Mazda MX-5e Tesla Powered
Discussion
How will it sit weight distribution wise with the battery in the front?
It feels like it would be further forward than before, especially given the lack of fuel tank?
If that's the case it would almost be worth spending some weight budget (~50kg) to even it up by putting a pack in the back too, would it not?
It feels like it would be further forward than before, especially given the lack of fuel tank?
If that's the case it would almost be worth spending some weight budget (~50kg) to even it up by putting a pack in the back too, would it not?
It's an interesting question. My preference is for a single 32kWh battery pack in the engine bay as this keeps the CoG as low as possible and massively simplifies and shortens the HV wiring to the motor (sits in the tunnel) and the inverter (sits above the batteries). It also massively simplifies the cooling system and volume of coolant required.
The plan is to fit a mounting plate over the fuel tank space and to mount the dc-dc converter in the underside and in the air flow (it is air cooled) and the charger above it, close to the charging port (inside the existing petrol filler cap). This makes for a very tidy solution with minimal materials and weight.
I'm not sure how big an impact this will have on the F/R distribution as we have a much smaller cooling system in the space where the radiator and fans previous sat. We have also lost a lot of other stuff that was in the engine bay, including over 5kg of wiring to support the ICE, air intake system, air conditioning hardware, power steering hardware, etc.
My feeling is that the F/R weight distribution will be very similar to the stock car and any changes will not really be noticable. I think the power and torque improvements will be the thing you notice first
As a new car back in 1992 it had 86kW (115bhp) at 6,500 rpm and 136Nm of torque at 5,500 rpm. We must have lost some of that over the last 32 years and it being an automatic really didn't help! My son's 1990 Eunos Roadster 1.6 manual felt a lot quicker. As an MX-5e it will have 136kW (182bhp) and 350Nm of torque from zero rpm, with a top speed of 109mph. We also have an upgrade path to 215bhp/400Nm/119mph, which adds no more extra weight 
Lots of other dynamic improvements made too, including a fully rebuilt and upgraded LSD.
The plan is to fit a mounting plate over the fuel tank space and to mount the dc-dc converter in the underside and in the air flow (it is air cooled) and the charger above it, close to the charging port (inside the existing petrol filler cap). This makes for a very tidy solution with minimal materials and weight.
I'm not sure how big an impact this will have on the F/R distribution as we have a much smaller cooling system in the space where the radiator and fans previous sat. We have also lost a lot of other stuff that was in the engine bay, including over 5kg of wiring to support the ICE, air intake system, air conditioning hardware, power steering hardware, etc.
My feeling is that the F/R weight distribution will be very similar to the stock car and any changes will not really be noticable. I think the power and torque improvements will be the thing you notice first
As a new car back in 1992 it had 86kW (115bhp) at 6,500 rpm and 136Nm of torque at 5,500 rpm. We must have lost some of that over the last 32 years and it being an automatic really didn't help! My son's 1990 Eunos Roadster 1.6 manual felt a lot quicker. As an MX-5e it will have 136kW (182bhp) and 350Nm of torque from zero rpm, with a top speed of 109mph. We also have an upgrade path to 215bhp/400Nm/119mph, which adds no more extra weight Lots of other dynamic improvements made too, including a fully rebuilt and upgraded LSD.Before we rewire the backend of the MX-5e, we are stripping the boot and tidying it up a bit. We have resprayed parts of it. The boot hinge/springs have also been removed and cleaned up.
The rewiring from scratch is progressing well. Fabricating a custom, light-weight loom which is colour coded for diagnostics.
We have decided to rework the radiator shroud and add a second fan. The fans weigh just 850g. This means we should be better able to maintain a stable 400V battery temperature under higher loads and in hotter weather. The whole radiator assembly is just 5.2Kg and less than half the weight of what was originally on the car. Less coolant also saves more weight in the engine bay. When we have finalised the design, the mounting plate will be powder coated too.
We are currently fitting the Inductive Autoworks connection kit to the Nissan Leaf motor and inverter, so that we can finalise the position of the motor in the centre tunnel and start fabricating a mounting frame for this and the battery pack.
The rewiring from scratch is progressing well. Fabricating a custom, light-weight loom which is colour coded for diagnostics.
We have decided to rework the radiator shroud and add a second fan. The fans weigh just 850g. This means we should be better able to maintain a stable 400V battery temperature under higher loads and in hotter weather. The whole radiator assembly is just 5.2Kg and less than half the weight of what was originally on the car. Less coolant also saves more weight in the engine bay. When we have finalised the design, the mounting plate will be powder coated too.
We are currently fitting the Inductive Autoworks connection kit to the Nissan Leaf motor and inverter, so that we can finalise the position of the motor in the centre tunnel and start fabricating a mounting frame for this and the battery pack.
There are some great suppliers out there when it comes to EV conversions and general car modifications. We are really lucky to have G19 Engineering very close by. Doug at G19 sells a range of parts to upgrade MX-5s and he's done a custom modification on our old automatic pedal box, to mount to our Tesla iBooster. He has then strengthened it and added two-position mounts for the MX-5 mk 3 digital throttle pedal, which will work perfectly with our Thunderstruck VCU. The whole thing has then been zinc plated.
Doug also supplied a second-hand mk 3 throttle pedal and new connector for it. Stuff like this makes our conversion look much more professional and saves us a whole heap of time in the process.
Doug also supplied a second-hand mk 3 throttle pedal and new connector for it. Stuff like this makes our conversion look much more professional and saves us a whole heap of time in the process.
robcollingridge said:
There are some great suppliers out there when it comes to EV conversions and general car modifications. We are really lucky to have G19 Engineering very close by. Doug at G19 sells a range of parts to upgrade MX-5s and he's done a custom modification on our old automatic pedal box, to mount to our Tesla iBooster. He has then strengthened it and added two-position mounts for the MX-5 mk 3 digital throttle pedal, which will work perfectly with our Thunderstruck VCU. The whole thing has then been zinc plated.
Maybe it's the picture, but that welding doesn't look that great to mesmn159 said:
robcollingridge said:
There are some great suppliers out there when it comes to EV conversions and general car modifications. We are really lucky to have G19 Engineering very close by. Doug at G19 sells a range of parts to upgrade MX-5s and he's done a custom modification on our old automatic pedal box, to mount to our Tesla iBooster. He has then strengthened it and added two-position mounts for the MX-5 mk 3 digital throttle pedal, which will work perfectly with our Thunderstruck VCU. The whole thing has then been zinc plated.
Maybe it's the picture, but that welding doesn't look that great to meIt's a lot stronger than the original unit, which was prone to cracking and having to be swapped out with another one. We had to do this job in my son's 1990 Eunos Roadster.
The new pedal box made up and installed in the car. All the bits have been refurbished. It mates to the iBooster perfectly.
The new pedal box made up and installed in the car. All the bits have been refurbished. It mates to the iBooster perfectly.
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