evilbada

iTrader: (14)

So, I got into an argument about displacement.

If it's not too time consuming, I would like to ask an AMS engineer to explain the technical aspects of why 2.3L stroker makes more torque but makes SAME HORSEPOWER as 2.0L with all mods being equal.

The reason why I ask this is because some people swear by stroking a particular engine, you're increasing the displacement.

More displacement = more hp.

But I know for a fact that 2.3L makes same hp as 2.0L but spools turbo faster and create higher peak torque.

Can you explain why above is true?

2k4EvoVIII

iTrader: (15)

I know you asked AMS but i would hope that you know non of the highest HP cars are all 2.0 or destroked 2.1. Non are a stroked motor they just cant support the rpms that are needed for the size of the turbo to break 1100whp.

IMO i had a 2.0 then a 2.4 now back to a 2.0. Depending on your application i think the stroker motors are great. Lots of torque that is for sure. But if you think about how many rpms you are spooling a certain turbo faster then minus the rpms you are lossing on the top end becouse of the stroker it just doesnt seem to work out in the strokers favor. But im a drag racer other sports are different and the stroker would be better suited.

Chris

evilbada

iTrader: (14)

Thanks for the response, but that's not exactly what I was asking.

I'm not talking about the power potential of 2.0L vs 2.3L.

I'm talking about when you have SAME MODS other than the motor,

Let's say

Stock block 2.0L
GT35r
supporting mods

And 2.3L stroker
GT35r
supporting mods

2.3L stroker makes greater torque but makes same peak hp as 2.0L.

Why is this so?

What is the mechanic that is involved in this?

badhabit90

iTrader: (13)

can you specify PSI your running on each combo?? can you also specify what rpm you are revving to in each combo?? too many variables still in question, however, i will try this out...


first off, remember the ENGINE 101 class...the engine is just one big air pump. air gets sucked in, gets squished, goes bang, and gets blown out. the more efficient you can get this, the more power you can generate.

whelll, for one, you have more volume to move through the engine with the extra .3 more displacement. more volume to move the turbine wheel at slower engine speeds, thus, spooling faster.

the torque comes from the angle of the rod in relation to the crankshaft at a particular timed event. not "timing" as in ignition timing, but crankshaft timing in relation to "ignition" timing.

once the fuel is lit, energy is being produced in the name of heat and pressure. the heat and pressure pushes the rod past the 90* point in relation to the crankshaft and rod angle, thus, producing said torque. the amount of torque that is produced depends upon the amount of energy (air and fuel) that was squished a few milliseconds ago. once that energy is lit by the ignition, the energy changes form in to heat and pressure pushing the piston downward on the crankshaft....and so on and so on...

IF the combination of events/parts do not arrive at 90* exactly to the crankshaft, bad, bad things can occur. think of .....block, hole, rod...and you have a bad day..

you are also limited to the amount of angle in relation to the piston before piston side load problems can occur. th s used to be a big problem on 347ci mustang engines. rev limit may also become a factor in a particular combination. piston rock atop the cylinder walls may be an issue at higher rpms too...too many things to take into account. that is why some things just dont work.

i know im not AMS, but i hope this helped a little.

evilbada

iTrader: (14)

^ Thanks for the write up, but that's not exactly what I was asking either...

Stock 2.0L vs Stroked 2.3L

both rev to ~7500rpm

Same boost level, same mods, same everything.

https://www.evolutionm.net/forums/sh...hlight=2.0+2.3

Look at this chart Al has posted. 2.3L shifts powerband to the left but 2.0L still makes same peak hp as 2.3L. Why is this so?

DeiPro

There are two ways to increase displacement in an engine. Increase the bore or increase the stroke, or a combination of both while maintaining the same rod length. If you increase the bore, you simply increase displacement. If you increase stroke, 88mm vs the 100mm for a 2.0L to a 2.3L stroker, you are also increasing the distance away from the crank centerline that that the piston and rod act on. Thus, with a larger or longer stroke, you increase the mechanical advantage the piston and rod have on the crank. This creates more torque for a given RPM. its like using a long lever arm or a teeter toter effect if you want to think of it simply.

Now if you make more torque at a given RPM with two different engine combinations, you will make more horsepower at the same RPM. This is because Horsepower and torque are related by a simple equation.

I think that you might not be comparing RPM to RPM Horsepower output.

scorke

iTrader: (18)

Yeah, RPM is what changes it.

a 2 liter can safely rev a lot higher than a 2.3.

HP = rpm x T(torque) 5252(constant)

The higher you can rev with more tq the more power you make, the 2.3 makes more hp down low because it can make more tq at lower rpms.

Scorke

evilbada

iTrader: (14)

I know the horsepower equation, and I know stroker makes more power at given rpm.

That is UNTIL the horsepower curve of STOCK 2.0L which cannot rev any higher than 2.3L, and 2.3L merge together at upper rpm.

If you look at the PEAK hp. Stock 2.0L with 35r and 2.3L make same peak hp as shown in this thread

https://www.evolutionm.net/forums/sh...hlight=2.0+2.3

I'm not asking rpm vs rpm comparison.

I'm asking why doesn't stroker make higher peak hp than stock 2.0L?

AutoMotoSports

iTrader: (42)

DEI pro put it very well. I will add that a 2.3 At the same RPM as a 2.0 with no other variables changing the 2.3 will make more Torque AND Horsepower. I think that is where the argument is a little flawed.

As DEI stated HP is a function of torque, if you are making more torque at a given RPM you are making more HP as well.

Hope that clears it up a bit.

Eric

evilbada

iTrader: (14)

But why does 2.3L not make any more hp than stock 2.0L at upper rpm range?

In other words why does 2.3L make same amount of torque as 2.0L at upper rpm range as shown by the link I just posted?

Boltz.

iTrader: (42)

Hah, I feel your frustation here bada. Seems as if everyone is missing the meat of the question entirely and just answering why the stroker makes more torque which a lot of us already understand.

I'm guessing its a function of mainly the head and the way it flows but also the amount of flow from the turbo at X boost pressure with no changes in the head since all boost is, is restriction to flow.... Hopefully that could either shed some light or change the direction of some of the other answers here.

JordanS4

iTrader: (11)

Bobby I understand exactly what your asking, I just don't have the correct answer.

The reason for them making the same peak HP is the torque becoming equal at 6.5k RPM. The 2.3 has a HP and TQ advantage to this point but when the 2 motors attain equal TQ the horsepower stays the same until the 2.3 runs out of steam.

What causes the 2.3 to drop off as fast as a 2.0 does in the upper ranges and lose its lower RPM advantage?

I wonder if this would happen on a car that was designed to be a perfect square 2.3 (same bore and stroke) versus a 2.0 converted to a 2.3...?

Bump for an answer.

AutoMotoSports

iTrader: (42)

There are I'm sure some variables in that test.

1. weather could of been a bit off between the two tests.
2. peak boost might of been the same but what was it at peak HP readings?
3. The 2.3 kicks that 3065 on a lot earlier and the HP difference could be that the turbo is falling off sooner on the 2.3

I think much of you questions are stemming from the fact that your definition of HP is simply the peak HP fixed point. If you took these two cars and say roll raced them next to each other the 2.3 car would pull away pretty hard. HP isn't just a fixed point but more importantly the entire curve. Just look at the two setups at 5000 rpm. the graph is a bit hard to read but it looks like the 2.3 is making 60 more hp and almost 70 more ft lbs of torque. look at the entire graph from the start of the run until about 6500 RPM....its no contest.

HP is a function of torque. If you notice as the torque curves from the two motors start to meet so does the HP. At peak power on these two setups the motors are making almost the same torque and thusly almost the same HP. Again, now you could be getting into the VE of the engine and how the parts are working together which could open up another can of worms.

Does this mean you should get a 2.3 well no, it just means 2.3 stroker motrors make more HP and Torque across the curve. If you are drag racing now you have to worry about peak RPM, how your gearing coincides with it etc etc etc. In EVO world there are many schools of thought but the most common seems to be Drag race a 2.0 and road race a 2.3...but again thats very general and their are exceptions to every rule. IE we have a car in Denmark with our 2.3RR running 9.30's in the quarter on only 36 pis of boost.

Eric

JordanS4

iTrader: (11)

Maybe this wouldn't happen if the car could flow enough to take full advantage of the extra displacement. The head, IC piping, TB, IM, and turbo could be the problem, not the motor.

AutoMotoSports

iTrader: (42)

exactly it could just be the VE on this setup is not ideal for a 2.3 or more ideal for a 2.0 at peak RPM.

eric