarket ones. You can, however, change that, since most FI cars will have an aftermarket behind them that supplies parts to get more power. In addition, service will be easier since it came from the factory with the extra stuff.

A NA engine can keep right up with a FI engine, if it's built right. And because there's less parts there, there's less to go wrong. I don't really see a downside to this, unless you count a bit of extra care keeping the tighter tolerances in check.

All the systems have their sides, just choose what you do and don't want from the car and find the result that fits.
 
Apparently, my supercharged XJ is more reliable than the N/A one, thanks partly to not having VVT. I've tended to own torquey cars with flat curves, but I've enjoyed my test drives in high-revving cars. They're both fun in different ways.

EDIT: Just read your question more thoroughly. In a daily driver, you want low-end to midrange torque, and it doesn't matter if it's displacement, a supercharger, or small turbos that deliver it. I've been told by people with high-strung cars that revving the nuts off an engine just to get anywhere gets tired fast.
 
Last edited:
I like the versatility of NA, but am not ruling out owning an FI car in the future.
 
The Passat is the first turbo car I've owned. I was a bit unsure about it to begin with, it doesn't rev quite as much as a N/A engine. With all the torque and power coming in at low RPM, it doesn't need to. Peak torque comes in at only 1800rpm, so it packs a pretty potent punch off the line.

Now, I really do prefer having forced induction.
 
2 litre Evo FQ400 = 205.31 bhp per litre.

8.4 litre SRT-10 ACR = 59.54 bhp per litre.

At what RPM?

And the biggie: What does the torque curve look like?
 
Forced Induction every day of the year.
 
At what RPM?

And the biggie: What does the torque curve look like?

You hit the nail on the head with that. The FQ400 is a bit of a dyno queen; as in, sure it produces a mountain of horsepower, but it's not all that usable or accessible. In the Viper, you can mash it at nearly any speed in any gear and you'll get a reaction of biblical proportion, whereas the FQ400 will struggle under many circumstances, owing to the gigantic turbo lag.

My God, I can't believe I just defended the Viper...:p
 
You hit the nail on the head with that. The FQ400 is a bit of a dyno queen; as in, sure it produces a mountain of horsepower, but it's not all that usable or accessible. In the Viper, you can mash it at nearly any speed in any gear and you'll get a reaction of biblical proportion, whereas the FQ400 will struggle under many circumstances, owing to the gigantic turbo lag.

My God, I can't believe I just defended the Viper...:p

Look at it this way, the Viper may have a mountain of torque, but it's very difficult to control. For a track, the control of a turbo is better. :p
 
Top