Page 1 of 10 123 ... LastLast
Results 1 to 10 of 97

Thread: NST lightweight/underdrive pulleys.

  1. #1
    Senior Member Qrush's Avatar
    Join Date
    Oct 2017
    Location
    Jacksonville, FL
    Country
    United States
    Posts
    211
    Thanks
    68
    Thanked 77 Times in 47 Posts

    Talking NST lightweight/underdrive pulleys.

    Been in contact with a rep from Non Stop Tuning. They specialize in underdrive/lightweight pulleys for various imports.

    Sent him some rudimentary illustrations of our pulleys, heres the response:
    "Based on your photos, we should be able to offer crank and water pump pulleys, but will need to see photos of actual pulleys and will need to have these actual pulleys in hand for measurements etc. We may also be able to offer an alternator pulley IF the alternator pulley is NOT a clutch style pulley (it is not)".

    So, does anyone have any good pics of the crank/water pump/alternator pulleys? Better yet, anyone have the pulleys themselves? Im gonna make some calls locally and see what I can find myself. They seem pretty confident about the fabrication and once we get one set, we got a "rosetta stone" so all can have a set. Any help is greatly appreciated.



  2. #2
    Still Plays With Cars Loren's Avatar
    Join Date
    May 2018
    Location
    Florida
    Country
    United States
    Posts
    859
    Thanks
    188
    Thanked 652 Times in 378 Posts
    eBay or salvage. Get a set. Send 'em.

    This is another one of those things that I'd buy if the price was right.
    Simplify and add lightness.

  3. The Following User Says Thank You to Loren For This Useful Post:

    Gnarles2 (07-24-2018)

  4. #3
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,846
    Thanks
    2,781
    Thanked 1,632 Times in 947 Posts
    At first, I thought that a underdrive crankshaft pulley would be a waste of money on the Mirage. I had thought the water pump was driven by the timing chain. However, I checked the service manual today and found out I was wrong.

    Name:  belt patter.jpg
Views: 750
Size:  44.9 KB

    I am skeptical how much you would really see from the pulley as you're only really underdriving the water pump. The alternator will spin slower, and that means the internal fan won't waste as much power, but the voltage regulator will use more power because its spinning slower. Older vehicles using hydraulic power steering would see further gains from reducing the power steering pump speed. I guess you could still claim the same since the power is now just coming from the alternator instead of a pump though.

    That all being said, I have developed and sold underdrive pulleys before. If there is interest I can look into it.

    This is one pulley I had made for the Chevy Aveo.

    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  5. #4
    Senior Member Qrush's Avatar
    Join Date
    Oct 2017
    Location
    Jacksonville, FL
    Country
    United States
    Posts
    211
    Thanks
    68
    Thanked 77 Times in 47 Posts
    Sent NST a pic of the alternator pulley, heres the response:
    "That is a standard pulley and it's something we can definitely work with. So far it looks like we should be able to offer all the main pulleys, crank, alt, wp, if you can send us a set of OEM pulleys to work with".

    I hunted down the pulleys, it down to cost now. Heres the quote:
    "Just for a very rough estimate for now. Custom Crank, Alternator, Water Pump Kits are usually in the $388.00 range".

    He referred me to this page for pricing:
    https://www.shopnonstoptuning.com/st...T_Pulleys.html

    So, thats $388+cost of the 3 pulleys+shipping = north of $500. Its going to be costly, so im not 100% sure im going to do it. If Daox has a similar alternative at a better price, perhaps more members that just myself would be interested.
    Last edited by Qrush; 06-26-2018 at 08:59 PM.

  6. The Following User Says Thank You to Qrush For This Useful Post:

    Daox (06-26-2018)

  7. #5
    Moderator Eggman's Avatar
    Join Date
    Sep 2015
    Location
    Cleveland, Ohio
    Country
    United States
    Posts
    7,527
    Thanks
    3,460
    Thanked 1,914 Times in 1,448 Posts
    I would like to hypothesize on the potential results of installing a smaller crankshaft pulley. Please tell me where my reasoning is wrong and please forgive my long-winded stream-of-thought post.

    Smaller crankshaft pulley = slower accessory belt speed. This amounts to less rotational energy available for the devices which use this energy, and more for vehicle propulsion.

    1. Slower alternator, but unchanged electrical load means the alternator now must work harder to provide the same energy required. Whatever electrical needs the vehicle has is provided by the alternator - the voltage regulator will adjust the field voltage to compensate. This limits the amount of power the alternator is able to deliver. This has implications beyond the typical high electrical loads such as headlights & A/C operation - think of potential safety concerns such as anti-lock brake & electric steering assist operation. No gains will be found here unless the electrical load is reduced, which does not require a change in rotational speed. It would be helpful to find operational specifications on the alternator, such as maximum amperage generated at any given RPM. The alternator may reach it's peak output at a given RPM and faster rotational speed will have no affect (but not necessarily draw more or less energy.)

    2. Slower A/C compressor speed may free up more energy for vehicle propulsion, but similar to the alternator, the A/C compressor still has a load which isn't affected by the change in accessory belt speed. The compressor will either run for longer periods of time or fail to keep pace with it's requirements. Again, no energy gains to be found. However, having the A/C compressor cycle less does have a certain appeal...

    3. Slower water pump speed may result in more energy available for vehicle propulsion but at the expense of engine cooling. While the radiator may be able to dump whatever excess heat it is designed for it cannot do it as effectively if this heat isn't delivered & passed through with the same velocity.

    The details for heat transfer such as air conditioning and engine cooling are better described by someone more versed in that subject. It is my understanding that faster velocity in terms of fluid flow (both coolant in it's liquid state and air in it's gaseous state) improves heat transfer but somewhere one reaches a point of diminishing returns.

    I'm impressed with the efficiency of the Mirage platform as it is and wonder if Mitsubishi engineers thought all this out already.

    Probably not. It is, after all an economy car.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)


  8. #6
    Administrator Daox's Avatar
    Join Date
    Jan 2013
    Location
    Germantown, WI
    Country
    United States
    Posts
    4,846
    Thanks
    2,781
    Thanked 1,632 Times in 947 Posts
    Underdrive pullies are also typically made of aluminum and are therefore much lighter than their steel OEM parts. In the instance of the Aveo, the OEM pulley is 5.5 lbs, and the underdrive pulley is 1.2 lbs. Not an insignificant rotational weight reduction. This helps improve engine response.
    Custom Mirage products: Cruise control kit, Glove box light, MAF sensor housing, Rear sway bar, Upper grill block

    Current project: DIY Nitrous oxide setup for ~$100

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)


  9. #7
    Still Plays With Cars Loren's Avatar
    Join Date
    May 2018
    Location
    Florida
    Country
    United States
    Posts
    859
    Thanks
    188
    Thanked 652 Times in 378 Posts
    Quote Originally Posted by Eggman View Post
    I'm impressed with the efficiency of the Mirage platform as it is and wonder if Mitsubishi engineers thought all this out already.

    Probably not. It is, after all an economy car.
    Oh, you can bet that the Mitsu engineers very much thought all this out! But, they thought it out for a particular set of design parameters that included cost of production, fuel economy (!!!), drivability (power), reliability, and NVH. If your particular needs, wants and desires are the same as what they designed for, then rejoice!

    But, if you seek more power, or more fuel economy, and are willing to give up a little NVH, probably a lot of money, and maybe a little reliability... then you might want to explore crankshaft and/or accessory pulleys.

    UNDERDRIVE:
    You focused on this, and it is certainly something that can be done. As you noted, however... there is probably little to be gained by it on this particular car. Modern alternators are controlled by the ECU, and are already turned off (which reduces their load to almost nothing) whenever possible. The AC, of course, has a clutch on it and cuts out when it achieves the required pressure. And the cooling system is surely designed to produce the absolute minimal amount of drag and provide just the right amount of engine cooling.

    If anything, this car is overengineered... and I would tend to agree with pretty much everything you said. The accessories don't necessarily need to be underdriven. That said... the typical underdrive pulley is only making a 10% difference. Typically not enough to have any harmful effects.

    CRANK PULLEY WEIGHT:
    Now, here's where a slight difference could be made. But, there are pros and cons.

    Every ounce of rotating mass on the engine or anywhere in the drivetrain is mass that must be accelerated. It takes energy to accelerate it. So, removing ounces... and ultimately pounds... pays direct dividends in performance and fuel economy.

    Replace that chunk of cast iron crankshaft pulley with an aluminum part that weighs 2 pounds less, it's going to make a difference. Is it enough to feel? By itself, probably not. But, as a part of a lightening program that includes a lightweight flywheel, light wheels, etc, etc... it's all going to add up. Worth doing on a Mirage? Oh, now there's the question!

    The downside is that the crankshaft pulley is part of the engine rotating assembly, and COULD be required to be that heavy to dampen harmonic vibrations in the crankshaft. Now, we gearheads will suffer some added noise and vibration in the name of power! But, it is within the realm of possibility that removing that crankshaft pulley (that is perhaps acting as a "harmonic balancer") and replacing it with a lighter part COULD introduce some nasty vibrations that could cause a fatigue failure of the crankshaft over time. Some cars have proven susceptible to this kind of failure, particularly if they are then turbocharged. (Miatas are always my favorite example... lightweight EVERYTHING is great on a Miata! But, if you run stupid high boost on a Miata engine with a light crank pulley... you can shatter the oil pump gears due to the extra flex in the crankshaft! Not a problem if you're not boosted, or if you're lightly boosted... only if you're running lots of boost and at high RPM.)

    The Mirage engine being a 3-cylinder, which is inherently imbalanced... this is something that should be carefully considered before messing with the weight of the crankshaft pulley OR the flywheel. Those parts could be made heavy on purpose to help smooth out the "feel" of the engine. Feel, meh, we don't care. But, if the crankshaft is literally tearing itself apart... then we care. I did a little bit of research on the closest engine I could find, the old 1.0 Metro engine. Got as far as to learn that people have run lightweight flywheels on them without issue, and the vibration from such a setup isn't terrible. Rougher idle, of course.

    ACCESSORY PULLEY WEIGHT:
    I'm betting these are already pretty darned light. But, if they could be made lighter, there is ZERO downside to making the accessory pulleys lighter. Besides expense, of course.
    Simplify and add lightness.

  10. The Following User Says Thank You to Loren For This Useful Post:

    Daox (06-27-2018)

  11. #8
    Moderator Eggman's Avatar
    Join Date
    Sep 2015
    Location
    Cleveland, Ohio
    Country
    United States
    Posts
    7,527
    Thanks
    3,460
    Thanked 1,914 Times in 1,448 Posts
    Sheeoot - drop weight in that there big ol' lead-acid battery. You ever change yours out for something smaller, even if only for race days?

    One of these days I ought to try starting my Speck with a 12V7AH SLA just to see if it can be done.

    There's got to be a better thread for this... sorry.

        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)


  12. #9
    Still Plays With Cars Loren's Avatar
    Join Date
    May 2018
    Location
    Florida
    Country
    United States
    Posts
    859
    Thanks
    188
    Thanked 652 Times in 378 Posts
    I've had expensive Lithium batteries before. Had a 2-pound battery in one of Miatas. But, those are expensive and finicky. Leave your lights on once and run them flat... they're done. (ask me how I know)

    I actually DID buy a cheap small motorcycle battery to put in my Mirage. It's the poor man's alternative. Just a sealed lead-acid battery. Probably 1/3 the size of the stock battery, and plenty enough power to start the car... if you live in Florida. But, I ordered it from Amazon, and the seller shipped it packed poorly. Arrived leaking acid. I couldn't return it... and they wouldn't refund or replace it because I wouldn't return it. Go figure.

    Someday I'll run down to WalMart and just pick one up locally. Then fab up a bracket to fit it to the car and all that.

    But, yeah... batteries are a great place to save some weight!

    Back to rotational inertia, though... removing 3 pounds of rotational weight is equivalent to removing about 12 pounds of stationary weight. So... the weight you could save with a battery is the same as the weight you could save from a crank pulley. The cool kids will DO BOTH!

    I tell myself I'm not going to get that crazy with this car. But, I just spent somewhere around $500 doing the complete exhaust... my wife just laughs at me. She knew I was going to do it before I did.
    Simplify and add lightness.

  13. The Following User Says Thank You to Loren For This Useful Post:

    Gnarles2 (07-24-2018)

  14. #10
    Moderator Eggman's Avatar
    Join Date
    Sep 2015
    Location
    Cleveland, Ohio
    Country
    United States
    Posts
    7,527
    Thanks
    3,460
    Thanked 1,914 Times in 1,448 Posts
    [zaniness]Yeah I was just thinking of all the ways I can cut weight:
    1. Drain out half that heavy coolant, motor oil & transmission fluid.
    2. Remove all seats and install a cool milk-crate driver's seat.
    3. Take off half of all lug nuts - lots of rotational mass right there. Shave down tread to slicks too.
    4. Remove exhaust from the manifold back.
    5. Lose all them heavy windows. They're transparent anyway.[/zaniness]



    Quote Originally Posted by Loren View Post
    I tell myself I'm not going to get that crazy with this car. But, I just spent somewhere around $500 doing the complete exhaust... my wife just laughs at me. She knew I was going to do it before I did.
    That's peanuts, and you know what I'm talking about.

    You know how to make a small fortune in racing? Start with a big fortune.


        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •