How Do They Do That?

[ftpiercecracker1]

I searched for hours on google trying to find a thread that explained this in vain. How on earth is it possible that these guys can get a 1000hp+ out of these tiny 4cyl?? Even with all billet/forged internals and obviously massive turbo(s) there has to be something else going on. I assume it is simply a matter of how these engines are engineered from the start that makes them capable of handling such HP, but that being said what is that something? Extra thick block walls? Space-age alloys? 

 

I got on this kick that, if a guy with _____ import can cram 20+ lbs of boost into his little 4-6cyl, take a little time tuning, and make insane hp/tq why can't I? From an engineers POV what is limiting us from doing the same? Stroke length? Oiling system? Cam design?  I know the standard answers already like, "It'll just push the head gaskest out", "the 4.0 head simply doesn't flow that well" or "the internals simply aren't up to that"

 

OK, to that i say, Solid copper head gasket, all billet/forged internals (crank, rods, pistons), not sure what the solution would be for the head aside from a total redesign/ custom one off. 

 

The most psi I have EVER heard of someone running in a jeep 4.0l straight six was about 10-12psi, i read all. the. time. of guys running 25-30+ psi in their little imports. how? How?? HOW!?

 

This has been bugging the absolute hell out of me. 

 

and for your viewing pleasure, here are a few examples of some relatively small motors make crazy power. Please disregard the lambo and/or ferrari.

This is probably the best video on youtube, at least as far as car freaks go.

 

https://www.youtube.com/watch?v=pgfhGEw03k8

[Oyaji]

I'll try... tell me how I do (it may take several posts).

.

There are 2 basic ways to increase horsepower in an internal combustion Otto cycle engine: by increasing torque, or by increasing RPM. Since torque is just twisting force, it is not a measure of power: it does not describe useful work. But "torque events" (like one revolution, for example) combined over time do describe work.  If you increase the  magnitude of the  individual "torque events", then the same number of them will add up to a greater amount of work done, thus more power. The other way is to increase the number of "torque events" by making more of them rather than increasing their magnitude: more revolutions at a given torque equals more work done, thus more power.

.

 Increasing torque depends on BMEP (Brake Mean Effective Pressure).  This  can be increased by raising compression ratio  and by increasing the amount of combustibles of the intake charge. There is an upper limit on compression ratio that depends on a number of factors that ultimately change the nature of the combustion event from a progressive burn to detonation; among them  are octane rating  of the fuel, spark advance, and engine design (intake charge distribution, combustion chamber shape, materials, and cooling). Increasing combustibles can be done in several ways also: increasing volumetric efficiency  (by adjusting camshaft profile and timing, and by intake passage optimization  or "porting"), forced induction (supercharging), and substitution of a better oxidizing agent than atmospheric air (ie, NO2 [edit: N2O - good catch Mvusse - guess I should have had my coffee this morning before posting - thanks!]). Note that increasing combustibles depends on extraordinary methods to enhance the amount of oxygen in the intake charge, as gases are notoriously harder to get into an engine than liquid fuel!

.

The remaining avenue for increasing power is by increasing revolutions of the engine. The upper limit is ultimately what the materials used in the engine can withstand before they fling themselves apart from the strain (or buckle from the stress). For the best materials out there this is around 20,000 Gs (if memory serves). Practical considerations are crankshaft  stroke (short stroke = smaller radius of rotation = smaller G-load at a given RPM), crankshaft and engine block twist (dependent  on both design and manufacturing expertise), careful attention to balancing of all components and their final assembled state, and esoterica such as supersonic flow through intake valves.

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I'm sure I left some things out, and could go into greater detail on any of the points  I mentioned, but that is what comes to mind this early morning. I hope others contribute here as well, as I would welcome interchange with them on what was once a favorite subject of mine.  

[mvusse]

If by NO2 you mean nitrous oxide, is it N2O.

 

A given molecule of nitrous oxide only has half the oxygen as a molecule of oxygen (O2). Where the advantage of nitrous comes is that it is pure or nearly pure, whereas air is only 21% oxygen with 78% being (inert) nitrogen and 1% other mostly inert gasses. Theroetically pure O2 from a bottle would work better than N2O, but pure O2 is too dangerous to work with.

[shelbyluvv]

I've been playing with boosted 2.2/2.5 ChryCo 4 poppers for years. I run 22 PSI through my 2.2 engine. The Honduhs have a much bigger aftermarket than the Mopar 4 holer crowd does. With that said, they can get blocks, heads, pistons, cranks, and cams until their hearts are content. While I have to depend on what basically Ma Mopar put out in the 80s and 90s stock. There are some forged cranks and rods that were factory depending on the application. There are also DOHC heads available as well. The Neon DOHC  swap is real popular as of late on the 2.2/2.5 engines.

 

I have been to a few Honda shops and have seen the R/D that goes into those little motors and it is awe inspiring to say the least! I have seen everything from one off cast blocks, to sleaved blocks, to 1" head spacers welded to the blocks with sleeves to contain the boost. The crarks are works of art as well. Some of those little 4 banger engines can cost as much as $25K! Those are full on drag motors though.

[Incommando]

I am sure someone will cite some scientific treatises disproving it but saying that torque is is not a measure of power is misleading. How do you "twist" something without power? How do engines that increase that twisting force at very low RPM's, such as a CTD, have such huge power in the form of the work performed, such as moving at 15,000# trailer at 800 RPM's, at well below the RPM range that most other engines require to equal that number? As power is a measure of the work performed than that twisting must be power as it effects work independently of horsepower. The first CTD's made a measly 160 hp yet had 400#'s of TQ at 800 rpm. If RPM related horsepower is all that matters hook your turbo 4cyl Fiat 500 Abarth  to that trailer mentioned above. It should pull it just fine, right? It didn't? How is that possible? The Fiat makes the same 160 horsepower at a much higher RPM so it must be more powerful, yes?Theatricals do not always apply apples to apples, do they? Torque at the drive wheels is the power that moves the vehicle, plain and simple. 

 

Most really high horsepower 4 bangers have to use high RPMs due to a lack of torque "power" at lower RPM's. Look at the peak torgue of one of these hi-po 4banger versus that CTD or even one of our beloved 4.0's and you will see what I mean. Your peak performance not only comes from engine power but from proper gearing which includes tire size. Properly matching the engine/transmission/ring gear ratio/tire size is required for peak performance yet the definition of peak performance changes according to your goal. If smokey burn outs impress you and you want to do some epic ones in an MJ/XJ change your gears to 4.88's, throw some 23" tall 185/65/14's on it, and they will roll smoke until you run out of gas. Just remember that as you sit there spinning you are not efficiently moving forward. 

 

A simple fact is that the extreme 4bangers also sacrifice longevity for performance. This is much like the most extreme v8's, the NHRA top fuel classes, except the V8's engine make 7,500 horsepower and 6,000 foot pounds of torque out of 500 cubic inches. I have yet to see a 4banger touch those numbers in a car-like application. The much longer lasting naturally aspirated pro-stock engines are also limited to 500 CID but make about 1,500 hp and 1,000 #.' Notice that no 4bangers compete at the top levels of drag racing? It is no wonder why. Extreme RPM performance cars are very rare from the factory for many reasons. Drivability issues are one reason as they make such little power at low RPM's (aka they lack torque) that light-to-light traffic is a pain. Another issue is the generally poor efficiency, emissions, and reliability. Look no further than Mazda's craptastic RX8 for an example.

 

There is no replacement for displacement. Very rarely are you going to achieve numbers for a small displacement engine that the same mods would not produce much higher numbers in a larger displacement engine (which also conversely generally creates more torque at a lower RPM range.) Although you can make relatively big power out of a 4banger the question is "why" when for the same time and cost you can probably have a much more powerful engine or you can have equal performance to the 4banger while using much less time and money and achieving greater reliability. 

 

Definitions from one discipline do not necessarily directly translate to all disciplines directly. Google "power" to see the various different definitions depending on subject matter.

[jimoshel]

There sure is a lot of brain power expenditure cited above and they all miss the real happening. DUCT TAPE!! That's right kiddies. Duct tape. They wrap everything in duct tape. Block, heads, rods, crank and cam shaft, bearings, Everything. Ever see a duct tape wrapped spark plug fire? IMPRESSIVE! :doh:

[shelbyluvv]

I choose to build a fast 4 holer Dodge. When was the last time you were in a 11 street car that still got almost 30 MPG? Add to it that my car is rare (only 445 garnet and silver 87 Shelby Chargers produced) it was a no brainer for me. I prefer to be different. I can build a V8 all day and run it. It's still a V8. Pull up to the line in a little Dodge econobox and whip a Musclang or a Vette and people notice. It's even more fun to do it in a Caravan. Yes Dodge put turbo 4s in minis too. I have always been one to follow my own path. Do I have way more money in a 4 popper than I should? Oh yeah, and then some. I don't care either. My cars are a labor of love for me. I build what I want. I took one of the first MJs known to exist and put a V8 in it. Because that's how I wanted my truck.

 

The import guys are the same way. They build what they do for the love of the chase. The R/D that goes into those cars is nothing but impressive. While I hate tuner imports I still give Steven Papadakis his props. He is the Godfather of import tuning and has spun a whole new realm into the drag racing world. You can't say those cars aren't impressive. Two liter motors dropping 800 ponies is cool.

[Oyaji]

If by NO2 you mean nitrous oxide, is it N2O.

 

A given molecule of nitrous oxide only has half the oxygen as a molecule of oxygen (O2). Where the advantage of nitrous comes is that it is pure or nearly pure, whereas air is only 21% oxygen with 78% being (inert) nitrogen and 1% other mostly inert gasses. Theroetically pure O2 from a bottle would work better than N2O, but pure O2 is too dangerous to work with.

.

Dead on - nice catch, should have had my coffee this morning before posting. :)

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Post edited to correct error - thank you.

[Oyaji]

I am sure someone will cite some scientific treatises disproving it but saying that torque is is not a measure of power is misleading. How do you "twist" something without power? How do engines that increase that twisting force at very low RPM's, such as a CTD, have such huge power in the form of the work performed, such as moving at 15,000# trailer at 800 RPM's, at well below the RPM range that most other engines require to equal that number? As power is a measure of the work performed than that twisting must be power as it effects work independently of horsepower. The first CTD's made a measly 160 hp yet had 400#'s of TQ at 800 rpm. If RPM related horsepower is all that matters hook your turbo 4cyl Fiat 500 Abarth  to that trailer mentioned above. It should pull it just fine, right? It didn't? How is that possible? The Fiat makes the same 160 horsepower at a much higher RPM so it must be more powerful, yes?Theatricals do not always apply apples to apples, do they? Torque at the drive wheels is the power that moves the vehicle, plain and simple. 

 

Most really high horsepower 4 bangers have to use high RPMs due to a lack of torque "power" at lower RPM's. Look at the peak torgue of one of these hi-po 4banger versus that CTD or even one of our beloved 4.0's and you will see what I mean. Your peak performance not only comes from engine power but from proper gearing which includes tire size. Properly matching the engine/transmission/ring gear ratio/tire size is required for peak performance yet the definition of peak performance changes according to your goal. If smokey burn outs impress you and you want to do some epic ones in an MJ/XJ change your gears to 4.88's, throw some 23" tall 185/65/14's on it, and they will roll smoke until you run out of gas. Just remember that as you sit there spinning you are not efficiently moving forward. 

 

A simple fact is that the extreme 4bangers also sacrifice longevity for performance. This is much like the most extreme v8's, the NHRA top fuel classes, except the V8's engine make 7,500 horsepower and 6,000 foot pounds of torque out of 500 cubic inches. I have yet to see a 4banger touch those numbers in a car-like application. The much longer lasting naturally aspirated pro-stock engines are also limited to 500 CID but make about 1,500 hp and 1,000 #.' Notice that no 4bangers compete at the top levels of drag racing? It is no wonder why. Extreme RPM performance cars are very rare from the factory for many reasons. Drivability issues are one reason as they make such little power at low RPM's (aka they lack torque) that light-to-light traffic is a pain. Another issue is the generally poor efficiency, emissions, and reliability. Look no further than Mazda's craptastic RX8 for an example.

 

There is no replacement for displacement. Very rarely are you going to achieve numbers for a small displacement engine that the same mods would not produce much higher numbers in a larger displacement engine (which also conversely generally creates more torque at a lower RPM range.) Although you can make relatively big power out of a 4banger the question is "why" when for the same time and cost you can probably have a much more powerful engine or you can have equal performance to the 4banger while using much less time and money and achieving greater reliability. 

 

Definitions from one discipline do not necessarily directly translate to all disciplines directly. Google "power" to see the various different definitions depending on subject matter.

.

I think you  would benefit from a review of the definitions of power and torque. Though I doubt you would agree, pretty much everything you had to say was in support of my first post in this thread.

.

You asked "How do you "twist" something without power?" Here is an example for you: clamp the square end of  a spring-beam torque wrench into a bench vise. Pull on the handle, and watch the pointer on the torque scale rise. You are generating torque, but doing no work because you have not moved anything, nor  are you generating  power, because power is a measure of how fast work is done. Another example: sitting on the lowered tailgate of your MJ generates torque about the tailgate hinge equal to your weight times the distance you sit from the hinge, but  doing  so    does no work nor generates  any power at all.

.

Horsepower and torque are related, just as I said in more detail in my first post, but torque alone does nothing at all. 

[ftpiercecracker1]

My brain hurts trying to comprehend all of this.  :smart: 

 

To understand the original question we must break things down into the simplest terms possible. We need to define what torque is and what horsepower is and how they relate to one another.

 

From what Oyaji said it would seem that an increase in torque results in an increase of HP, how this is so i do not fully understand. Since big diesel generators can create 800ft/lbs yet only develop 100hp. From what i understand neither an increase in TQ or HP dramatically effects the other. They are two separate decriptions of expended energy. TQ a stationary, HP involves movement. TQ describes how much force is applied, while HP is the duration or the length at which the given TQ can be sustained. 

[mvusse]

. Look no further than Mazda's craptastic RX8 for an example.

 

The RX-7 and RX-8 use a Wankel rotary engine. Completely different beast than an Otto cycle engine. It'd be like comparing a bicycle to a skate board.

 

 

From what Oyaji said it would seem that an increase in torque results in an increase of HP, how this is so i do not fully understand. Since big diesel generators can create 800ft/lbs yet only develop 100hp. From what i understand neither an increase in TQ or HP dramatically effects the other. They are two separate decriptions of expended energy. TQ a stationary, HP involves movement. TQ describes how much force is applied, while HP is the duration or the length at which the given TQ can be sustained.

 

HP is torque multiplied by rpm.

[jimoshel]

I bet I can really confuse things. If you're not familiar with electricity don't bother reading this. Think of horse power, HP as voltage E. Think of torque as Current or amperage I. The voltage provides the potential to do work but does nothing itself. The current does the work but it needs a potential, voltage to determine how much work it can do. The higher the potential, E, the more work the current, I, can do.Or something like that.

[nitroxsteve]

I always understood torque as the ability to do work and HP is how fast it can get that work done. Maybe thats an over simplified definition.

[airspeed]

Another way to state it: Horsepower is the rate at which torque can be applied.

[Keyav8r]

To clarify the terminology:

 

Torque is generally measured in foot-pounds and is defined as the twisting force acting perpendicularly about a pivot at a distance of one foot to lift one pound or, conversely, the force exerted by a one pound weight at the end of a one foot horizontal lever.

 

Horsepower is measured by a dynamometer that measures the twisting force (torque) applied by the engine crankshaft to a load. (Simplified description)

 

Horsepower is equal to torque times RPM divided by 5,252.

 

As far as how they do that (get insane HP out of small four holers) - beats me.

[Oyaji]

As far as how they do that (get insane HP out of small four holers) - beats me.

.

Same as I mentioned at the outset of the thread, there are 2 ways: to increase torque by increasing BMEP (Brake Mean Effective Pressure, or more force on the piston, which is more "push" per stroke), or by increasing RPM (getting more "pushes"/strokes per minute).

.

It's the same for all Otto cycle engines - you can do either or both  sorts of modifications until you start bending things from too much "push" or until the engine starts flinging parts off from  too much "spin".

.

From here on the talk should be about how much increase that a stock engine can take, or about what modifications  to make to  which parts  that break first,  and the ensuing shift  of failure to other parts    as you continue to modify the engine beyond stock in the effort to increase  power.       

[Oyaji]

I bet I can really confuse things. If you're not familiar with electricity don't bother reading this. Think of horse power, HP as voltage E. Think of torque as Current or amperage I. The voltage provides the potential to do work but does nothing itself. The current does the work but it needs a potential, voltage to determine how much work it can do. The higher the potential, E, the more work the current, I, can do.Or something like that.

.

For some reason I always had trouble with getting an intuitive grasp of electricity, but isn't it better to say power is E*I? Then you are there - a kilowatt is 1.34 horsepower.

[ftpiercecracker1]

Ok, now that I have a firmer understanding of the difference and correlation between HP and TQ I think i feel a little more confident moving onto the actual mechanics of what goes into these insane little 4cyls. Since the majority of us here do not have much import experience, lets use old reliable 2.5 4cyl and see what it would take to squeeze a 1000hp out of the poor bastard.  Or better yet if anyone here has built a 1000hp GAS 4cyl please share the build process.

 

Going back to the fantasy 1000hp 2.5 build. Obviously budget is a term that has no meaning for this particular conversation so disregard any kind of perceived cost prohibiting factors whatever they might be. What is preventing someone, with deep enough pockets, from reaching a 1000hp? What is the weak link in 2.5? How can it be overcome?

[ftpiercecracker1]

Here is a good example of what is possible with enough money and engineering friends. 

 

http://www.turbomagazine.com/tech/0202tur_norwoods_racing_funnycar_integra/

[Keyav8r]

Just goes to show that it's easy to make insane HP. All it takes is the forced injection of massive amounts of money.

[mvusse]

GM developed and raced a 1000hp ecotech Sunfire 10 years ago. Stock block, mostly stock head, destroked to 2.0l displacement, all custom internals and 40lbs of boost.

[Incommando]

I choose to build a fast 4 holer Dodge. When was the last time you were in a 11 street car that still got almost 30 MPG? Add to it that my car is rare (only 445 garnet and silver 87 Shelby Chargers produced) it was a no brainer for me. I prefer to be different. I can build a V8 all day and run it. It's still a V8. Pull up to the line in a little Dodge econobox and whip a Musclang or a Vette and people notice. It's even more fun to do it in a Caravan. Yes Dodge put turbo 4s in minis too. I have always been one to follow my own path. Do I have way more money in a 4 popper than I should? Oh yeah, and then some. I don't care either. My cars are a labor of love for me. I build what I want. I took one of the first MJs known to exist and put a V8 in it. Because that's how I wanted my truck.

 

The import guys are the same way. They build what they do for the love of the chase. The R/D that goes into those cars is nothing but impressive. While I hate tuner imports I still give Steven Papadakis his props. He is the Godfather of import tuning and has spun a whole new realm into the drag racing world. You can't say those cars aren't impressive. Two liter motors dropping 800 ponies is cool.

I had a Garnet & Silver '86 Shelby Charger that I bought new. Those claimed MPG numbers are impressive as my stock version could not achieve nearly those numbers from its 2.2 Turbo. Wouldn't the same money invested in that Musclang or vette as the  4banger get you a much faster version of either of those two as compared to their 11-second versions?  With a few hours notice I can be driving a daily-driver '01 C5 that will run low 9's in the quarter and get 25 mpg highway out of 427 cid. For about  $5k I had an entirely streetable ( by swapping tires and exhaust) Road Runner  that would run 11.30's all day while weighing an elephantine 4,300 pounds. I wonder what the torque figures for the 800 hp 2.0L were and at what RPM? Would it launch that lead sled of mine without a tremendous clutch dump or even then? I have posted this before but here is an 1,800 RPM launch that would pull both front wheels with an the original 25 year old suspension on a good run:

I can't see even the 800hp 2.0 doing that to that car but I will admit that I could be dead wrong. My car only has 530hp at the flywheel ( but 560 tq at that 1,800 rpms), though. Theoretically the same drivetrain in a Demon body would be mid-10 second car. 

[Incommando]

GM developed and raced a 1000hp ecotech Sunfire 10 years ago. Stock block, mostly stock head, destroked to 2.0l displacement, all custom internals and 40lbs of boost.

And what cost? I never heard that. I do recall that expirement and other similar versions as the attempt a sport compact class in NHRA. The now decades old claim that hipo 4-bangers would lead to the abandonment of v8 pro-stock & other v8 drag cars was entirely wrong and the compact class using such engines died quickly. Right or wrong most every form of motor racing in America is still dominated by V8's. 

[Incommando]

 

I

.

I think you  would benefit from a review of the definitions of power and torque. Though I doubt you would agree, pretty much everything you had to say was in support of my first post in this thread.

.

You asked "How do you "twist" something without power?" Here is an example for you: clamp the square end of  a spring-beam torque wrench into a bench vise. Pull on the handle, and watch the pointer on the torque scale rise. You are generating torque, but doing no work because you have not moved anything, nor  are you generating  power, because power is a measure of how fast work is done. Another example: sitting on the lowered tailgate of your MJ generates torque about the tailgate hinge equal to your weight times the distance you sit from the hinge, but  doing  so    does no work nor generates  any power at all.

.

Horsepower and torque are related, just as I said in more detail in my first post, but torque alone does nothing at all. 

I am pretty certain that torque wrenches, including the beam type, do move as you apply torque in order for the pointer to move along the scale for measurement don't they? Even you say "watch the pointer...rise..." which clearly indicates movement, however small, as the pointer is directly connected to the wrench shaft.  

[Incommando]

Ok, now that I have a firmer understanding of the difference and correlation between HP and TQ I think i feel a little more confident moving onto the actual mechanics of what goes into these insane little 4cyls. Since the majority of us here do not have much import experience, lets use old reliable 2.5 4cyl and see what it would take to squeeze a 1000hp out of the poor bastard.  Or better yet if anyone here has built a 1000hp GAS 4cyl please share the build process.

 

Going back to the fantasy 1000hp 2.5 build. Obviously budget is a term that has no meaning for this particular conversation so disregard any kind of perceived cost prohibiting factors whatever they might be. What is preventing someone, with deep enough pockets, from reaching a 1000hp? What is the weak link in 2.5? How can it be overcome?

The 2.5 is a dandy basis to begin mods and is used in a few NHRA classes. Maybe searching in that direction will help you out. Good luck.