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Thread: KTM500EXC water pump

  1. #11
    The OP is getting terrific value here.

    Quote Originally Posted by JT A. View Post
    You seem to have a lot of knowledge but very little logic or common sense.
    (This is going to be fun).

    OK, I'll play. I'll happily contend you're wrong there.

    Quote Originally Posted by JT A. View Post
    If the team is "stuck" because they don't know the flow rate of the cooling system, how does buying an electric water pump get them "unstuck"? They still won't know what the system flowrate is until they test it on their own engine & radiator system.
    It's the difference between not understanding whether the pump an engine is supplied with has the characteristics you require, which are themselves unknown - but committing to a pressure characteristic prior to designing your coolant system - and being noncommittal about what's required of a pump when there's little understanding about what's inherent in the broader system it supports.

    I'd find it hard to believe that KTM designed this particular engine, the engine calibration, the coolant system and the like around the water pump. So why would you design an FSAE car around one? You'd have to have, as you suggest, "very little logic or common sense" to do this.

    If a design lends itself to a place where an engine-driven driven pump is suitable - let alone the very same one that comes with the engine - then so be it. As this isn't a given, don't bet on it. Granted, the same assembly or parts thereof probably appear on a number of engines for reasons of resource rationalization and economy of scale (at the least). it likely works in a number of scenarios. Assuming it works in yours is silly. Insisting that it needs to... is stupid.

    Let alone that you're betting on the characteristic the pump provides beign a best fit for use, all integration factors considered.

    Quote Originally Posted by JT A. View Post
    It basically just gets them "unstuck" by forcing them to make a decision, and commit to figuring out the details and making it work later on.
    No, it fundamentally moves the design process beyond that particular decision by adding degrees of freedom (pick any pump you want to design what cooling system you need) vs an inherent limitation (design your cooling system around a given pump, which was designed around a different application and different constraints).

    If at the end of this journey what's required can be met with the pump on the engine, so be it.

    Quote Originally Posted by JT A. View Post
    But they could just as easily (or more easily) get "unstuck" by committing to using the stock pump, measure its flowrate is once they get the engine, and figure out the rest of the system based on what they find.
    Designing a cooling system around a pump, when there's so much flexibility in choice at negligible penalty in so many areas... is illogical.

    If you're still talking in terms of flowrate, you're fundamentally not understanding what a pump does and how to design accordingly. As an aside, if by chance you're planning on turning up to FSAE-A 2014 this much understanding about coolant system design, I'd revise a bit first.

  2. #12
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    The pump clearly cooled the bike just fine and can quite easily cool an FSAE car just fine with an appropriately sized radiator. Why the hell would you add the extra complexity of an electric water pump that's going to screw the power budget of your single's stator to design a cooling system to be absolutely 99% perfect amazing etc. Use the stock pump, it's simple it's there, it'll easily do the job you need. Run the engine with the inlet in a bucket and the outlet to another bucket to get an idea of flow rate.

    Your cooling system design just needs to work it doesn't need to be the most perfectly designed thing in the world. Cooling systems don't make cars go fast, put your time into things that do. Chase the 20% gains before you chase the 0.2%. So long as the system can keep the car cool you'll be fine.

  3. #13
    An electric water pump does not:
    1. make your car faster
    2. make your car more reliable
    3. get the car finished faster
    4. help your cost score

    It maaaay potentially help your fuel efficiency score. Hey Kettering, how compromised was your award winning powertrain when you dominated fuel economy without an electric water pump?
    It does open up some packaging options, that value is contingent on your car/team/goals.

    Yes engineering is about finding the smart solution. Smart doesn't always mean technically best when weighed against the big picture goals.

    To adequately design a cooling system you need a pump map and it is not a simple task to get that data. Advice to OP: Centrifugal pump calcs will get you close enough inputs to design your system. Leave room for more radiator, you will never cross the finish line and say "damn, that cooling system packaging really kept us off the podium!" Take an integral part of the cooling system that will not be changed and spend some time testing to generate a pressure drop curve for that part. Now install a couple pressure sensors on that part and log the data. You have now created a simple flow meter that will help you refine the system. Hey you could even use it to test an electric water pump if you choose!

  4. #14
    Quote Originally Posted by Menisk View Post
    The pump clearly cooled the bike just fine and can quite easily cool an FSAE car just fine with an appropriately sized radiator.
    Sure does cool the bike.

    No guarantee of cooling every particular FSAE configuration.

    Quote Originally Posted by Menisk View Post
    Why the hell would you add the extra complexity of an electric water pump that's going to screw the power budget of your single's stator to design a cooling system to be absolutely 99% perfect amazing etc.
    Why would it necessarily screw your power budget?

    What's the difference between "99% perfect amazing" and what it'd be for a given install? What'd be in effort?

    Quote Originally Posted by Menisk View Post
    Use the stock pump, it's simple it's there, it'll easily do the job you need.
    Not the original question, and convention isn't a way to characterize an engineering problem.

    Quote Originally Posted by Menisk View Post
    Run the engine with the inlet in a bucket and the outlet to another bucket to get an idea of flow rate.
    C'mon, there's better ways to test than this - even at the undergrad level.

    Quote Originally Posted by Menisk View Post
    Your cooling system design just needs to work it doesn't need to be the most perfectly designed thing in the world. Cooling systems don't make cars go fast, put your time into things that do.
    Cars need to finish events before they go fast, and judging by the rate of engine attrition in FSAE relative to the production configurations the original powertrains usually came from, statistically there's some weight to the notion that some added effort in design to a few ends (cooling included) could be of use.

    Do you recommend such effort in all critical systems?

    Quote Originally Posted by Menisk View Post
    Chase the 20% gains before you chase the 0.2%.
    Understand engineering basics before wrapping assumed knowledge at speed into convention. The OP required flowrates, and this series of replies has been fun - the suggestion is far less about explicit solutions, and far more about challenging the question. Is the OP seeking an answer to the best question for the given need?

    Quote Originally Posted by Menisk View Post
    So long as the system can keep the car cool you'll be fine.
    Correct.

    Good integration means not doing this at any cost, however. Understanding the tradeoffs demands solid design principles... not reflected in the OP or in a few answers here.

    Quote Originally Posted by Mumpitz View Post
    An electric water pump does not:
    1. make your car faster
    2. make your car more reliable
    3. get the car finished faster
    4. help your cost score
    1. It can.
    2. It can.
    3. It can.
    4. No, certainly doesn't, though what compromises make the cut partly define integration.

    Quote Originally Posted by Mumpitz View Post
    It maaaay potentially help your fuel efficiency score.
    It may do a lot of things.

    Quote Originally Posted by Mumpitz View Post
    Hey Kettering, how compromised was your award winning powertrain when you dominated fuel economy without an electric water pump?
    Pulling one solution out of a complex space to fit out of context is poor advice. There's never been any suggestion that an EWP is a requirement, or that a built-in pump is an impossibility.

    Me-too engineering works as research to head-check a base contention - should be more of it. Runs into limits as an ultimate replacement for fundamental knowledge.

    Quote Originally Posted by Mumpitz View Post
    It does open up some packaging options, that value is contingent on your car/team/goals.
    The value of any advantages are so contingent.

    Quote Originally Posted by Mumpitz View Post
    Yes engineering is about finding the smart solution. Smart doesn't always mean technically best when weighed against the big picture goals.
    Could argue "technically best" (whatever that means) to be to use the existing pump, select another pump, any number of things. Relative to the OP, the 'big picture' goals in engine selection shouldn't hinge around alleged flowrates.

    Quote Originally Posted by Mumpitz View Post
    To adequately design a cooling system you need a pump map and it is not a simple task to get that data. Advice to OP: Centrifugal pump calcs will get you close enough inputs to design your system. Leave room for more radiator, you will never cross the finish line and say "damn, that cooling system packaging really kept us off the podium!" Take an integral part of the cooling system that will not be changed and spend some time testing to generate a pressure drop curve for that part. Now install a couple pressure sensors on that part and log the data. You have now created a simple flow meter that will help you refine the system. Hey you could even use it to test an electric water pump if you choose!
    Best advice in this thread so far (please take note anyone competing at FSAE-A 2014).

  5. #15
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    If you really think an electric water pump is going to make your car faster at the level FSAE teams are at there's no helping you.

  6. #16
    Quote Originally Posted by Menisk View Post
    If you really think an electric water pump is going to make your car faster at the level FSAE teams are at there's no helping you.
    If you really think this is what I'm suggesting, read again - quite far from it.

  7. #17
    GTS, your unconstructive criticism is approaching troll level stuff here. Still don't see your EWP logic and reasoning as promised.
    You claimed an EWP to be a smart option and have provided no logical explanation as to why. "it decouples the system" and "it can" isn't going to win any favor with design judges and isn't helping anyone here. Are you going to add any content here or just pick at others? If you want to get your rocks off trolling take it elsewhere.

  8. #18
    Quote Originally Posted by Mumpitz View Post
    GTS, your unconstructive criticism is approaching troll level stuff here. Still don't see your EWP logic and reasoning as promised.
    You claimed an EWP to be a smart option and have provided no logical explanation as to why. "it decouples the system" and "it can" isn't going to win any favor with design judges and isn't helping anyone here. Are you going to add any content here or just pick at others? If you want to get your rocks off trolling take it elsewhere.
    EWP as one solution is well explained - the OP isn't necessarily asking for a specific solution - it's about robust processes to reach a good solution. To this end, there's been plenty of content added.

    I'm pretty sure any reasoned approach will win favour with the design judges. Calling what doesn't gel with a given opinion "unconstructive"... won't.

    I'm amused as your assertions of trolling - particularly given that where you made a solid contribution, it was highlighted and supported.

  9. #19
    Quote Originally Posted by Mumpitz View Post
    Hey Kettering, how compromised was your award winning powertrain when you dominated fuel economy without an electric water pump?
    It does open up some packaging options, that value is contingent on your car/team/goals.
    In 2013, we ran a WR450F engine (2012 MY, EFI stock) with the stock radiators mounted in the left sidepod. We made relatively minor engine changes internally (stock piston, new cams, etc.) and with intake/exhaust changes we reached 56hp peak (~42kw). We had no cooling issues ever, we had a hard time getting the car up to temp at MIS (it was a quite cold that day) and had to cover one half of the radiator at Formula North for the endurance to keep the car up to temp.

    In 2014, we located radiator behind the intake (off the MHR braces), and had a hard time ducting air to it. We never had a cooling-related failure, but virtually all of our airflow came from the fan and we ran ECTs of over 100C normally (the hottest I measured was 113C).

    The pump was definitely not the weak point of the 2014 cooling system. We do not know the flow data of the pump, but we have test data to show that the cooling system as a whole performs adequately, especially with sidepod-mounted radiators on the 13 car.


    I will warn though that we have had several failures of water pump seals and shafts degrading in pure water. Using coolant when testing helps.


    Edit:
    Before we switched to the 2012MY bike (stock EFI) with a 3-phase stator, we had charging system issues with the 2011MY bike (stock carb, smaller 2-phase stator). We were usually running at a slight loss, with a small electric radiator fan and relatively small other loads. With the 2012MY bike charging system, we were able to run a larger fan in 2014 with a net power excess in most cases, with a larger ignition coil as well. Every watt does count, spend them wisely. If we could shaft drive more of our engine loads I would be happy.
    Last edited by apalrd; 11-24-2014 at 11:36 AM. Reason: more information
    Andrew Palardy
    Kettering University - Computer Engineering, FSAE, Clean Snowmobile Challenge
    Williams International - Commercial Turbofan Controls and Accessories

    "Sometimes, the elegant implementation is a function. Not a method. Not a class. Not a framework. Just a function." ~ John Carmack

    "Any sufficiently advanced technology is indistinguishable from magic" ~Arthur C. Clarke

  10. #20
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    Quote Originally Posted by apalrd View Post
    56hp peak (~42kw)
    Proud alumni chiming in to say "to the wheels".
    -----------------------------------
    Matt Birt
    Engine Calibration and Performance Engineer, Enovation Controls
    Former Powertrain Lead, Kettering University CSC/FSAE team
    1st place Fuel Efficiency 2013 FSAE, FSAE West, Formula North
    1st place overall 2014 Clean Snowmobile Challenge

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