So I just bought a partially complete GTM...now what?

[John Rubicon]

Hello Lords and Ladies,

I have so many dumb questions that are a result of picking up someone else's project, and a few more such questions that are all me.

The trouble all started when someone I know showed me a flyer for a commercial bankruptcy auction and highlighted a "cool car" among the lots of industrial junk being offered. He asked me what it was, but of course, I knew too well what lay under the dusty primer colored exterior and in the boxes also pictured - a first gen GTM basket case.

The vehicle was a test mule for a company that developed hydrogen-powered electric vehicles, and it was missing all the cosmetic elements that might inspire someone unfamiliar with the GTM to bid much for it. Alarm bells should have been going off, but I've kind of been smitten with the GTM since I attended the 2009 Knott's Berry Farm Kit Car Show and met the FF guys in their full-court press. Instead of alarm bells, a little guy with horns and a pitchfork started whispering.

Short story: I now own a vehicle that reached the runner stage while powered by a now missing electric motor. It is on C5 donor running gear, I am told, and has a G50 trans installed. The frame has been lightly modified to allow some electric drive components to fit. All sheet metal is installed, brakes are plumbed. and electrical is in rudimentary form. One door is hung, but the hood and the driver door were duct taped on. No glass, mirrors, lights, etc, are mounted on the primered body. What else is lurking in the boxes? Ey! What did I get myself into?

I moved the vehicle to the aircraft hangar/shop I share, and rolled down the door last night without telling anyone.

Get ready for the stupid questions. Anyone in the San Diego region willing to allow me to look at your build/completed car and begin to get my mind around this?

Mentors wanted.

[carbon fiber]

What kind of frame mods? Do you have pics of what has already been done? Best thing to do is an inventory of what you have and go from there. Also there are some things that usually need to be done to get the bodywork right. (door/door glass fitment, hatch glass, front wheelwells, etc.) I'd check the work over carefully before moving to paint. There's no dumb questions, good luck with the project.

[Kalstar]

Welcome to the club, as Carbon said, there are no dumb questions. I am happy to offer advise and suggestions.

[Presto51]

Welcome to the party. Like stated before their are no dumb questions here to ask, so ask away and don't fear any flame throwers.

So let me start off with a question or two of my own to you..... Have you envisioned what you what your GTM to be or do? And do you have build plan started?

Also check out the "other" forum http://www.ffcars.com/ which has a ton of additional information and builds.

Again welcome

Ron

[John Rubicon]

Thank you Carbon, Kalstar and Presto for your cordial welcomes.

Carbon, I appreciate your advice on cosmetics. I built my first kit car over 20 years ago with the Beck 550 Spyder, and learned a couple of similar lessons. The cosmetics will be some of the last things I take on, and I'll likely have them done by a local acquaintances's paint and body shop. I'm more of a wrench than a skilled fabricator, so the kind of fit and finish craftsmanship I want in my car will be the result of someone else's skills. Since the kit is a little dinged up from its journeys through other people's hands, it needs a skilled body man to shine again.

Presto, I bought the kit at auction with a strong preference toward making it an electric-powered performance vehicle, as was intended for it by its original buyer. Now, at first blush, this may seem incompatible (given the state of development of electric vehicles--with Tesla as an exception) with the spirit of performance that most of you have build into your GTMs. But. I am a founder of a company that designs and builds electric Class-8 (Big-rig) trucks, and have been building performance electric solutions for over 15 years on other people's money. I have access to all the tools, talents and components required to field a 500hp, 1050 ft-lb electric drive system. As this kind of electric performance is not cheap, it may take a while and a few iterations to reach this level of performance on my own dime. I have found a generic build plan on the "other" site, and have started to modify it. I have twin 250hp electric motors (as used on the Fisker Karma) on the boat over from China as we speak, and a starter pack of pouch cell battery modules is arranged and awaiting my check. The inverter drive is a product my company co-develops, and is capable of minutes (not seconds) of full power operation. Chief impediment to making this work is fitment of enough battery storage in the spaces available in the vehicle using current battery technology. All this said, my path will likely take this vehicle forward as a test mule for the electric drive, and then as a street car with limited racing potential in local autocross, but only as new battery technology allows.

So the long list of questions starts below.

1. If the chassis has a FFR serial number plaque attached, where would that be located? The car sold at corporate bankruptcy auction with no title, so that aspect will dictate my future choices.
2. Can anyone here share a complete parts list with me so that I can perform an inventory of what is here?
3. Does anyone (besides FFR) have a CAD model of the frame that I can use to both verify what's been altered and to plan my changes?
4. As with homebuilt aircraft I expect that a list of recommended changes or additions has emerged over the years of best practices in the builder community. IS there a centralized list of such?
5. What else should I consider up front that I am missing?

Thank you all for entertaining my notions of electric sacrilege. Now who's going to be the first to point out that 1050 ft-lbs doesn't leave me with an affordable transmission option?

[Presto51]

Electric power very interesting indeed

Also reach out to Eric Hanson on the forum, if you haven't already https://www.factoryfive.com/whats-ne...electric-818s/

Exchange ideas or at least he might tell you of some traps to avoid. Please keep us in the loop even if you don't think it's news worthy the forum would still like to follow along

Ron

[John Rubicon]

Don't pre dog on yourself: The GTM has an established history of use as an interesting driveline test bed including the following:

White House "Makers" showcase as a hybrid:
http://www.pbs.org/wgbh/pages/frontl...t-philly-high/

High MPG X-Prize as a hybrid:
https://www.factoryfive.com/whats-ne...x-winning-gtm/

Turbine powered PHEV:
http://electricnick.com/2009/12/05/l...ury-5-chassis/

You're joining a grand tradition!

Here are examples of other FFR products that also have well-received electrified variants:
818 http://www.topspeed.com/cars/others/...-ar163384.html
Coupe http://www.ffcars.com/forums/43-off-...-f5-coupe.html
33' Hotrod https://www.factoryfive.com/whats-ne...-all-electric/
Mk4 roadster http://www.ffcars.com/forums/54-chev...ctric-mk4.html

As to over torqueing the transmission, isn't that a matter of properly spec'ing your electric motor to match? On the otherhand, with enough torque all you need is the final drive!

Hi Waitin2b,

Thank you for laying out the history of similar vehicles - I learned something. My team and I were in competition with the West Philly HS group when they first fielded a vehicle back in the 2002 period. I am glad to see they are still at it, but had only READ the X-prize results and not seen a picture of their car. Heck, I even work now with folks at Capstone (Micro-turbine car). So both of these were GTMs and I didn't know it.

Here is a little background on where I got my experiences with early performance electric hybrids. http://www.vanityfair.com/politics/f...deshow_item6_7

You mention spec'ing the motor for the transmission, and I agree, when the right motor exists at that spec. The transmission has always been the most immovable constraint due to the cost of pursuing a custom solution. For the vehicle my team built over a decade ago, we fabricated our own 2-speed, unbreakable transaxle from scratch to take the input of both a diesel engine and a 200 hp electric motor. In this case, the motor I use now is going to dictate the rest of the driveline because it is affordable and well characterized and matched with a worthy motor controller. Direct drive is the safest and most direct path, as Tesla has illustrated with their offerings, and I may go that way at some point to prove other parts of the system. But if this vehicle can only duplicate the Tesla experience, I will have failed. I believe I will ultimately seek a three-speed gearbox solution that can handle the torque and speed of two motors, or I will split the two motors and seek an AWD solution if such a solution can fit in this chassis.

Perhaps another builder will get the fever for a high-performance electric FF car that doesn't retail at $529,000 like the Renovo Daytona Coupe does. I'd be glad to work through these challenges with someone.