9th Gen Civic Forum banner

21 - 40 of 74 Posts

·
Registered
Joined
·
313 Posts
I don't understand when people refer to drive train loss in percentage. let's say my car is all stock and i have 200hp. so with your rule of thumb, drive train loss is 40 hp.
Let's now add some power to it on the same exact car with the same drive train and now has 400 hp. So I doubled the power to the car and all the sudden that same drive train that took 40hp before now some how takes 80hp? (400 x 20%)

It's more of a fixed value imo and not a percentage.

Now you can argue that it can take more power to turn the drive train because higher hp cars will create more heat compared to a lower hp car but I'm sure even if that is accounted for, it shouldn't take double the original amount.

Now, I do agree with you about loss in rotational mass will show an increase in hp on a dyno. What your effectively doing is not really MAKING more power but REDUCING the amount of drive train loss that the car sees due to the lower weight of the rotating masses.
 

·
Registered
Joined
·
11,032 Posts
Discussion Starter #22 (Edited)
I don't understand when people refer to drive train loss in percentage. let's say my car is all stock and i have 200hp. so with your rule of thumb, drive train loss is 40 hp.
Let's now add some power to it on the same exact car with the same drive train and now has 400 hp. So I doubled the power to the car and all the sudden that same drive train that took 40hp before now some how takes 80hp? (400 x 20%)

It's more of a fixed value imo and not a percentage.

Now you can argue that it can take more power to turn the drive train because higher hp cars will create more heat compared to a lower hp car but I'm sure even if that is accounted for, it shouldn't take double the original amount.

Now, I do agree with you about loss in rotational mass will show an increase in hp on a dyno. What your effectively doing is not really MAKING more power but REDUCING the amount of drive train loss that the car sees due to the lower weight of the rotating masses.

it is why the most ideal to know how much drivetrain loss is chassis dyno. with the actual #, you will know how much % is loss...


here is a good article about drivetrain loss by super street... link: Drivetrain Power Loss - The 15% "Rule"- Modified Magazine

another one by hot rod: http://www.hotrod.com/articles/ccrp-0311-drivetrain-power-loss/

"What your effectively doing is not really MAKING more power but REDUCING the amount of drive train loss that the car sees due to the lower weight of the rotating masses"

absolutely correct... parts like tires, wheels, rotors, axles, flywheels, clutch, transmission, are all part of the rotating mass that cause drivetrain loss.

 

·
Truck? What truck?!
Joined
·
27,340 Posts
Dyno results will only take into account drive train components, not the weight of the car. Out on the road or track the weight of the car will come into play.

Power at the flywheel, disconnected fro the drivetrain, is a different story, again. That's the most that will be registered.

Just some basic stuff to keep in mind.
 

·
Registered
Joined
·
313 Posts
it is why the most ideal to know how much drivetrain loss is chassis dyno. with the actual #, you will know how much % is loss...
but my question is why would it be registered into a %. It should be a flat value.
Let's say you dyno a 9th gen SI and it registered 160whp. That would be a loss of 45 hp which is 45/205 = 21.9%, or the car makes 78.1% of crank hp.

Now we force induction the same car and we make 400whp. So if it follows a % formula like above, the car has a 21.9% drive train loss so it should have 400/0.781 = 512.16 crank hp which means, the loss is 112 hp
the SAME exact drive train now some how takes 112hp instead of 45 because I added boost to the car? No matter how much hp you have the drive train loss for the 9th gen SI should be valued at a FLAT 45 hp or close to it instead of a 21.9% value. Why would the car all the sudden take 70 more hp to turn the same exact drive train because you add more power.
 

·
Registered
Joined
·
181 Posts
^did you read the link team3d posted? It was very informative IMO. Brings up the issue of cooling for me, since part of drive train loss is directly related to heat. I was thinking of the benefits of an oil cooler and/or a transmission cooler. I wonder what % if any would increased cooling help the engine function better in terms of physical numbers. Interesting topic.
 

·
Registered
Joined
·
313 Posts
^did you read the link team3d posted? It was very informative IMO. Brings up the issue of cooling for me, since part of drive train loss is directly related to heat. I was thinking of the benefits of an oil cooler and/or a transmission cooler. I wonder what % if any would increased cooling help the engine function better in terms of physical numbers. Interesting topic.
Yes I actually have already read the modified magazine article before he posted it. They are just another google link that anyone can search. I am only asking him because I don't believe you can follow his 20% fwd drive train loss "rule of thumb" because it would be imo a lot closer to a FIXED value over a PERCENTAGE value. Which is why I asked how he came up with a percentage value.

I even mentioned about the "heat" issue with more hp before that link was posted in the post above.
Now you can argue that it can take more power to turn the drive train because higher hp cars will create more heat compared to a lower hp car but I'm sure even if that is accounted for, it shouldn't take double the original amount.
 

·
Registered
Joined
·
11,032 Posts
Discussion Starter #27 (Edited)
Yes I actually have already read the modified magazine article before he posted it. They are just another google link that anyone can search. I am only asking him because I don't believe you can follow his 20% fwd drive train loss "rule of thumb" because it would be imo a lot closer to a FIXED value over a PERCENTAGE value. Which is why I asked how he came up with a percentage value.

I even mentioned about the "heat" issue with more hp before that link was posted in the post above.
the drivetrain loss % average are studied & published by SAE. the fwd 20% average rules are years of data collected from various chassis dyno results from bone stock fwd honda dyno on chassis dyno.

it's why within honda community, from all the data we have seen for almost 20yrs, the average is around 20%. ofcourse, we all know elevation & air density plays a big role on chassis dyno... it's why we need to know the date & the location of the dyno it perform to understand if there is any advantage was being utilized..

example: church dyno.. everyone likes to bash church's high dyno #, there is a reason why church's # are much higher than other socal dyno.

#1 church use dynapack, dynapack is not a chassis dyno, it's a hub dyno, when you remove the friction & the wheels/tires weight out of the equation, the reading will be higher than chassis dyno which factor in tire frictions & wheels/tires weight.

#2 Torrance is at near sea level, dyno # read the highest when it's near sea level.

#3, Torrance is near the beach, Torrance have much cooler temperature than in the valley/san gabriel valley/inland empire. thus when dyno cars at colder temperture gives you a better advantage to have higher dyno reading


if chruch move to our region, even with dynapack, when you dyno a car at 100f and hotter and at a 500~1400 above elevation ? the # will read much lower...

example, stock r18 automatic is 140hp, when AFE dyno inno's FG3 in 2012, it was 104whp on a mustang dyno in socal, the 20% rule will be 112, his civic actually had a drivetrain loss of little over 25% due to his transmission.

dyno link: http://www.9thgencivic.com/forum/ecu-tuning/22418-2012-civic-si-k24z7-baseline-dyno-results-chart.html
 

·
Registered
Joined
·
181 Posts
Yes I actually have already read the modified magazine article before he posted it. They are just another google link that anyone can search. I am only asking him because I don't believe you can follow his 20% fwd drive train loss "rule of thumb" because it would be imo a lot closer to a FIXED value over a PERCENTAGE value. Which is why I asked how he came up with a percentage value.

I even mentioned about the "heat" issue with more hp before that link was posted in the post above.
Nothing in engines can ever be fixed. Not unless every single engine was created the same, and even then, you have to take into account all of the environmental factors, which would give you certain readings at certain times of the day, weather temp, humidity etc, that's SEVERAL hundreds of factors when it comes down to it.

Not all Civics and Si's for that matter were created the same anyway, so for me, despite how Honda data for the past 20 years or so showed certain percentages, that number doesn't even matter, with new engines come new variables.

It will never be a fixed number and likely it would never be a simple rule of thumb. I think having a general idea of how much drive train loss would be a good thing to have, just for self-reference sake, but in all honesty there are hundreds of calculations you would have to do to even start comprehending the actual loss number.

Think about it from a transmission perspective only. All civics have different types of transmissions, some 6 speeds, some 5 speeds, and earlier models at 4 speeds (correct me if I'm wrong on that). All transmissions don't have the exact same gear ratios either, meaning different gear sizing, number of teeth, the physical transmission case, the other rotating parts like the bearings, all of that plays a role and all of that is completely variable.

Doing a test with new engine oil vs older engine oil is a perfect example of how a simple variable can cause different dyno reads.

If it were a fixed number than we wouldn't have all of the jobs, careers, scientific studies etc around this very topic. It would be a simple calculation and engineering as we know it would seem like working at walmart. However, that's simply not the case.

I was just reading today about the benefits or supposed benefits of fuel coolers, which in theory sound good, just like transmission cooling and oil cooling, they all sound good and smart and worth while, but it's hard to find good scientific data from forums just like on this one. You gotta be in the field. You gotta be behind the scenes, at the desk where the calculations are done for each physical part and then all of those figures are put into a much larger equation. Then theory comes into play because as much as we believe we know about shit, like scientists and the sort, we really don't know why certain things happen the way that they do. There is no certainty in science, because science is never fixed or permanent, it is and will always stay, a process.
 

·
Registered
Joined
·
989 Posts
What do buddy club rotors weigh? is there a big difference between these 2pc rotor weight and the buddy club BBK rotor weight?
 

·
Registered
Joined
·
11,032 Posts
Discussion Starter #31
What do buddy club rotors weigh? is there a big difference between these 2pc rotor weight and the buddy club BBK rotor weight?
buddy club 330mm rotors are 21lbs each, like friction of a tire, unless heat dissipation is very important for you, always try to use the smallest (narrowest tires for that matter) rotor possible.


bigger the rotor, heavier it gets

wider the tires, more friction it creates
 

·
Registered
Joined
·
313 Posts
example, stock r18 automatic is 140hp, when AFE dyno inno's FG3 in 2012, it was 104whp on a mustang dyno in socal, the 20% rule will be 112, his civic actually had a drivetrain loss of little over 25% due to his transmission.
I'm not even asking about readings on other dynos. So with your example above, if that r18 was boosted pushing 300 crank hp it would have 225whp according to the 25% drivetrain loss due to his transmission. The same exact transmission somehow now takes 75 hp to turn compared to 36 hp when it was stock? All I am saying is, wouldn't you think the drive train loss for THIS particular vehicle would be 36hp and not 20%? Why does the same exact car all the sudden take 40 more hp to turn the same exact drive train/transmission when you add power.

Nothing in engines can ever be fixed. Not unless every single engine was created the same, and even then, you have to take into account all of the environmental factors, which would give you certain readings at certain times of the day, weather temp, humidity etc, that's SEVERAL hundreds of factors when it comes down to it.

Not all Civics and Si's for that matter were created the same anyway, so for me, despite how Honda data for the past 20 years or so showed certain percentages, that number doesn't even matter, with new engines come new variables.

It will never be a fixed number and likely it would never be a simple rule of thumb. I think having a general idea of how much drive train loss would be a good thing to have, just for self-reference sake, but in all honesty there are hundreds of calculations you would have to do to even start comprehending the actual loss number.
I understand it will never be a fixed value. I never said it is a fixed value. Just saying that shouldn't it be closer to a fixed value over a percentage value. For example, instead of saying 20% drive train loss, it should be that the 9th gen SI drive train loss is 40hp.

With a 20% rule, 500 crank hp 9th gen has 400whp (20%), while a 200 crank hp 9th gen has 160 whp. Assuming, same dyno / sea lvl / humidity / temperature, the same exact drive train for some some reason takes 60 more whp to turn when i added 300 crank hp? I understand the added heat as another variable but i don't think heat alone would make you lose more than double the amount of stock.

You wouldn't think it would be CLOSER to 460whp (-40hp) instead of 400whp (-100hp, 20%)?

Am I just not explaining myself correctly? Anyways this isn't the right place for this so i will stop.
 

·
Registered
Joined
·
181 Posts
Its a forum, where would it not be the right place to post? I see exactly what you mean, and honestly, it might turn out to stay at the 40hp loss, who knows.

However, some of the drive train loss on a higher HP car also has other moving parts to consider due to it being boosted. For a SC, there is another pulley added, for Turbo, the spool is added, yes those things ultimately negate the power increase but Im sure those things play a role in drive train loss. Adding another pulley for example, means using a longer belt, using the crank pulley to do more work than it was originally intended for. Some of those big blower hot rods take a lot of electrical energy just to start the damn thing, which again affects drive train loss.

Im sure if we got deeper into the topic we would find rules of thumb for % loss if a Turbo vs SC to boost. With every action comes some type of reaction. Higher HP motors usually have different internal components too.

Those components, lets say are "better" than OEM, but come at a potential cost. One would reference car vibration. Adding more HP changes the balancing of the crank (ever so slightly) simply because of added force, does the vibration play a role in drive train loss? Im sure it does, how much, not sure. You get my point.
 

·
Registered
Joined
·
11,032 Posts
Discussion Starter #34 (Edited)
domestics markets already been proven drivetrain loss is %, and actually higher the hp, higher the drivetrain loss... from engine dyno to chassis dyno, they have seen as much as 25% to even 30% drivetrain loss

example link: Comparing Chassis and Engine Dynos - Hot Rod Network


here is a 2017 Ferrari 488 spider with engine dyno @ 660hp, this dude put the car on a chassis dyno... see how much % the drivetrain loss is ?
 

·
Registered
Joined
·
313 Posts
Its a forum, where would it not be the right place to post? I see exactly what you mean, and honestly, it might turn out to stay at the 40hp loss, who knows.

However, some of the drive train loss on a higher HP car also has other moving parts to consider due to it being boosted. For a SC, there is another pulley added, for Turbo, the spool is added, yes those things ultimately negate the power increase but Im sure those things play a role in drive train loss. Adding another pulley for example, means using a longer belt, using the crank pulley to do more work than it was originally intended for. Some of those big blower hot rods take a lot of electrical energy just to start the damn thing, which again affects drive train loss.

Im sure if we got deeper into the topic we would find rules of thumb for % loss if a Turbo vs SC to boost. With every action comes some type of reaction. Higher HP motors usually have different internal components too.

Those components, lets say are "better" than OEM, but come at a potential cost. One would reference car vibration. Adding more HP changes the balancing of the crank (ever so slightly) simply because of added force, does the vibration play a role in drive train loss? Im sure it does, how much, not sure. You get my point.
This was a 2pc rotor thread so I didn't think it would be the right place to post lol.
I agree by adding the supercharger, you add another variable to the equation. For turbo though, the spool doesn't really create a loss imo since you are just using the exhaust gasses that would otherwise exit out the exhaust to make the power but that's another topic for another time.

better yet let's make it more simple and add only an intake, downpipe, and a tune. There are no new variables, exact same drive train. Would you still believe it's a 20% drive train loss and not 40 hp drive train loss?

If stock is 205 crank with 160 whp(20%), most ppl with a bolt on+ tune has like 210 whp so with the 20% rule thats a 270hp crank car. so adding a intake downpipe and a tune somehow costed the car 15 more hp to turn the same exact drive train? Doesn't make much sense right? The heat generated from just a bolt on and a tune i'm sure is negligible compared to adding force induction.

Actually, let's make it even more simple. Let just add only a tune to the stock car. I see ppl pushing like 180 whp with just a flash pro tune on a stock car. if you follow the 20% rule, the car has 231 crank hp. By just tuning the car, it costed the car 6 hp with everything else exactly the same?

I'm glad you get my point though since he doesn't seem to not understand what I am trying to say. The point above was basically what I was trying to get across.

domestics markets already been proven drivetrain loss is %, and actually higher the hp, higher the drivetrain loss... from engine dyno to chassis dyno, they have seen as much as 25% to even 30% drivetrain loss

example link: Comparing Chassis and Engine Dynos - Hot Rod Network
No offense but I don't think you get what I am trying to say. I give up. I don't need google links and videos. I've already done my own "googling" and my question has yet to be answered by you.

I am not going to watch a 7 min video but let's say that 660 hp engine dyno ferrari put out 560hp (15%). Now is the car really taking 15% of the power to move the drive train or is it taking 100 hp to move the drive train? Do you get me now? I'm not sure how else to explain myself better.
 

·
Registered
Joined
·
11,032 Posts
Discussion Starter #36 (Edited)
This was a 2pc rotor thread so I didn't think it would be the right place to post lol.
I agree by adding the supercharger, you add another variable to the equation. For turbo though, the spool doesn't really create a loss imo since you are just using the exhaust gasses that would otherwise exit out the exhaust to make the power but that's another topic for another time.

better yet let's make it more simple and add only an intake, downpipe, and a tune. There are no new variables, exact same drive train. Would you still believe it's a 20% drive train loss and not 40 hp drive train loss?

If stock is 205 crank with 160 whp(20%), most ppl with a bolt on+ tune has like 210 whp so with the 20% rule thats a 270hp crank car. so adding a intake downpipe and a tune somehow costed the car 15 more hp to turn the same exact drive train? Doesn't make much sense right? The heat generated from just a bolt on and a tune i'm sure is negligible compared to adding force induction.

Actually, let's make it even more simple. Let just add only a tune to the stock car. I see ppl pushing like 180 whp with just a flash pro tune on a stock car. if you follow the 20% rule, the car has 231 crank hp. By just tuning the car, it costed the car 6 hp with everything else exactly the same?

I'm glad you get my point though since he doesn't seem to not understand what I am trying to say. The point above was basically what I was trying to get across.


No offense but I don't think you get what I am trying to say. I give up. I don't need google links and videos. I've already done my own "googling" and my question has yet to be answered by you.

I am not going to watch a 7 min video but let's say that 660 hp engine dyno ferrari put out 560hp (15%). Now is the car really taking 15% of the power to move the drive train or is it taking 100 hp to move the drive train? Do you get me now? I'm not sure how else to explain myself better.

the Ferrari actually dyno'd around 520, it's a 20% loss... i understand what your asking... how about this... here is a link for the same argument link: VWVortex.com - Drivetrain Loss: Percentage or fixed value?

read through it & we can discuss this later today.. also, civil, open discussion is always great for the community, even if this is off-topic, this is how we learn, at our local 9th gen civic only car meet, that is all we do, we learn and discuss each parts 1 of us have put on the car and we do test on it. that is how we know what parts works what parts don't and why it works and why it doesn't...
 

·
Registered
Joined
·
181 Posts
Boosted,

You are very clever when it comes to making your argument, I like the style! However, my counter argument will be a repeat unfortunately. When you said

"better yet let's make it more simple and add only an intake, downpipe, and a tune. There are no new variables, exact same drive train. Would you still believe it's a 20% drive train loss and not 40 hp drive train loss?"

The intake, DP and Tune are all new variables, since you added them vs keeping stock set up. Regardless of what you add or take away, the physical act of doing such constitutes as a “variable”. Now the intake, DP or tune doesn’t havea rotating assembly so it doesn’t directly play into the drive train since it’snot part of that system.

However, adding more HP always, no matter the amount, will change how the car performs and I assert that with more or less HP/TQ, it will affect drive train loss. Think of it in terms of heat (referring to the turbo),the turbo may not really pose a resistive factor, due to using the energy of the exhaust to spool the turbo. However, with more intake, from the compressor side, that gets shoved into the valves, those valves, rockers, pistons, rings,crank, the entire engine basically, will be affected. (I purposely avoided responding to your comment about the added HP if the drive train loss stays at the same %)

Yes, the turbo makes more HP and TQ, no doubt, but it also generates a TON of heat in the process, which was one of the main highlights ofone of the articles Team3d had posted and something that more or less is commonknowledge. More heat = less power.


Let’s zone into the effect of a turbo on the physical enginefor a sec:


The engine takes in a ton of more air, and thus changes the speed of the pistons, which turn the crank. So now the pistons are basically flying up and down at radically higher speeds and putting a substantial load of force on that crank shaft, which was built with a tolerance spec of how much power it can handle before cracking, but it’s even more detailed that just that (think of the radical increase in engine vibration). The crank now, with all of that new force turns at a much faster speed, faster than the engine was originally designed for. This affects the longevity of all of the internal working parts (oil system, bearings, rings, rods, pistons etc.) and also this affects the head of the engine too. Those tiny little valves that are moving faster than rabbits getting it on, are generating significantly more heat now that the turbo was added.

On top of that, the internal engine temperature can reach very high temperature to the point where physical parts can break/deform.

I look at this even simpler. No matter what, materials are never held constant, basically I’m pulling out some 10[SUP]th[/SUP] grade chemistry now. Metals: (iron, aluminum, titanium, copper, zinc, etc) they all function differently at different temps. Some metals have higher tolerances that can withstand more heat but that doesn’t necessarily affect the structural integrity of that metal, some metals however can experience deformation/bending at certain temps.
I could go on forever, but I think you get my point. Adding heat to an engine which is what forced induction does, will affect in some way shape or form the performance of the working components of the engine. When you start affecting so many working parts of the engine, it will affect drive trainloss, to what extent, who knows!

And I would even assume that more drive train loss occurs because of forced induction (just ask those members who experience wheel hopafter they added their turbo/SC, a perfect example of the drive train being effected)
 

·
Registered
Joined
·
4,055 Posts
Power train loss is from the loads of the transmissions and weight. Too many variables and just like tuning there is no guarantee to actual torque increase or loss because of cycle to cycle variations. It will only tell that you're heading in the right direction. Friction of the oils and temps also play a role because as the engine produces more power, friction is greater because of increased heat and pressures so torque gains might not be accurate, that is why racing teams time and datalog everything to see a pattern and then predict expected results. Turbo/SC produces positive air flow compared to vacuum in a N/A engine.
 

·
Registered
Joined
·
313 Posts
the Ferrari actually dyno'd around 520, it's a 20% loss... i understand what your asking... how about this... here is a link for the same argument link: VWVortex.com - Drivetrain Loss: Percentage or fixed value?

read through it & we can discuss this later today.. also, civil, open discussion is always great for the community, even if this is off-topic, this is how we learn, at our local 9th gen civic only car meet, that is all we do, we learn and discuss each parts 1 of us have put on the car and we do test on it. that is how we know what parts works what parts don't and why it works and why it doesn't...
I actually already did read that. It's one of the results that pop up when i search "drive train loss is fixed or percentage" I don't go into a debate with absolutely no research. That would give me no chance of winning:pray:

Boosted,

You are very clever when it comes to making your argument, I like the style! However, my counter argument will be a repeat unfortunately.
I love to debate! Just one of the things I like to do. Just really hard because sometimes people get frustrated and mad at you when you don't agree with them.

Yeah, you are correct about turbos actually. Bringing up the turbo was not really a smart thing to do on my side lol since you add tons of heat and pressure into the system which does technically produce more loss. And with a supercharger we all know that it takes power to make power.
I mean, things can never really be a fixed value because of the many variables that it has. if that is the case, the rule of thumb is also wrong also because you are assuming a 20% FIXED percentage value.

If all else is stock and you add a Tune to the car you really believe that it creates enough heat/friction to lose an additional 6hp? Your right that it might possibly lose more than the factory loss of 40hp but I doubt heat/friction from just a tune causes that much of a loss.

The conclusion is most likely "in between". It is neither fixed value or fixed % but rather a number in between which is impossible to find due to the number of variables that it has from the air intake cycle to the exhaust cycle.
It just has always been on the back of my mind when people refer to the 20% loss.
 
21 - 40 of 74 Posts
Top