For the type of steering where the motor directly drives the steering column, I guess it would be zero, when you're not turning the wheel. I think there's also a type where the electric motor turns a conventional hydraulic pump. The power loss there would be interesting to know.
I was thinking about this some more and it's a somewhat dumb idea because you can just measure the wattage the EPS is drawing which directly correlates to horsepower (748W = 1HP).
On my '99 the PS was 14lbs, and most of that would have been on the heavy corner. I swapped to a welded rack. For the first couple days, you think you have made a mistake, but once you get to understand it, you wouldn't go back. PS has the biggest effect when you are parked or moving very slowly. At highway speeds or autocrossing I don't notice it. What I do notice is that I get more feedback from the wheel. On low grip surfaces and near the limit, the wheel feels a little dead, so it lets you know how much traction is available. On an off ramp near the limit, the resistance on the wheel changes with momentary changes in grip level. Your hands do shake a bit, and you or your passenger may find that disconcerting. But to me, the connection between car and driver is just that much better. I'm pretty big, but don't lift weights-- small drivers might find this mod to be too much.
I've found this to be accurate on the 89 Civic I had with manual steering. Heavy real slow/still, gets lighter when traction lessens like at speed or wet pavement. Feel is amazing though. Makes you work when parking.
I'd love to see the same test with AC on vs off. It would also be cool to see this comparison done with an older car (NA or NB) compared to a modern one (ND).
For the NA/NB cars, Mazda knew they didn't have enough power to both accelerate and run the AC compressor :) so if you go to WOT, the AC clutch disengages automatically. For the newer ND cars, they switched to electric power steering, which would still be a valid test, as we'd be testing the extra load on the alternator. Speaking of alternator, that would be a good test. I'm already imagining installing a switch to disconnect the alternator before each autocross run :)
I've always had a theory about skin friction in a few of the pumps in an engine, like the oil and coolant specifically. I've always wanted to polish the inside of the passages to reduce skin friction and pumping losses. I put this theory into practice years ago with a td04 turbo. I polished the inside (all the way through the housings) and i took it a step further by polishing and sharpening the compressor and exhaust turbines so they would slice through the air. After installing i went way lean on acceleration, had to add throttle enrichment, once I did that, the additional torque smoked my transmission in about 7 days. The turbo eventually blew too because I didn't get it balanced. Anyway it would be cool if you could try something like this if anything on the water pump or oil pump. It would awesome to see the dyno numbers.👌
Yeah that’s pretty interesting. I removed the power steering on my 90 last week. For now it’s just looped but in a few weeks I plan on finishing the job. Was waiting on new SuperPro bushing for the rack. For me I didn’t notice much of a performance difference. I don’t have A/C but I’m sure there is but it wasn’t noticeable. As it is looped I like the weight of it driving. It’s on the heavy side bellow 20km/h but driving it’s really nice. I think there’s probably still too fluid inside though. If I hit a bump well making a hard turns at low speeds it kicks back a little but it’s manageable. Roundabouts are two handed now lol. The most positive thing is now it’s super easy to access the heater pipe to change that o ring 👍
Niceee!!! I was conscient that the power steering pump takes some hp away, but i wasn't expecting to take that much OMG, specially when in full lock. Love your videos, could you make a video testing the diferent octane fuels and if more octane influences the hp, or not. Thanks keep the good work
I drove my 90 Civic hatchback for years without PS. Light cars with a manual rack are fine as long as you are moving. In fact, the steering feel is amazing with a manual rack.
Same, honda didn't put PS on the hatchbacks, only sedans. I removed the PS on an 89 accord, you could only tell when parking and it was still not bad, my wife drove it without complaint.
Yeah - so - what about ELECTRIC power steering? They don't have that for Miatas? Also - if you're up for it - what about testing the benefits of weight reduction in general, when using: 1. Aftermarket aluminium cam gears(adjustable - which tend to be lighter than stock - ESPECIALLY in some VVT engines) 2. lighter flywheels(& driveshafts - if within your budget) 3. lighter crankshafts(knife edged etc to remove unnecessary material) 4. lighter pistons 5. lighter wheels(& or the different effect wheel diameter has on performance\dyno figures) 6. lighter brake rotors(carbon ceramic or budget Drilled AND slotted 2 piece rotors - more so for a FWD car, but as ling as it's needs to be spun up it requires energy so...) ...My point being to see how much overall power can be had from an engine & drivetrain focused weight reduction - & to prove that several small tweaks like the one in this video can add up to decent power\efficiency\performance gains(so one should not stop at doing just one)...🤔
Less related to the Miata being setup for STS/STR - I’ve wanted to do a pseudo hybrid setup for years that has an electric steering pump, water pump, and AC compressor, with a custom lithium ion battery the same physical size as a stock lead acid, and then have the only accessory be a motor/generator that can start the motor and also blend how much torque is used for generation down to nothing at WOT. I’ve read BMW cuts alternator output to zero at WOT in some cars, and G.M.s mild hybrids of the past were interesting. The GMA T.50 has a mild hybrid like this too.
The NC Miata (MX-5) has a computer-controlled alternator. I don't have data showing exactly what the stock ECU does with it, but I remember needing to replicate the signal to keep the alternator charging the battery when doing standalone ECU stuff with those engines.
Manual rack has way better feel on corners least with the older stuff I used to drive, but I can imagine with the heavier car and some sticky tires you can turn out to be a pain in the parking lot
Interesting, thanks for doing this test, have to admit that I was a little surprised by the HP consumed by just having the pump installed. Would be very interested in see the test results of no alternator and water pump. I race in SCCA's STL (Super Touring Light). Most sprint races are from 20 to 35 minutes long. Some of my competitors use a large battery with no alternator and run an electric water pump. How much it is really worth?
Great question! In a racing application, I suspect most of the alternator's losses would be inertial rather than as a result of generating electricity. A race car may draw, for example, 20 amps to power the fuel pump, ECU, ignition, gauges, etc, which is only 280 watts. If we say the alternator is only 50% efficient and double that wattage, we're still only at 560 watts, which is around 0.75 HP. If he ever tests an alternator, it would be cool to see the difference between the alternator spinning under no load with the control plug disconnected compared to spinning against a load with all accessories on. Another variable is voltage though. With a lower voltage from the alternator not charging, the operation of the ignition system, fuel pump, fuel injectors, etc will be somewhat affected, which could affect the engine's performance.
I depowered my rack and could absolutely feel a difference on my 1.6. Unfortunately I hated the driving experience without it, so i added E-power steering. I've often wondered if the E-power steering adds additional drag on the alternator and if that can be quantified on a dyno. Great vid!
Absolutely it adds load, nothing is free and energy is energy. The question becomes is the belt powered alternator feeding an electric motor to power a pump more efficient than the belt powered pump. But the electric system only works when demanded so in a straight line you're free of that extra parasitic loss.
This is awesome info, is there an under drive pulley option for the Miata so you could reduce the amount the power steering pump would have to work but also retain some power steering?
I had an 89 accord lxi, the power steering system had a leak, so i removed it. I swore i could feel a power difference. I wonder if older cars had PS pumps that ate even more hp, or if they were just as efficient as modern ones
Your test is a little inaccurate... You are testing removal of BOTH the PS and AC - not just the PS. When I tested PS w/o AC on a 99, it was only a 2 HP loss (with the wheel straight). Still a good video and test but would be interesting to see the results w/o the AC for accuracy
Just go to a junk yard and pull an electric power steering system off a mid 2000's GM sport compact vehicle (Saturn ION, Vue, Chevy Cobalt, HHR, Equinox, etc.) and use that in place of the hydraulic system. Yes, you can spend 4 figures for a commercial electric power steering system, but most of them are literally just GM systems packaged to work on nearly every platform... The trick is that the CAN bus controller that normally feeds vehicle speed to the power steering system doesn't need to be present for the electric power steering system to work. The module that is attached to the steering system "fail safes" to a voltage input that can be controlled by a potentiometer when wired to certain input pins. There is a little more to it than that, but there are a few videos and DIYs online for adapting GM electric steering to other applications. Note: this is not a rack, but an assembly that goes inline with the steering wheel to assist the rack. A few yeas back my local pick-a-pull didn't realize they existed so they were selling steering wheel assemblies for like $25 each. On 50% off day I snagged a half dozen of them.. I put that sh!^ on everything...
No ac compressor I bought a 86 325e from someone who wanted to turn it into a drag car and took out the compressor I’m kinda wondering how much of a difference it makes because also something I didn’t notice was it had like a bump stop thing on the floor for the gas pedal side so I’d only be able to open up to about 40% throttle and when I had noticed it the car kinda just died on me weirdly (everyone tells me it’s wiring and I don’t doubt it is just because everything about it) it’s a rebuilt m20 so stock motor just no ac compressor (also 5 speed manual so I could technically go a bit higher in rpm highest I went once was 3500 other then when shit hit the fan and it got stuck at 4k steady end of red line is I think 6k or 5k somewhere in that range
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Next video idea: How much horsepower does electric power steering consume (from the increase in alternator draw).
For the type of steering where the motor directly drives the steering column, I guess it would be zero, when you're not turning the wheel. I think there's also a type where the electric motor turns a conventional hydraulic pump. The power loss there would be interesting to know.
yes but on a dyno there’s no actual load on the power steering and i guess the same would be true for the electric column
I was thinking about this some more and it's a somewhat dumb idea because you can just measure the wattage the EPS is drawing which directly correlates to horsepower (748W = 1HP).
@@ajsmith7018 A car guy would know that when the steering is hitting it's stops the power steering pump works it's hardest.
Much less than a power steering pump at least.
another interesting video, you guys honestly have great content
On my '99 the PS was 14lbs, and most of that would have been on the heavy corner. I swapped to a welded rack. For the first couple days, you think you have made a mistake, but once you get to understand it, you wouldn't go back. PS has the biggest effect when you are parked or moving very slowly. At highway speeds or autocrossing I don't notice it. What I do notice is that I get more feedback from the wheel. On low grip surfaces and near the limit, the wheel feels a little dead, so it lets you know how much traction is available. On an off ramp near the limit, the resistance on the wheel changes with momentary changes in grip level. Your hands do shake a bit, and you or your passenger may find that disconcerting. But to me, the connection between car and driver is just that much better. I'm pretty big, but don't lift weights-- small drivers might find this mod to be too much.
I've found this to be accurate on the 89 Civic I had with manual steering. Heavy real slow/still, gets lighter when traction lessens like at speed or wet pavement. Feel is amazing though. Makes you work when parking.
I'd love to see the same test with AC on vs off. It would also be cool to see this comparison done with an older car (NA or NB) compared to a modern one (ND).
For the NA/NB cars, Mazda knew they didn't have enough power to both accelerate and run the AC compressor :) so if you go to WOT, the AC clutch disengages automatically. For the newer ND cars, they switched to electric power steering, which would still be a valid test, as we'd be testing the extra load on the alternator.
Speaking of alternator, that would be a good test. I'm already imagining installing a switch to disconnect the alternator before each autocross run :)
Adding the manual steering increased the fun for me.
Thanks for putting the actual data out into the real world. I've called people biotches for keeping the P/S for track driving.
It’s nice for drifting
Thanks for taking the time to do this test and the right way! Its nice to have data instead of wive's tales and anecdotes about this topic.
Makes me wonder what the impact of electric power steering has. In a straight line it shouldn't be pulling any amps.
I've always had a theory about skin friction in a few of the pumps in an engine, like the oil and coolant specifically. I've always wanted to polish the inside of the passages to reduce skin friction and pumping losses. I put this theory into practice years ago with a td04 turbo. I polished the inside (all the way through the housings) and i took it a step further by polishing and sharpening the compressor and exhaust turbines so they would slice through the air. After installing i went way lean on acceleration, had to add throttle enrichment, once I did that, the additional torque smoked my transmission in about 7 days. The turbo eventually blew too because I didn't get it balanced. Anyway it would be cool if you could try something like this if anything on the water pump or oil pump. It would awesome to see the dyno numbers.👌
Yeah that’s pretty interesting. I removed the power steering on my 90 last week. For now it’s just looped but in a few weeks I plan on finishing the job. Was waiting on new SuperPro bushing for the rack. For me I didn’t notice much of a performance difference. I don’t have A/C but I’m sure there is but it wasn’t noticeable. As it is looped I like the weight of it driving. It’s on the heavy side bellow 20km/h but driving it’s really nice. I think there’s probably still too fluid inside though. If I hit a bump well making a hard turns at low speeds it kicks back a little but it’s manageable. Roundabouts are two handed now lol. The most positive thing is now it’s super easy to access the heater pipe to change that o ring 👍
Niceee!!! I was conscient that the power steering pump takes some hp away, but i wasn't expecting to take that much OMG, specially when in full lock. Love your videos, could you make a video testing the diferent octane fuels and if more octane influences the hp, or not. Thanks keep the good work
I drove my 90 Civic hatchback for years without PS. Light cars with a manual rack are fine as long as you are moving. In fact, the steering feel is amazing with a manual rack.
Same, honda didn't put PS on the hatchbacks, only sedans. I removed the PS on an 89 accord, you could only tell when parking and it was still not bad, my wife drove it without complaint.
@999benhonda some of the hatchbacks came with PS. My 89 DX hatchback has PS, but looking to go manual.
Back in 95 I bought an R model (94) with AC. Steering was a little heavy if barely moving but autocrossing had great feel and wasn't tiring.
Convert to electric-over-hydraulic pump.. it works great to free up power and it provides steering boost when you need it.. but not when you don't.
Yeah - so - what about ELECTRIC power steering? They don't have that for Miatas? Also - if you're up for it - what about testing the benefits of weight reduction in general, when using: 1. Aftermarket aluminium cam gears(adjustable - which tend to be lighter than stock - ESPECIALLY in some VVT engines) 2. lighter flywheels(& driveshafts - if within your budget) 3. lighter crankshafts(knife edged etc to remove unnecessary material) 4. lighter pistons 5. lighter wheels(& or the different effect wheel diameter has on performance\dyno figures) 6. lighter brake rotors(carbon ceramic or budget Drilled AND slotted 2 piece rotors - more so for a FWD car, but as ling as it's needs to be spun up it requires energy so...) ...My point being to see how much overall power can be had from an engine & drivetrain focused weight reduction - & to prove that several small tweaks like the one in this video can add up to decent power\efficiency\performance gains(so one should not stop at doing just one)...🤔
Great information. Thanks for putting that wear on your car so we all can learn.
5hp to turn a hydro pump makes sense. The big heavy trucks out there probably have bigger pumps that use more hp.
Thanks for the video. Was looking for a reliable source for a long time for this kind of data!
Less related to the Miata being setup for STS/STR - I’ve wanted to do a pseudo hybrid setup for years that has an electric steering pump, water pump, and AC compressor, with a custom lithium ion battery the same physical size as a stock lead acid, and then have the only accessory be a motor/generator that can start the motor and also blend how much torque is used for generation down to nothing at WOT. I’ve read BMW cuts alternator output to zero at WOT in some cars, and G.M.s mild hybrids of the past were interesting. The GMA T.50 has a mild hybrid like this too.
The NC Miata (MX-5) has a computer-controlled alternator. I don't have data showing exactly what the stock ECU does with it, but I remember needing to replicate the signal to keep the alternator charging the battery when doing standalone ECU stuff with those engines.
Manual rack has way better feel on corners least with the older stuff I used to drive, but I can imagine with the heavier car and some sticky tires you can turn out to be a pain in the parking lot
Great video, looking forward to more of these!!
Interesting, thanks for doing this test, have to admit that I was a little surprised by the HP consumed by just having the pump installed. Would be very interested in see the test results of no alternator and water pump. I race in SCCA's STL (Super Touring Light). Most sprint races are from 20 to 35 minutes long. Some of my competitors use a large battery with no alternator and run an electric water pump. How much it is really worth?
Great question! In a racing application, I suspect most of the alternator's losses would be inertial rather than as a result of generating electricity. A race car may draw, for example, 20 amps to power the fuel pump, ECU, ignition, gauges, etc, which is only 280 watts. If we say the alternator is only 50% efficient and double that wattage, we're still only at 560 watts, which is around 0.75 HP.
If he ever tests an alternator, it would be cool to see the difference between the alternator spinning under no load with the control plug disconnected compared to spinning against a load with all accessories on. Another variable is voltage though. With a lower voltage from the alternator not charging, the operation of the ignition system, fuel pump, fuel injectors, etc will be somewhat affected, which could affect the engine's performance.
I depowered my rack and could absolutely feel a difference on my 1.6. Unfortunately I hated the driving experience without it, so i added E-power steering. I've often wondered if the E-power steering adds additional drag on the alternator and if that can be quantified on a dyno.
Great vid!
Absolutely it adds load, nothing is free and energy is energy. The question becomes is the belt powered alternator feeding an electric motor to power a pump more efficient than the belt powered pump. But the electric system only works when demanded so in a straight line you're free of that extra parasitic loss.
Great video ❤ didn't think it would be that much! Maybe 1-2 but 5 hp wow !
This is awesome info, is there an under drive pulley option for the Miata so you could reduce the amount the power steering pump would have to work but also retain some power steering?
I had an 89 accord lxi, the power steering system had a leak, so i removed it. I swore i could feel a power difference. I wonder if older cars had PS pumps that ate even more hp, or if they were just as efficient as modern ones
Check with electric power steering
Awesome video!
Your test is a little inaccurate... You are testing removal of BOTH the PS and AC - not just the PS. When I tested PS w/o AC on a 99, it was only a 2 HP loss (with the wheel straight).
Still a good video and test but would be interesting to see the results w/o the AC for accuracy
De - Powered vs manual rack is different.
Ty for making this informative video
Just go to a junk yard and pull an electric power steering system off a mid 2000's GM sport compact vehicle (Saturn ION, Vue, Chevy Cobalt, HHR, Equinox, etc.) and use that in place of the hydraulic system. Yes, you can spend 4 figures for a commercial electric power steering system, but most of them are literally just GM systems packaged to work on nearly every platform... The trick is that the CAN bus controller that normally feeds vehicle speed to the power steering system doesn't need to be present for the electric power steering system to work. The module that is attached to the steering system "fail safes" to a voltage input that can be controlled by a potentiometer when wired to certain input pins. There is a little more to it than that, but there are a few videos and DIYs online for adapting GM electric steering to other applications. Note: this is not a rack, but an assembly that goes inline with the steering wheel to assist the rack.
A few yeas back my local pick-a-pull didn't realize they existed so they were selling steering wheel assemblies for like $25 each. On 50% off day I snagged a half dozen of them.. I put that sh!^ on everything...
Great video thanks for your efforts subscribed
test crank ventilation to the atmosfere, vs to the intake vs to exaust
thanks!
I wonder what the loss would be through the alternator on something with electric power steering.
No ac compressor
I bought a 86 325e from someone who wanted to turn it into a drag car and took out the compressor I’m kinda wondering how much of a difference it makes because also something I didn’t notice was it had like a bump stop thing on the floor for the gas pedal side so I’d only be able to open up to about 40% throttle and when I had noticed it the car kinda just died on me weirdly (everyone tells me it’s wiring and I don’t doubt it is just because everything about it) it’s a rebuilt m20 so stock motor just no ac compressor (also 5 speed manual so I could technically go a bit higher in rpm highest I went once was 3500 other then when shit hit the fan and it got stuck at 4k steady end of red line is I think 6k or 5k somewhere in that range
I wonder how much the PS takes on my NC...
5:55
Well, yeah, of course you got a test of an electric power steering pump helped gain this horsepower
5hp ? I was expecting like 20-25 by how people talk like it's some big drag on an engine 🙄🙄🙄