Talk Me Out Of Converting My 2.7 to Electric...

[M.D. Holloway]

I know, its heresy! I have thought about pulling my 2.7 out of the Targa and dropping in an E-motor...why? Because...

Ideas, comments...

[Ian Comerford]

Because this is simple, any car where the drivetrain is a major part of its character should never be converted to EV. So never convert an air cooled 911…..

[Qtrfoil]

No, because it's an awfully big loss if you decide you've made a mistake. If I was juiced up (ha) about making my own EV I think I'd find something more like an MGB with good externals for $5-6k and try that one first.

[maverck]

Originally Posted by Qtrfoil

No, because it's an awfully big loss if you decide you've made a mistake. If I was juiced up (ha) about making my own EV I think I'd find something more like an MGB with good externals for $5-6k and try that one first.

Great answer IMO - and yes and EV MG would be AWESOME!

And yes - the character of an air cooled seems so obvious!

[76FJ55]

Does you car currently have a functioning or salvageable aircooled engine? If so I concur with the others that it is probably best to keep it. I could see looking for a roller that didn't have a drivetrain and the building it up as an electric.

[ADDvanced]

Nah, cars are worth too much, and EV swaps tend to have terrible/barely usable range. If you want an EV I'd buy one.

[eastbay]

Do it, will be cool.

[Zuffenwerker]

Ya do it, 2.7 mid year car is a good candidate if you really want an electric 911

[fanaudical]

It's your car, Mike - You get to do what you want with it.

My opinion/prediction - We'll see lots of companies offering electric conversion kits for lots of vehicles within 10 years.

My story: I acquired my '75 911 Targa in 2010 (for super-cheap) and was uncertain of the condition of the motor. Car was trashed. My initial thought was to attempt to get it running and go electric conversion if the motor was not salvageable. I abandoned that idea after I got it to run a short time (oh - that sound....) and eventually did a complete rebuild and replaced the transaxle. In the process I had done a lot of research on EV conversion. Motors and drive train modification weren't the problem at the time - motor electronics and batteries were.

Today, I think it would be much easier to source EV components and do the refit. I also think it's reasonable to do an EV conversion on a G-series 911 that is reversible in case you ever change your mind:

- Keep transaxle and clutch, adapt motor to transaxle.
- Remove gas tank, build and bolt in tray for battery pack and motor drive.
- Add additional batteries in the back to get the weight balance close to original.
- Pull fuel lines from tunnel, route electrical from front-to-back through there.
- Remove the oil tank and console. Remove front oil cooler and lines. Use that space for routing a cooler for motor and motor drive cooling.

There are a few conversion companies out there already:

https://electricporsche911.com/

https://www.zelectricmotors.com/

https://www.evwest.com/catalog/product_info.php?products_id=224

And some other examples:

https://cleantechnica.com/2022/07/08/converting-this-1977-porsche-911-to-electric-yields-600-bhp/

https://www.caranddriver.com/features/a39211023/porsche-912-ev-conversion/

And maybe the best of both worlds:

https://www.vonnen.com/technology/

Honestly - I'd probably drive my Targa more if it were electric. I live a short distance from work and barely get the oil warm in the summer driving to/from (unless I take extra back roads...). As it is it just now goes out on longer drives.

I also think there are tons of cars that would make good conversion candidates if you just need a driver:

Porsche 914, 924, 944
VW bug / Ghia
VW Rabbit / Golf
MG's like stated above
Pretty much anything with a simple drive train and manual transmission.

Hope that helps. Let us know what you decide to do.

[manbridge 74]

Do it.

More mid-years back dated, outlawed and e-converted will only make mine worth more when I need the money for my kids college tuition.

[PeteKz]

You won't be the first to do a 911EV. Several articles about others are out there. If you want to do this swap because you think it's technically interesting or challenging, and the car is not a rare or collectible version, then go for it. BUT, don't reinvent the wheel. Use the lessons from others, and start with proven and available components from a Tesla or Chevy Bolt or the like.

EV West and other vendors can sell you the complete motor/transmission/axle/suspension from a wrecked Tesla. I've been involved with a couple electrification projects of other makes and models, but those were pretty much built from components, and bolting an electric motor to the original car's transmission or driveshaft. I wouldn't do that again. Instead, I would buy a complete Tesla or similar drive unit and graft the whole thing into the target vehicle. Tesla, GM, et al, have done all the hard engineering for you and optimized these packages for efficiency and weight better than you can. Then you will need the drive electronics, which EV West and others will also sell to you, ready to install.

Batteries are a different story. The battery packs in production EV's are also carefully engineered and optimized for the spaces in which they fit, along with the cooling systems required to take away the waste heat from both charging and discharging. They typically constitute the floor of the vehicle, which also keeps the weight low in the vehicle. I haven't specifically looked at converting a 911, but I'll bet that none of the OE battery packs will adapt easily to the floor of a 911. So you will have to design your own battery pack and cooling, or put together modules of packs sold by one of the vendors.

I would try to split the batteries between the frunk, in place of the gas tank, and the engine compartment, to INCREASE the polar moment of inertia. And I would aim for a front/rear weight distribution of between 50/50 to 45/55. Why? Increasing the polar moment of inertia makes the car less apt to swap ends quickly. For a good demonstration of the advantages, consider a 944 versus a 914. A 914 has much more of a big go-kart feel because it has very low polar moment of inertia, but once it starts sliding, it will spin very quickly (trust me on this!). A 944 on the other hand, distributes its weight by moving the transmission to the back of the car. It has very near a 50/50 weight distribution, and with its high polar moment, it swaps ends slowly, which allows you to drive near the limit of adhesion, and even step across it a little at a time, and "save" it before it gets away from you. A reasonably good driver who can drive a 914 or 911 at 8/10ths, can drive a 944 at 9/10ths. Now, if you're the kind of pro driver who can throw a Yellowbird around the Nordschliefe in record times, maybe you really want a low polar moment, but for the other 99.9% of us, high polar moment is a good thing. Therefore, distribute the batteries to the front and rear. Of course, keep them as low as possible, as low CG almost always helps handling.

The EV OE drivetrain you choose should be substantially lighter than the original engine/trans combo, which will take weight out of the rear of the vehicle. Be sure to account for that in figuring out where to put batteries. The last time I rebuilt and modified my 3.2 motor, I weighed the major assemblies and components, since I found conflicting and incomplete info online. The completely assembled 3.2 engine with flywheel, clutch, oil cooler, fan, alternator, fan shroud, engine tin, engine mount and crossbar, and CIS system weighs right around 330 lbs. That does not include the exhaust manifolds/heat exchangers and muffler. (FYI, Renegade Hybrids in Las Vegas, that sells Chevy LS conversion for 911's, claims the LS swap weighs less than a 3.2 engine. I don't see how that is remotely possible.)

[Cloggie]

Of course, it is your car, but I concur with the opinion that you don't buy a 911 because it is eco friendly...you buy it as it is an experience that cannot be reproduced in another car (speaking of air cooled cars only of course).

Making it electric just defeats the purpose of a 911 and turns it into some sort of 911-shaped appliance that may as well be a fiberglas 911 body fitted to a Prius.

it won't handle like a 911, it won't feel like a 911, it will have all the quirks of the 911 suspension without the benefits of its balance and joys of mastery that a 911 brings.

Don't do it unless you just want to play with a car to make it electric....and then go for a more common car, maybe Corvette or perhaps a Miata that no one will feel like you glued a monkey's head on a thoroughbred...

D.

[rokemester]

I always thought a later year 75-76 914 would be good candidate for an EV conversion.

[ADDvanced]

Just sell it and get a model 3. They are really fun, esp w the over the air update for more speed. And it will crush 99% of 911s you find on the street, of any generation.

[Coblue]

If you choose the right conversion method, the conversion from fuel to electric can be completely reversible, without cutting or welding. You can use most of the same gauges you are using now, and the suspension should only need a little tweaking - maybe heavier torsion bars is all you'd likely need.

The power and range on these depends on how many of what batteries you put in, Putting 16 Tesla modules in , 12 in back, 4 up front, will get you around 225 miles or range but it's very heavy and won't feel right. The 911 was designed and built long before any aerodynamic characteristics were taken into consideration, and so it's got the drag coefficient of a brick, right around .61 or so. For comparison, a modern Tesla is around .21. I bring this up because pushing your car through all that air is what requires so much energy. You can see from these numbers that pushing a car with almost three times as much air-drag will take almost three times the energy, and will mean that the batteries don't last anywhere near as long.
But that may be OK, because when was the last time you drove your car for more than 100 miles at a sitting? If you drive it from point A to point A, or just quick errands, or such, or do trips of 50 miles or less each way, a 100 mile range is very livable, especially if you can use fast charging and can plug in when you're in town, because a 24kwh or 32kwh battery will charge quickly on a level 2 charger., and you don't need to fully charge it, you just need enough to get you home. Fast chargers are popping up everywhere. And , by the way, last I checked, you can't charge anything but a Tesla at a Tesla charging station, even if it had a Tesla motor in it. It'll check the VIN your motor was installed on and if it's been marked as salvaged, it won't charge the car.. AND if you're using the Tesla battery management system, it will disable fast charging as well.

IF you have about $60k you can have it done right and get 150-200 miles range with fast charging and a great feel, and the car will do 0-60 in 3 seconds or less, and 0 to 100 in about 7. Who will complain about a car's character if it can run like that?

Now, having said that, most electric-converted cars that I've driven drive like fancy golf carts. It isn't that it doesn't have any character, but I keep missing the rattle of the golf clubs, there's no reason to shift anything, and to top it all off, there's no cup holder in a 911, and you'll really miss that a lot more if you aren't clutching and upshifting and double-clutching and down-shifting all the time...

[Cloggie]

Originally Posted by Coblue

"The 911 was designed and built long before any aerodynamic characteristics were taken into consideration, and so it's got the drag coefficient of a brick, right around .61 or so. For comparison, a modern Tesla is around .21. I bring this up because pushing your car through all that air is what requires so much energy. You can see from these numbers that pushing a car with almost three times as much air-drag will take almost three times the energy, and will mean that the batteries don't last anywhere near as long."

Tiny correction....according to Frere, the drag coefficient of a '70's 911 is around .40, Tesla model 3 around .23...still a big difference but not all that bad as the 911 has a pretty small cross sectional area

..and the way, the 911 was designed with serious consideration for drag and particularly lift as you can read in Frere, but they just did not know how to do it and did not have access to the kind of modelling and wind tunnel work manufacturers have today.

D.

[al lkosmal]

Here is the best reason I can provide to...... not go electric.
Just my opinion...i could be wrong!





regards,
al

[shoooo32]

Removing the flat six guts a 911. Without that noise and vibration, you'd focus on the light weight and precise handling. Except now there's a huge battery pack over the front axle. No bueno.

There are so many better options for electrification. Sell the 911 to fund the ev project. There are plenty of cheap project cars out there with garbage engineered drivetrains just waiting to be updated.

[EC900]

What’s wrong with the 2.7L ? Where is the dissatisfaction? What gains are you seeking or expect converting to EV?
Yes this mid-year engine gets a lot of bad reviews, probably the most swapped engine candidate if not only for base performance but because of heat warping issues and the subsequent associated oil leaks.
It would be difficult to determine what this EV convo would deliver over a gas engine without trying one out. Battery life and range, safe recharging, etc. may outweigh periodic fuel delivery, management and valve adjustments. No savings either way and performance will still be negligible.
A pleasing sound and occasional waft of petrol is half the point, I would find it better to slip on an oil slick than trip on an extension cord.

[ant7]

Nooooooooooooooooooooooooo don't do it!