100 horsepower per liter naturally aspirated
10-01-2012, 09:35 AM
#821
6600 rpm clutch dump of death Administrator
100 horsepower per liter naturally aspirated
Also, much of what is beging regurgitated now is the same material that was posted in this thread many years ago....HP/L is ricer math, and is pretty much useless...
10-01-2012, 09:44 AM
#822
6600 rpm clutch dump of death Administrator
05-07-2006
https://ls1tech.com/forums/4769253-post45.html
https://ls1tech.com/forums/4769253-post45.html
Originally Posted by racer7088
Louie,
What people don't seem to be understanding is that HP/L is not efficiency. It's called specific output. HP/inch or HP/L on it's own won't make you go any faster ever on it's own. If it's the same SIZE engine turining more rpm then you have more power and will go faster hence the bigger bore stuff at the same engine size.
What dumb people do is to destroke their engines! This is not adding power via a larger bore size but rather taking away power and torque by reducing engine size while NOT making the bore larger which is the only reason the bigger bore engine might make more power at all in the first place. You will have more HP/L this way but you will also have less TOTAL POWER! The best is the big bore AND the big stroke!
HORSEPOWER is what makes you go fast and that's it along with the WEIGHT of the car and how well you can hook the power up. If you put a silly *** japanese motor with WAY more HP/L into a real car that isn't 1500 pounds it will be SLOWER not faster.
That's all we are saying. It's way easier to make power with a LARGER engine including stroke than with rpm plus with good heads the big stroke engine can still usually turn just as high. I know you are already agreeing with me anyway but I think this topic confuses people all the time.
HP/Lb wins races not HP/L! You are right that HP/L is mostly based on power adders and/or rpm though. The higher the rpm the more HP/L but still the larger stroke engine will make more total power everytime and accelerate faster in the same car.
What people don't seem to be understanding is that HP/L is not efficiency. It's called specific output. HP/inch or HP/L on it's own won't make you go any faster ever on it's own. If it's the same SIZE engine turining more rpm then you have more power and will go faster hence the bigger bore stuff at the same engine size.
What dumb people do is to destroke their engines! This is not adding power via a larger bore size but rather taking away power and torque by reducing engine size while NOT making the bore larger which is the only reason the bigger bore engine might make more power at all in the first place. You will have more HP/L this way but you will also have less TOTAL POWER! The best is the big bore AND the big stroke!
HORSEPOWER is what makes you go fast and that's it along with the WEIGHT of the car and how well you can hook the power up. If you put a silly *** japanese motor with WAY more HP/L into a real car that isn't 1500 pounds it will be SLOWER not faster.
That's all we are saying. It's way easier to make power with a LARGER engine including stroke than with rpm plus with good heads the big stroke engine can still usually turn just as high. I know you are already agreeing with me anyway but I think this topic confuses people all the time.
HP/Lb wins races not HP/L! You are right that HP/L is mostly based on power adders and/or rpm though. The higher the rpm the more HP/L but still the larger stroke engine will make more total power everytime and accelerate faster in the same car.
Originally Posted by louie83
Excuses? It's simple physics - do a little research.
Horsepower = (Torque * RPM) / 5252
That is the equation for horsepower, there is nothing to argue here, that is what it is.
Now, when looking at that equation, do you not agree that more RPM's will yield more HP? Obviously it will, it's gradeschool math.
Now what is going to be easier to get higher RPM's out of, a big engine with a long stroke and larger pistons, or a smaller engine with a shorter stroke and smaller pistons? Once again, the answer is obvious. Now you can see why tiny motorcycle engines can effectively make 200 HP/L.
So no one is making any excuses, it's simple physics that idiot ricers who brag about HP/L know nothing about.
Horsepower = (Torque * RPM) / 5252
That is the equation for horsepower, there is nothing to argue here, that is what it is.
Now, when looking at that equation, do you not agree that more RPM's will yield more HP? Obviously it will, it's gradeschool math.
Now what is going to be easier to get higher RPM's out of, a big engine with a long stroke and larger pistons, or a smaller engine with a shorter stroke and smaller pistons? Once again, the answer is obvious. Now you can see why tiny motorcycle engines can effectively make 200 HP/L.
So no one is making any excuses, it's simple physics that idiot ricers who brag about HP/L know nothing about.
10-16-2012, 10:37 PM
#823
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so no one really specified rwhp or crank..atleast i didnt go back to look all the way.
I've always wanted to build a small cam, badass heads and intake setup (like mast and 4150 or 4500 and see what it does.
I did do a c6 vette that made 455rwhp with tea stock ported heads, 228/232 .580 115 cam (driveablity was close to stock as anything can be that "big", not really noticeable though) and a ported ls2 intake and TB with headers. thats not too far off the mark
I've always wanted to build a small cam, badass heads and intake setup (like mast and 4150 or 4500 and see what it does.
I did do a c6 vette that made 455rwhp with tea stock ported heads, 228/232 .580 115 cam (driveablity was close to stock as anything can be that "big", not really noticeable though) and a ported ls2 intake and TB with headers. thats not too far off the mark
05-21-2014, 11:27 AM
#825
TECH Resident
After years of watching this and other threads regarding "drivable" power. My stock LS 5.7 in my 1935 sedan is very calm, smooth and drivable...that being said I'd like to make some more power but not at the cost of "drivability". Now, as a yardstick for the type of power I'm referring to is my daily driver...a 2008 Chevy HHR SS. This tiny 2.0l engine with the GM Performance upgrade makes right at 300 hp and 305 ft lbs of torque. The powerband on this little screamer starts just below 2000 rpm and as the boost ramps up it starts pulling. No lag, no flat spots, just torque and it pulls to 7000 rpm and that nets 23-24 pounds of boost. This is how I want my "big" 5.7 to pull and I think I'm going to have to resort to force-feeding it to avoid the light throttle low speed drivability. Since my son has been at A & A Corvette for over 7 years, I see how this is done...like the 2014 Corvettes they just finished.
All it takes is money and I'm eventually going to wedge a supercharger under the hood somehow (not much underhood room) and with just mild boost I look for the power I want.
I will now install my Nomex underwear so let the flames begin.
All it takes is money and I'm eventually going to wedge a supercharger under the hood somehow (not much underhood room) and with just mild boost I look for the power I want.
I will now install my Nomex underwear so let the flames begin.
05-23-2014, 02:09 PM
#827
On The Tree
I worked for BMW from 01-08, the time when they were attempting to perfect NA power/economy/reliability. They had variable intake runners, variable cam timing, variable lift, etc... Engine electronics were beyond complicated. It worked but at a high development cost and high production costs. It worked, the engines made great useable power, were efficient and pretty reliable. The really advanced engines had a peculiar feel. Then BMW re-discovered turbocharging, a paradigm shift happened. A lot of their NA technology went on the shelf. They had made NA engines perform very well and have other technology that was in the pipeline that would have taken it to another level. Unfortunately they could do the same thing cheaper by going FI. Profit margins trump uniqueness. They pushed the limits for oem NA technology.
That being said, all there tech couldn't overcome the cheap power of FI. A reliable, high horsepower, NA motor could be done using their technology. The costs would be astronomical with fuel mileage mandates and warranty cost issues. 100hp/l is easy, even with a pushrod V8. 200hp/l with oem reliability and fuel mileage is doable, even with 5-8 liter displacement, but the costs are prohibitive.
That being said, all there tech couldn't overcome the cheap power of FI. A reliable, high horsepower, NA motor could be done using their technology. The costs would be astronomical with fuel mileage mandates and warranty cost issues. 100hp/l is easy, even with a pushrod V8. 200hp/l with oem reliability and fuel mileage is doable, even with 5-8 liter displacement, but the costs are prohibitive.
06-12-2014, 07:33 PM
#829
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I won't claim to be an expert at all but I would like to point out a few things.
Around 2008, the 2AR-FE engine was introduced to the Toyota line up. It replaced the 2AZ-FE. The new motor was .1L larger and was built for fuel economy. Why? Toyota found that the added torque of the larger engine resulted in a real world gain in MPG. The vehicle would get up to speed faster where it would cruise at a lower RPM.
I didn't just spend my life trying to find this obscure example, I actually owned a newer Camry and researched it. I found it interesting and have never forgotten it, especially in relation to my project vehicles.
I know a lot of you guys have most of your experience in domestic vehicles, but it's extremely common among imports doing LS swaps to experience a sizable MPG gain.
This can be a 1.8L Miata, 240sx, or any generation of BMW. The result is always better MPG and incredible performance gains.
I personally am doing this on my E36 M3. The stock motor (3.2L DOHC I6) gets an average of ~24mpg. A lot of guys who to swap to LS motors claim 28-30mpg.
Obviously there is a huge change of engine architecture and the results aren't directly comparable. However, the end result is a large displacement, high torque motor obtaining more fuel efficiency than the original motor.
If you read up on most any import vehicle that has enough under-hood space, you will find LS swaps. You will find tons of guys hating, and you will find tons of guys who have realized that no matter how high your motor revs, what your peak HP figures are, or how much boost you throw at it, in the end there is no replacement for displacement.
MPG, reliability, and power all across the band are why the LS motors are bar-none the most popular motor swap in the world.
That being said, I have noticed something strange in my wife's new vehicle. Her 2012 GTI has around 250lb/ft and will most efficiently cruise at 1200-1400rpm. This is where the OSD tells you to shift, and where you can see maximum fuel efficiency is achieved. She can average 37mpg with 60/40 city/highway driving in this vehicle. It's 2.0 liters. Definitely not an engine designed for HP/L pretty numbers, as it's only rated at 205hp, but it's interesting to see how low it cruises and what the results are.
Somewhat on topic, I've also been wondering this for a while: In the same way that Hartley fuses two 4 cylinder engines, why can't GM cut an LS6 in half and throw the result into the Spark or Sonic for a 2.8L 202hp naturally aspirated four cylinder engine? Why do they go with DOHC instead?
I know it's not that simple, but I haven't been able to figure out why.
Around 2008, the 2AR-FE engine was introduced to the Toyota line up. It replaced the 2AZ-FE. The new motor was .1L larger and was built for fuel economy. Why? Toyota found that the added torque of the larger engine resulted in a real world gain in MPG. The vehicle would get up to speed faster where it would cruise at a lower RPM.
I didn't just spend my life trying to find this obscure example, I actually owned a newer Camry and researched it. I found it interesting and have never forgotten it, especially in relation to my project vehicles.
I know a lot of you guys have most of your experience in domestic vehicles, but it's extremely common among imports doing LS swaps to experience a sizable MPG gain.
This can be a 1.8L Miata, 240sx, or any generation of BMW. The result is always better MPG and incredible performance gains.
I personally am doing this on my E36 M3. The stock motor (3.2L DOHC I6) gets an average of ~24mpg. A lot of guys who to swap to LS motors claim 28-30mpg.
Obviously there is a huge change of engine architecture and the results aren't directly comparable. However, the end result is a large displacement, high torque motor obtaining more fuel efficiency than the original motor.
If you read up on most any import vehicle that has enough under-hood space, you will find LS swaps. You will find tons of guys hating, and you will find tons of guys who have realized that no matter how high your motor revs, what your peak HP figures are, or how much boost you throw at it, in the end there is no replacement for displacement.
MPG, reliability, and power all across the band are why the LS motors are bar-none the most popular motor swap in the world.
That being said, I have noticed something strange in my wife's new vehicle. Her 2012 GTI has around 250lb/ft and will most efficiently cruise at 1200-1400rpm. This is where the OSD tells you to shift, and where you can see maximum fuel efficiency is achieved. She can average 37mpg with 60/40 city/highway driving in this vehicle. It's 2.0 liters. Definitely not an engine designed for HP/L pretty numbers, as it's only rated at 205hp, but it's interesting to see how low it cruises and what the results are.
Somewhat on topic, I've also been wondering this for a while: In the same way that Hartley fuses two 4 cylinder engines, why can't GM cut an LS6 in half and throw the result into the Spark or Sonic for a 2.8L 202hp naturally aspirated four cylinder engine? Why do they go with DOHC instead?
I know it's not that simple, but I haven't been able to figure out why.
06-20-2014, 11:11 AM
#830
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The capabilities of DOHC variable cam phasing to broaden the powerband of a tiny engine, as well as the vibration of a large displacement 4 cylinder keep the 4's and 6's in the multi-valve field.
The synergy of DI, variable cam phasing and turbocharging makes these tiny engines that much more potent.
The synergy of DI, variable cam phasing and turbocharging makes these tiny engines that much more potent.
