Difference between "Free up" and "Add" Hp
11-16-2003, 05:14 PM
#1
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Difference between "Free up" and "Add" Hp
hey all,
I was just wondering if someone could simply clear this question up. What kind of mods free up hp instead of physically adding hp to the car? My answer to myself would be, say an intake would Add or make more hp, but at the same time it just freed up the restriction that was in place. So where do things like Ypipe injectors, exhaust, ecu, and other mods stand? Thanks
I was just wondering if someone could simply clear this question up. What kind of mods free up hp instead of physically adding hp to the car? My answer to myself would be, say an intake would Add or make more hp, but at the same time it just freed up the restriction that was in place. So where do things like Ypipe injectors, exhaust, ecu, and other mods stand? Thanks
11-16-2003, 05:58 PM
#3
this is kind of a tough question... a supercharger for example definetely adds hp, while exhaust, intake, and ypipe most likely just free up hp, but i think you can argue either way for those last 3 things.
11-16-2003, 06:00 PM
#4
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Originally Posted by luckee2bhere
everything "adds" hp that i know of cept UDP i think...i think that just gets more power to the ground.
Add these to free up hp... intake, chip, y-pipe, exhaust, headers... things that don't "have their own" hp.
Add these to add hp... supercharger, turbo, nitrous.
I'm sure there are more things to add to each list. I'm also sure people would argue about "chip" but IMO it does not 'add' hp, it only allows the engine to use the existing hp more effectively/efficiently.
11-17-2003, 06:13 AM
#8
You can think of it this way.
Some mods improve the volumetric efficiency of the engine, i.e. they allow the engine to pump more air through it. More air means more fuel as well, so this adds hp. Intakes, exhaust, FI, cams and a lot of other mods I can't think of do this.
Some mods improve the thermal efficiency of the engine. For instance timing and fuel mapping changes from a modified ecu. These also add power.
Still other mods don't do anything to how the engine pumps air or burns fuel, instead they improve the mechanical efficiency of the engine by allowing the power that is made to flow to the wheels better. Lightened flywheels, cranks, pistons and UDPs are in this category. They free up horsepower that would otherwise be spent on accelerating them as the engine revs up.
Some mods improve the volumetric efficiency of the engine, i.e. they allow the engine to pump more air through it. More air means more fuel as well, so this adds hp. Intakes, exhaust, FI, cams and a lot of other mods I can't think of do this.
Some mods improve the thermal efficiency of the engine. For instance timing and fuel mapping changes from a modified ecu. These also add power.
Still other mods don't do anything to how the engine pumps air or burns fuel, instead they improve the mechanical efficiency of the engine by allowing the power that is made to flow to the wheels better. Lightened flywheels, cranks, pistons and UDPs are in this category. They free up horsepower that would otherwise be spent on accelerating them as the engine revs up.
11-17-2003, 08:47 AM
#10
It's a matter of semantics. As far as I'm concerned, the drivetrain should be taken as a system. Anything that is done to that system to increase power to the ground "adds" power.
Hell, even boost "frees up" power lost to volumetric inefficiency.
Hell, even boost "frees up" power lost to volumetric inefficiency.
11-17-2003, 09:39 AM
#11
i would say free up hp is hp lost by your car through restrictions and/or loss in power due to wear and aging. Grounding kits, intakes, y-pipes, catbacks, variable intakes(hard to say) all free up hp that your car would have had if they didnt put this or that in the way.
added hp is hp that the car just doesnt come with being forced upon the car such as your supercharger and turbo and nitrous and variable intake (hard to say).
added hp is hp that the car just doesnt come with being forced upon the car such as your supercharger and turbo and nitrous and variable intake (hard to say).
11-17-2003, 02:47 PM
#12
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Anything you add to the car, with better charactersistics and specs(oil don't count) to REPLACE an existing part is freeing HP. Adding something that is non existant on the car originally is adding hp. And no I don't mean stickers, neons, or roof spoilers and stuff. Only things that are advertised as power adders...
11-17-2003, 04:15 PM
#13
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i agree with ivelweyz. to improve on an existing system is to be more efficient (in one sense of the word) and to free up the power the original part held back. by putting on something the car didnt have is making power. but hold up...stickers are obvious power additives 
11-17-2003, 04:55 PM
#14
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for ivelweyz look at "free up" vs. "add"So in essence, all the talk about if so-and-so will lower an engine or tranny's life is partially nonsence when you speak in terms of things like Y-pipes, exhaust, intake, etc then? I mean, the manufacturer wouldn't design an engine that's not able to support the true full potential of any given section that's eligible for a better part... would they?
11-17-2003, 10:01 PM
#16
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yea...they made a maxima to be a family sedan, and sell well in that market. not have a loudass cold air intake, buzzy y pipe, harsh lowered ride...etc. it appeals to its market
11-20-2003, 03:03 AM
#21
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I've always considered free hp to be mods that are significantly cheaper and don't really involve all that much work.
intake, ground kit, stickers, weight reduction (illusion of more hp though, but who needs 5 people in a race car anyway, hehe), etc.
intake, ground kit, stickers, weight reduction (illusion of more hp though, but who needs 5 people in a race car anyway, hehe), etc.
11-20-2003, 05:37 AM
#22
Originally Posted by davebond007
I've always considered free hp to be mods that are significantly cheaper and don't really involve all that much work.
intake, ground kit, stickers, weight reduction (illusion of more hp though, but who needs 5 people in a race car anyway, hehe), etc.
intake, ground kit, stickers, weight reduction (illusion of more hp though, but who needs 5 people in a race car anyway, hehe), etc.
11-20-2003, 05:33 PM
#24
Well, think about this though.
If you run a car with no exhaust/y-pipe/manifolds, it's probably going to make less power than with a good exhaust setup. Otherwise, wouldn't all of the research into the scavenging effects of headers and such be pointless? Do you ever see an all motor race car run no manifolds? Just straight out the exhaust valves of the engine? Nope. Race cars also run intakes if you notice. None of them just runs a straight throttle body with nothing on it. At the minimum, they have air horns and some piping. All that research and development money wouldn't be spent if all they had to do was rip it off.
Intakes, and exhaust components can add power and not just free it up. Why do different intakes/exhausts result in different power gains? If they only freed up hp, just make them as big as possible to get rid of all restriction. But that isn't the case.
The factory pieces do restrict flow and power, so it's true that intakes and exhausts do "free" up some power. But they add power too through proper design.
That 255 hp is rated with no transmission, alternator, and auxillary pumps installed. That's what is sucking most of the power away. The only mods that only free up power are pullies and flywheels (TQ's, clutch packs, and fluid for autos). Everything else will add power if properly designed.
for ivelweyz look at "free up" vs. "add"
So in essence, all the talk about if so-and-so will lower an engine or tranny's life is partially nonsence when you speak in terms of things like Y-pipes, exhaust, intake, etc then? I mean, the manufacturer wouldn't design an engine that's not able to support the true full potential of any given section that's eligible for a better part... would they?
If you run a car with no exhaust/y-pipe/manifolds, it's probably going to make less power than with a good exhaust setup. Otherwise, wouldn't all of the research into the scavenging effects of headers and such be pointless? Do you ever see an all motor race car run no manifolds? Just straight out the exhaust valves of the engine? Nope. Race cars also run intakes if you notice. None of them just runs a straight throttle body with nothing on it. At the minimum, they have air horns and some piping. All that research and development money wouldn't be spent if all they had to do was rip it off.
Intakes, and exhaust components can add power and not just free it up. Why do different intakes/exhausts result in different power gains? If they only freed up hp, just make them as big as possible to get rid of all restriction. But that isn't the case.
The factory pieces do restrict flow and power, so it's true that intakes and exhausts do "free" up some power. But they add power too through proper design.
That 255 hp is rated with no transmission, alternator, and auxillary pumps installed. That's what is sucking most of the power away. The only mods that only free up power are pullies and flywheels (TQ's, clutch packs, and fluid for autos). Everything else will add power if properly designed.
Originally Posted by NYC 92 GXEr
for ivelweyz look at "free up" vs. "add"So in essence, all the talk about if so-and-so will lower an engine or tranny's life is partially nonsence when you speak in terms of things like Y-pipes, exhaust, intake, etc then? I mean, the manufacturer wouldn't design an engine that's not able to support the true full potential of any given section that's eligible for a better part... would they?
11-20-2003, 05:59 PM
#25
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Originally Posted by Shadow
Well, think about this though.
If you run a car with no exhaust/y-pipe/manifolds, it's probably going to make less power than with a good exhaust setup. Otherwise, wouldn't all of the research into the scavenging effects of headers and such be pointless? Do you ever see an all motor race car run no manifolds? Just straight out the exhaust valves of the engine? Nope. Race cars also run intakes if you notice. None of them just runs a straight throttle body with nothing on it. At the minimum, they have air horns and some piping. All that research and development money wouldn't be spent if all they had to do was rip it off.
If you run a car with no exhaust/y-pipe/manifolds, it's probably going to make less power than with a good exhaust setup. Otherwise, wouldn't all of the research into the scavenging effects of headers and such be pointless? Do you ever see an all motor race car run no manifolds? Just straight out the exhaust valves of the engine? Nope. Race cars also run intakes if you notice. None of them just runs a straight throttle body with nothing on it. At the minimum, they have air horns and some piping. All that research and development money wouldn't be spent if all they had to do was rip it off.
11-20-2003, 06:08 PM
#26
Sorry, guess I wasn't totally clear. On a forced induction system, you're right, it doesn't matter. As long as the path from the blower into the engine is smooth, everything's good. Without a blower though, an intake system does matter. According to some of the other posters, removing the entire intake and exhaust would result in the most power since all those do is "free it up". That just isn't true.
And when I say exhaust, headers only counts. That is still an exhaust system. I was referring to nothing at all, no headers, no manifolds, nothing. That would be the ideal setup if all an exhaust system did was "free up hp"
But even dragsters run headers. Do any of them simply have the exhaust ports directly venting with absolutely nothing attached?
And when I say exhaust, headers only counts. That is still an exhaust system. I was referring to nothing at all, no headers, no manifolds, nothing. That would be the ideal setup if all an exhaust system did was "free up hp"
But even dragsters run headers. Do any of them simply have the exhaust ports directly venting with absolutely nothing attached?
Originally Posted by SXN
Think about a belt driven blower on a v8. the air just goes straight into the blower, and in the engine...no intake system persay. cars might not "run a throttle body with nothing on it" but plenty of people running big power, dont have intake piping/intake systems. also if exhaust system made power, why do dragsters run headers only? why do guys run cut off exhausts for the track?
11-20-2003, 06:29 PM
#27
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You can test whether you "freed up" horsepower or "added" it very easily with an OBD-II scanner and some before/after tests. All you have to do is monitor the MAF sensor which reads in lb/min I think. You'll need to be on the highway where you can get a nice strong run in 3rd gear for a manual or 2nd maybe for an auto. Better yet - a dyno. 
If you add a mod that gives you more power but the max flow rate from the MAF doesn't go up then you "freed up" power. If it does go up (more air getting through the engine) then you added power.
I think a y-pipe or any downstream mod will "free up" horsepower since you make the engine less restrictive. An upstream mod like an intake may do a combination of both. It makes the intake less restrictive (which frees up power) but whether that results in "more air" getting into the engine (add power) or not you can only really tell via monitoring the MAF sensor.
FI is definitely a 100% "add power" mod.
If you add a mod that gives you more power but the max flow rate from the MAF doesn't go up then you "freed up" power. If it does go up (more air getting through the engine) then you added power.
I think a y-pipe or any downstream mod will "free up" horsepower since you make the engine less restrictive. An upstream mod like an intake may do a combination of both. It makes the intake less restrictive (which frees up power) but whether that results in "more air" getting into the engine (add power) or not you can only really tell via monitoring the MAF sensor.
FI is definitely a 100% "add power" mod.
11-20-2003, 06:36 PM
#28
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Originally Posted by Shadow
Sorry, guess I wasn't totally clear. On a forced induction system, you're right, it doesn't matter. As long as the path from the blower into the engine is smooth, everything's good. Without a blower though, an intake system does matter. According to some of the other posters, removing the entire intake and exhaust would result in the most power since all those do is "free it up". That just isn't true.
And when I say exhaust, headers only counts. That is still an exhaust system. I was referring to nothing at all, no headers, no manifolds, nothing. That would be the ideal setup if all an exhaust system did was "free up hp"
But even dragsters run headers. Do any of them simply have the exhaust ports directly venting with absolutely nothing attached?
And when I say exhaust, headers only counts. That is still an exhaust system. I was referring to nothing at all, no headers, no manifolds, nothing. That would be the ideal setup if all an exhaust system did was "free up hp"
But even dragsters run headers. Do any of them simply have the exhaust ports directly venting with absolutely nothing attached?
11-20-2003, 06:53 PM
#29
Originally Posted by SXN
not just blowers. if you have hood scoops or vents, you can just put a filter on the end of your TB and call it a day. If air is getting to the filter, why do you need an air intake system? Think to stock muscle car intake from the 60s and early 70s. on top of the intake manifold is the carb, and on top of the carb is a filter. There is no uneccessary components. Also, dragsters run headers as a safety percausion, and in some cases for back pressure (but 3000hp top fuel cars dont "need" headers)
You're comparing things that should not be compared now...and there is no backpressure for the umpteenth million time...
*Backpressure = 2 stroke engine way of sucking unburnt fuel into the combustion chamber so as to help control temp and utilize most of the fuel available
*Exhaust gas velocity = what any 4 stroke motor needs in order to produce any significant amount of power. A certain velocity (which is also known as flow) must be maintained throughout the entire exhaust system (dependant on a variety of things, such as piping diameter, crossover points, exhaust impulse routing/collisions...etc etc etc)...
Also, just putting a filter on the end of your TB is NOT going to give you any powre gains b/c the air passing the MAF and going into the TB and upper intake plenum will not be stable/straight air. It will have all kinds of eddies and tumbles and such, actually causing a reduction in HP. Ask WILLSE about that...we proved it on a dyno
11-20-2003, 06:59 PM
#31
Originally Posted by SXN
i didnt compare anything, because i didn't speak of 2 strokes, just used the wrong word if you're going to yell at me, get it right
if you're going to yell at me, get it rightActually, I was referring to your carb engines vs. fuel injected engines comments...
And you can never use the term "backpressure" for any type of 4 stroke engine, but you know that now
So,
again 
11-20-2003, 07:04 PM
#32
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yes, but i was just saying how he was wrong saying you lose power by not having an intake system. he used the example of throttle bodies, but didnt say JUST fuel injected cars. so i made examples of fuel injction AND carborated engines...i didnt compare them. Also, i KNOW the backpressure comment was wrong, so yes, smack away
11-20-2003, 07:07 PM
#33
Originally Posted by SXN
yes, but i was just saying how he was wrong saying you lose power by not having an intake system. he used the example of throttle bodies, but didnt say JUST fuel injected cars. so i made examples of fuel injction AND carborated engines...i didnt compare them. Also, i KNOW the backpressure comment was wrong, so yes, smack away
Fair enough
It's all about getting the info straight...
11-20-2003, 07:19 PM
#35
Now we just need to combine all of our answers into one totally perfect one that will solve this issue once and for all...
Originally Posted by SXN
yes, i corrected him (i was right about part) then you corrected me all good
all good
11-20-2003, 07:51 PM
#40
Guys, I was kidding about combining our answers, not trying to get credit here.
And how was I wrong? For carb setups, I may be, I'm not familiar with them. I was totally thinking fuel injection setups when I posted just because that's all I know of personally. But you even stated that you can't just put a filter on the TB and make power. That it will lose power over a good intake due to turbulence and so on. That was pretty much my point. Some other posters basically stated that an intake just frees up hp, and I was trying to explain that they can make power through proper design.
Same with the exhausts. If we subscribe to the theory that they just free up power, then there would be no point to design. Just take it all off, I was trying to refute that point. I just didn't do it as elegantly as you did, so maybe I wasn't clear. You are 100% right in your answer. But my post didn't really disagree with anything you said.
Anyways, people, just read what Quicksilver said. It should make things more clear
And how was I wrong? For carb setups, I may be, I'm not familiar with them. I was totally thinking fuel injection setups when I posted just because that's all I know of personally. But you even stated that you can't just put a filter on the TB and make power. That it will lose power over a good intake due to turbulence and so on. That was pretty much my point. Some other posters basically stated that an intake just frees up hp, and I was trying to explain that they can make power through proper design.
Same with the exhausts. If we subscribe to the theory that they just free up power, then there would be no point to design. Just take it all off, I was trying to refute that point. I just didn't do it as elegantly as you did, so maybe I wasn't clear. You are 100% right in your answer. But my post didn't really disagree with anything you said.
Anyways, people, just read what Quicksilver said. It should make things more clear
Originally Posted by Quicksilver
So let me get this straight...
him < you < me
him < you < me