QUOTE(Superhawk996 @ Jun 26 2022, 08:15 AM)
QUOTE(bbrock @ Jun 26 2022, 01:07 AM)
The drive train PLUS rear battery pack and cooling is roughly the weight of a six cylinder engine and transmission according to the vid.
@bbrock You know I can't resist a good debate.
I think we are all over the map. I'm not debating that you can get 100 miles of range out of a 914 with a 26 KWh battery. That is agreed.
What I want to focus on is the falsehood that the EV conversion doesn't destroy the 914 dynamic handling character. I get people will do conversions - that's fine if they want to spend a whole lot of money to build a less capable 914 (less range than gasoline, degraded handling vs. a stock 914, and shitty range as compared to purpose designed EV).
I call
that the power pack unit in the video is roughly the weight of a six:
From information I can find on-line
Tesla rear motor unit: 290 lbs
26Kwh batteries (let's use the Beetle numbers) -- 280 lbs
Two cooling tanks with lets say 4 gallon of water - 32 lbs
Cradle with sufficient structure to support all the weight - 75 lbs (estimated)
Radiators -- 2 @ 4 lbs each = 8 lbs
Fans --4 @ 1 lb each = 4 lbs
Total = 689 lbs.
I'm a little unclear on where the power electronics are - are they in the front battery module or the rear? How much do they weigh (guessing about 10 lbs based on weight of Tesla SiC MOSFET inverter)? That looks like it may be the
inverter DC to DC converter on the side of the rear battery pack?
Now lets talk moments of inertia
Look at this picture - that is A LOT of mass siting up at the TOP of the engine compartment. Not only the coolant but probably also the power electronics (inverter, DC/DC converter, some of the batteries, etc.) that are sitting up high in the engine compartment. This is unlike a boxer engine that puts most of that mass low in the vehicle. That is going to lead to increased propensity for the vehicle body roll as well as fore/aft pitch when braking and accelerating.
Click to view attachmentNow let's look this one
Click to view attachmentSo the motor is well behind the rear axle. This is a 290 lb mass that is going to seriously degrade the handling by adding moment of inertia to the vehicle. Not only because of the mass and it's rearward placement, but also because it's running (and its gyroscopic rotation) laterially across the car. This is unlike the gas powertrain where the crankshaft, transmission gears, and differential, are centralized and rotating along the central axis of the vehicle.
Then of course we have the radiators stuck out at the farthest end. At least they are relatively light.
edited to keep this shorter
@Superhawk996 My goal is to weigh the same as a six. One thing I should point out is those conversions used a small drive unit which is roughly 198 pounds. The battery weight sounds about right. The contactors, relay, BMS and so on are in the high part of the battery box, next to the large coolant tank.
On my car I will start at the front. The front pack weighs 95 pounds, the mount, fuses, BMS around 14 pounds. So roughly the weight and location of a full full tank.
I have a 2.5 pound 12 volt battery where EGR counter was located.
The motor is a Hyper9 125 HP, 170 lbs/ft of torque it weights 120 pounds (with the inverter/controller), The transaxle dictates the motor location, the flywheel is 5.25 pounds, the pressure plate is 13 pounds, the disc is stock. I would love to find a lighter pressure plate and disc.
The two rear packs are also 95 pounds each. They are located 1-3/8" above the floor pan, the case is about 1/4" from the firewall and sit on each side of the motor. All the rear mass is a below the top of the trans axle. My engine/ battery cradle weighs 24.5 pounds, the battery cases are a total of 26.5 pounds. Two chargers at 11.5 pounds each. One at the original battery location one at the relay box location. 23 pounds of copper cabling and 15 pounds of contactors, fuses, relays, and DC to DC convertor.
So I'm a around 428 pounds at the location that from what I can find is around 350 pounds for a four and 450 pounds for a six. I believe the mass is a little lower and closer to the center than a six. From what I have found of people weighing complete engine and ancillary parts that seems to be close.I never had an engine to weigh so I have to go off what documentation I can find.