Anglin's Racer Build and History

[John Brennan]

Simple... and elegant.

[Ray]

wow, i honestly forgot what the hatch looked like with stuff in it like that.

[anglin]

I really appreciate Allan for posting this test data. It would be VERY difficult to get better test data. A chassis stiffness test rig usually involves the chassis rigidly fixed at one end and being torqued about the axis of the chassis, not bent along the front-to-rear midline. It gets worse, since one 22 year old chassis will not give the same result as a different 22 year old chassis, given rust and other factors. Yay.

Wouldn't you know it... There is a book that discusses the crash dynamics of the Merkur XR4Ti. Not exactly chassis stiffness data, but it's the next best thing. It is a text book, so anybody who has been a student recently knows that the book is going to cost at least one limb. (In fact, my university requires that you cut off your own limb right in front of the book store manager to prove that it is indeed your own limb and not one from a body parts harvester.)

ISBN-10: 0849301041
ISBN-13: 978-0849301049

http://www.amazon.com/Vehicle-Crash-Mec ... 849301041/

Here's an excerpt I snagged out of the "search:"



If we only had the next page!

[anglin]

I recently decided to become a YouTube member and I've uploaded a handful of videos. One of the videos I posted is of my racer at the Carlisle 2000 autocross. You can see a great example of a left/right front brake bias problem in the video. I know the video is 8 years old, but it's the newest I have of that car (that was early in my first full season, too).

http://www.youtube.com/watch?v=maYD-o73k0I

[anglin]

Well, it has been a while since I've updated this thread with any project work done directly to the car because I haven't had much of a chance to do the work.

The Odyssey battery has been discharged due to lack of use. Of course the car sat for about two years being completely ignored with my trip to Iraq, so that left me without the ability to start the car. Because the battery was positioned with vehicle performance and safety in mind, the battery is very difficult to access with jumper cables. In fact, the first time I did it, I used the battery that was doing the jumping right on the starter terminal (the Odyssey battery had enough juice to run everything else).

When I designed the remote system I was aware that problems like this may occur and came up with a plan to address the problem. Today I put that plan into effect.

When buying the components for the battery relocation project, I picked up some quick disconnect plugs for a jumper port. I even machined a mounting bracket, but that stuff has been sitting around waiting for me to install it.

I picked up a set of new jumper cables and chopped the giant alligator clamps off one end and installed the jumper plug on it.


I have now made the most application-specific jumper cables on the planet. The next trick was to put the jumper port on the car. I connected the ground from near the passenger kick panel where I 'reinforced' the existing ground by connecting the negative battery cable when I did the relocation originally and then tapped into the always-hot side of the battery cutoff switch.

You can see the additional positive cable coming off the left side of the cutoff switch in this picture.


Here's the plug. If you look carefully right at the top edge of the following picture you can see the reinforced ground where I connected the jumper plug (look for the copper terminals just above the red plug with the yellow wire).


This is one of the positions where I am considering mounting the plug when I get the chance to complete the installation.


Here's the jumper cable connected to the jumper port ready to wake the dead battery.


Finally, I previously used black cable for the positive and negative main wires because that's what I had available. I didn't like the solution at all, so I replaced the positive cable with the red that you see in this picture.

[Ray]

what gauge wire are you using, and is your main positive cable fused @ the battery or just the switch itself?

[anglin]

what gauge wire are you using, and is your main positive cable fused @ the battery or just the switch itself?

The cable is 4 gauge. The battery is not fused. The next incarnation of the system will likely have a giant fuse in it like the one you and Brad were discussing a while back.

[Ray]

i'll email you some info on that anglin.

[anglin]

Just when you thought it was dead and never coming back.

I'm busy with winter stuff which, conveniently, is also school stuff. I'm deep in my senior design now and figured I'd drop a hint or two here. Here's some SolidWorks goodness.

front anti-roll bar


front crossmember


SolidWorks is getting increasingly ridiculous features. Ever wondered what a front crossmember would look like if it were made of glass? I didn't think so, but here it is anyway compared to the stock color:

[BeefFajitas]

Nice, so does that mean you'll be offering tubular cross members soon?

[DPDISXR4Ti]

SolidWorks is getting increasingly ridiculous features. Ever wondered what a front crossmember would look like if it were made of glass?

Does it give you weight estimates? What would it weigh if it was made of Titanium?

[anglin]

Nice, so does that mean you'll be offering tubular cross members soon?

You know... a tubular crossmember would be a very good project. One issue with that is the same as what Pete Sowitcky is dealing with on the front strut tower brace project, everybody wants a different combination. Some may want a crossmember that bolts everything up in exactly the same place and some others may want one that uses the Pinto rack, fixes the bump steer from the TCA pivot and inner tie rod being on different planes, allows for TCA pivot point relocation, maybe even allows for different motors to be mounted to the car or even accomodates XR4x4 stuff. Lots-o-combos.

Does it give you weight estimates? What would it weigh if it was made of Titanium?

Yes but. I made the crossmember model dimensionally correct in all the places that count (bolt holes, brackets, shape, etc.) but the model isn't made of stamped steel. It's solid. The best I can do is compare weights between mild steel and titanium and give a comparison. If it were made the same way out of titanium, it would weigh 58% of the mild steel part. So, a 10 lb crossmember would become a 5.8 lb crossmember. The great thing about titanium compared to steel is the increased strength per volume, so you could use less material to make it to receive further weight savings. The not so great thing about titanium is the cost.

[anglin]

More stuff.



That TCA was good entertainment. It was actually pretty straight forward to draw. Where's that thread about making an XR entirely out of SolidWorks part files? The number of hours in the three parts you see there is absurd (nearly 30 hours). I can't imagine what a complete car would take. There's no way I would do an accurate spindle without a CMM.

[anglin]

I've been at it again. This time I've been in the garage instead of at a CAD computer. Here's what's going on.

as it arrived:






tedious clean up process underway:

[yottabit]

Good job on those solid models! It always takes way longer than you expect, especially if you want to do it correctly, hah.

http://forum.merkurclub.com/forum/viewt ... solidworks

That is the thread you were talking about but I quickly lost steam after actually trying to model some parts and junking the car. Nevertheless, make sure you hold on to those part files!