Gabe Alexander

Hi, I just joined rennlist from New Orleans, Louisiana, to tell you about this 924S I just got from dallas!
It was a lovely drive back home, I'm young so I'm used to all the cars, even the junkers, having cruise control, first thing I want to do is install cruise control, I have the control circuit, actuator, cable, and clutch switch in the mail, I've read that you just need the bolts and its plug n' play but we'll see



there is also a screetch when engine braking
I'm not sure , but I think its the pinion bearing, because its at high speeds regardless of clutch/engine rpm, when the car is dragging against the transmission, but when the transmission pushes the car forward (ie acceleration) it becomes the normal ,quieter, porsche whine

Something I do on the side is EV conversions, fitting in batteries, machining adapter plates to mate motors to the stock transmissions and having them be alot faster than stock, so I have experience making electric drive trains

But with this car, it has a lovely engine already, I want to shorten the torque tube and fit an electric motor between the torque tube and transmission, based on stuff I've done with porsche 914s and vw bugs, it shouldn't be too hard to machine the parts for it, and I don't mind sacrificing the never used back seat for batteries or something, or perhaps in the spare tire compartment

I don't need very much batteries, hence mild hybrid

Based on the math, it should get up to 40ish mpg with the added weight included, but that's not the point, the point would be to add a boost of 200-300 foot-pounds of torque in the drive shaft, and replace the components that snap over time , the motor could apply a minor drag for power regeneration that can be charged up and used for acceleration later

This may be a possible buildthread as I gather the components over time, and a place to ask for advice, but I might make a different thread for the buildthread because it won't start for...a while ($$$)
Anyway, here is a graphic I put together in like, 30 seconds for you:

Gabe Alexander

I'm planning to use a 200kW ac-induction motor with a rotor shaft that extends out on both sides, so it can couple to the torque tube and transaxle easily after I make a thing to mount it

Similarly to this, I circled the shaft not attached to the trans

MAGK944

There’s been a few built, two in Canada to my knowledge and then there’s <this one>. Search on yt for the others, I seem to recall watching videos a while back.

Gabe Alexander

oh thats perfect! This is a complete EV swap though, I know what motors they're using (80% sure anyway) , I'm going to ask them what they did with the transmission to avoid stripping the teeth off the gears and ring/pinion because I've done this

NelaK

I'm going to follow this closely!

Are you sure you want to use the original transmission though? They are really expensive to rebuild, and it seems most of them need a rebuild at this point.

Aivar88

i would also be interested for all the details, as gas prices go up electric would be great alternative considering the power they can create.

V2Rocket

rather than shortening the tube and trying to stuff a motor in there, how about a belt/chain drive to a sprocket mounted on the driveshaft coupler where driveshaft meets trans shaft?

Gabe Alexander

I am not sure if I want to use the stock transaxle, as it is very expensive to rebuild, I might go with a mendeola transaxle made for offroad vw bugs and such thats stronger, that way its a one time spending deal rather than repeated repairs on part not made to handle it

As for a belt/chain from the motor to a sprocket on the driveshaft, I'm not sure if that could take the power either, without breaking eventually, the instant torque from the motor puts alot of shock that isn't normally there with gas, but perhaps putting it in parallel with the driveshaft another way (a gear?) would do the trick
The problem with that however, is that it might take more machining, design, and eventual re-iterations of that design than what its worth, as compared to just fitting it inline with the driveshaft

The motor is about 9-10 inches in diameter, 14 inches long, and is pretty rugged (splash mud on it all day as long as you can cool it under high load)
I'm planning to cover it from the bottom and have a fan cooling it from the top

Gabe Alexander

Actually would anyone have any suggestions as for what I could use for a transaxle, assuming 600-1000 footpounds of torque peak? (thats the kind of power that allowed the car mentioned in the first reply to smoke a mclaren)

jhowell371

. Any transaxle made for a VW dune buggy sure won't stand that kind of torque. You might try ZR1 Corvette transaxle to absorb that kind of power when you drop the hammer.

Dave W.

haha, 1000 lb-ft is a mild hybrid?
It takes a lot of batteries to make that much torque.
Here's a good thread that talks about power capacity of the popular Warp9 motor;
https://www.diyelectriccar.com/forum...ri-166938.html

Gabe Alexander

okay, maybe not that much torque, maybe peak bursts of 300-400ft-lbs at most, with the peak 200-300 footpounds from the gas engine combined
Definitely alot of batteries, the hardest part is finding a place for them and saving up for the amount I need, (20kWh/ 200v/100Ah) or using the batteries from a car I already made , but that car would be my 1986 nissan sentra which is my actual daily

but I'm thinking a using a more efficient motor (ac induction) than the warp for a few reasons
it would be bad to have a motor with a max rpm of 4-5krpm (brushed series motors like the warp, which I do like to use) coupled with the stock inline 4 engine that makes 7krpm , and difficult to have to go under the car to change the brushes in a series motor, that can do regen, but barely, which would be a critical part of keeping an electric motor in the drive-line and using the gas engine to generate power to use later

I'm thinking of posting the nissan I made actually , just to show you guys but I haven't because its not very rennlist-y

The Forgotten On

There is a company called Elephant Racing that installs a hybrid drive system inside of the clutch housing in air cooled 911s.

Going that route might save you some complications in machining everything.

NelaK

Only $75,000 or about 75 times what the 924 is worth.

That kind of tight packaging is probably more important for the cramped area that you have to work with in the 911. The 924 isn't trying to fit the engine, transaxle, diff, hybrid motor, and cooling system in the same tiny area.

Arominus

You're looking for Tesla level performance out of a mild setup? seems unrealistic. Most "mild" hybrids are rocking a motor on the motor via the belt system or in the trans or bellhousing area. They add enough to get you off the line for MPG gains. If you want full ***** out electric performance, you need to ditch the hybrid idea and go pure electric. Then you can just mount a big *** electric motor at the front of the torque tube. Thats how this car has been done in the past.