[Zappo]

Hi all. 1st post here (please be kind ). I have been reading many of the posts for a few weeks now. I'm getting ready to start my first conversion. I have a really nice 11" GE series wound 48v motor and a 1980 Triumph TR7 convertible with a bad engine. 5th speed is 0.83-1 ratio. I'm planning on going with 144v or 156v.
I know an 11" motor is a little large for such a small car but it is what I have. With such a large motor, do you think it would be better to also pull the transmission and go direct? I would like to be able to hit at least 60 mph. With the differential ratio and tire size, it looks like the motor would be running at about 2300 rpm with 5th gear or 2700 rpm direct at 60 mph.
I'm not looking for racing performance but I don't want it to be a real slug either.
Any advice (besides not do it )?

 

[Woodsmith]

Nothing wrong with an 11" motor in a small car!

Welcome to the forum.

There are a few of us building/converting with 11" motors for differing reasons.

Yabert has one in a Smart car, Todd has one in a model T hotrod, and I have one for the reverse trike build in my signature.

Whether to keep the transmission or not will depend on a few things. You will need to look at how you intend to run the car.

Running the motor slowly under load will draw more current and create more heat then running it fast. It will also be less efficient and reduce range a bit.
So, if you are mostly urban driving at slow speeds then you might want to keep the trans to allow the motor to run at a higher speed to improve its efficiency.
If, like me, you are mostly on the faster roads with little urban driving then it is less of an issue.

However, the motor will have a lot of thermal mass and a huge torque and so for urban use it may not be too hot nor need to draw too much current if the car is light enough anyway.

The other thing that may decide it is will the motor fit where the transmission was? If it will then you could remove the trans and fit the motor in the tunnel leaving the space where the ICE was for batteries.
If it won't fit then the space will not be useful for anything else as it will either have the trans still there or a shaft from the motor to the axle running in the space.

Lets see some photos of the car and motor, we like photos here.

 

[Zappo]

Thanks Woodsmith. After reading many of your posts, I'm not at all surprised that you wouldn't think the 11" motor was too big . I'm planning on using this as my daily commuter but it is not in an urban environment. It is about 18 miles to work on mainly 45 to 55 mph roads. I've made it in a Zap Xebra PK truck I bought this summer but it is really pushing its limits (even with upgrading to 84v). I will be able to plug it in at work but I will try to put in enough batteries to make the round trip without worry. Te PK would be much better suited in an urban environment.
I just pulled the motor from the TR7. I will need to pull the tranny, but it looks like the 11" will tuck in there nicely. I will probably need to lengthen the driveline a little. Like you said, that would open up a lot of room up front for batteries and electronics.
Since I live in the Pacific NorthWET, I will probably add a belly pan under the motor to try to keep it dry.
Thanks for the links to the other 11" monsters. I'm going to go check them out now.

 

[Duncan]

Hi Zappo
I'm putting an 11 inch in my Locost thingy - direct drive

http://www.diyelectriccar.com/forum...-dubious-device-44370p2.html?highlight=duncan

For a TR7 I would keep the gearbox as it gives more choice in ratios

 

[Zappo]

Hey Duncan,

Thanks for the input. That is quite a project you have going there. How is the openrevolt controller kit working out for you? I'm probably also going to build and use one of them. I actually live about 20 miles from Paul and Sabrina. I almost bought his VW last month but dragged my feet too long and lost out.

I'm pretty new to this whole forum idea but really appreciate the plethora of information. I will try to post some pictures of the TR7 and motor this weekend.

 

[Duncan]

Hi Zappo

I have built the controller - not too difficult even for a non electronic type like me
I did need to buy two soldering irons - tiny (25w) and huge (80w) - the correct light comes on BUT I have not tested it on the motor or with a computer
So I could still come unstuck!