Tag Archives: technical stuff about building cars

I need to think out loud some more

And you get to read it, lucky you! This is one of the ways I solve problems, but I usually don’t keep the process after I’m done, but I’m thinking since this isn’t how to make a man-portable nuke, or how to shut down the stock market, or any other destructive thing that could cause chaos and destruction if I let it out in the wild, this one I will let people see the process.

The problem needing solution tonight is the question of will using a Powerglide transmission and a quick-change rear axle be better for the autocross and still usable for just driving? From known data the QC has about 10 pounds less mass than the 9″ Ford rear end or is way cheaper than an equal weight fabricated aluminum housing 9″ Ford, going back to the Eternal Triangle: Light, Cheap, Strong, pick any two.

The other thing is you can’t street drive with the PG without changing the final drive ratio from the race setup, the ratio is Too Low for any highway driving. The final drive for the autocross setup is top of the RPM band in first gear at 40 MPH. For an LS engine that would be 6500 RPM. Now because the PG comes in two low gear ratios, 1.78 and 1.82 you can see the problem. Even going from the 23″ tall race tires to the 27″ tall street tires that would make the freeway RPM an unbearable 3110 or 3042 depending on which ratio transmission I get. Either one would result in horrible mileage, horrible engine noise and added wear and tear on the engine. What I’m looking for is a highway cruise of 1900 RPM or less, so you can see what the problem is.

Now the reason I want to run the PG is weight, both absolute and rotating mass. My other options are the 4l60 and variants, or the 4l80, the first weighing in at almost 200 pounds with fluids, the second is 240± with fluids. A fully race prepped PG is [drum roll] 96 pounds with fluids so 100 to 140 pounds less weight on a car that would weigh 1800± pounds with the 4l80. And do I really need to show how much 140 pounds off an 1800 pound car is as a percentage? Plus I don’t have the actual rotating mass for all 3 transmissions but I know the 4l80 is the highest and the PG is way lower and the 4l60 is somewhere in the middle but closer to the 4l80. And going back to Commonly Held Beliefs About Rotating Mass For Hot Rodders every pound of mass rotating at engine speed is equivalent to 5 HP, so going from the 4l80 to a PG not only takes 140 pounds off the static mass and sprung weight, but it takes a Large Amount off the rotating weight. As an added bonus the PG is one of the strongest automatic transmissions you can buy for normal car engines. Of my two choices the 4l80 has the best power handling but slightly worse ratios which is why I was looking so hard at the 4l60 based transmission. But neither of them can hold a candle to the PG in torque capacity. The PG is pretty much the standard transmission for a Monster Truck with 1800-2000 HP alcohol-fueled big-block engines, so strong, and light, and low rotating mass.

But to use it with the Sprint-T I need a way to easily change the final drive, or invest in a truck and a trailer to haul it between races and pretty much resign myself to only driving to my local grocery which is close enough to not drive me crazy with the RPM and noise from the engine. That’s where the QC axle comes in, it takes about 15 minutes and about $70 for a different set of spur gears to set the highway cruise to 1900 RPM. Now the QC cost is about $1k over the Ford 9″ unless you try to get the Ford as light as the QC and carry two center sections to have the race and highway ratios because part most of the higher cost of the QC over the 9″ is magnesium and aluminum EVERYTHING. Also changing the final drive on the 9″ requires hours of work setting the lash and engagement depth on the gears, or carrying around a spare centersection to swap from one to the other, and also about an hour of laying on my back at the race track going from one to the other. The QC requires an extra set of spur gears at $70/set and about 15 minutes unbolting the rear cover, swapping the spur gears, and bolting the cover back on and putting the gear oil back in the housing. That last bit is very important if I want to keep driving more than a few miles from the track.

Now I have been thinking about it and I can live with a PG and highway gears without much problem beyond the one they made fun of back when the PG was a production transmission installed on common road cars, driving 70-80 MPH still in 1st gear, as there are only two plus reverse. Actually if I have my sums right the shift from 1st to high under full throttle would be at 131.5 MPH. Which is even funnier than the vaunted 70 MPH shift from 1st to high ridiculed in the magazines of the times. The engine would remain below 3500 RPM all the time and would rely on low RPM torque and the torque converter to run without stalling. Which is almost the same as the speed the engine would be forced to spin at 60 MPH with the race gear all the time, so from one extreme to another in engine speed. Engine speed in 1st gear at 40 MPH with the highway gear would be 1976. That is a swap I can live with. Especially with the benefit of 100 pounds less empty weight and a similar but lower reduction in rotating weight for racing the autocross. But if I decided I needed a higher engine speed for around town but not making long trips on a freeway, all it takes is consulting a chart, picking a gear set, plonking down another $70, and spending another 15 minutes under the back of the car changing the spur gears. Or maybe just swapping the gears top for bottom on the race gears, because that would be a thing that was possible because the spur gears for the race gear would be a reduction set to get the RPM that high for that slow is WOW! The race gear needs to be 6.11:1, and the highway gear needs to be 2.54:1 and there is no way to get from one to the other without using different spur gears. If I get the low-inertia (rotating mass) 4.12 ring and pinion I can get close at 6.08 and 2.79 with only one set, giving me 2083 RPM at 60 MPH, but if I get the more common and slightly cheaper 4.86 the 6.12 spur gears give me 3.85 swapped top for bottom, which would be a decent setup for around town but loud and drony 2875 RPM for highway use. The bad thing about the 4.86 is the tallest final drive I can get is 2.58 which is Really Close resulting in 1926 RPM at 60 instead of 1900.

I shall have to let this one percolate through the grey matter for a while, comparing the costs of the 4l60 variant that will support the engine I get with a 9″ rear housing to fit the Sprint-T, and the costs of a PG and QC to fit the Sprint-T including 2 sets of spur gears, or a 9″ to fit and another center section. And looking at the assembled and ready to go 9″ center sections the cheap ones with a spool are $620 plus tax, for a race-only application. The ones with the highway gearing higher than 3.00:1 are scarce and expensive because most vehicles are equipped with overdrive transmissions to bypass the need for such tall gears. They used to be very common in the ’70s before overdrive transmissions were common, but I’m only finding used gears above 3.0 and even those are way expensive, so I might have to run the QC if I choose to run a PG. Or it just might not be economical to run a PG because of how expensive the support equipment required to run it on the street especially when a 4l60 can get 6500 RPM at 40 MPH with a 3.62 rear end ratio on the 23″ race tires, and get 1900 RPM at 60 MPH with the same rear end ratio and the 27″ tall street tires. Now that’s not a standard ratio but the common 3.50 is super cheap (for a 9″ rear end ring and pinion) and gets the race ratio close (41 MPH) and is just a tiny bit tall for the highway ratio resulting in 1830 RPM instead of 1900. Even closer is the Ford 8.8″ rear axle which (some of them) came with a 3.55 and a limited slip. Much more thinking is required, and as you can see there was already much thinking and consulting of texts and web pages done to get this far.

Still thinking, but more specifically

Relax, I’m thinking about the steering on the Sprint-T, not doomsday devices. Besides doomsday devices are a one and done thing, and unlike most mad scientists (we actually prefer the term aggravated engineers, thank’ewverra’much) I actually thought ahead and know if I blow up the world I lose my place to sleep at night, lacking a means of space travel. Besides have you checked the price of plutonium lately? No, thanks, I’m out of the doomsday device business.

So, back to the main topic, I’m pricing the specialty metal to make the steering arm that makes the steering quicker, and it’s super expensive for what I need. I mean in absolute terms it’s not much, it’s just I have to buy 4 linear feet of stock to make a part that will be just over 6″ long finished. And that 4 feet of stock costs $33, so most of the stock is wasted unless I find something else that needs to be that strong.

Cutting the stock to the length I need for the steering arm, henceforth to be named “the part” in this doc, I need to cut about 8″ to make the part. The part needs to have an arm that is 33/16” from the spindle axis to center of the hole for the drag link, but there is the attachment hole to the spindle on the other side of the axis from the drag link hole to also account for, plus the gussets needed to prevent flex in the part because the load will be off-axis no matter how I bolt up the drag link to the part. And dropping the drag link down to clear the suspension links will make the leverage off-axis greater causing more flex in the system. Therefore the part needs to be made from heavy stock, and gusseted, to keep the flex as low as possible.

I don’t think there will be any detectable flex in normal driving, but autocross and SCCA Solo Racing are not “normal” and put the steering under about as high a stress as you can get without going off-pavement or banging curbs. And now that I think of it there is a slight possibility of banging an actual concrete vertical-faced curb doing that, so I guess that means another gusset. The plan is now to have a gusset on either side of the bolts holding the part to the spindle, because curbs. Anyway, this stock is right at the limits of my welding equipment and cutting tools, so if I need to use heavier stock to make this part I will have to farm the part out to a professional with better equipment.

Just a passing note, I made the suggestion on Twitter that if @realDonaldTrump refuses to vacate the White House as he claims he will, then he should be treated like he says protestors against police brutality should be treated, but obviously in fewer characters because: Twitter. I’m now locked out of reading Twitter until I apologize by taking the tweet down, which obviously I will do as soon as Agent Orange apologizes for saying the same thing about protestors or when pigs fly. I don’t care, either one is equally likely. I don’t really need Twitter, it was just something to kill time with.

And with that act of defiance I’ma put this thing to bed.

More thinking about the Sprint-T

Just because I’m not working any more doesn’t mean I can’t stay awake at night and think about things on the Sprint-T. On the contrary, now that I don’t have to think about working, I can think even more about the Sprint-T. And because I don’t have any budget to build things I can think about how to do things as cheaply as possible.

I was thinking about how many turns lock-to-lock the steering will have with the shorter steering arm on the spindle compare that to other methods of changing the ratio. OK with just changing the steering arm on the spindle the turns lock-to-lock won’t actually change unless something in the steering hits something before the steering box hits its internal stops, but the front wheels will turn twice as far for each turn of the steering wheel. But since the front tires can’t turn anywhere near as far as the box can try to turn them, assume a stop in the system limits the travel, so how many turns lock-to-lock can we get from the system instead of the box?

The 20:1 box has 5 turns lock-to-lock by itself, moving the pitman arm 90° of arc. That’s 45° left and right of center, which is pretty decent angle but not great. But 5 turns lock-to-lock is terrible. So the problem then becomes how much angle to allow vs. steering wheel turn. Doing the steering arm half as long as the pitman arm gets 180° of movement which has already been categorized as “too much”, but the total ratio is “not quick enough”. Seriously this will be a huge improvement, but still not quick enough for the autocross racing the car is intended for. But at the double throw, the overall ratio is 10:1 at the tires, with 2½ turns to get the stock 45° of steering movement. Now if I restrict the angle at the front wheel to 120° of lock which is way more than what I get with the steering arms from Speedway (which are designed for freeway driving and cruising around a fairground car show, not racing autocross so nothing bad about that) I still get 31/3 turns lock-to-lock, which gives the equivalence of a 131/3:1 box with everything set to “out of the box” in the steering linkage. The really annoying thing about making this post is I have one word “wheel” that refers to two completely different things, and trying to disambiguate the difference between the steering wheel and the wheels the car drives on. I had to go back and change a few words back and forth.

Anywho, I can rapidly change the overall ratio at the front wheels by making a new arm with the distance from the steering axis of the spindle to the pivot point of the arm closer or further away. I should probably make at least one arm with several pivot points to see how the turn-in of the car changes, then build one arm to not have a bunch of holes in it and be neater for appearance. And I should also be looking at what’s available in angle iron to see what I will be working with to build the final arm. But this seems a good place to put this to bed, and maybe myself as well.

Nothing much new

I’ve been doing some figuring on the intake manifold and cam combination, but TBH this one is not well covered in the public literature and simulations. Except for the Holdener videos this is pretty much terra incognita for published data. And not to be tooting my own horn, one of the things I was really good at was drawing correct conclusions from insufficient data. And right now I’m dealing with way too little data, essentially only 5 data points between the Holdener videos and two other TPI videos, and those two went with the commonly accepted practice of short duration cams with the long runner intakes. Like 240° advertised duration or less short. My theory hypothesis is 270°@0.050″ lift at a minimum and 290°@0.050 preferred, those are considered radical durations that would have terrible idle and low RPM manners if not for the stupid long runners, but even so would not work without the large cross-sectional area of those long runners giving good airflow for the upper RPM ranges.

On other things I’m putting out an ad for someone to make my car work as DLC for GT5 so I can drive it on the gokart tracks I built with the track editor in the game. Translating that to English I’m asking for someone to code the Sprint-T as Down Loadable Content for Gran Turismo 5, so I could make it usable in the game. I could use the free classifieds in Grassroots Motorsports to request submissions. The thing is I have zero idea of what information would be needed for the game version of the Sprint-T. I know the tuning choices give 3 selections each from 3 categories of tire, and some cars have the option for tuning the power output from the engine, to that means a variable with a range for power and also variables for grip and hydroplane resistance in the tires. Now how sophisticated the tire modelling is??? it could be as simple as a simple ratio for grip that is dependent on tire choice or a multi-variable algorithm that takes temperature and depth of standing water along with a bunch of other things into consideration. And there’s nothing I can find on the internet about it. I can find some of what has to be simulated in this formula “Pacejka Magic Formula” Physics Doctorial thesis on the web and simplified formulas for designers and in video format Brian Beckman: The Physics in Games- Real Time Simulation Explained. The biggest thing is the physical limitations of the CPU and GPU as the formulas get to various limits that end up dividing by very small numbers and the answers get larger than the registers in the CPU or GPU. Which has nothing to do with how GT5 stores its car models, just a taste of what’s involved in building that model. And after all that I still don’t know how to get from the piles of parts distributed around the house to driving pixels on my TV screen, which is why I’m thinking about paying someone to do it for me.

And I just face-planted in the keyboard because I’m glazing over at the programming details that don’t apply to this situation, so this is a good place to put this to bed and me shortly after.

It’s finally here!

And by “It” I mean the steering box that has been on backorder since early June because of the Stupid Virus. I’m changing the name because the existence of COVID19 seems to make people stupid, besides what it did to my employer and the GOP. Anywho, this is a picture of it below.
Steering box, remotes and bumpersticker for scale

I’m keeping it in the plastic bag for the nonce, having learned my lesson about surface corrosion from the spindles I bought a few years ago. I may be slow, but I’m not stupid. And FYI that thing is HEAVY! no, it’s HEAVY! That tiny chunk of metal has to be over 15 pounds (6.8 Kg) which brings up the question of why they still use iron in the main casting? Probably because steel or iron is cheaper than aluminum, but then the question is why it isn’t an option since this is a repop for a part that has been out of production for five decades, the Vega stopping its run in 1977, and presumably GM stopping production of replacement parts shortly after.

And it turns out that it was fortunate I bought the Pitman arm for the 5/8” heim joint, because this was shipped with the arm for the Ford taper tie rod end. There is something I can use the extra Pitman arm for, by placing the two arms side by side with the ends reversed I can get an fairly accurate center-to-center distance to use in making the steering arm to mount on the spindle. I mentioned this in a post a while back, this post to be precise, that I can use the steering arm to change effective steering ratio without adding any weight. In the post I was thinking that since I was using the steering arm at the spindle instead of a steering quickener the difference between the arm and the quickener box was the amount of weight I was saving, but in reality the arm at the spindle has to be there regardless of what I do at the box, so I save the entire weight of the steering quickener when I go with the shortened steering arm on the spindle, plus the weight loss of using a shorter arm instead of the one normally used. I think what I was thinking about was there’s no need to use a steering arm at the spindle because there is an extended bolt to attach the drag link on the arms I already have, except that unless I move the steering box further behind the axle the drag link will hit the tie rod, and I don’t have that problem with the steering arm for the drag link mounted to the lower holes of the spindle and the steering arms for the tie rod mounted to the upper holes of the spindles, especially if I use the extended bolt on the drag link arm to drop the drag link even further from the suspension links.

Now I just need to figure out the load path from the steering box mount that was in the kit with the box, to the rest of the frame. For the application the kit was made for the box mount welds directly to the frame rail of a ’23-34 Ford. This is going to be a bit more complicated as the frame rails are either over a foot above the box or several inches below it, and beyond just holding the box in a certain place in space relative to the frame and axle there are significant forces that will be applied to the mount, off axis forces at that. That means either the mount will be very heavy and apply torsion to the frame tube, or the mount will have to be braced from the other side of the frame. Since there’s nothing in the way of the mount going to the other side of the frame I’m going with that unless and until something else has to be put in the space between the radiator and the front axle. The radiator will be mounted slightly to the right to make the nose symmetrical and keep everything under cover, but since the tie rod and the pitman arm are both going to have to extend beyond the side of the nose it’s actually a moot point. The steering will come out of the left side of the nose because it has to, the Pitman arm will swing to the left further than the confines of the nose at full lock anyway, even the reduced amount of lock with the shorter steering arm at the spindle. The fun part now is how do I adjust the internal stops in the box to prevent the steering linkage from getting damaged by over travel caused by the steering box? Without internal stops the drag link could be overcentered and the car be unable to return to center when the steering wheel is turned the other way. Or I could use a stop on the axle that hits something on the spindle to prevent turning far enough to the right get to that point. Turning to the left the drag link hits the back of the spindle before getting to the over center point, I could use a stop on the axle that stops the spindle at the same point of rotation in the opposite direction. Hitting those stops would generate substantial forces on the steering mount, getting back to the original topic of internal stops in the steering box and the steering box mount. There is also the point that at full lock the tires will be almost perpendicular to the axis of the car. This would be useful for moving the front of the car sideways when not running, but I don’t see any practical application for this much steering angle.

And here we see yet another example of how I think, wandering here there and everywhere as I solve a problem. I’m not sure which part of my mental problems this typifies, but I know this isn’t my PTSD or depression at work, the only mental illnesses I have that I can’t blame this thinking style on. Maybe my ADHD, yes this is undoubtedly what happens when genius meets butterflies and squirrels. And since I just noticed my word count has tripped the 1K mark for this post I think this is a good spot to put this post to bed.

Beer was drunk, brownies and ice cream were eaten, and my survival was celebrated

And Death was invited to take a hike. The headline should read (A) beer was drunk, as in I had a 12 oz. bottle of Shiner and then switched to generic Mt. Dew (Mountain Breeze citrus flavored soda with other natural flavors is the name on the label).

I also took a long walk to pay my phone bill and deposit a check in the bank and get a slight heat injury because the index spiked to 114° while I was out. I have things that have to be done at home for the next two days, then on Thursday I’m planning on getting a haircut and buying stamps. I can’t track the package, but the order with the steering box has been shipped and the money removed from my account. I have about $180 left now for various things like getting a drink or a meal while I’m out away from the house, or buying stuff online again. Edit to add, as I was composing the post package tracking became available and my package is in Omaha as of last update.

I have a solution to the steering shaft conundrum I was fighting, both the problem of snaking the shaft around the radiator and the problem of snaking the shaft around/over the alternator on the engine. Basically I’m going to use the steering box as one of the supports for the steering shaft by using a solid steering coupler and welding a stub shaft long enough to get past the radiator before switching to the cheaper less expensive DD style U-Joints. Now obviously I don’t want to “cheap out” on something like steering components that might cause me to die if they fail at the wrong time, but I also don’t have a very large budget for this. Also a major problem with the welded joints is when you’re done you basically have a non-repairable assembly, and any intermediate bearings have to be left on the shafts. Now for a strictly street car that gets limited use this could work, until the car hits a curb or something and damages the steering linkages.

Also the changes I have had to make to the driver’s side of the frame are adding weight in a place I don’t want to add weight, driver’s side front of the car. I had to add 3 tubes to the frame and front bulkhead just to have some way to physically mount the box to the car, but one of those tubes will also serve as a mount for the J-Bar that locates the front axle laterally, so partial win, maybe? Anyway the weight is right in front of and under the front axle on the left side which means something else will have to go passenger side rear axle to balance, and the total moment of the car will increase which is bad, high total moments make the car change direction less quick and the whole raison d’être for the car requires rapid changes in direction. And yes I had to copy-paste the French translation because my keyboard doesn’t support diacriticals or reverse accents.

Anywho, the design criteria requires the lowest possible total moment, also called the polar moment of inertia. This allows the car to respond to inputs for rapid changes in direction, like in slaloms. That’s why I have been doing things like putting heavy things in the middle of the wheelbase as much as possible, and also putting things close to the rear axle which is the pivot point for vehicles that steer from the front wheels until traction is broken. In cars that steer with the front wheels the front wheels push the front end sideways around the rear axle so the less weight up front the better for changing direction. This is another reason why rear mid-engine cars are preferred in classes where engine placement is free. In the class I’m building for the back of the engine has to be in the same general vicinity as the make and model the car is based on. In this case the “based on” is a 1923 model T Ford, so ahead of the firewall behind the front axle and the body can be moved back until it hits the rear axle and stay within class rules for Goodguys, SCCA doesn’t care as long as legs and lower torso don’t hang out of the body and I sit someplace behind the front axle and in front of the rear axle. And the design changes are two tubes added to the front bulkhead on the left side to support a tube running from the front bulkhead to the left side front bottom frame rail, to provide a place to mount the radiator and the steering box and secondarily provide a place to hang the frame end of the front J-Bar.

And that looks like a decent place to stop the rambling that has developed for some reason.

Now I have time and I have something to write about

OK I was thinking last night and I figured out how I can do the thing by myself without having to spend $40 for the other thing to use to make the thing. I just need to buy a chunk of extra heavy angle iron and drill 3 holes after cutting to length.

Seriously I can get some thick angle iron from Lowe’s or the Metal Supermarket (yes that is a real place near downtown in Dallas), a step drill bit from Harbor Freight, and drill 3 pilot holes and use the step bit to get the desired size holes and I would have the thing I desired for less than half the cost of modifying the other thing because I would still have to get the step drill to drill the hole in the steering arm from Speedway at the right distance. I already have the cutting tools for the cutting to length and to clear the kingpin boss on the spindle from when I was building bicycles (what, you forgot about when I used to build bicycles?), and I still have many things that can be used to drill precision holes in (other) things if I have the right drill bits. And as I was just saying, I need to get a step bit anyway.

Anywho, it’s really simple. I know what the distance between the ½” holes on the vertical part of the steering arm need to be, and when I get the steering kit from Speedway I’ll know what the distance of the pitman arm is, and by simple ratios I’ll know what the distance to the 5/8” hole for the drag link end needs to be. There will be no need for anything like Ackerman or the like because this is strictly to transfer the motion of the pitman arm to the spindle and the Ackerman is already taken care of through the other steering arms and the tie rod. If I wanted to get fancy I might weld part of the vertical web that I need to remove to clear the kingpin boss on the spindle to the vertical and horizontal part of the arm between the spindle and the hole for the drag link to reduce deflection of the horizontal part under hard cornering. It likely won’t do any good if I buy thick enough angle iron but, you know there’s no such thing as “too safe”. And there is also the possibility that I can’t find angle stock in that thickness. And adding the support from the vertical to the horizontal flanges of the piece will stiffen it up considerably. And if I can’t get the thick stuff I will have to weld the connection from the vertical to the horizontal.

That’s it, I’m starting to get a sore butt from sitting in front of the computer.

Still thinking part infinity gauntlet

Basically I’m a non-stop thinking machine, grinding on the problem that is the Sprint-T. The problem I’m grinding on this time is quicker steering and more angle at minimum cost. I keep wanting to change the input on the steering box, but last night as I was staring at the ceiling it came to me that it would be much cheaper to change the steering arm on the spindle than to put a steering quickener on the input shaft.

Basically I buy this flat plate steering arm and drill 1 hole to change the ratio at the spindle instead of this steering quickener box which is more than twice as much and weighs more than twice as much and has no adjustability. The change in steering ratio is fixed by the gears inside the quickener, but I can change how much I speed up the steering by drilling another hole in the arm closer to the kingpin than the original 1:1 arm. I can make the steering as quick as I want, not just twice as quick, and unlike the steering quickener box, I get more angle to go with the faster steering. And the small hunk of steel is seriously lighter than the steering quickener box, a few ounces compared to just under two pounds. I can’t emphasize that part enough. The downside is that is unsprung weight at the spindle compared to sprung weight at the box.

Something else I can’t stop thinking about is the limit to angle is the tierod hitting something on the axle, which means I get the most angle by putting the tierod in front because of nothing to hit except the axle itself which is almost 180° of angle. I can’t actually get that because the drag link then becomes the limit as it hits the brackets holding the axle to the frame, but placing the tierod in front means one less thing to get in the way. And thinking about that makes me think that if I route the drag link under the brackets that hold the axle so that it can’t hit anything I have no limit except how far the pitman arm moves before hitting something or the limit stops in the steering box. If I drill the hole to make the steering arm effective length 3/4 the length of the pitman arm I get 120° total steering angle which TBH is way more than enough, but only 1.5 times as quick. Drilling that hole half the length of the pitman arm quickens the ratio by 2 times and requires less throw on the pitman arm.

So to summarize, by changing one part there’s no limits to how quick I can make the steering, and no limits to how far I can turn the front wheels to the side. That’s a win on multiple fronts.

Ooopsie! The box won’t fit there

Doing the figures again, and the steering box won’t fit behind the radiator. The problem is how high the drag link has to be and the fact that the pitman arm has to go under the radiator if I put the steering box behind the radiator. The box fits fine, it’s everything else that doesn’t fit. So the box can’t go there.

So, putting the box in front of the radiator the problem is getting the steering shaft around the radiator. Now a brainstorm I just had before I sat down to compose this post would be to split my steering quickener in half and put half in front of the radiator and half behind the radiator and extend the shaft between the two to fit around the radiator. Since I have to put in the quickener anyway, I might as well use it to sneak the steering around the radiator. There is a minor problem with one side having to be pretty large to get the reduction right, so there will be that hanging out in the wind, but in the grand scheme of things that is pretty minor. And I can make that better by having most of the reduction behind the radiator behind the fan shroud where it doesn’t block airflow so the part hanging in the breeze can be smaller. In case you didn’t figure it out, my homemade quickener uses two stages of reduction to keep the size of the slow side sprockets down to something reasonable. The company I’m sourcing the parts from has parts I could do a single stage reduction with, but the one sprocket would be about 8.6″ across not counting the chain on it which is a lot to hide behind the radiator fan shroud. And then there is still the other side that has to stick out the side of the car.

But, anywho, putting the steering box in front of the radiator and getting the steering shaft around the radiator with the steering quickener lets me put the radiator lower in the car because I don’t have to put anything under it except the lower radiator mount. I have been measuring the nose to see how far the front has to be in front of the axle to get the radiator underneath the bodywork or if I have to finagle the steering quickener to get everything under the nose. Easy way to figure that out is use the vertical part of the radiator mockup and see how far forward in the nose it will fit and still have room for the frame and lower radiator mount. And since that is a bit of a job that will have to wait until later, after I finish this post.

Speaking of finishing the post, I have something to do in meatspace for the lady we used to rent a room to. So I’ll proof and post this now.

Thinking about what I need to make an autocross-specific engine

I have been watching Richard Holdener videos on YouTube, for data on making the “best” engine for my Sprint-T. The TPI intake from the late 1980s had extremely long intake runners that made huge torque at low RPM, way more than what a “normal” engine of this size could produce.

TPI MEGA TEST-WHAT WORKS BEST? As you can see, Richard ran a “too big” cam for the stock TPI, and basically lost nothing at low RPM while the big cam prevented the engine from falling on its face as the RPM went past peak torque.

TURBO TPI-BOOSTED TUNE PORT Boost just made things more awesome

TPI TECH PLUS BOOST-FASTER THAN FORD? More boost makes more better.

Taking the results and projecting to the LS, what I need is a super long runner manifold with as large intake ports as will bolt up to the heads, and as much displacement as I can get controlled by a 300° duration cam with big lift, about 0.600″. Basically what I’m looking for would be something like this intake with spacers to extend the runners or maybe 3d printed plenums with extended runners built in, plus a super rowdy cam and let the intake runners “fix” the low RPM problems caused by the too-large cam while the cam “fixes” the lack of power at high RPM problems caused by the intake manifold to make an engine that makes power everywhere on the RPM range. That is what I would do if I had an unlimited budget.

But because my budget is very much limited, I’m going to have to take what I can get and like it…