LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently October 19, 2021, 3:35 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
PostPosted: September 14, 2021, 2:53 pm 
Offline

Joined: September 14, 2021, 2:51 pm
Posts: 1
Crossposted from the Locostuk BEC forum (in case you read both).

Hello BEC Locosters!

I am working on something pretty different, but it shares a lot in common with your mid-engined BEC builds.

Starting with a $5k 2013 Nissan leaf with a pretty sad battery (~40 miles range), I'm keeping all the EV componentry in place while adding a little ICE boost in the form of a 2009 ZX10R engine powering the rear wheels, creating a 300hp AWD DIY hybrid with a 13K redline and sequential box of course. I completely understand that this isn't to everyone's taste and the Nissan Leaf is objectively an ugly non-performance car. But this is being done as a proof of concept build for future projects using a similar hybrid drivetrain and MAY be one of the easiest ways to get a BEC on the road (in California at least). Reverse: solved (via EV powertrain), no need for a big bore 'busa motor or off the line torque/clutch torture (again because EV), emissions (what emissions?), quiet when you're driving through neighbourhoods (nice!).

To make this work mechanically, I'm taking a complete Gen2 Lexus IS rear subframe, and will be mounting the engine on it directly above a Quaife chain drive differential (using a Honda Civic based one). Because of this arrangement the chainline is more complex than your average BEC build.

To help with the design I followed the lead of one of my favorite youtubers and fellow mechanical egineering & BEC enthusiast Superfastmatt and started with 3D scans of all the components. This has been a revelation and has allowed me to spend a bunch of time figuring out things in advance before cutting any metal.

I've designed a cradle from laser cut 3/8" 6061 that supports the front corner of the engine and manages the chainline and supports the differential. This will bolt up to the rear subframe that will have welded structure to support the engine in 3 other spots. I've run FEA based on expected peak chain loads and everything is looking pretty good with >4X factors of safety and minimal deflection.

The output sprocket is a 5/8" offset 15T, the idler is 18T with dual 25mm bore bearings riding on a hollow 25mm shaft, the output sprocket is and aluminum 56T and rides on 40mm bore 80mm bearings which are in machined bearing mounts that are spaced out from the main plates. The final sprocket is a tensioner to take up slack -- 15T on single 17mm ID bearings cantilevered off an idler mount made of a pair of 3/8" 6061 plates.

https://imgur.com/6vbZ6NQ

https://imgur.com/h89xlyg

https://imgur.com/OkZc9XW

Now on with the questions:

1) Any glaring gotchas from this design?

2) The 5/8" offset sprocket has me a little worried about loads on the engine output shaft, although the vendor (PBI sprockets) didn't seem to think I should be worried. I considered designing a support bearing, but as I'm trying to make it easy on my self, the car probably won't see a ton of miles (and have a spare engine available if things go really wrong), I'm currently feeling like taking the risk.

3) Hybrid halfshafts -- is there a way around having scratch built custom axles made? Have people successfully cut-and-welded two different CV halfshafts together (in this case Lexus outer + honda inner) in 1000cc bike engine applications? The internet has mixed feelings on this. I'm almost willing to risk it, but I'd have to have someone do the welding anyway so maybe I should just do it right the first time with custom splined axles.

I will be posting more about this project as things develop, but I'd love to hear experienced peoples thoughts on what I'm up to! Happy to answer other questions about the build as well, as this ICE engine driveline portion is just a small part of it!

If you want to see it all, I have an active google photos album that I just dump everything relevant into as I go along.

https://photos.app.goo.gl/hBUezQtiCVuvTPQ99


Top
 Profile  
Reply with quote  
PostPosted: September 20, 2021, 10:54 am 
Offline

Joined: November 6, 2020, 6:29 pm
Posts: 251
Location: Spring, TX
Definitely sounds interesting. Reminds me of the Hayabusa powered Smart Fortwos, but with a bit more functionality having 4 doors.

_________________
13B Powered Rotus Geauxkart
http://www.locostusa.com/forums/viewtopic.php?f=35&t=20899


Top
 Profile  
Reply with quote  
PostPosted: September 20, 2021, 5:10 pm 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 207
I really like the concept, can see from the photos you have the blood and sweat in it already.

What scanning package did you use? Those are nicely detailed meshes, did you post process?


Top
 Profile  
Reply with quote  
PostPosted: September 20, 2021, 6:31 pm 
Offline

Joined: September 22, 2005, 10:29 am
Posts: 522
Please keep us up to date. It's a very cool project. Reminds me a little of the guy who took a Fiero and put a salvage electric motor (Prius? Leaf? I forget) in the front for the Grassroots Motorsports Challenge.

Besides the technical hurdles, there's the weight issue. The leaf comes in Just under 3,300 lbs. Add the motorcycle bits and things are getting a bit porky. You can take 500 lbs or so out by going the Ghettocet route (Basically cut off everything non-essential), but it's still no flyweight.

So could you be charging the batteries when the bike motor's running and the vehicle's at speed? Lot's of interesting stuff to figure.


Top
 Profile  
Reply with quote  
PostPosted: September 22, 2021, 8:59 am 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 7093
Location: "Banana Republic"
My understanding is that a LEO can impound your vehicle pending an inspection or site for noise, emission, etc.

Even a car manufactured as a hybrid would likely be ticketed or towed, much less an electric non-hybrid. Just fyi.

_________________
My posts are my own opinion and do not represent an official public position by any other person, place, thing, animal, vegetable, mineral, etc.
https://www.azsenaterepublicans.com/audit
https://www.oann.com/india-govt-declares-most-populated-state-officially-covid-free-after-widespread-use-of-ivermectin/
https://www.oann.com/fauci-hhs-officials-discuss-using-new-virus-from-china-to-enforce-universal-vaccines-in-footage-from-oct-2019/
https://www.oann.com/the-story-of-iverm ... -the-drug/


Top
 Profile  
Reply with quote  
PostPosted: September 22, 2021, 11:28 am 
Offline

Joined: September 19, 2009, 12:33 pm
Posts: 479
Love this idea. I'm interested to see how the integration of the controls goes.

_________________
Ford 5.0 into an M3
mikaelvroom.com


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
POWERED_BY