Sunday, October 5, 2008

Problem Solving......Mopar Purists, Better Just Look Away

As we all know, most problems have several possible solutions. We have to choose the best solution according to our needs. I have not mentioned this problem in the blog thus far because I wanted to wait until I knew for sure what I was going to do about it. Well, today is the day :)

This problem begins with my choice of voltage. The 'usual' and most common voltage used for heavier vehicles is 144 volts. I wanted to ensure that my performance would be at least as good as other 4,000 pound conversions so I chose to use 156 volts and found a reasonably priced and readily available motor controller that could handle that voltage. This necessitated using 26 batteries instead of 24.

I have been solidly committed to using 26 batteries from the start and that has never been negotiable. However, placement of those two 'extra' batteries has been something in the back of my mind. For proper weight distribution, I wanted, if at all possible, to place 12 batteries in the rear and 14 under the hood. I knew 14 under the hood would be tight. The best solution was to place 4 batteries down low in front of the motor, with the remaining batteries on the racks above the motor. The problem with this configuration is the limited height I have available.

So ok, I'm getting closer to coming to the point here :) My number one rule for this project is not to 'harm' this classic Mopar. Cutting some sheet metal is ok. Welding to the frame is ok. But THIS is something I really did not want to have to do. However, going back to my first paragraph, this was the best solution to achieve the end result I want. So, without further ado...



Cutting and modifying the K-frame allowed me to position the bottom rack low enough to get the clearance I need. In fact, if my measurements are correct I don't even have a half inch to spare. Had it been a rack for just two batteries, I would not have had a problem. Oh well, I guess it's not the end of the world, but it was still traumatic for me to perform that surgery.

6 comments:

Anonymous said...

Hey Bruce: Cool project. Earlier in the blog you mentioned thinking of making the car lighter. Easy ways to do this would be fibreglas parts like fenders,hood,decklid and maybe doors. These might be availible for this car as it is quite off a race car. Another item is the front crossmember. These are now availible in tubular form. Along with light control arms & coil springs & rack/pinion steering you would safe a ton of weight. Changing the subframe may also give you more room for your battery racks.

Bruce said...

Thanks Kooba. Yeah, there are lots of fiberglass parts available for the Duster and I am familiar with some of the lighter suspension components. Lighter parts are expensive, so after I get the car on the road, I plan to see where I can get the best weight savings per dollar spent.

Anonymous said...

I wouldn't be concerned. Even "purists" would chop the k-member up if they were transplanting a bigger motor in.

You can get a number of fiberglass parts for the Duster. It was a popular race car. Here's one place, there are others. I would check swap meets and ebay for cheap parts.

rod n race

Looking at your motor mount, you could strengthen that a great deal with just a little bit more work. Looks like you could put another strap across going through the lower bolt in the motor. I could send you a picture if you want.

I think you could also tie in the rack going over the motor to the motor mount pads, and gain same rigidity. Just remember, anywhere you've got a 90 degree angle, putting a brace across it add's stiffness.

If you're around Indy, I'd be glad to help you on this.

Bruce said...

Hey Keith,

Thanks for the suggestions and the link to Rod N Race. I know of two other places that sell fiberglass parts but I had not heard of this place.

I'm in Oklahoma - not too close to Indy - but thanks for the offer. I should be completing the racks soon and I'll see how they handle the weight, then add support if necessary.

Anonymous said...

No problem. I'm a gearhead since my teen years and love solving problems.

I would think the stationary weight wouldn't be a problem, it would be the lateral (side to side) forces when making turns at speed. For that matter, acceleration and stopping as well. That's a lot of weight to chance shifting around.

Have you worked out holding the batteries down yet? When I've needed to I've taken angle iron, and some 3/8" threaded rod, and built a decent battery hold down.

When you get there, make your test drives are slow and easy at first. A little bracing can go a long way towards safety and peace of mind.

DriverMag said...

Hi there, I am writing for an automotive magazine in New Zealand and would like to run a small news story on your Duster.

If you could email me on karl@drivermagazine.co.nz that would be great. I'd like to get hold of some info and shots.

CHeers!

Karl.