6versus8

[Zenmervolt]

Originally posted by: exdeath
Anything more than approx 400-450 to the wheels in a four-banger is borderline and taking it a step beyond being a pump gas street car.

I have one caveat on this: You don't specify displacement. Theoretically someone could build a 5.0 litre 4-cylinder and get 400-450 hp at the wheels without making things too peaky. Of course a 5.0 litre 4-cylinder would need some pretty massive balance shafts, but you get the idea.

At normal engine sizes though, you're right that a 4-pot would be awful damn peaky at 400-450 wheel horsepower.

ZV

 

[KIAman]

Originally posted by: Dman877
Now if they would just put that engine in a decent car...

Kind of a lame premise too. There are people out there making 600+ hp on four-bangers. Number of cylinders really isn't important when it comes to turbo setups.

In their commercials, Ford claims the power of a V8 with the fuel economy of a V6 but that's a farce. Everything review I've seen has found the ecoboost to get high-teens for mileage and that's worse than you'd get with some V8's (LS3 for instance).

According to how the EPA defines MPG, their claim is correct. As to the EPA's testing methodology, that needs some work. Just look at the Volt and the Nissan Leaf as examples of how much they need to change.

According to real world testing with real world driving conditions, who cares? (sarcasm) LOL.

 

[EightySix Four]

Originally posted by: Zenmervolt

Originally posted by: exdeath
Anything more than approx 400-450 to the wheels in a four-banger is borderline and taking it a step beyond being a pump gas street car.

I have one caveat on this: You don't specify displacement. Theoretically someone could build a 5.0 litre 4-cylinder and get 400-450 hp at the wheels without making things too peaky. Of course a 5.0 litre 4-cylinder would need some pretty massive balance shafts, but you get the idea.

At normal engine sizes though, you're right that a 4-pot would be awful damn peaky at 400-450 wheel horsepower.

ZV

For the 2.0l I have, you start to screw up the curve pretty heavily if you try and move beyond 340-350 whp, with a single turbo at least.

 

[exdeath]

Originally posted by: Zenmervolt

Originally posted by: exdeath
Anything more than approx 400-450 to the wheels in a four-banger is borderline and taking it a step beyond being a pump gas street car.

I have one caveat on this: You don't specify displacement. Theoretically someone could build a 5.0 litre 4-cylinder and get 400-450 hp at the wheels without making things too peaky. Of course a 5.0 litre 4-cylinder would need some pretty massive balance shafts, but you get the idea.

At normal engine sizes though, you're right that a 4-pot would be awful damn peaky at 400-450 wheel horsepower.

ZV

Heh true. The flat 4 aviation engines come to mind: 4L+ 4 cyls.

If you build it right you can have a typical 2 liter 4 cyl (Toyota 3SGTE, Honda K and B series, etc) making up to 400 WHP on 91 pump gas with a pretty broad and flat curve. It really has to do with the turbo size, cam profile, exhaust manifold, etc. everything to keep the exhaust heat in and spool that turbo up as quickly as possible. One of my favorite examples of a MR2 was making 400 HP to the wheels and something like 300 ft lbs at 2500 RPM, before they decided to chase more peak power.

Beyond that and not only are you destroying your power band for peak power, but you can no longer run pump gas either. There are a few examples of 500+ WHP on pump gas, using a very laggy large turbo at low boost, which pretty much destroys your power band just to make a bigger number on a dyno. I suppose you'd have a decent highway monster if you can keep it in the 500 RPM power band, but for the purposes of this topic, that's not how you would build a production car, hence the V6.