Not really sure where I should've put this, but I've seen some people across the internet lately ask about running the Mountune 2.3L EcoBoost keyed crankshaft in their Mazdaspeed, and conveniently, I've had the pleasure in dealing with this hell already. I'll just summarize this entire post. Don't buy the Mountune crankshaft for your Mazdaspeed if you want to use the keyway. If you don't care about the keyway, but want a crank with no balance shaft sprocket, send it.
The 2.3L EcoBoost crankshaft will work on an L3-VDT with no issues. This is includes the Mountune crankshaft. At first, the Mountune option seems to be very enticing; for $500 you get a brand new crankshaft, keyed to 3mm, and the balance shaft sprocket is machined off, meaning you'll need to throw out your balance shaft. This results in a 5lb weight saving over the stock Mazdaspeed crank due to the thinner counter weights and the missing sprocket, and a total weight savings of 20-23 (I personally saw a 22.2lb loss) including the weight of the balance shaft. Just as strong, but faster revving.
Now that's a very glamorous offering. The catch for Mazdaspeed owners though: you'll never be able to take advantage of that keyway. Not without coming out of pocket for machining costs, anyways. And a lot more.
Here's the deal, the Mazdaspeed accessory drive is based on a single belt system that uses 6 ribs. In contrast, the EcoBoost accessory drive uses a 2-belt system with 4 ribs per belt, running the A/C on a separate belt than the alternator and water pump. Both systems utilize a 60-2 trigger configuration. An important thing to note, Duratecs and naturally aspirated MZRs use 36-1 triggers. That's a lot of yapping, but the takeaway: you can't use EcoBoost crank pulleys*, and you can't substitute that with a Duratec or NA MZR pulley. Don't bother wasting money on the 146mm and 164mm underdrive pulleys that Mountune sells (P/Ns E1000-3180-AA2146 and E1000-3180-AA2164 respectively, both $280); while they're keyed appropriately you can't use them unless you run a standalone ECU.
* Edit: You might be able to use the EcoBoost crank pulleys, but you must run a 4-rib belt on your 6-rib accessories (assuming you didn't switch them all to EcoBoost mounting locations), and you will also have over half of your crank pulley become unused. Truthfully, though I don't even think the EcoBoost pulley would fit due to how close the pulley is to the A/C lines and the frame rails. Even if it did fit though, and you wanted to switch your accessories to the EcoBoost mounting locations, you'd need a new oil pan, new idlers, and if you're a speed6 or a gen 1 speed3, you're losing your power steering unless you convert to electric).
To take full advantage of the key, you'll have to purchase the Mountune keyed drive gear, which comes in their keyed pulley and sprocket set (P/N 6069-KP-AA). That's $390, comes with a new key, a drive gear, and a keyed EcoBoost pulley (which, as previously discussed, can't be used on a Mazdaspeed). What that boils down to is you'll be spending ~$400 for just a keyed drive gear (I've personally called and e-mailed Mountune about this, you cannot purchase just the gear. You have to buy their whole set). When you buy the Mountune keyed crank, you get a key with it, so coming out the other end of buying their keyed sprocket set and crank you'll have 2 keys. And if you switch to an EcoBoost drive gear, you need to change your entire timing system to a Ford equivalent. The toothing on MZRs and EcoBoost drive gears/oil pump gears are different. You can use one or the other, either will work, but you can't mix and match them (the EcoBoost drive gear is a single drive gear with 2 sprockets combined in a single unit, contrary to MZRs which use 2 separate sprockets for timing and oil pump).
By now, if you still want to run the Mountune crank, you're going to be spending some good money. First, the crank itself, $500. Second, the $400 drive gear. The third cost is going to be machining costs, for which you'll need to buy an OEM Mazdaspeed crank pulley (P/N L3K9-11-400, ~$200), and have to have a machine shop super impose the keyway from the EcoBoost crank onto the Mazdaspeed crank. So you're out minimum of $1,100 before machining costs, and that's not even converting the rest of your timing system. Now you can go through and figure out part numbers for each of the Ford equivalents for your timing system (reference Ford 2.5 NAs, do NOT use the EcoBoosts as reference for part numbers. They're built with intake and exhaust variable valve timing, whereas MZRs [L3-VDT included] and Duratecs [2.5 NAs are Duratecs, not EcoBoosts] use only intake-side VVT). If someone wants, I could throw my parts list in this thread at a later time, but truthfully, someone has already done that homework long before I did. So there's another $500-$570 for this project, totaling $1,600 (again not including machining costs).
I love my Mountune crank. After I built my engine, I could immediately feel the difference in how quickly it revved. I went from completely stock to Mountune crank, no balance shaft, Damond motor mounts, and Fidanze flywheel. It was night and day, and really woke the engine up. Truthfully though, it is a very expensive rabbit hole to put yourself in, and I would know, I put myself into it. Here's what my suggestion is: skip out on Mountune. They make good products, but they're overpriced in my opinion. And as a Mazdaspeed owner, you put yourself into one expensive pickle. If you want to run an EcoBoost crank, go with a company that makes parts for both EcoBoost AND Mazdaspeed (be careful about using "MZR", MZR refers to the entire family of Mazda engines at the time, which includes naturally aspirated engines that use parts incompatible with an L3-VDT). A good example of this, SP63. They make keyed parts for both EcoBoosts and Mazdaspeed engines, and they're all keyed to 5mm (I had to e-mail them and ask because it's not listed on their site), and the keys are rectangular (easily reproducible), so you can easily mix and match EcoBoost and Mazdaspeed parts that are keyed by them. If you still really want that balance shaft sprocket gone, have it machined and balanced.
If you've got any questions about running the Mountune crank (or an EcoBoost crank or parts for that matter) in a Mazdaspeed, feel free to ask. I've had to learn a lot, and this was one of the things I learned a bit ago.
The 2.3L EcoBoost crankshaft will work on an L3-VDT with no issues. This is includes the Mountune crankshaft. At first, the Mountune option seems to be very enticing; for $500 you get a brand new crankshaft, keyed to 3mm, and the balance shaft sprocket is machined off, meaning you'll need to throw out your balance shaft. This results in a 5lb weight saving over the stock Mazdaspeed crank due to the thinner counter weights and the missing sprocket, and a total weight savings of 20-23 (I personally saw a 22.2lb loss) including the weight of the balance shaft. Just as strong, but faster revving.
Now that's a very glamorous offering. The catch for Mazdaspeed owners though: you'll never be able to take advantage of that keyway. Not without coming out of pocket for machining costs, anyways. And a lot more.
Here's the deal, the Mazdaspeed accessory drive is based on a single belt system that uses 6 ribs. In contrast, the EcoBoost accessory drive uses a 2-belt system with 4 ribs per belt, running the A/C on a separate belt than the alternator and water pump. Both systems utilize a 60-2 trigger configuration. An important thing to note, Duratecs and naturally aspirated MZRs use 36-1 triggers. That's a lot of yapping, but the takeaway: you can't use EcoBoost crank pulleys*, and you can't substitute that with a Duratec or NA MZR pulley. Don't bother wasting money on the 146mm and 164mm underdrive pulleys that Mountune sells (P/Ns E1000-3180-AA2146 and E1000-3180-AA2164 respectively, both $280); while they're keyed appropriately you can't use them unless you run a standalone ECU.
* Edit: You might be able to use the EcoBoost crank pulleys, but you must run a 4-rib belt on your 6-rib accessories (assuming you didn't switch them all to EcoBoost mounting locations), and you will also have over half of your crank pulley become unused. Truthfully, though I don't even think the EcoBoost pulley would fit due to how close the pulley is to the A/C lines and the frame rails. Even if it did fit though, and you wanted to switch your accessories to the EcoBoost mounting locations, you'd need a new oil pan, new idlers, and if you're a speed6 or a gen 1 speed3, you're losing your power steering unless you convert to electric).
To take full advantage of the key, you'll have to purchase the Mountune keyed drive gear, which comes in their keyed pulley and sprocket set (P/N 6069-KP-AA). That's $390, comes with a new key, a drive gear, and a keyed EcoBoost pulley (which, as previously discussed, can't be used on a Mazdaspeed). What that boils down to is you'll be spending ~$400 for just a keyed drive gear (I've personally called and e-mailed Mountune about this, you cannot purchase just the gear. You have to buy their whole set). When you buy the Mountune keyed crank, you get a key with it, so coming out the other end of buying their keyed sprocket set and crank you'll have 2 keys. And if you switch to an EcoBoost drive gear, you need to change your entire timing system to a Ford equivalent. The toothing on MZRs and EcoBoost drive gears/oil pump gears are different. You can use one or the other, either will work, but you can't mix and match them (the EcoBoost drive gear is a single drive gear with 2 sprockets combined in a single unit, contrary to MZRs which use 2 separate sprockets for timing and oil pump).
By now, if you still want to run the Mountune crank, you're going to be spending some good money. First, the crank itself, $500. Second, the $400 drive gear. The third cost is going to be machining costs, for which you'll need to buy an OEM Mazdaspeed crank pulley (P/N L3K9-11-400, ~$200), and have to have a machine shop super impose the keyway from the EcoBoost crank onto the Mazdaspeed crank. So you're out minimum of $1,100 before machining costs, and that's not even converting the rest of your timing system. Now you can go through and figure out part numbers for each of the Ford equivalents for your timing system (reference Ford 2.5 NAs, do NOT use the EcoBoosts as reference for part numbers. They're built with intake and exhaust variable valve timing, whereas MZRs [L3-VDT included] and Duratecs [2.5 NAs are Duratecs, not EcoBoosts] use only intake-side VVT). If someone wants, I could throw my parts list in this thread at a later time, but truthfully, someone has already done that homework long before I did. So there's another $500-$570 for this project, totaling $1,600 (again not including machining costs).
I love my Mountune crank. After I built my engine, I could immediately feel the difference in how quickly it revved. I went from completely stock to Mountune crank, no balance shaft, Damond motor mounts, and Fidanze flywheel. It was night and day, and really woke the engine up. Truthfully though, it is a very expensive rabbit hole to put yourself in, and I would know, I put myself into it. Here's what my suggestion is: skip out on Mountune. They make good products, but they're overpriced in my opinion. And as a Mazdaspeed owner, you put yourself into one expensive pickle. If you want to run an EcoBoost crank, go with a company that makes parts for both EcoBoost AND Mazdaspeed (be careful about using "MZR", MZR refers to the entire family of Mazda engines at the time, which includes naturally aspirated engines that use parts incompatible with an L3-VDT). A good example of this, SP63. They make keyed parts for both EcoBoosts and Mazdaspeed engines, and they're all keyed to 5mm (I had to e-mail them and ask because it's not listed on their site), and the keys are rectangular (easily reproducible), so you can easily mix and match EcoBoost and Mazdaspeed parts that are keyed by them. If you still really want that balance shaft sprocket gone, have it machined and balanced.
If you've got any questions about running the Mountune crank (or an EcoBoost crank or parts for that matter) in a Mazdaspeed, feel free to ask. I've had to learn a lot, and this was one of the things I learned a bit ago.
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