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2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 13 2022 6:14pm
by evcts
Hello,

After some research, I'd like to change this.

I have a salvaged non running 2003 CTS I want to convert to an EV for a 25 mile round trip daily commute. I can make my own adapters, mounts, etc. However, I know nothing about any of the EV parts. I would like to source as much from junkyards as possible. What is the best path to take in learning how to choose parts and assemble the EV part of the conversion? I am looking to spend the least amount possible on the project. I am willing to DIY pretty much anything. I basically want to build a street legal go kart. Everything manual. I have no issue doing the research, there is so much info and some of it appears old. Some guidance would be really appreciated.

Thanks!
Harry

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 14 2022 10:43am
by CONSIDERABLE SHOUTING
I really hope you didn't buy these things Then go looking for advice. That CTS used LS-family V8s; it'll be far better (and arguably could be better for the environment even!) if you just dropped a junkyarded, working LS back into it instead of a 20HP-odd brushed forklift motor.

I'm still a newbie at this too but I have a huge interest in EV, and because of that I have a lot of "ground state" knowledge. I can say right away, that brushed DC is only acceptable for cars if you're trying to beat records like EV drags; otherwise, you give up nearly everything from regen to power to everything in between because of their inherent inefficiencies (brushes, commutators, ect). Batteries will also be a massive cost and I don't know what the space constraints you have; even with such small targets you might be tossing good money after bad, especially to get energy hogs like heat and AC working.

I'd suggest starting small with eBikes and "little" things to learn DC voltages and power. Like you, I WANT to make some awesome, bespoke EV- but at a minimum, great EV conversions are all AC motors, liquid-cooled (motor, inverter AND battery) and aerodynamic.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 14 2022 5:38pm
by electric_nz
You’ll need to specify your range, top speed and acceleration requirements, any hills, etc.

Then you’ll need a battery and controller and some sort of transmission.

Not impossible but you’ll need to squeeze it all in somewhere

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 14 2022 7:15pm
by amberwolf
The best source for conversion info in general would be DIYElectricCar forums; at least several cars have been converted that need accessory motors and/or system replacements for power-accessories, that should get you pointed in the right direction.

Note that "old" conversion info is still good info--it gets you started with the basics. Even if the specific parts they used aren't relevant or available, they still tell you what kind of stuff you need to do, use, etc.

However:

Before you even begin going down the conversion road, you should make a complete list of exactly what this conversion must do for you, and under what specific conditions it must do it under, worst-case.

For instance, for that 25-mile trip, would you be going 10mph, 30mph, or 65mph? Do you need to accelerate "like a car", or can you slowly ease up to speed? There is a HUUUUUGE difference in both the amount of power and the amount of battery capacity needed to do these things at different levels.

If there are any hills (even very small slopes), or any breezes or headwinds, they also increase power demands (possibly radically). If you have to guess, guess higher than you think it really is, never lower.

The total expected weight of the car, including motor and battery and passengers and cargo, etc., will be needed at least as a guesstimate (always overestimate that, worst case).

If there are published Cda/etc aerodynamics figures for the car, use those along with simulators like the one at http://ebikes.ca/tools/simulator.html to get at least guesstimates of power usage under your conditions, potential wh/mile efficiencies, etc. (yes, the simulator was made for bicycles...but it can be used generally for anything, as long as you have the right numbers to plug in).


Another thing: Will the car's computer system work without correct input from all the engine sensors and the like? If not, can you DIY a system taht will fake them out? Or can you rewire the car to operate without the computer? (not just "can you physically do it", but is it still going to be a legal conversion, titleable and licenseable where you are, after you do that?)


Note that most EV conversions never get finished. They take a LOT of time and work and money. Some of them take years (or more). Ask yourself: How soon do you need it? How much money and time do you have to spend on it?

evcts wrote:
May 13 2022 6:14pm

I have a salvaged non running 2003 CTS I want to convert to an EV for a 25 mile round trip daily commute. I also have a Crown electric forklift to use. I can make my own adapters, mounts, etc. However, I know nothing about any of the EV parts. What is the best path to take in learning how to choose parts and assemble the EV part of the conversion? I am looking to spend the least amount possible on the project. I am willing to DIY pretty much anything. I figure I'll have to do a powered column swap and a controller to add power steering, some kind of pump for the brake booster, or I could just swap a different master in w/o a booster. Something to serve as an alternator to run the 12V needs. I have no issue doing the research, there is so much info and some of it appears old. Some guidance would be really appreciated.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 16 2022 1:00pm
by evcts
CONSIDERABLE SHOUTING wrote:
May 14 2022 10:43am
I really hope you didn't buy these things Then go looking for advice. That CTS used LS-family V8s; it'll be far better (and arguably could be better for the environment even!) if you just dropped a junkyarded, working LS back into it instead of a 20HP-odd brushed forklift motor.

I'm still a newbie at this too but I have a huge interest in EV, and because of that I have a lot of "ground state" knowledge. I can say right away, that brushed DC is only acceptable for cars if you're trying to beat records like EV drags; otherwise, you give up nearly everything from regen to power to everything in between because of their inherent inefficiencies (brushes, commutators, ect). Batteries will also be a massive cost and I don't know what the space constraints you have; even with such small targets you might be tossing good money after bad, especially to get energy hogs like heat and AC working.

I'd suggest starting small with eBikes and "little" things to learn DC voltages and power. Like you, I WANT to make some awesome, bespoke EV- but at a minimum, great EV conversions are all AC motors, liquid-cooled (motor, inverter AND battery) and aerodynamic.
The CTS for this project is a 2.8V6 it's an insurance auction car, was vandalized, they cut a bunch of wiring out of it. I also have a CTS-V which is the LS6/6 speed manual car you're thinking of. I think I just want to build a crappy street legal go cart out of it. Where I live heat and AC aren't a necessity. Power steering would be nice, but I'm also used to driving old cars with manual everything.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 16 2022 1:09pm
by evcts
CONSIDERABLE SHOUTING wrote:
May 14 2022 10:43am
I really hope you didn't buy these things Then go looking for advice.
No, I've the car for a while. But, the forklift is worth enough to sell instead of scrap. So change of plans.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 18 2022 8:31am
by CONSIDERABLE SHOUTING
evcts wrote:
May 16 2022 1:09pm
CONSIDERABLE SHOUTING wrote:
May 14 2022 10:43am
I really hope you didn't buy these things Then go looking for advice.
No, I've the car for a while. But, the forklift is worth enough to sell instead of scrap. So change of plans.
Hey, making cash is pretty sweet!

I was going to say- It's a poor choice for a bunch of reasons (good to hear it's a salvage car tho!) but part of the problem was gonna be that "they cut a bunch of wiring out of it" bit; getting CANbus to play along with whatever motor you choose is bad enough, but with the harness all jacked up? That'll quickly turn into a tedious job just to get everything properly sorted and terminated, let alone getting what's left to play nicely with what motor you chose.

What did you chose to do?

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 18 2022 11:47am
by evcts
Still researching. Seems it's either full DIY or get a Nissan leaf for a donor. I don't think the wiring will be a problem. None of the gauges will be needed or the HVAC system. The other stuff is less complicated.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 18 2022 6:22pm
by CONSIDERABLE SHOUTING
Honestly? Leafs can be had super cheap- I think the lowest was a Jalopnik writer who got theirs for ~$2K- and now they have tons of modifications like supplementary batteries and DIY channels about them.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 19 2022 1:08pm
by evcts
CONSIDERABLE SHOUTING wrote:
May 18 2022 6:22pm
Honestly? Leafs can be had super cheap- I think the lowest was a Jalopnik writer who got theirs for ~$2K- and now they have tons of modifications like supplementary batteries and DIY channels about them.
Yes. It does seem like the most practical option.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 19 2022 10:33pm
by calab
Sounds like fake news to me, I'd need more proof that a certified mechanic didnt fix it up a little to make the story more appealing or that little to no major work or expensive parts werent conviently forgotten to write a story to get paid for. Maybe even the actual price for the car was actually higher, who knows what a cat will do for a buck.
CONSIDERABLE SHOUTING wrote:
May 18 2022 6:22pm
Honestly? Leafs can be had super cheap- I think the lowest was a Jalopnik writer who got theirs for ~$2K- and now they have tons of modifications like supplementary batteries and DIY channels about them.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 20 2022 8:18am
by Jordan325ic
calab wrote:
May 19 2022 10:33pm
Sounds like fake news to me, I'd need more proof that a certified mechanic didnt fix it up a little to make the story more appealing or that little to no major work or expensive parts werent conviently forgotten to write a story to get paid for. Maybe even the actual price for the car was actually higher, who knows what a cat will do for a buck.
CONSIDERABLE SHOUTING wrote:
May 18 2022 6:22pm
Honestly? Leafs can be had super cheap- I think the lowest was a Jalopnik writer who got theirs for ~$2K- and now they have tons of modifications like supplementary batteries and DIY channels about them.
Last year I saw 2011 Nissan Leaf's with 30 miles of range go for $3K in Texas. $2K was plausible for that time with a quick buyer and a motivated seller.

EV prices have shot up a lot the last year, but even a u cheaper than converting a 2000s Cadillac. Converting a modern luxury sedan to electric is impractical. They're too heavy and too complex to make conversion feasible, especially the super budget conversion considered here. Search around a see what sort of conversions people do... there's a reason it's mostly old sports-cars or compact pickups or VW bugs. They're all lightweight, with as few automatic/power/safety features as possible. You may think you're halfway there with cheap donor and a forklift motor, but those are the easy parts and two of the cheaper bits in any conversion. Whatever money you saved will be lost in time spent reverse-engineering/re-wiring the 12V side of the car since none of it will be usable as-is.

Re: 2003 Cadillac CTS Conversion w/ 30 mile range

Posted: May 20 2022 2:30pm
by evcts
calab wrote:
May 19 2022 10:33pm
Sounds like fake news to me, I'd need more proof that a certified mechanic didnt fix it up a little to make the story more appealing or that little to no major work or expensive parts werent conviently forgotten to write a story to get paid for. Maybe even the actual price for the car was actually higher, who knows what a cat will do for a buck.
There are a lot of stupid stories in regard to low cost EV conversions. Rich Rebuilds scored an expensive controller, might as well have been free considering the price. Then posted a ridiculously low project cost on the video. That said the leaf looks to be an disgusting looking POS not too many people want considering the very low resale value I saw when searching normal classified ads. I saw them less than $2k. There could be a problem with the batteries considering how many places were offering upgraded battery mods. Considering the used car pricing I can't imagine a wrecked, salvaged unit pulling anymore than $1500 depending on the year and mileage of course. It's likely not worth rebuilding considering the salvage title discount and potentially needing a new battery module.