DIY Electric Car Forums banner

1 - 2 of 2 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1 (Edited)
Hi everyone,
Sorry if this is wasting y'all's time but I would like to probe y'all about an idea for a conversion. Basically what I would like to do is convert my 2011 RX8 with a 6-speed manual to a parallel hybrid. For those who don't know the Renesis 2-rotor in the RX8 is seen by many (somewhat including me) as being unreliable, being inefficient, and lacking low-end torque. While I don't see the engine as horribly unreliable, I do agree with the other two points. Thus, I would like to use an electric motor to
a) Act as a very strong starter motor for cold starts and de-flooding
b) Allow stop-start (with a sufficiently warm engine) and low-speed electric propulsion when in city-like environments as well as provide regen braking to provide efficiency gains
c) Provide a significant low-end (below 5000rpm) torque boost and maybe increase top end power (above 7000rpm) a little (the system must be able to let the Renesis rotate at 9000rpm).
I would like to do all the above without adding much more than 300 pounds of weight to the car (with as much added to the rear as possible). Here is how I plan to do it:
- Remove the factory alternator and starter, and convert all engine-driven accessories (brake booster, heater, AC compressor, power steering is already electric) to electric.
- Connect a permanent magnet motor (roughly 10-20kW in size) directly to the engine somewhere before the clutch. I was thinking of doing this with a belt to the factory alternator location (or somewhere nearby) like an accesory or connect it right after the engine before the clutch in the transmission line (a different trans might be needed for this).
- Install motor controller and necessary components in engine bay.
- Install battery (expecting roughly the size of a larger Toyota hybrid battery), charger, and energy storage components in trunk.
- Use custom ECU programming or a standalone ECU for the engine coupled with a secondary controller board to control the whole shebang
- The electric motor will always be coupled to the Renesis. The Renesis will be able to run sans electric motor after the conversion, but for the purposes of the conversion, idle will be disabled to allow the engine to stop; fuel injection will be disabled with a button to provide an EV mode.
I know this has been done before with the StealthEV conversion at SEMA 2016 and a 350Z with a motor instead of a clutch/flywheel. My question is, am I over my head in assuming I can do this for less than $10,000 and without crazy fab work to make everything fit? Does everything presented seem sound, at least in theory? Thanks for your replies.

EDIT: Here are my answers to the stickied questions:
Your skill level with auto mechanics and fabrication: not much but I am willing to pay a shop to help me through the process. I am not too concerned about whether this is doable by *me*, just in general.
The range you are hoping to get: 3-5 miles EV only, otherwise operate in tandem with gas engine
What level of performance you are hoping to get: a little bit faster than stock (with gas engine only)
How much money you are willing to put into your project: $5-10k for parts
 

·
Registered
Joined
·
1,288 Posts
Interesting idea and I wondered similar. Recently saw the Mercedes hybrid stop start motor that goes between engine and clutch, would be ideal. 30kw max, plenty for low speed EV. Or replace starter with electric motor to act as starter generator and light ev using a toothed belt drive. Renesis has low compression so wouldn't be major restriction.

Cheers
Tyler
 
1 - 2 of 2 Posts
Top