Reducing parasitic loss in the transmission

Any form of normally aspirated power mods.
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Re: Reducing paracitic loss in the transmission

Post by PeteH » Tue Jan 24, 2017 1:36 pm

Right, here we go...

Alan, you got 90% right. The only bit that's slightly wrong is that when you pump the tyres up you don't necessarily get less grip. The reason is; when you add tyre pressure the contact patch area reduces, but the pressure in the contact patch increases. The two effects "counteract" each other to leave you with the same friction coefficient. It is easier to ignore areas and pressures, and just consider loads. The friction coefficient is "peak shear load / vertical load", and your vertical load has not changed, so your peak shear load doesn't change. Of course, in the world of tyres, nothing is simple, and there are many complications, but to a "first order assumption" grip is independent of pressure. I could go into more details about why this is the case, but that would be getting tediously nerdy :?

Is rolling resistance the same thing as friction? People do sometimes use them interchangeably ("rolling friction", which is a nasty phrase!), but no, they are not the same thing. Rolling resistance is caused by internal "hysteresis" within the tyre, which causes the tyre to heat up internally (without any sliding or slipping). Chris and Alan are right, and it is primarily belt bending. The mechanism that causes rolling resistance is this internal heating, and that is due to the nature of compounds that make up a tyre. If you take a piece of rubber and bend it backwards and forwards quickly it will get hot, and you will have done work, this is exactly the mechanism that causes rolling resistance. Nothing to do with friction (which is peak shear force / vertical load, as mentioned above).

Now people will often get into semantics here and say that if a tyre requires a force to push it along the ground then that is exactly the same force as you need to push anything along the ground, therefore that can be called friction. But you can't just define your own terms for these things (that's not the way we define words, to nick a phrase from BREXIT ;) )

Tyres have a friction coefficient (usually between about 0.8 and 1.2), and they have a rolling resistance (usually between about 50N and 500N, depending on many things). The two things are different.

Hope that helps.

Edit. I wrote this before your reply Conan. As I said, some people do use the term "rolling friction". It's often used with reference the things like rotating bearings. It can be helpful in that field, since it adequately describes the force (or torque) that opposes motion (which sounds a bit like friction). But even rotating bearings are actually subject to rolling resistance, not true friction. They suffer rolling loss due to localized bearing deformation, and lubrication shear losses. These cause the bearing to get hot (just like a tyre). In the world of bearings it doesn't get confusing because true friction (balls sliding against races) almost never happens, so they only have one term to worry about. The bearing people can do what they want, I suppose, but in the world of tyres rolling resistance is a separate mechanism to friction, and we keep the two terms discrete and separate.
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Re: Reducing paracitic loss in the transmission

Post by Conan » Tue Jan 24, 2017 2:10 pm

The OP has his car at Rotary Revs.
So we can conduct a clinical test : The OP can pump his tyres up to 50 psi before the power run.
He can then watch the wheels being removed and the hub dyno fitted.
In this instance it,s all the same and totally irrelevant ;)
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Pete
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Re: Reducing paracitic loss in the transmission

Post by ChrisHolmes » Tue Jan 24, 2017 2:24 pm

Oh dear, dear someone is getting flustered. At the risk of attracting yet another unnecessary comment from you Pete the point about increased tyre pressures is valid when the dyno in question is a rolling road type. I am sure everyone would realise that when its a hub dyno tyre rolling resistance etc; is not a factor to be considered.
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Re: Reducing paracitic loss in the transmission

Post by benedunn » Tue Jan 24, 2017 3:06 pm

PeteH wrote:If you get 200 rwhp at Ben's then I'd just be happy with having one of the most powerful NA cars around. :thumright:
Cheers Pete,

Ours is a hub dyno, I went that way to increase repeat-ability. We don't give calculated flywheel numbers to anyone on principle :thumleft:

The trouble is, as has been covered, there are already far too many variables so the more we can do away with the more accurate and consistent the results will be.

The 1st thing a good tuner needs to do is realize that the actual numbers that your car puts out are at the end the least important aspect of the process, and then try to explain that to a customer and help them understand that. What matters are how the car runs, performs and how much of an increase is made. That last bit is what the dyno is really there to measure, 'what have we achieved?' is measured in that gap between before and after, what the actual numbers are is irrelevant. And the only way to accurately measure that gap is to do away with as many variables as you can, repeatability is key and that is why we refuse to hand out figures that people want and measure everything by the same yardstick. I already cannot count how many disappointed faces I've seen whilst settling a bill over the dyno graph numbers, only to get a phone call 10 mins later from a very exited person shouting 'f*** me what have you done to my car!'. Take my word for it making average 15ftlp between 3000 and 6000 rpm is so much more noticeable and beneficial than making 20hp at 9000rpm!

Remember that horsepower is a CALCULATED NUMBER! Yep, and it might take a moment to for it to sink in, but think about it the calculation for HP is Horsepower = (Torque x Engine Speed)/5252 - Torque is the force measured, HP is only a calculation off of that measurement. So if you increase RPM but maintain the same amount of torque ... you make more HP without actually producing a single ounce more power ;)

Quickly though, I'll address the op's question :) Dan is right, reducing the rotating mass will increase wheel horsepower and yes that is measurable. If less force is required to move an object in its path then more force remains after the fact to be measured. The principle works in exactly the same way as carbon fiber prop shafts or lighter wheels etc etc


Back to my rant though, Ben the owner at Eurospec wrote this, basically a rant! It outlines a lot of hard truths and I can tell you address's the points that once on this side of the fence perfectly. I think it would be wise to print it off and stuff it down various facebook idiots necks to stop the spread of bull and stupidity :roll:

Have fun

One of the things that I really hate about the tuning industry is this:

Whoever quotes the least money in return for the biggest number of Horsepower; no matter how unrealistic either of those numbers, will get the job. The worst of it is that many companies have absolutely no intent whatsoever of delivering either that power figure, or for that number of pounds. This comes about either through ignorance, or through a deliberate attempt to blag the customer.

When its ignorance, for example, not realising that you need fuel injectors and an ecu to reach a certain horsepower target on a certain car, the tuner will try one of two things:-

1. Increase the price. In order to deliver what you want, the tuner will have to increase the price. He cant fund your ecu and injectors out of the profit in selling and fitting a turbo. Trust me, the margin isn’t there! Now you are not gonna be paying the amount you thought you were in the first place, so the whole basis of the purchase decision is gone.

2. Fake the results. Seriously, that’s what they do. They have told you £x, they figure out they have under-quoted and they need more stuff to make the car do the power they promised. They cant go back to you and tell you that you need x,y or z because it makes them look like they don’t know what they are talking about. Their pride prevents them from admitting they were wrong. So they fake the dyno results.


The true blaggers. These guys are out there and they are not uncommon. I could name a list of tuners who do this. Its morally wrong, its dishonest and it gets the industry a bad name. But trust me on this, it isn’t uncommon. They have no care or idea if they will get the results that they told you for the £ they have told you. None! They just take your money, say the right things, and then give you the results they told you they would. But since they cant truly deliver the results for the £ that you have agreed, they simply cheat on the Dyno. For a long time I did not believe the extent to which you can fudge a dyno, but after seeing a bone stock Impreza make 14,410 BHP, then I know that it can and is done.

While I’m on the subject of numbers, be wary of any tuner who confidently asserts you will get a certain horsepower number. You cannot ever know. Every car is different. The tuner hasn’t even seen your car. How do you, let alone he, know what its power output is now. And so how can he say you will get 400bhp for sure for the £200 you are going to spend without even clapping eyes on your car! Tuners who are more honest will couch their language, they will say ‘it should make’ or ‘in the region of’ or ‘ those mods normally see an increase of’.

Defending yourself against being ripped off. There is nothing I can do to stop the guys who deliberately quote low to get the job, and then ‘add stuff’ to the price afterwards. It isn’t a straightforward way of doing business, its certainly sharp practice, but there is little I can do to stop it. My only advice is, if it sounds too good to be true, it is.

But the guys who cheat the dyno, that I can help with. The more people who understand how a dyno works, the more people can defend themselves from being blagged by unscrupulous or dubious tuners. The more you understand, then the better protected you are, and the more you will understand about the tuning process.

FACT The process of tuning a petrol engine, any engine, is the same. It is a process through which you isolate variables, and test different combinations to deliver the best torque for a given operating condition. Most proper professional tuners, the people who know and use this process will get within 5% of each other in terms of out and out power output. So you know what? When someone claims to be able to get more power than anyone else, or who consistently gets higher numbers than anyone else, then its bull. Walk away. If they already worked on your car, then get it checked somewhere else.

So how do you spot a dodgy dyno graph? Lets have a look at a pucker one.

Dyno Mode First of all, dynos have multiple modes. Pretty much every dyno will have a power test mode. For Dyno Dynamics, which is more or less industry standard now, its called Shootout. In Shootout mode, the ramp rate, and inertia of the dyno are fixed. Changing these variables- particularly the inertia will dramatically change the power output which is calculated. So you want to make sure that the dyno graph shows the shootout mode that the car was run in. If its not there, then the dyno wasn’t in shoot out, and so the reading is bull.


On the digital dynos, the mode is shown in the data box. Its also shown in the run summary at the bottom of the page. Here is a data box for you. See it shows the Shoot out mode as shoot-4

On the older dynos, the same data is printed at the bottom of the page.

Dyno Dynamic Shoot Out Modes Shoot-4 4 cylinder Normally Aspirated Shoot-6 6 cylinder Normally Aspirated Shoot-8 8 cylinder Normally Aspirated Shoot-4F 4 cylinder Forced Induction Shoot-6F 6 cylinder Forced Induction Shoot-8F 8 cylinder Forced Induction Shoot-44 All 4 wheel drive NA and Forced Induction Shoot-2R Twin Rotary Shoot-3R Triple Rotary

So if you cant see the shootout mode displayed- start calling bull. If the data box is not there, then the data on your print out is useless. The databox only comes out as a check when the dyno is in shootout mode.

It’s a reasonable question to ask though, why do dynos have multiple modes at all if it simply introduces the possibility of a fudge taking place? The answer is that in order to remap a car, you have to put it through all the load cells in the map. In order to isolate a load cell, you need to hold the car at a certain load and certain speed. This lets you sit in that load cell and then optimise the parameters for it, before moving on to the next. This part of the tuning process is called steady state. The dyno needs a different mode to do this speed and load holding, and you need variable inertia to cope with heavy or light drive trains. You also need variable ramp rates to stress test an engine under the most arduous conditions it can face to ensure it is safe for your customers to use in those conditions.

While I mention steady state, here is something to consider. If you don’t see your tuner doing steady state, or at least checking the car in steady state, then you need to walk away too. Its lazy tuning, it’s the recognition by unscrupulous tuners that a customer will accept a car that drives like a bag of nuts as long as the full power delivery is okay and the number is big. A properly mapped car will drive nicely and even with pretty wild mods can be made to behave in a civilised manner. But only if the tuner can be bothered.

Atmospherics When a dyno gives a power reading- any dyno- it’s a reading that its corrected for standard conditions. That means standard temperature and pressure. That’s why a decent dyno will have a weather station on it. When it has a weather station, the dyno measures barometric pressure, relative humidity, air intake temperature and ambient temperature and it uses these to give a reading that is corrected to standard temperature and pressure.

So when you read a dyno graph, you need to look at the atmospheric data. Is it reasonable? On a day when the pressure is high, the air is denser and so the car makes more power. The dyno will compensate this out, to give a number that’s corrected for standard temperature and pressure. An unscrupulous tuner will use this to his advantage. By turning the weather station off and altering the atmospheric data, or on older dynos, by simply entering false data, the operator can generate a power output that is greater than the actual. So say it’s a high pressure day, but the dyno operator enters a baro pressure that is low, the dyno correction will increase in a positive direction, and so the power number that is generated will be artificially high.

Conversely, if he wants to show you how poor the last guys map was, he will enter a barometric pressure that is higher than it actually is, so as to generate a negative compensation and artificially lower the power number. He’ll then remap it, flip the barro reading down to invert the correction fudge again, and hey presto, a ‘mapping god’ who has just got 50bhp out of your car for zero work. The customer will drive off happy having had hundreds of pounds removed from them for nothing.

The same thing happens with intake temperature, but to a lesser degree. The higher the IT goes, the greater the atmospheric correction applied. If the intake temperature is 30 degrees c, but the dyno operator wraps the probe round the exhaust, then the recorded intake temperature will be much higher than the actual. This will give a false high power number. This happens because as air temperature increases, its density reduces something like 3% for every 10 degrees. The dyno compensates for temperature and pressure when it gives its result, so entering a false high IT will give a false positive correction.

Be careful however. Under bonnet temperatures can get very very hot, particularly on turbo cars. So when you call BS on a high intake number, be aware that you can easily see +30 or +40 degrees over ambient temperature on an intake temp. What you need to look for is consistency. If the intake temp was 5 degrees above ambient on the before run, but yet it was 35 degrees above on the after, then that’s BS. If the number variance is consistent, then that’s fine. Many tuners are also aware that since a high IT is visible and commonly known about, they don’t fudge the results this way. Its easier to run outside shoot out mode, or fudge the baro.

Lets take a look at the data box again.

The first line is labelled BP, barometric pressure. In this box its 970pa. That would be a pretty low pressure day. So the day this was done on would have to be a nasty poor weather day. The RH, relative humidity, is also high, which tends to support it’s a wet dull nasty day. If it was bright and sunny that day, its time to call horse poop!

The third line is AT, ambient temperature. 13 seems reasonable given that it was a wet, nasty day. IT is intake temperature. Its 17 degrees c. That’s a 4 degree variance. I’d be expecting that this graph was generated from a naturally aspirated car with a cold air intake with a short pipe run under the bonnet.

Loose Strapping When you buy a dyno, they teach you how to strap a car down. The straps are there for the safety of the car, the dyno and anyone else in the area. They hold the car to the dyno and then ensure proper grip at the tyres.

Loose strapping is when the straps are set very loose- so loose that the car is physically climbing out of the dyno bed. When this happens, the car will climb the rollers. When its doing that, not only is the force of the cars wheels turning the rollers, but gravity is having an effect too. This can introduce a variance of upt o 10%. It’s a favourite with your sketchy tuner, because you can't see it in a dyno graph. When your car is strapped correctly, it will move slightly on the rollers, not a lot. If it's moving around a lot, then the straps are too slack and someone is trying to pull something on you.
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Re: Reducing paracitic loss in the transmission

Post by Conan » Tue Jan 24, 2017 3:09 pm

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Re: Reducing paracitic loss in the transmission

Post by ChrisHolmes » Tue Jan 24, 2017 4:28 pm

Excellent post Ben, not to ignore other folks informative posts too, thank you.
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Re: Reducing paracitic loss in the transmission

Post by MARKTHOMASBRAND » Tue Jan 24, 2017 5:27 pm

Can someone change the title so it spells parasitic correctly please :?: :whistle:

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Re: Reducing parasitic loss in the transmission

Post by delta0 » Mon Apr 03, 2017 8:41 am

Keeping everything as straight as possible by using stiff mounts will help reduce losses. Using the best oil possible as the 2 easiest ways to keep the losses to the minimum.

I've seen in a few places that the 8 goes into save the cat mode on the dyno which causes power to reduce a bit and coupled with drivetrain losses around 20%.
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Re: Reducing parasitic loss in the transmission

Post by Velocity_Dan93 » Mon Apr 03, 2017 11:03 am

delta0 wrote:Keeping everything as straight as possible by using stiff mounts will help reduce losses. Using the best oil possible as the 2 easiest ways to keep the losses to the minimum.

I've seen in a few places that the 8 goes into save the cat mode on the dyno which causes power to reduce a bit and coupled with drivetrain losses around 20%.
I read somewhere that the red line gear and diff oils are suppose to give you an extra 1 whp :P cheapest way to improve power so far lol
Stiffness ect is also very relevant. Solid engine mounts and and full round polybush might improve things but where do you draw the line ? Mine was the solid engine mounts so I've dropped a set of poly filled ones in. Full polybush is on the cards though
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Re: Reducing parasitic loss in the transmission

Post by PeteH » Mon Apr 03, 2017 11:09 am

Sorry peeps, but the ppf keeps the engine, gearbox, propshaft, and diff perfectly in line. The only angulation that the stiff bushes will help is the rear driveshafts, but they are low loss CV joints that loose nearly nothing when running at an angle. Don't expect more power when you polybush!
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Re: Reducing parasitic loss in the transmission

Post by Velocity_Dan93 » Mon Apr 03, 2017 11:13 am

PeteH wrote:Sorry peeps, but the ppf keeps the engine, gearbox, propshaft, and diff perfectly in line. The only angulation that the stiff bushes will help is the rear driveshafts, but they are low loss CV joints that loose nearly nothing when running at an angle. Don't expect more power when you polybush!
Very interesting !
Out of interest Pete what gear and diff oil do you use ?
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Re: Reducing parasitic loss in the transmission

Post by PeteH » Mon Apr 03, 2017 11:15 am

MT90 and PA90. I'm not convinced by MT90 though, because it doesn't let me change gear fast enough.

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Re: Reducing parasitic loss in the transmission

Post by delta0 » Mon Apr 03, 2017 2:00 pm

PeteH wrote:Sorry peeps, but the ppf keeps the engine, gearbox, propshaft, and diff perfectly in line. The only angulation that the stiff bushes will help is the rear driveshafts, but they are low loss CV joints that loose nearly nothing when running at an angle. Don't expect more power when you polybush!
Interesting thanks! There must be increased losses from worn engine mounts? The gear changes being a little harder is a sign that things aren't as straight as they should be.
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Re: Reducing parasitic loss in the transmission

Post by PeteH » Mon Apr 03, 2017 4:09 pm

delta0 wrote:
PeteH wrote:Sorry peeps, but the ppf keeps the engine, gearbox, propshaft, and diff perfectly in line. The only angulation that the stiff bushes will help is the rear driveshafts, but they are low loss CV joints that loose nearly nothing when running at an angle. Don't expect more power when you polybush!
Interesting thanks! There must be increased losses from worn engine mounts? The gear changes being a little harder is a sign that things aren't as straight as they should be.
The power train alignment doesn't change. When the engine mounts collapse the gear lever isn't correctly aligned in the transmission tunnel, and can have its travel restricted, which can cause gear selection issues. Also, the gear lever can wobble around, making the change more challenging. But none of this affects the power train alignment, or the power train efficiency.
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Re: Reducing parasitic loss in the transmission

Post by delta0 » Mon Apr 03, 2017 4:54 pm

PeteH wrote:
delta0 wrote:
PeteH wrote:Sorry peeps, but the ppf keeps the engine, gearbox, propshaft, and diff perfectly in line. The only angulation that the stiff bushes will help is the rear driveshafts, but they are low loss CV joints that loose nearly nothing when running at an angle. Don't expect more power when you polybush!
Interesting thanks! There must be increased losses from worn engine mounts? The gear changes being a little harder is a sign that things aren't as straight as they should be.
The power train alignment doesn't change. When the engine mounts collapse the gear lever isn't correctly aligned in the transmission tunnel, and can have its travel restricted, which can cause gear selection issues. Also, the gear lever can wobble around, making the change more challenging. But none of this affects the power train alignment, or the power train efficiency.
That makes sense. :)
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Re: Reducing parasitic loss in the transmission

Post by StreetDragster » Mon Apr 03, 2017 4:58 pm

PeteH wrote:MT90 and PA90. I'm not convinced by MT90 though, because it doesn't let me change gear fast enough.
I also have moved away from mt90, using royal purple max gear at the moment.
Feels very slick, but a transmission oil cooler was added at the same time so maybe a factor.


Good post Ben, very interesting


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ChrisHolmes
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Re: Reducing paracitic loss in the transmission

Post by ChrisHolmes » Mon Apr 03, 2017 11:47 pm

MARKTHOMASBRAND wrote:Can someone change the title so it spells parasitic correctly please :?: :whistle:

Regards,Mark.
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zippyonline
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Re: Reducing parasitic loss in the transmission

Post by zippyonline » Tue Apr 04, 2017 4:36 pm

PeteH wrote:I'm not convinced by MT90 though, because it doesn't let me change gear fast enough.
In my BMW (6MT) I have a 50:50 mix of the redline MTL and ATL fluids in the gearbox - which made it slicker to change than just standard manual transmission fluid. (Mind you, I still find it a crap gearbox compared to the mazda gearbox I'm used to).
I did read into it first and make my own conclusions - but maybe something to consider?
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Re: Reducing parasitic loss in the transmission

Post by cyman » Tue Apr 04, 2017 5:12 pm

ive not read all of this but have browsed so these points have probably been brought up

with thing like flywheel reduction and weight reduction in wheels and the like, isnt that just changing the rotational mass that the engine has to push albeit in the same way you take weigh out of the body. i know there is a caluclation somewhere that confirms that removing rotational mass is better than removing x of the static the mass through normal weight saving from the body so if you removed xkg of rotational mass its as good as removing xkg out of the body. so lightening these things will not increase maximum horsepower but the speed at which the maximum horsepower is improved ie the acceleration of the car will become quicker once moving. now i say once moveing because isnt the flywheel also designed to act as an energy store ie weight and revolutions stores x amount of energy or bhp so this would mean if you rev the car to say 6k revs and dump the clutch you would actually have faster acceleration from standstill as you can exploit the stored energy or bhp held in the flywheel. so if you have a lighter flywheel you reduce the energy storage you would have at 6k revs but you would have less rotational mass to move when accelerating in gear when the flywheel is no longer acting as a store for energy but is moving at a constant rate with the engine.

pretty much everything else that can be improved like the engine mounts excessive movement in the drive train woll do the same thing no more peak horsepower but improvements in how that horsepower gets to the back wheels.

all other losses will be through every moveable item within the drivetrain and engine like the normal frictional loses within bearings friction between gears differential losses etc as im sure its already been said unless you strip the gearbox and have some super low friction gears and bearings all you can do is get the optimum oil for any scenario so one that is as thin as possible but that is thick enough to meet the demands of the gearbox and diff.

like i said its prob all already been said but i felt the need to post anyway :)

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Re: Reducing parasitic loss in the transmission

Post by PeteH » Tue Apr 04, 2017 5:59 pm

Mostly I agree, but two things I don't:
1) stiffening the mounts doesn't change the way the power gets to the rear wheels. That was the point of my post below. It makes no difference. At the most it slightly reduces the time delay between applying the throttle and getting a response. But that time delay is milliseconds, so you will never notice it.
2) Although you are correct that a flywheel can store energy, which can be converted to power when you drop the clutch, that extra power is useless because the engine has more than enough torque to spin the wheels anyway. So, yes, a heavy flywheel allows you to spins the wheels even more easily from a standing start, but it doesn't help the car accelerate any faster. And as soon as the clutch is fully home and the wheels have gained traction then the lighter flywheel will win every time.

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Re: Reducing parasitic loss in the transmission

Post by cyman » Tue Apr 04, 2017 6:15 pm

PeteH wrote:Mostly I agree, but two things I don't:
1) stiffening the mounts doesn't change the way the power gets to the rear wheels. That was the point of my post below. It makes no difference. At the most it slightly reduces the time delay between applying the throttle and getting a response. But that time delay is milliseconds, so you will never notice it.
2) Although you are correct that a flywheel can store energy, which can be converted to power when you drop the clutch, that extra power is useless because the engine has more than enough torque to spin the wheels anyway. So, yes, a heavy flywheel allows you to spins the wheels even more easily from a standing start, but it doesn't help the car accelerate any faster. And as soon as the clutch is fully home and the wheels have gained traction then the lighter flywheel will win every time.
Fair point in no expert and it was a long time ago for me that I learnt about this stuff in college like 30 years :)

I think for me I was just thinking to the nth degree based on the op,s first post.
I get the point about lightened flywheel and I wasn't saying it was better I was just remembering some of the stuff I was taught and why it's there in the first place.
Regarding engine mounts like you say very tiny differences but also remember it's the loading and unloading not only of pull aways but coming on and off throttle and gear changes that solid mounts firm up and even a change you may not be able to feel as it so small is worth taking. As there is no magic wand to massively improve things for those that are trying to reach rx8 nirvana it is the tiny things that add up to a tangible improvement no matter how small.

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Re: Reducing parasitic loss in the transmission

Post by PeteH » Tue Apr 04, 2017 6:32 pm

Again, I pretty much agree. I just wouldn't want people to spend hundreds on engine and diff mounts, thinking their car will go faster. It won't. I am chasing hundredths, and I haven't yet been able to justify stiff engine or diff mounts. The car just doesn't need them yet, and there are still many things I want to do that will make a tangible difference.

Don't get me wrong, stiff mounts may well make the power train feel more sporty (possibly at the expense of noise and vibration), and if that matters then go for it. But if you want to actually go faster then spend your cash on something else.

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Re: Reducing parasitic loss in the transmission

Post by WildMan10 » Tue Apr 04, 2017 7:07 pm

Good to see some meaty knowledgeable posts here, a pleasant change from the little bit of knowledge and masses of ignorance that abound.

My mate got another 30 bhp out of his RX8 with a cup of tea by sticking the dyno's temperature probe in it. IIRC he got over 350 bhp from a 231 using dyno cheats like that.

As for the initial point on parasitic losses, imo there is little, if anything, to be done. You can gain a little by using thinner gearbox and diff oils but the cost in lower gearbox reliability and life is IMO too high. Lighter flywheels won't reduce losses but will improve acceleration at the expense of road driveability.
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Re: Reducing parasitic loss in the transmission

Post by zippyonline » Tue Apr 04, 2017 8:23 pm

WildMan10 wrote: using thinner gearbox and diff oils but the cost in lower gearbox reliability and life is IMO too high.
Yes, about an hour later I realised what I posted, especially in respect to the 6 speed box on the 231 - and I even pointed it out to Pete in the first place :oops:
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