Monthly Archives: November 2016

OK, Seriously Bummed By This

Mrs. the Poet has placed her foot squarely on my dream of building a hot rod and ground it to flinders. I am not allowed to build my hot rod on the property where we have our house, and I don’t have any budget to build it any place else. So free parts car will have to be abandoned. Plans for the mid T will have to be discarded. Dreams of competing in Goodguys autocrosses are ruined. Hundreds of hours calculating frame member sizes wasted.

And the worst of it the $500 model T body sitting in the living room is now a literal white elephant (with a few spots).
Me in happier days
Dreaming of actually driving this thing.
Some of the spots
Here are some of the spots from the parting lines from the mold.

One thing that won’t change is moving forward on the Mini Sprint-T. I have to make a run to the hardware for another tube of mock-up glue (that I’ll also be able to use to repair Mrs. the Poet’s damaged Hummels she inherited from my mother) but the drills and adjustable collet I got for my Dremel tool have already been put to use cleaning up some parts and doing a little bracket fabricating. The dead toasters we got are being used to make a vacuum-forming machine to crank out modified bucket bodies in scale. (Three heating elements in a toaster, of which 2 can be used to make a heating unit for a vacuum former.) And I still have the 3 scale engines I can use (the SBC for the most-likely version, the LS7 for the “ultimate” version, and the Coyote Ford for the “Ford in Ford” version). The Coyote was dropped from consideration for 1:1 construction after doing a weight comparison to the LS series and actually seeing how far it hung past the sides of the bucket firewall. Not a good look without “blinging” the heck outta the engine to make it look goodbetter. Now don’t get me wrong, the Coyote is a good-looking engine, it just is Really Wide when installed in a T-bucket which makes it kinda dominate the visuals, forcing a cosmetic makeover.

And in other news I’m taking a day off from my walks, mostly because my left foot feels like it has been beat on with a big stick and my butt feels sore on the right side b/c I have been walking without the lifted left shoe. It has been years since I did any kind of walking without a lift on my left shoe to make up for the loss of about 17mm in my left leg from the crash, and the bottom of the foot is having to get used to just having a normal thickness sole between it and the concrete when I walk. It’s also really disconcerting when I walk in the house in my slippers and I hear rice crispy sounds with each step, but that’s the reality that has been getting louder the last 15 years. Part of that is just the reality of getting older unrelated to surviving getting hit @ 60 MPH with a truck.

Billed @€0.02, Opus the Unkillable Badass

Well, the de Dion suspension just isn’t in the budget

I was looking at the budget for the T-bucket now that I have an engine and transmission along with the rest of the donor vehicle it came in to scrounge from. Basically the budget remains pegged on $0 in spite of everything I have done to raise money for the project. So compromises must be made if this project is to continue. I’m still going to go sell plasma to make up the majority of the budget, to go along with the lab rat gig. Yay, more holes in my arms.

Another compromise is reusing as many parts as possible from the front suspension of the donor vehicle to make the rear suspension of the mid bucket, instead of just the knuckles so that there will be something to connect to the half-shafts that fit the transmission. I’m hoping that I can swap out the stock springs in the struts for ones that work better from my catalogs of various diameters, lengths, and spring rate, springs and get a ride height and roll stiffness that will work. The best candidates so far are $40 each or $80 total (plus shipping), but I’ll have to wait until I get hold of the actual struts before I can know for sure. There are other springs that can cost as much as $100 per spring because they are strange diameter/length/rate combinations, and I’m really hoping I don’t need to go to those.

This will save a bunch of $ and time to build at the cost of compromising the handling for what essentially is intended to be a car that depends on handling for speed in the competition it is being built for. The intended outcome for this car is winning Goodguys autocrosses outright. I won’t have the best dig coming out of corners so I will have to get the best corner speed to make up for the lack of power.

There are days when it looks like I will never get my hot rod built. Today was one of those days.

Billed @€0.02, Opus the Unkillable Badass

The boogieman of my childhood is dead, now what?

It was confirmed today that Fidel is dead Cuba’s former revolutionary leader Fidel Castro dead at 90 and I’m somewhat at a loss. When I was growing up Fidel was literally the boogeyman, a cigar chomping, baseball playing boogeyman coming to take away our freedom. Fidel didn’t need a last name with us, he was like the evil Elvis, Marilyn, or Gilligan, only needing the one name to identify him. And now he isn’t.

There is a minor meme propagating on Twitter that Fidel wouldn’t die until the US had been destroyed, and after Trump was elected Fidel’s job was done…

Jokes side, Fidel has been part of the background noise and frequently the foreground noise for all of my life, it feels strange that after the funeral and subsequent folderol we won’t hear anything more about him except for documentaries. And also seriously, most of my childhood my southern relatives used “Fidel” almost interchangeably with “Satan”. I don’t know what caused them to quit because when I came back after graduating HS in the mid ’70s they had stopped. But at least during the mid ’60s to early ’70s while I was there Fidel was Evil Incarnate. Chalk it up to short attention spans I guess.

So, farewell Fidel Castro, may whatever afterlife you experience be as pleasant as you envisioned.

PSA, Opus

Wow was I underestimating my walks

Someone mentioned an app on Twitter that did something I needed, tracking walks and estimating calories burned. So I looked it up at the Google Store and found out the price was right (free) and the basic version did in fact do everything I needed from such an app. So I now have “Map My Walk” installed on my phone.

What I learned is my “short walk” is 3.31 miles long instead of my estimated 2.5 miles I’ve been telling everyone, and that I burned 500 calories on my “short walk”. I’m thinking my “long walk” is closer to 5 or 6 miles than the 3.5 or 4 that I thought. This also explains how my shoes keep wearing out so fast, since I go for a walk almost every day. I’m also faster than I thought but still nothing to brag about.

Also while on my walk I contemplated the one remaining issue I have to solve with the rear suspension: keeping the rear wheels from steering the car under power because the toe angle changes. With the 2D Pratt truss the knuckle could have had enough bending torque to change the toe angle uncontrollably, so I had to make it 3D without adding to the weight or making it take up too much space behind or over the transmission. Thinking the problem through I realized the 4-link was going to be taking almost all of the forces that would be changing the toe, so all I really needed to do was give the 2D truss a fighting chance at using the depth of the structural members to resist toe change by using some diagonals connecting to the vertical member of the last bay before the knuckle, in as many planes as I could so the last bay would be 3D but everything else could remain 2D, only slightly increasing the weight of the truss and not changing the vertical stiffness needed to keep the wheel aligned on the other 2 axis. In doing so I would not be using a true Pratt truss in that the diagonal members will be under compression rather than tension, and the end bay would not have an upper horizontal member or terminating vertical member but would be similar to a kingpin truss in 3 planes, with another triangular bay under the truss from the bottom of the knuckle up to the bottom horizontal member in the plane of the main truss keeping the camber angle constant. I wish my CAD skills were good enough to draw this out and output a .gif or .jpg file to put in the blog, because words are only so good in describing this.

Another stab at it, the plate that holds the knuckle to the truss is going to be rectangular or maybe a right triangle with the hypotenuse facing down and forward and the right angle on the top rear side. Diagonal members will run from all 3 corners of the triangle to the first vertical member of the truss, one from the bottom corner to the bottom of the first vertical member from the bottom, one from the top front corner to the bottom of the vertical member on its front side, another from the top front to the top of the vertical member on its front side, and a last one from the top rear corner to the top of the first vertical member, that diagonal in the plane of the truss. That should be more than enough to keep the forces driving the wheel under control so the toe and camber don’t change. And none of the added members will interfere with the drive shafts or the lateral links of the Watts link that keeps the whole shebang located from side to side. That’s because all of the added structure is either behind or above the knuckle and therefore above or behind the driveshafts and lateral links.

I really need to learn how to use the AutoCAD 360 program I downloaded to the laptop and not just so I can draw pictures of the car to post to the blog. Anyone know of some good tutorials to teach me to use it?

Billed @€0.02, Opus the Unkillable Badass

I feel like the turkey we just ate, stuffed

Well we ate good on Celebrate American Genocide Day II. I actually had to skip the pumpkin pie this time (no room on the plate after getting apple, cherry cheesecake, and peanut butter pie slivers). Someone brought a creamed corn dish with jalapeño peppers that was absolutely out of this world. There were 3 different kinds of dressing including a vegan one made by my daughter visiting from Scotland. We even had canned cranberry sauce. It just isn’t Thanksgiving without “purple good stuff”.

And for those wondering what the II means, think October 12, 1492 and subsequent anniversaries as I.

PSA, Opus

More on that T-bucket

I know my old readers from back in the day 8 years ago today (yay!) might be getting a little tired of my building a car here. but I have to write and I can’t write about bicycles for a while. So building a car from scratch and scraps it is for now. Are any of you reading now still reading from back then? Leave a comment please if you are.

I have pondered the plusses and minuses of the three suspension designs I mentioned a couple of days back and made a decision based on what will work best and still not break the budget. Before I tell the winner I have to explain what went into the decision.

The overall design of the original car called for a tube front axle with reproduction early Ford spindles running adapted Mopar disks and GM Metric calipers held up by coilovers and connected to the frame with a parallel 4 bar and a long panhard bar for lateral location much like a sprint car. Since I had already bought much of this setup economics demanded that I make the rear suspension compatible with this. The biggest feature with this suspension is zero camber change in roll compared to the road as long as both tires remain in contact with the road, and a mostly fixed roll center height. This makes for a predictable and controllable front end which is worth way more than extracting that last 0.01 lateral g from the front tires. But to make the front suspension work the rear suspension has to be equally predictable and controllable.

So we start with the minivan strut suspension. Plusses are mainly low cost as all the parts are right there. Most of the minuses were spelled out in that other post, the biggest being lack of tunability , and a secondary one being that ride height would have to be set during the frame building process without knowing the spring rate or how much the back end will weigh. Well in addition to the construction issues there are the geometry issues. The biggest of those is the camber changes pretty much in tandem with the body roll, causing the outside tire to roll over on the outside shoulder and pretty much killing mechanical grip making the back end much less predictable and also drastically reducing overall grip. So as much as it pains my Scots ancestry this cheap solution ends up not the correct solution.

The second possibility was using a heavy wall aluminum tube like the axle tubes on a quick change rear end for a front engine car to make a de Dion rear suspension. This has pretty much the same geometry as the front end making it a much better choice for the midengine Bucket than the salvaged struts from the minivan. It is very easy to make the camber and toe adjustable at the plate that mounts the minivan knuckle to the tube which aids in setting tracking and adjusting the rear to match the front. Another advantage is the coilovers can be located pretty much anywhere on the top of the tube making setting the initial roll stiffness very easy. The major disadvantage is I don’t have the equipment to weld aluminum except in very thin material so the welding would have to be farmed out. That is an additional expense.

That brings us to the third possibility, the steel truss de Dion rear suspension. Again we have a very compatible geometry for the front end, that is also highly adjustable for everything and has a similar weight to the aluminum tube version, but one that I can build using the equipment I have on hand. One slight disadvantage is the mounts for the coilovers have to be over or very close to a vertical member of the truss (I decided on a modified Pratt truss) which means either the truss will have to be iterated somehow (probably with a shear plate that would be removed after the mounting point was determined) or the initial mounting point will have to be SWAGed (Scientific Wild Ass Guess) and then tuned with an anti-roll bar. For simplicity I would prefer to not have anything extra on the car for street use, so SWAG for the initial mounting point on a shear plated truss then do a limited iteration on both sides for the final mounting point, then complete the truss. Or just leave the extra mounts and one bay of the truss shear plated for adjusting the rear roll stiffness at the track. I like this because instead of bringing a rack of anti-roll bars to the track I just move the coilover from side to side on the axle to adjust the balance of the car.

So the Final Solution to this problem is the steel tube Pratt truss with one bay shear plated and several mounts for the coilover along that bay and matching arrays of upper mounts on the frame crossmember on the rear, with the tube axle and early Ford spindles and the coilover mount as close to the spindle as possible without getting tire rub, parallel four bar longitudinal location on both ends with a long panhard rod on the front to eliminate bump steer from the cross steer steering and a Watts link mounted low in the center of the frame running out to the knuckle mounting plate for lateral location. And I literally came to this conclusion while composing this post, because that’s how I think. You just got to watch my mind at work iterating a design specification. I had already decided on the truss but the details got finalized while doing the post.

Billed @€0.02, Opus the Unkillable Badass

I just got a check from Facebook

I’m going to be quite honest about this and say I had forgotten completely about the issue that resulted in my getting the check, to wit Facebook using my name and avatar picture for advertising purposes without requesting permission first. This took place shortly after MySpace started censoring the sh!t out of links in my blog and I left MS for WP and FB.

So anywho, I have a check for $15 that I will now spend on useless things like groceries and comic books. Probably more groceries than comic books.

Also while I am doing a post, I bought a keyless chuck for my Dremel tool through Amazon using the gift cards I get from the mobile game, and a set of tiny drills to use in the chuck from Lowe’s using the card that I can’t use everywhere but I can use in a few places they pay me with at another one of my side gigs. This means I can finish building the scale SBC for the Mini Sprint-T. And yes I’m still building the Mini Sprint-T even though the full-scale car will now be mid-engine with a Mopar V6. One slightly ironic thing is the Sprint-T had to have an automatic transmission because there was no room for 3 pedals between the transmission tunnel and the side of the car, while the mid-engine car will have a flat floor and acres of room for pedals but no manual transmission available, just a full manual controller on the slush box.

While on the subject I have mostly finished redesigning the frame for the switch from front to mid engine. One thing I changed was the location of the forward hoop of the roll cage, which was also a crossmember of the frame, that had a diagonal running from the top of the rear hoop to the bottom of the front hoop. On the front engine version this ran through the passenger compartment, but on the mid-engine version I’m moving the bottom rail out from under the body and the bottom of the hoop likewise meaning I don’t have to figure out how to get the painted body back on the frame with parts of the frame under and over the body and one big part running through the body, because that “one big part” will now be outside the body. It will be a close fit but it will clear. The other thing changed was the location of the front coilover mount both on the axle and the frame. The new axle mount will be as close to the end of the axle as possible without the back of the spindle making contact with the unit at the ends of the turning travel, on top of the axle tube. The new frame mount will be high above the axle so that the front wheel doesn’t hit the diagonal from the frame mount to the bottom of the front hoop of the roll cage at full compression and full turning travel. This is a very unlikely place for the wheel to be but it is possible so the frame has to clear the tire. This has the secondary effect of increasing d which increases the torsional rigidity of the frame, meaning better handling.

And that’s about it today, go ride a bike. I’m still stretching to be able to ride mine again.

Billed @€0.02, Opus the Unkillable Badass

Need input from my readers on my T-bucket

I’m at a dilemma here on the rear suspension design, so I’m asking for your help. I have narrowed down the rear suspension to 3 candidates, 2 of which are interchangeable as the major difference is method of construction, and the third would require cutting most of the back end off the car to go from either of the other two to it or from it to either of the other two.

Anyway here are the choices:

1) Reuse almost everything under the front of the minivan including the subframe. That means the struts, springs, hubs, knuckles, axles and CV joints, A-arms, and the tie rod ends. Advantages are reduced fabrication as almost everything is reused except the upper strut mount to the frame of the minivan. Major disadvantage is no way to adjust ride height except to cut the spring to make it shorter, no way to change the spring rate except to cut the spring to make it stiffer, no way to reduce roll stiffness to improve rear grip, very little way to predict the ride height, and poor camber control with body roll. Also ugly with a capital UGH! The front suspension bits of a Chrysler Town and Country are strong, but they will never win the “Rear Suspension” category of a beauty contest.

2) De Dion beam with fabricated brackets to fit the knuckles attached to a 3″ dia 0.25″ wall aluminum tube, probably a 7075 alloy. This has the main advantage of keeping the wheels pointed in mostly the right direction in all 3 axis all the time unlike option 1. It’s also much better looking than option 1, but that is faint praise from a bad comparison. Another advantage is roll stiffness can be reduced by mounting the coilovers closer to the center of the car. The major disadvantage is I can cut the pieces for the bracketry but not weld them as none of my equipment will work on the thicknesses of aluminum needed for this job and the budget does not run into buying welding equipment that will only be used for one major assembly. Secondary disadvantage is coilover shocks and springs will need to be purchased to keep the frame from dragging the ground, but that is offset with the ability to choose shock and spring rates better suited to the reduced overall weight (compared to the donor vehicle), and the ability to adjust the ride height. This will reuse the knuckle and hub along with the parts attached like brakes etc. but probably not the tie rods. Lateral location will be by a Watt’s Link mounted under the differential and connected to the hubs or the bracketry the hubs are bolted to. Fore and aft location by a parallel 4-link connecting the frame and the end bracket on the de Dion tube.

3) Bird cage style de Dion beam from thin wall small diameter steel tubing in a 3D Warren or Pratt truss that sweeps back from the knuckles to clear the transaxle while leaving room for the axle shafts to come through without hitting the structure when the suspension travels vertically. Advantages include looking cool, something I could fabricate on my own, looking cool, slightly lighter and slightly stronger than the single 3″ aluminum tube, looking cool, all the advantages of the 3″ tube version, and finally looking cool. Disadvantages are much harder to fabricate since it’s basically a space frame for the rear axle and leaves less room for the trunk and gas tank behind the engine and transaxle.

Options 2 and 3 are interchangeable, just unbolt the tube or space frame and bolt in the space frame or tube to replace, so I could make both and see which works better. Probably not going to happen because I don’t have the budget for iterative development.

Right now I’m trying to decide which of the three options I’m going with. #1 is cheapest but has the most negative compromises, #2 and #3 have similar costs but #2 is much quicker to build because there is less actual cutting and welding. So help me make up my mind

Still working through the T-Bucket problems in my head

I prefer to think through all the problems and their solutions before I start to work cutting metal, it generally works out better that way.

One of the things that has been bothering me is the spread between the torque rating and the horsepower rating of the engine. The engine is rated 158 HP at 5000 RPM and 203 ft-lb of torque at 4000. Given that HP = Torque * RPM/5252 the power curve is basically flat from 4k to 5k RPM as it makes 154 HP at the torque peak. This means something is choking the engine off above the torque peak, and I’m betting it’s the exhaust. That’s the big reason why I’m planning tube headers to replace the crappy cast-iron manifolds on the engine as it is installed in the minivan. The manifold on the front bank is the likely culprit as it is just something to collect the exhaust and run it away from the head while tucking up as close to the head as physically possible, the one on the rear bank is much better except for the place where the front bank dumps into it. I’m sure that after I install the headers I will see pretty close to 180 HP at 5200 RPM. That torque curve makes a lot more sense than 203 at 4k dropping to 166 at 5k, and it might be even higher because the rest of the exhaust system will be less restrictive than the minivan as well since I’m going to dual exhaust with high flow quiet mufflers instead of the single exhaust and restrictive muffler on the minivan.

Also while I have the engine out of the car I’m going to clean up the inside of the intake manifold, because I can and because I want to make sure there are no horsepower killers in there. Nothing fancy, just cleaning up any port mismatches where things bolt together or to the heads and removing any rough spots or flash inside the manifold so that air moves smoothly inside the manifold. I’m not trying to add horsepower, just keep from losing the power that is already there. I’m just doing the stuff that Chrysler would have done if they had the time and money to hand fit and assemble the engine at the factory. Like I said I think this engine is capable of 180 HP without changing any internal parts or losing any power below the torque peak. I also think there is some power and fuel economy to be found in the fuel and spark maps in the computer which will happen when I hook the new controller up to the engine. I’m thinking that 200 HP is within reach without changing the cam or other internals as installed in the T-bucket. This will give me the same around-town and autocross performance as a 2017 Stingray base model, but better fuel economy than the 15/22 hwy estimate for the 1996 minivan, assuming I can keep my foot out of the gas driving around town. Changing the transmission controller to full manual will help by keeping it in as high a gear as possible to keep the RPMs down.

And those have been my thoughts on the subject for today. Keep riding your bikes, I’ll keep riding mine.

PSA, Opus

Thankful I have nobody personal to remember on the Transgender Day of Remembrance

I have many Trans friends. They are all as far as I know (one or two may have stopped speaking with me) still alive and well. I’m trying to get in touch with the Trans people I have lost contact with in honor of the day.

For the Trans people who read this who I don’t know personally I hope this day finds you well. For the people who have lost Trans friends to H8 or bullying or some other cause or no cause at all, peace be with you.

And for all my Trans readers, peace be with you always.

Thus says the Witch on a Bicycle, so mote it be.

PSA Opus