Electric SLK Anyone?

[jcwright45]

Welcome to the electrification of a Mercedes Benz SLK. Goal is to convert a pre February 2001 as there are currently massive tax saving implications in London for electrically converted cars up to 28/2/2001; no road tax £285per year, £15 congestion charge per day, £11.50 Ultra Low emissions zone (ULEZ) per day. I attended a New Electric Ireland course in Sep 19 and was instantly hooked on taking the next steps. The consolidated Lexus GS450H gearbox concept intrigued me, given the fact many of the requirements of a EV conversion were wrapped up in one peice. Upon returning home I purchased a Lexus GS450H gearbox and inverter from eBay.

Since Sep 19, I have acquired not one but TWO registered Jan 2001 manual 320 SLKs. Both car have under 75k miles on them. One is the project car and the second remains intact to assist in reverse engineering when required and to put the top down to have sun when the sun is out. In April 2020, the donor car was stripped of all ICE components by another class participant I met while on the course. Thanks Pedro, www.Inautos.co.uk had to give a little plug.

Since receiving the car back and cleaning the engine bay I’ve been busy playing around with different battery box configurations, defining the new 4 corners weight distribution and possible gearbox placement.

More to follow

[jcwright45]

The gearbox fits like a glove and the car is now with a fabricator to create new mounting points, gearbox face incorporating the spline to lock the two motors, bracing underneath, and interface the prop shaft between the Lexus and Merc differential. I know my limitations...

Given the car is currently away getting a makeover it was time to focus on the wiring and software side. It’s been a couple of days over a couple of weeks but I created a testing loom after finding some data interface connectors from a breaker, got 3 in total and distributed them to other participants. Thanks to the forum and Wiki pages I have sourced all the connectors, taught myself how to crimp Molex connectors to wire the project up for testing purposes. I purchased the VCU and brass connectors from EVBMW of course! Test batteries are 4 electric scooter batteries combined to deliver 50 volts, thanks to Steveknox for this idea.

I have been able to power up the VCU and browse to the WIFI gauges page.
Next challenge was to download Arduino software and fumble through getting GS450H_v7 uploaded and throttle pedal calibrated. It might look messy, but I have uploaded the v7 software and can see changing parameters via the serial monitor. Big thanks to James Brown (project-figleaf), again another participant for helping me navigate the installation and configuration of Arduino due board. Using Skype and screen sharing helps explaining parameters set much easier. I have documented this process and will post it soon as soon as its peer reviewed for accuracy.

Afternoon, I was able to get the Lexus GS450H gearbox spinning using V7 of the code and using a leaf pedal apply acceleration. Short video to follow. Next will be figuring out how to convince the software the gearbox is NOT in neutral.

[mdrobnak]

You may wish to go back to v3 - past that was updates for the BMW 7 series specific items.

This diff is useful for you though - v3 vs v7 diff

Code: Select all

162c300
<     gear=get_gear();
---
>     //gear=get_gear();

But this looks awesome so far.

2001 - is this still all analog gauge clusters etc? Any info on ABS / traction control?

-Matt

[Alibro]

Awesome project and very sensible given how cheap they are to buy two.
As I'm a recent convert to Merc I'm watching with interest.

[jcwright45]

Thanks Matt, I was able to tweak the following in V7 of the code define drive versus neutral.

//set initial conditions/////////////////
T15Status=false;
dash_status=false;
can_status=false;
RPM=750;
Gcount=0x0d;
gear=NEUTRAL;
shiftPos=0xb4; //select neutral
//////////////////////////////////////////////

I changed gear=neutral to gear=DRIVE
also changed the shiftPos to 0x78

Gauge clusters, I believe Speedo, Tach and temp are controlled via Canbus. ABS and traction control to be address once I get a brake vacuum pump installed and running.

[mdrobnak]

Ah, so then the later version of v7 gives you a relatively good idea of where you'll end up in terms of integration anyway, but you may end up with certain aspects of v3 (like using a simple pin input to select a gear).

shiftPos is probably used in the dash gear 'echo' code, so that may or may not have an effect on test operation.

-Matt

[jcwright45]

Update: 10/7/2020

Car has returned from fabricators and I'm well impressed. Shout out to Zack @Anarchy_Kustomz for the professional looking work!! The gearbox isn't going anywhere.. Dropping the gearbox easily was one of the main requirement. Zach and I are working on costings if anyone wants a face plate (flat, no mounting wings) for the GS450H gearbox with holes drilled for bell housing and spindle, spacers for spindle, motor mounts and hardened nuts and bolts. I'll post that part under the classified section as well. Next is determining where everything can fit and work out battery box locations. Getting there...

[jcwright45]

Couple of additional pics

[mdrobnak]

Looking good!

[Mhs]

Nicely made.
The luxus gearbox/motor leaves a great space upfront.

[Speedy]

Looking great so far.

Loving the front plate and gearbox mount.

Zach and I are working on costings if anyone wants a face plate (flat, no mounting wings) for the GS450H gearbox with holes drilled for bell housing and spindle, spacers for spindle, motor mounts and hardened nuts and bolts.

I'd be interested in seeing pricing on these.

[jcwright45]

Its been a while, so time to update the group. What's changed?
High Voltage cables have been installed
CANBus capture and hacking in progress
Nissan Leaf battery pack delivered, not dismantled as I want some stats from the BMS first if possible
GS450H gearbox, ATF fluid changed, fully wired up and reinstalled in the car. Pics to follow..

[bobby_come_lately]

Looking really neat!

[johu]

Yes super well done. It's awesome how the entire drivetrain just disappears under the car with these RWD builds.

[Cookie6000]

Awe man. That's tidy.
What type of ties are you using there for the HV cables under the body? Way-hey better than my 'cable ties a go-go' attempt

[jcwright45]

Awe man. That's tidy.
What type of ties are you using there for the HV cables under the body? Way-hey better than my 'cable ties a go-go' attempt

Thanks, I'm extremely jealous of your complete build!! Hilltop cable management, 6mm hole, some sealant and these babies..

https://www.hilltop-products.co.uk/cata ... 00+X+4.6mm

[Cookie6000]

Cheers! Was only saying to someone earlier, if it wasn't for Covid induced unemployment, I would be nowhere like where I am now.
Got to get me a load of those. thanks. Keep it lit

[konstantin8818]

Awesome build! I as well want to make an RWD conversion... unfortunately car like this and even older ones costs ridiculously expensive here.

[jcwright45]

[jcwright45]

[Boxster EV]

The build looks great. Thanks for the tip re the cable ties. I’ve just ordered a few for stock.

[arber333]

The build looks great. Thanks for the tip re the cable ties. I’ve just ordered a few for stock.

Really tidy build! Congrats.
I caught hell for using plastic ties on power cables from TUV inspector. I needed to use metal straps around tubes to fit them to the chassis. I put some shrink wrap over them so they dont damage the plastic tubes. But they are really firm. Just saying...

[Speedy]

How has this been running? Any updates?

[DkubusEV]

Super cool build and awesome photos of your progress, really motivational as I'm currently just starting on my R170 SLK with gs450h conversion too. How has everything been going? Hope you're well and the car is progressing (or providing great driving adventures)?

Really looking forward to your next update. Cheers from Australia

[DkubusEV]

Wood block and strap to hold up while I design mountings

Seeing as how JC has discontinued his SLK conversion (unfortunately as it was looking awesome), I've finally started putting parts into mine and have lots still to do and decide upon related to battery and mountings etc so that it'll suit road registration in Australia... anyway here's some update pictures.

Flush with bottom of vehicle chassis level (so eventually a flat floor can be fitted for aerodynamic improvements...

From above (can't fit any further back into tunnel as its hard against the tunnel sides. Will require "massage with a persuader" to gain a little clearance.

Top down view of space for battery pack in front of gs450h "power unit"

Rear view, I did some 3d scanning attempts, that's why there's tape in there to assist the scanner to not get lost on large plain surfaces...