[Bowser330]

I love the parallel hybrid idea, you could use the front motor of a Tesla model s, 300hp added to the 911.

Alternatively couldn’t you get a rwd 911 and just switch over the front suspension hardware to the C4 model?

I have seen a a few white papers online about parallel hybrids but I haven’t seen any diy hybrid performance cars.

The charging could be through regen, you could actually have regen on slightly turned on all the time to charge up what you used on your bursts of acceleration.

My question is on the power delivery control, when you press the throttle the gas motor will rev up and the electric motor will rev upas well, how does the electric motors rpm get determined by the road speed? No electronic speed synchronization is needed?

 

[Bowser330]

The last post before mine was 11 months ago, Sept 16th 2019, not 18 months ago. Try to get your dates right.

“Necroposting is seen as a form of spam and clogs up the forums with old and unneeded topics.”

I don’t deem this thread to be about an old or unneeded topic, nor is what I posted spam or with intent to clog the forum. I was actually searching for diy parallel hybrid setups and came upon This thread. if I’m researching it others might be too, plus you did too before you realized it was soooooo 11 months ago.

this forum has a ton of very intelligent people and if i have a damn question I’m asking it no matter what trendy new word little kids are using these days.

 

[Bowser330]

That's called a "through the road" hybrid, and it's very inefficient.

That may be one of the explanations why we haven’t seen them more.

Didn’t Toyota/Lexus use a parallel hybrid technology for the rear electric motor in one of their hybrid suvs?

 

[Bowser330]

Sorry, I didn't see the date on the post before. Jan 10 2019 is 18 months ago, and since then the OP has been gone. In my experience necroposting usually means replying to an old thread, I didn't exactly look up the definition before using the word (probably a mistake of mine, not the first one).
I'd really appreciate if you wouldn't go calling people little kids though

BTW, to answer your question, as long as there's a direct connection (gearbox or otherwise) between electric motor and wheels there is no problem with motor RPM synchronization.
A Tesla motor is especially painless, since it's induction rather than PMAC (no back EMF problems when unpowered) and it's torque controlled rather than speed controlled.
If you want a cheap SDU controller take a look at openinverter, for 300 euros (maker is in Germany) you can get a replacement logic board which will get tons of power out of the SDU (though maybe not matching the efficiency of the Tesla logic board.) There is also a forum with lots of bleeding edge development, mostly in repurposing OEM motors and inverters.
-Isaac

Thank you for the reply

 

[Bowser330]

Thank you for the information Brian but I guess I’m just especially dense on this topic. Do I have the below written correctly?

If a rear engine car had an independent electric axle upfront, it would be considered a Parallel hybrid. Because the motors are disconnected from one another and paralleled through the road.

And remain a parallel hybrid when under braking or zero throttle the electric axle regenerates power back into the e-axle driving battery pack.

but the minute the regen is activated while the car is being powered by the gasoline rwd engine it becomes an inefficient series hybrid, because you are using rear mounted gas engine to power up the battery of the front e-axle.

 

[Bowser330]

IIRC the rx400h had a small rear motor. But that was powered normally by the battery pack (the car also had a FWD hybrid transaxle).

That’s the one, thx

also I checked out openinverter and woah does Damien have some amazing products. Currently has some boards coming out for independent model 3 motor control, very cutting edge as you pointed out.

 

[Bowser330]

I think the dynamics and stability statements have made it very clear that it can be straight dangerous to be regenerating while driving, so then how to keep the smaller battery pack charged?

Isaac97's idea of using the now unused output shaft of the AWD transmission is a good one if a generator can be appropriately sized for the RPM range. I'm not sure on the SW controls the cars have regarding torque split between the rear diff and front diff... i assume some custom ECU work would be required to determine the right amount of torque split to the generator based on the state of charge of the battery.

a lot of work but could make quite the performance hybrid!

 

[Bowser330]

Thank you gents. Very interesting about using an older 911 for this project. I haven't verified which years used the VC vs. the MC.

The newer 911 Carrera 4 uses an entirely different AWD system. Instead of a viscous coupling, which responds to slip mechanically, a computer-controlled multiplate clutch actively engages the front differential to transfer torque forward.

Behavior modification: All-wheel drive tames the 911 | Hagerty Media

These days, you can’t walk through a Porsche dealership without bumping into an all-wheel-drive-equipped vehicle. Customers for Porsche’s SUVs, the brand’s best-selling vehicles, expect the all-weather traction of four driven wheels. On the other hand, 911 loyalists remain split over rear-wheel...

www.hagerty.com

 

[Bowser330]

A few minutes of Wikipedia checks (might be wrong) tells me that 996 and 997 have viscous clutches, no data on 991 (generation after).

EDIT 993 (1995-1999) had viscous too, generation before that had a real differential.

Thanks for the research. I think that might apply to the carrera only, the 997 turbo i think used the multiplate clutch, but the 996 turbo did use the viscous. Very cool.