Why the low torque?

[billwot]

Originally Posted by ZionsWrath

There is no replacement for displacement.

Forced induction is the replacement for displacement!

[ftc~brz]

Originally Posted by Tcoat

^ If you get bored you are driving it wrong!

i only drove it wrong once.

[Tcoat]

Originally Posted by ftc~brz

i only drove it wrong once.

AH yes I have seen the pictures!

[Target70]

I think OP is curious not why it is weak overall, but ratio of tq to hp is so low, at least that was my inital thought. my ka24de 240sx has as much or more torque than hp, which is why I liked it over the sr20, with the lower torque higher hp. I take his question to mean: why aren't they more even 180hp/180tq. I could be pulling this out of my ass, but I believe it is because this block has a square bore(same bore to stroke).
Displacement counts for power, but the design also determines what type of power. With an 86mm bore and 86mm stroke It makes for a balanced bottom end which is good for high revs. But for good low end torque, you need more leverage. To maintain the same size engine, if the stroke goes up, the piston size has to go down. If the stroke was longer, that would mean that the rods would have to be longer and or the crank lobes would have to be pushed out away from the center line. This would throw the balance out at higher rpm's but would provide a longer lever. With more leverage you get more torque, but less balanced, so it will spin slower top end, thus lower hp. Also increasing stroke would mean needing more crank case room, and taller cylinders, which would mean a wider engine. We already have to jack up the engine to change the spark plugs, so I do't know how much wider they could make it. I wouldn't mind sacraficing a little higher rpm's for more bottom end umph, because I DD, and almost never get over 5k rpm's. That's my assessment anyway.

Originally Posted by Tcoat

...Or, you can always say "it is low hp but it is a BOXER engine". Again, if they give you a knowing look and go "ah yes that makes all the difference" then you confirm that they don't know sh*t about cars.

lol, a guy at work liked how the car looked, and did the whole it must be fast thing. I told him not really, but it has a low center of gravity due to the boxer engine.. he replied boxer engine! So that thing is basically a Porsche!

[stonenewt]

Originally Posted by Target70

Displacement counts for power, but the design also determines what type of power. With an 86mm bore and 86mm stroke It makes for a balanced bottom end which is good for high revs.

On a different engine I worked out that when you started exceeding something around 120meters/min of piston travel at high loads for extended periods nasty (e.g. flat out for 10-15 seconds or so) things started happening for long term bore/piston/engine life. Interestingly 86mm bore @ 7000 rpm = 120.4m/min of piston travel.

I also discovered that as you increased the piston travel you widened the power band as a % of maximum revs. The thing is the area under the torque graph stayed more-or-less the same so you had a wider power band with less peek power. Easier to drive with but not as fast.

I have no idea if this is a universal concept or specific to that particular engine. I was wanting to made engine which was high-revving but had a wide power band.

Originally Posted by billwot

Forced induction is the replacement for displacement!

What'll make more power a 2l turbo engine at 1 bar boost or a 3l turbo engine at 1 bar boost?

[ftc~brz]

Markymore novellas errrywhere

[DarkSunrise]

As a rule of thumb, most well-tuned NA cars will have roughly 75-80 lbs-ft torque per liter.

So for a 2.0 L car, you're looking at 150-160 lbs-ft torque.
- FR-S/BRZ, 151 lbs-ft
- S2000, 153 lbs-ft
- RSX Type-S, 141 lbs-ft

For a 2.4 L car, you're looking at 180-192 lbs-ft torque.
- Civic SI, 174 lbs-ft
- Jeep Cherokee, 171 lbs-ft
- Santa Fe Sport, 181 lbs-ft

For a 2.5 L car, you're looking at 188-200 lbs-ft torque.
- 986 Boxster (2.5L), 181 lbs-ft

For a 3.4L car, you're looking at 255-272 lbs-ft torque.
- 981 Cayman S, 273 lbs-ft

For a 6.2L car, you're looking at 465-496 lbs-ft torque.
- C7 Stingray, 465 lbs-ft

And so on. Moral of the story is, if you want more low-end torque, go bigger (or go FI).

[Tromatic]

The greatest part of this car is learning to drive it around it's limitations. People who complain about the stock car have a PEBSWAS (Problem Exists Between Steering Wheel And Seat) problem. Or, as has been said one or twice, "you bought the wrong car."

Nick Ienatsch's "The Pace" applies to this car as well as bikes. People who's only answer is "MORE POWER" (fun as that is) generally suck at the basics.

ETA: I'm starting to think the designer(s) of this car really put one over on Corporate. They managed to put into production a car that is totally opposite of almost all cars in production (not counting real "supercars), a vehicle that requires, and rewards, real driver involvement. I've said before that the FR-S is a throwback, and a small taste of "supercar". I have had a number of cars, some crappy, some very nice. The FR-S is the most awesome little car of all. I literally love mine. Young dudes who have this as a first car have no idea how great it really is.

What exactly is a driver's car?

[Tcoat]

lol, a guy at work liked how the car looked, and did the whole it must be fast thing. I told him not really, but it has a low center of gravity due to the boxer engine.. he replied boxer engine! So that thing is basically a Porsche![/QUOTE]





Ya that T makes a big difference! Never thought of that before maybe when I said "boxer" people were hearing "boxTer". They may have been smarter then I gave them credit for after all.

[strat61caster]

Originally Posted by Tcoat

Ya that T makes a big difference! Never thought of that before maybe when I said "boxer" people were hearing "boxTer". They may have been smarter then I gave them credit for after all.

Or that most Porsche's have boxer engines.

[Target70]

Originally Posted by strat61caster

Or that most Porsche's have boxer engines.

I had to google it just now to make sure I hadn't typed it out wrong . it's actually boxSTer. As I'm cheap and broke, I never looked into porsche cars so all that I knew was that they had flat engines, I think/thought it was usually a flat 6. I was unaware of the whole boxer / boxster thing.

[Tromatic]

Originally Posted by Target70

I had to google it just now to make sure I hadn't typed it out wrong . it's actually boxSTer. As I'm cheap and broke, I never looked into porsche cars so all that I knew was that they had flat engines, I think/thought it was usually a flat 6. I was unaware of the whole boxer / boxster thing.

Just slap an RB kit on your Boxer, viola! Boxster!

[Target70]

with the danger of going wildly off topic, I'll say that i bought this car with the intention to modify it for more power, and I do not feel like I bought the wrong car. It was either put a turbo kit on my 240, then go about replacing the open diff/axles, the 15" 4 lug spendles/wheels/rotors brakes, the cooling system, fuel pump.. etc, etc.. and end up with a dented, faded, rattley, worn out 2500lb 350hp car with no ac, and a busted rear defroster. Or I could finally break down and by a new similar platform/weight car and spend the same or less money modding it, and have a higher performance, cleaner, more reliable car, I can enjoy for the next 20 years.(if I live that long)

[strat61caster]

Originally Posted by Target70

I had to google it just now to make sure I hadn't typed it out wrong . it's actually boxSTer. As I'm cheap and broke, I never looked into porsche cars so all that I knew was that they had flat engines, I think/thought it was usually a flat 6. I was unaware of the whole boxer / boxster thing.

Typically, the layout has cylinders arranged in two banks on either side of a single crankshaft and is sometimes known as the boxer, or horizontally opposed engine.

[ame="http://en.wikipedia.org/wiki/Flat_engine"]Flat engine - Wikipedia, the free encyclopedia[/ame]

Boxer engines got their name because each pair of pistons moves simultaneously in and out rather than alternately, like boxers clashing their gloved fists together before a fight

http://en.wikipedia.org/wiki/Flat_engine#Boxer_engines