[pickPear]

Hello!

For a while now, I've been planning on doing an electric conversion, but, due to various reasons, I need to make the car appear to be an ICE driven vehicle.

My question is, how can I integrate a small electric drivetrain into my vehicle without using the engine compartment?

Ive considered putting a dual shaft warp 9/similar motor into the rear subframe, or ideally the front subframe, but im not sure if that would be compatible with steering/all the stuff already in the front subframe. Is mounting a motor beneath the vehicle, directly to the driveshaft possible? How about having a motor within the engine compartment, coupled to the engine's crankshaft with a chain?

Ideally the electric drive wouldn't have to be super powerful, just something sufficient to get around town with.

any ideas? The vehicle im planning on using is an FC rx7.

Thank you!

 

[Kato659]

Who are you attempting to fool? People on the street won't see under your hood, and may or may not notice the lack of engine noise.

Emergency responders trying to save your life? Cutting into the HV line with a saw while trying to extract you (thinking it's a gas powered car) could put them at risk.

Vehicle inspectors? In my district the inspection takes place on a lift and hiding the EV stuff will have to be VERY stealthy.

Some clarification about why you wish to hide it would be helpful.

 

[pickPear]

Who are you attempting to fool? People on the street won't see under your hood, and may or may not notice the lack of engine noise.

Emergency responders trying to save your life? Cutting into the HV line with a saw while trying to extract you (thinking it's a gas powered car) could put them at risk.

Vehicle inspectors? In my district the inspection takes place on a lift and hiding the EV stuff will have to be VERY stealthy.

Some clarification about why you wish to hide it would be helpful.

The issue for me is that where I live, vehicle inspections are done Every 2 years, and Inspectors here Don't like anything different from stock on the vehicle, I have friends whose vehicles haven't passed bc of Lowered suspension/stancing. While its not illegal to build an EV, vehicle safety inspectors tend to not approve of them. It's a bit of a funky situation.

Also, Emergency responders wouldn't really be able to differentiate a converted EV from a regular car when working, but I see what your point is. Id be building this EV in as safe as a manner as possible, especially since Myself and my loved ones would be the people in the vehicle if anything were to happen.

That all being said; does anything come to mind?

 

[brian_]

While the whole exercise seems pointless to me, it's not my project....
If it were, and I could stand the idea of an automatic transmission RX-7, I would consider making it into a hybrid (capable of electric-only operation or "EV mode") by swapping in a suitable transmission. That could be one of the Lexus units (such as from a GS 400h) but the continuously variable drive ratio would be evident when it is driven; it could be one of the transmissions with a motor buried in the bellhousing, as found (for instance) in various BMW hybrids.

Any conversion will be immediately evident to anyone inspecting a vehicle closely enough that the inspection has any value. If someone is just looking for externally obvious modifications such as protruding tires, significant lowering, or removal of bumpers, then it might be missed.

 

[Kato659]

Honestly in that case your best solution is going to be finding a used EV and driving that. You haven't listed any other requirements (range, performance) but having to hide the battery compartments will limit your capacity.

Hybrid components such as those Brian listed will give you the best shot, but none of it will be easy or particularly inexpensive. You might go through all this work and still get denied by the inspector, which would be a huge waste.

 

[TeZla]

Where are you going to hide the battery?

 

[Jordan325ic]

Batteries in a fake subwoofer box and in the fuel tank, motor where the transmission goes or replace the axle with a tesla drive unit. But the battery would be tiny and there would be many design compromises to make this work. Most people need all the space they can get in a small car to make even a half functional EV conversion, and you want to leave the entire engine bay out of the design?

Obviously inspections work very differently where you live. Won't they notice when you drive into the inspection station in silence? Obviously it won't 'pass' an emissions test. And even a cursory glance underneath the car when checking the brakes will make it obvious, no matter how clever you are.

 

[Electric Land Cruiser]

I know rotaries get horrible gas mileage but it can't be THAT bad!

 

[remy_martian]

eAssist? So stealthy even the guy selling them has no clue where the motor is:

 

[brian_]

I know rotaries get horrible gas mileage but it can't be THAT bad!

🤣

With the rotary engine, you could put just about anything under the hood and the average person might not notice because they have no clue what they're looking at even with just the stock engine.

 

[pickPear]

Honestly, Bad on my part for not going into further detail.

1- During Vehicle inspection, I plan on removing all easily visible electrical components. Vehicle inspections are done once every 2 years here; and removing the obvious electrical drive, ie motor, battery pack, etc is something Id be willing to do, even if it takes a week or more it'd still be viable. Gas is very expensive where I live, The equivalent of roughly 60 usd per gallon (in terms of itd take 4-6 hours of work to be able to purchase 4L of gas on minimum wage; Its a funky situation).

2- The reason I want it to be stealthy is that in case I get pulled over, I want to have a functioning ICE engine to avoid running into issues explaining it.

3- Having Batteries, A control Unit, Etc inside the vehicle would be acceptable, and I don't expect it to cause me any real issues. However, An effectively empty engine compartment, except for an electric motor, would be kind of problematic.

4- All in all, the main issue I have is that Im not sure where I could place the motor; The vehicle im buying has a ford granada engine, which is a bit smaller than the normal rx7's rotary, so I had considered Placing the motor offset to the transmission, and connecting a chain to the crankshaft, and running the engine/transmission that way. (the engine wouldnt be running.) Effectively, I guess im asking how to Build a Hybrid.

 

[pickPear]

How realistic/Possible would it be to have a Direct drive DC motor interface with the rear differential? My understanding is that many EV's ditch the Transmission completely, and Ive heard something along the lines of the transmission's reduction gearing not being 100% necessary.

When I think about it; How about mounting a motor, possibly with a 90 degree transaxle-type deal, to the back of the differential, and spinning the diff/rear tires that way?

First issue that comes to mind would be Length, but a 90 degree set up to have the motor parallel to the rear axle could fix that, as could potentially mounting the motor upright, to enter the car's interior? Im just spitballing here, what reasons would stop that from working?

Would it be possible, theoretically, to Set up a rear drive system like a tesla motor, but with an actual Dc motor? Have a Separate rear subframe that could theoretically be swapped?

I understand Its not an easy route to go, and that its far more of a headache than the traditional route of slapping an electric motor onto the transmission, but It is what it is.

 

[Kato659]

SuperFastMatt Hybrid-ized his Honda S-600 in much the way you are contemplating (chain drive to the drive shaft). Disclaimers: he's an automotive engineer and makes things seem easier than they actually are. Also, he removed the hybrid bits after a while because he didn't like them.

Of course, your plan is to not run the engine at all as opposed to his performance boosting, so you'll need much more battery (and better camouflage besides).

As to the question about bypassing the transmission, most motors you will find need some kind of gear reduction but not multiple gears. The Nissan Leaf has a 7.94:1 gear ratio, single speed.

 

[brian_]

How realistic/Possible would it be to have a Direct drive DC motor interface with the rear differential? My understanding is that many EV's ditch the Transmission completely, and Ive heard something along the lines of the transmission's reduction gearing not being 100% necessary.

I think that you have misunderstood EV transmissions, or the meaning of the term "transmission". Every production EV has a motor which needs to turn at a much higher speed than the axles, so they all have reduction gearing, and that's a transmission. What almost none of them have is a multi-speed transmission; instead, they have one fixed gear ratio... but that's still a transmission.

The reduction ratio of the final drive (rear differential unit) is not enough to effectively use the motor of most EVs, but lots of conversions are done with lower-speed motors for which the final drive ratio is enough.

 

[MattsAwesomeStuff]

I would use the rear end from a Mitsubishi Outlander, Prius Gen 2 inverter with a control board from OpenInverter.org or a Gen 3 from EVBMW.com, and put batteries in the trunk. There are a handful of people who have already done this.

Makes it pretty easy to swap.

$60/gallon?
$15/liter?

Hmm, this to me says "I want to appear to be rich (who could afford to drive when gas is that expensive?) but am actually poor."

 

[OR-Carl]

Yeah, with gas that expensive, how about a bicycle? Or maybe better yet, a plane ticket to somewhere else? If you have the fabrications skills to pull off this project, you should be employable just about anywhere.

Even a very modest battery is going to be tough to find space for in a car, and if you worry the police want to open your hood at a traffic stop, I suspect they will want to look in the trunk too. If the inspections of the car are thorough, I suspect you would be hard pressed to return the car to a satisfactory condition before having it inspected.

Maybe if you bought a car, had it inspected, did a lightning fast conversion on it, drove it for part of 2 years and then pulled all your gear out and then repeated the process with another one it might work. If you can keep getting the same model of car, you will eventually get the conversion time down under a year . Just put a set of speakers under the hood to play engine noises for when you get pulled over.

 

[remy_martian]

Buck a liter: Turkey Gasoline Prices - January 2022 Data - 1995-2021 Historical - February Forecast

This says he may want to get past a checkpoint and sneak up on something in stealth.

Now why would you want to do something like that, if true? Rhetorical, no answer needed.

 

[pickPear]

Buck a liter: Turkey Gasoline Prices - January 2022 Data - 1995-2021 Historical - February Forecast

This says he may want to get past a checkpoint and sneak up on something in stealth.

Now why would you want to do something like that, if true? Rhetorical, no answer needed.

Ah well, The issue is that Here we dont earn wages in usd. Gas is 13.5 tl/liter, which is a little less than an hour of work. Most people here make less than 400 usd/month, and so gas is very expensive.

Also, what are you implying? Are you okay there bud?

 

[pickPear]

I would use the rear end from a Mitsubishi Outlander, Prius Gen 2 inverter with a control board from OpenInverter.org or a Gen 3 from EVBMW.com, and put batteries in the trunk. There are a handful of people who have already done this.

Makes it pretty easy to swap.

$60/gallon?
$15/liter?

Hmm, this to me says "I want to appear to be rich (who could afford to drive when gas is that expensive?) but am actually poor."

That sounds like an awesome idea; Im having trouble finding the threads/builds that used an outlander's rear drive unit, Do you have any idea what specifically I should google to find more info on that specific type of conversion? "Outlander EV swap" and so on aren't giving me any results.

 

[brian_]

1- During Vehicle inspection, I plan on removing all easily visible electrical components. Vehicle inspections are done once every 2 years here; and removing the obvious electrical drive, ie motor, battery pack, etc is something Id be willing to do, even if it takes a week or more it'd still be viable.

I would use the rear end from a Mitsubishi Outlander, Prius Gen 2 inverter with a control board from OpenInverter.org or a Gen 3 from EVBMW.com, and put batteries in the trunk.

So the pre-inspection plan would be what... remove the drive unit and replace it with the original RX-7 final drive? Wouldn't it be easier to swap VINs on gas car and an electric car, and have them inspect the gas car then drive the electric car?

If the inspectors are stupid enough to not notice an electric drive unit under the rear, then use that drive unit and split the battery into two packs: a small pack in the back just large enough to get to and from the inspection, and a large pack under the hood which is replaced by a non-functional engine for inspection. Of course, it would be even easier to just bribe the inspector...