Here we go again. My buddies are arguing about engine size, ie. 4, 6 and 8 cylinders with or without turbo's or superchargers as to what is more power full. Given that the old Indy cars had 4 cylinder Offenhausers, then V-8's, aspirated then injected, turbo or supercharged , the 84 Fiero Indy pace car had a modified 4, I've also wondered who has the biggest you know what. I know there is a relationship between torque and H.P. but that's all I know. Ok guys, lets have some input on this. Whats better or whats the difference.
Big aftermarket support, easy to gain more power (simply throwing on a smaller pulley on the Super Charger makes it a beast.) Plus, that engine is extremely reliable. I have one in my Grand Prix GTP and it has over 400,000 miles on it and still runs great.
V8s are also a great option, but they cost a lot more and usually don't hook as well as V6 engines.
4 cylinders on the other hand, are useful for gas mileage. But they don't necessarily make a big amount of torque to REALLY get you off the line.
When all is said and done, it really depends on you and what you want to achieve with the car. Everyone has their personal preference, and its silly to argue about things that we all enjoy. ------------------ Every fiero has a story, It's our job to keep that story alive.
[This message has been edited by zzzhuh (edited 09-20-2015).]
Big aftermarket support, easy to gain more power (simply throwing on a smaller pulley on the Super Charger makes it a beast.) Plus, that engine is extremely reliable. I have one in my Grand Prix GTP and it has over 400,000 miles on it and still runs great.
V8s are also a great option, but they cost a lot more and usually don't hook as well as V6 engines.
4 cylinders on the other hand, are useful for gas mileage. But they don't necessarily make a big amount of torque to REALLY get you off the line.
When all is said and done, it really depends on you and what you want to achieve with the car. Everyone has their personal preference, and its silly to argue about things that we all enjoy.
Strictly speaking, power output is related to displacement. The more air you're displacing, at a greater pressure, the more power you can make. Forced induction is roughly the same as increasing displacement, but allows a much greater range of tuning for fuel economy, so you can make the same power as a N/A 5.0L, with 2.5L, but retain the fuel economy of the 2.5L engine, when it's not necessary to make as much power.
Everything else being equal, more displacement means more power.
Especially for the sound. Seriously. Nothing sounds better than a rumbling V8 with a lumpy cam. And you get to enjoy it the whole time the engine is running.
I have heard that one too!!! Lmao.......I got an email from a friend a while back called "Acceleration Explained.....". Might try a Google search to find it. It was quite amazing!!!! Talked about just how fast a top fuel dragster is. Anyone who is a car guy should read it!!!!! Brian
[This message has been edited by bkw88 (edited 09-20-2015).]
I have heard that one too!!! Lmao.......I got an email from a friend a while back called "Acceleration Explained.....". Might try a Google search to find it. It was quite amazing!!!! Talked about just how fast a top fuel dragster is. Anyone who is a car guy should read it!!!!! Brian
I've seen it, think it was my Dad who sent me a copy. Reading that was neat for all the information it contained but I still think sitting in the stands just past the launch line is something everyone car guy or not should experience at least once in their lifetime. The thumping of the exhaust and fumes of the nitro meth, I'll never forget it.
Although I love big blocks, the key is power to weight ratio. A 500cu in engine putting out a thousand horses in a 20,000lb vehicle is going to have it's doors blown off by a small block putting out 150hp in a car that weighs 1500lbs. Ever try to catch a Lotus that has a Toyota 1.8?
Originally posted by tebailey: Although I love big blocks, the key is power to weight ratio. A 500cu in engine putting out a thousand horses in a 20,000lb vehicle is going to have it's doors blown off by a small block putting out 150hp in a car that weighs 1500lbs. Ever try to catch a Lotus that has a Toyota 1.8?
Why do you need a 20,000lb truck for a 500 cube engine? And being 500 cubic inches doesn't necessarily mean it's a big block. The Ariel Atom 500 is a 3.0L V8 making 500 HP in a car that weighs about 1000 lbs. The topic isn't power vs weight though, it's displacement vs power. If you want more power, you need more displacement, whether that's by bore, stroke, more cylinders, or increased cylinder pressure (forced induction, nitrous).
If you want to argue about how efficient an engine is, though, then you should talk about HP/L. Fieros are generally going to stay around 2700-2900 lbs.
Sorry, but I think even fans of the 3800sc will acknowledge that it isn't a nice sounding engine.
While not a SC, I liked the sound of the 3800 NA in our 02 Bonneville we owned for several years. I mean as far as stock exhaust sound, it was nicer than a many other vehicles I've owned. Maybe it sounds different with such a short exhaust system as compared to that in the Bonneville?
I liked the sound of the 3800 NA in our 02 Bonneville we owned for several years.
I guess you're just weird.
Seriously though, I've heard it mentioned numerous times that the 3800 sounds crummy because it's basically a V8 with two cylinders lopped off. This makes for an odd sounding firing order. The 3800 was never designed from the ground up as a V6, such as the lowly 2.8 was (which by the way, sounds pretty good).
Sorry, but I think even fans of the 3800sc will acknowledge that it isn't a nice sounding engine.
Depends on the exhaust that you matte to it. The big complaint is that you hear the SC whine all the time. If you put sound detonator in the engine bay, it makes it very quiet in the cabin.
[This message has been edited by zzzhuh (edited 09-21-2015).]
Wow that got a bit crazy.....lol. Anyway. I agree with Khw........go to a major top fuel/ funny car race at least once in you life. Race person or not. I was lucky enough to be less than 5 feet from one when they fired it up in the pits!!¡!! You couldn't hardley breath from the pressure of the exhaust hitting your chest!! That proves my point and others about if you want more power.......you need more CUBIC inches. However you achieve it, There's really no way around it.......... Brian
The OP asked about engine size vs. power not displacement vs power. Just wanted to clarify that their is a difference between the two. SBC displace a lot more than most DOHC V8's, but are physically smaller and lighter engines. Also, when it comes to the Fiero this topic is a moot point in my mind b/c in this day and age it doesn't matter if you go with 4, 6, or 8 cylinders. You can generate more power than any transverse drive-train can handle no matter which engine you choose. I think the real consideration comes down to the engine's real physical size and weight vs power and the affects on the drive-ability of the car as well as fuel economy with the tiny fuel tanks we are stuck with. Other consideration is sound quality and all things being equal most of us prefer the V8's (especially the N*'s!). Basically it comes down to personal preference (and budget...) as how you go about making big power in a Fiero b/c there is definitely more than one way to skin this particular cat... But hey, that's just my $.02
Originally posted by zzzhuh: "Old saying" well, it's old for a reason. You can make plenty of power out of a 4 cylinder OR a V6 and beat a V8, or V10.
That saying is out dated, and has been proven to be false.
Nope.
As an example, a 2.5L 4 cylinder vs a 5.0L V8. Both being N/A, the 2.5L will never be able to produce more power than the 5.0L. Both being forced induction, the same holds true. However, if the 4 cylinder is turbocharged, at ~15 PSI (roughly doubling the pressure of the air being pumped through the engine), then you have effectively doubled the displacement, because you've forced the same volume of air that the 5.0L engine would be pumping, into a 2.5L volume of space.
Like I said earlier, if you want more power, then you need to displace more air. You can do that by increasing the physical air displacement of the engine, at atmospheric pressure, or you can do it by using forced induction to increase the pressure in the engine to some amount above atmospheric. Similarly, nitrous causes a greater rise in cylinder pressure at ignition.
Originally posted by jediperk: The OP asked about engine size vs. power not displacement vs power. Just wanted to clarify that their is a difference between the two. SBC displace a lot more than most DOHC V8's, but are physically smaller and lighter engines. Also, when it comes to the Fiero this topic is a moot point in my mind b/c in this day and age it doesn't matter if you go with 4, 6, or 8 cylinders. You can generate more power than any transverse drive-train can handle no matter which engine you choose. I think the real consideration comes down to the engine's real physical size and weight vs power and the affects on the drive-ability of the car as well as fuel economy with the tiny fuel tanks we are stuck with. Other consideration is sound quality and all things being equal most of us prefer the V8's (especially the N*'s!). Basically it comes down to personal preference (and budget...) as how you go about making big power in a Fiero b/c there is definitely more than one way to skin this particular cat... But hey, that's just my $.02
When you're putting a turbo on a smaller engine though, you need to include that in any dimensional and weight comparison you're making. Just because the engine itself might be physically smaller, doesn't mean the total package is going to be smaller, or weigh less.
What will it mean when I finally get my swap done, and my V8 weighs less than an Ecotec and gets 40 MPG on the highway?
When you're putting a turbo on a smaller engine though, you need to include that in any dimensional and weight comparison you're making. Just because the engine itself might be physically smaller, doesn't mean the total package is going to be smaller, or weigh less.
What will it mean when I finally get my swap done, and my V8 weighs less than an Ecotec and gets 40 MPG on the highway?
Y'up, that is possible. LSX engines are very light weight for the amount of displacement and tq they make and with the right gearing can do surprisingly well in the highway fuel economy ratings which is great if you do most of your driving on the highways. Most people drive in the city more though and I have always felt that number is more important for overall real world fuel economy. If I were doing an ecotec though it would be with the S/C'er not the turbo b/c of all the extra weight of the turbo and plumbing. Especially now that zzp offers a super efficient TVS S/C for the ecotec. That setup would be extremely light due to the exhaust being so short and the intake being the same as a 3800 as far as weight. The engine would get great highway and city fuel economy while easily making 320+ HP/TQ setup for daily driving and if fuel economy is no concern it can be taken up over 500 HP. As for your swap I think you will be extremely happy with it once you get the A/F dialed in. The LSX engines make so much TQ right off of idle that I imagine you will be starting in second gear a lot though
[This message has been edited by jediperk (edited 09-22-2015).]
Originally posted by jediperk: Y'up, that is possible. LSX engines are very light weight for the amount of displacement and tq they make and with the right gearing can do surprisingly well in the highway fuel economy ratings which is great if you do most of your driving on the highways. Most people drive in the city more though and I have always felt that number is more important for overall real world fuel economy. If I were doing an ecotec though it would be with the S/C'er not the turbo b/c of all the extra weight of the turbo and plumbing. Especially now that zzp offers a super efficient TVS S/C for the ecotec. That setup would be extremely light due to the exhaust being so short and the intake being the same as a 3800 as far as weight. The engine would get great highway and city fuel economy while easily making 320+ HP/TQ setup for daily driving and if fuel economy is no concern it can be taken up over 500 HP. As for your swap I think you will be extremely happy with it once you get the A/F dialed in. The LSX engines make so much TQ right off of idle that I imagine you will be starting in second gear a lot though
There's a good reason that I chose to destroke my engine and retrofit VVT into it.
Once I get it dialed in, and all the aero and suspension mods done on my car, I'm hoping it'll make a nice broad and flat torque curve, with peak HP somewhere around 8000 RPM. With the VVT, I should be able to tweak the tune to make much less power at cruise, to maximize MPG.
Nowadays, there are substitutes for cubic inches. Cars all make more power with smaller displacements. My friends Bentley has a 4.0 ltr w/ twin turbos that makes 500+ hp. Its the fastest street car Ive driven of any year. 0-100 is less than 8 seconds. Think its got around 500-600 ft pnds of torque. Its a true 'rocketship'. He also has a Callaway Corvette convertible, and the Bentley will destroy it in a race. His 2014 Stingray drives like a Cobalt next to it. The vettes lay down all the rubber you want, but the Bentley is just 'gone' when you mash the gas...no muss , fuss or noise. Look at what Porsches do with 2.0 ltrs.
Nowadays, there are substitutes for cubic inches. Cars all make more power with smaller displacements. My friends Bentley has a 4.0 ltr w/ twin turbos that makes 500+ hp. Its the fastest street car Ive driven of any year. 0-100 is less than 8 seconds. Think its got around 500-600 ft pnds of torque. Its a true 'rocketship'. He also has a Callaway Corvette convertible, and the Bentley will destroy it in a race. His 2014 Stingray drives like a Cobalt next to it. The vettes lay down all the rubber you want, but the Bentley is just 'gone' when you mash the gas...no muss , fuss or noise. Look at what Porsches do with 2.0 ltrs.
You're spot on. The lsx 454 sbc will destroy a ram jet 502 that's why they make a 672? Ram jet now which brings us back to the displacement theory. But I read an article on a twin sc SBC that puts out over 2000hp. It all boils down to application. I would want as preference the sbc in corvettes and f body's and BBC in chevelle and trucks
I will say my statement again.......there is no substitute for CUBIC inches. So all these cars have been geared and have marvelous me traction control systems that allow them to turn the 0-100 times etc. If you want raw power in anything......is real sime......bigger motor. You always have to remember. The small little motor may make all this power. But its gonna run out of power long before the big motor. The internal combustion engine is real simple to make power. Make it breathe. You can't breathe as much air with a small motor. That is why you don't see top fuel dragster and such running a 2.0 dohc motor. You can't make the 8,000-10,000 horse power with a small motor! Think about it Brian
I will say my statement again.......there is no substitute for CUBIC inches. So all these cars have been geared and have marvelous me traction control systems that allow them to turn the 0-100 times etc. If you want raw power in anything......is real sime......bigger motor. You always have to remember. The small little motor may make all this power. But its gonna run out of power long before the big motor. The internal combustion engine is real simple to make power. Make it breathe. You can't breathe as much air with a small motor. That is why you don't see top fuel dragster and such running a 2.0 dohc motor. You can't make the 8,000-10,000 horse power with a small motor! Think about it Brian
There's a good reason that I chose to destroke my engine and retrofit VVT into it.
Once I get it dialed in, and all the aero and suspension mods done on my car, I'm hoping it'll make a nice broad and flat torque curve, with peak HP somewhere around 8000 RPM. With the VVT, I should be able to tweak the tune to make much less power at cruise, to maximize MPG.
Given that you define "power" as torque - which is a fair thing to say - there is no replacement for displacement. But given that we are talking about cars that are expected to operate over a wide range of speeds it's fair to say we're also talking about gearing, in which case torque may not be more important than horsepower. If you define "power" as horsepower, then displacement isn't the be-all and end-all. Larger combustion chambers lose efficiency pretty rapidly - the ability to control the flame front and fully use the fuel air charge diminishes as the hole gets bigger. There are also mechanical limits to consider - limits of bore to stroke, and limits for piston speeds that limit stroke. You aren't going to find 502ci motors screaming to 14,000 or 18,000 rpm like you will sub 2.0l motors. With RPM comes horsepower, and you make it useful with gearing.
While a big motor may offer the ability to turn big gears, a small motor can turn small gears faster. At the end of the day, there are some basic limits to internal combustion engines that kind of place both approaches in the same camp in terms of ultimate performance. It's more about efficiency goals, the driving experience, and what sort of gearbox you have at your disposal. In a vacuum one simply is not better than another. You have to start at the goal and work your way backwards to the approach.
Given that you define "power" as torque - which is a fair thing to say - there is no replacement for displacement. But given that we are talking about cars that are expected to operate over a wide range of speeds it's fair to say we're also talking about gearing, in which case torque may not be more important than horsepower. If you define "power" as horsepower, then displacement isn't the be-all and end-all. Larger combustion chambers lose efficiency pretty rapidly - the ability to control the flame front and fully use the fuel air charge diminishes as the hole gets bigger. There are also mechanical limits to consider - limits of bore to stroke, and limits for piston speeds that limit stroke. You aren't going to find 502ci motors screaming to 14,000 or 18,000 rpm like you will sub 2.0l motors. With RPM comes horsepower, and you make it useful with gearing.
While a big motor may offer the ability to turn big gears, a small motor can turn small gears faster. At the end of the day, there are some basic limits to internal combustion engines that kind of place both approaches in the same camp in terms of ultimate performance. It's more about efficiency goals, the driving experience, and what sort of gearbox you have at your disposal. In a vacuum one simply is not better than another. You have to start at the goal and work your way backwards to the approach.
The fastest wheel driven gas powered single engine car is powered by a small block bowtie.
Originally posted by thesameguy: Given that you define "power" as torque - which is a fair thing to say - there is no replacement for displacement. But given that we are talking about cars that are expected to operate over a wide range of speeds it's fair to say we're also talking about gearing, in which case torque may not be more important than horsepower. If you define "power" as horsepower, then displacement isn't the be-all and end-all. Larger combustion chambers lose efficiency pretty rapidly - the ability to control the flame front and fully use the fuel air charge diminishes as the hole gets bigger. There are also mechanical limits to consider - limits of bore to stroke, and limits for piston speeds that limit stroke. You aren't going to find 502ci motors screaming to 14,000 or 18,000 rpm like you will sub 2.0l motors. With RPM comes horsepower, and you make it useful with gearing.
While a big motor may offer the ability to turn big gears, a small motor can turn small gears faster. At the end of the day, there are some basic limits to internal combustion engines that kind of place both approaches in the same camp in terms of ultimate performance. It's more about efficiency goals, the driving experience, and what sort of gearbox you have at your disposal. In a vacuum one simply is not better than another. You have to start at the goal and work your way backwards to the approach.
Given that HP is a function of both RPM and torque, you can't simply eliminate it from any comparison. No street cars are spinning to 18000 RPM either, so if we're going to limit the discussion to what's only applicable to the street, then the upper RPM limit is really about 10000 RPM. On average, most small displacement 4 cylinder engines are not even spinning faster than 8500 RPM. It's certainly possible to spin an 8L engine to that speed, but the cost to do so will be much higher than for a small displacement engine.
If you want more power, you need to displace more air. It is physics. There used to be a time when a "high" compression ratio was 9:1, too. The Gen V LT1 is 11.5:1, in a 6.2L pushrod V8.
