Good stuff. Fun to see it come together.
I love your idea of making the center tunnel be a big air duct - functional!
Are you going to box around the engine? Seems like it would be way too much heat and noise without that.
Good stuff. Fun to see it come together.
I love your idea of making the center tunnel be a big air duct - functional!
Are you going to box around the engine? Seems like it would be way too much heat and noise without that.
Definite progress, great to see it getting closer each week. I also will be interested in how you box in the engine, shame it won't be exposed but that is a lot of moving parts just behind the driver's seat!
In reply to TVR Scott and dherr (Forum Supporters) :
Engine will be boxed in with NHRA-compliant firewall material for Challenge. Box top will be removable and I will likely make a second one of Lexan for cruise nights, cars n coffee, etc.
I was thinking that would be really cool, just was not sure if it would pass any safety requirements, so I like your plan for the challenge and beyond.
AngryCorvair (Forum Supporter) said:In reply to TVR Scott and dherr (Forum Supporters) :
Engine will be boxed in with NHRA-compliant firewall material for Challenge. Box top will be removable and I will likely make a second one of Lexan for cruise nights, cars n coffee, etc.
My CAYman has a lexan cover over the engine. LED light too.
Seat mount still needed work. Added a crush tube to outer rear:
welded nuts to extensions for one-tool assembly:
then made a new foot for forward outer from a bunch of little scraps. Started with a wedge of 2" rectangle tube. This shape will be strong fore-aft and lateral:
then drilled a 11/32" hole in a flat piece of same tube, which will spread the load into the floor:
ran a bolt up through the OE welded nut, then put a nut on the bolt from above, clamped, and tacked all the bits together:
then I drilled the threads out of the OE nut, as the bolt will thread into the nut that's welded to the new foot:
took it out of the car and welded it all up, then bolted it in place and clamped the new foot to the old leg. Pulled the seat, removed outer rail, tacked the new foot, then finish welded it and put it outside to cool.
AK2 is on the hook to sandblast and paint these parts. Pix of finished product tomorrow.
Painted parts would stand out too much, so it's staying natural:
the welder has changed my life. Seriously.
Just imagine how awesome it will be when you get good with it 
AK2 is about 5'7". I might have to put blocks on the pedals for AK1, who's 5'4".
In reply to Patrick (Forum Supporter) :
I hate you. That was a great one. 
this post is gonna be loooooong.
TL;dr -- shifter not done yet. berkeley. if you don't want the rest of the story, leave now.
I wanted this post to say "check out my Audi trans being shifted by my Boxster cable shifter," and i wanted to post it about a week ago. Alas, neither of those goals has been reached, and here's the story of how we got here.
in a perfect world, shifter base would be positioned for optimum ergonomics, and cables would be made to exact length. in challenge world, cables are attached at trans and the shifter base falls where it may. as it turns out, the boxster cables are pretty near ideal length for this project (!), and the neutral cable is the slightly shorter of the two. the neutral cable pushes to Reverse and pulls to 5-6. the gear selector cable pushes to R-1-3-5 and pulls to 2-4-6. the Audi shift shaft neutral position is spring loaded to sit in the 3-4 gate, so the parts i'm making must allow the shift lever to sit in the corresponding position, as well as allow the neutral cable one gate of pull travel (from the 3-4 to the 5-6) and two gates of push travel (from the 3-4 to the R). the parts i'm making must also scale the movement of the trans shift shaft into a "sporty" amount of shift knob travel.
Step 1: Benchmarking. My buddy Jay has an SS sedan 6MT. I drove it once about a year ago and remember really liking the shift feel, so i asked him to measure shift knob travel. 1-2 travel confirmed at 3-3/4", and neutral travel about 7/8" between gates. So i'm going to target these knob travels with linkage design.
Step 2: measure trans shift shaft travel. Details below.
Step 3: Measure total shift knob travel. kinda hard since i don't have a shift knob, so i just measured at top of lever as-is, and will build some adjustment into the linkage. 1-2 knob travel about 5". Neutral travel about 4".
Step 4: Measure total cable travel. 1-2 cable total travel about 2". Neutral cable total travel about 2.25".
Step 5: MATHS! i need to design levers and bell cranks (rem: bell crank is just a lever with some included angle, so it takes linear motion in one direction and converts it to linear motion in a different direction), such that 3-3/4" fore-aft knob movement gives full 1-2 travel at trans, and 2-3/4" side-side movement at knob gives full neutral travel at trans. knob moves cables, cables moves levers, levers move shift shaft. easy peasy, right?
Step 6: Packaging. Can i put the shifter base exactly where i want it? Kinda. I mean, there's nothing in the way. But not really, because the business ends of the cables have to attach to levers, and those levers have to be packaged on or near existing mounting points *and* have room to move. There's a good pivot location for the neutral bell crank on top of trans, but it requires moving the shifter base rearward in car about 2" from ideal. if it's uncomfortable or cumbersome to drive in this location, i'll modify the shifter handle. at this point, i'm thinking that i'll add a short vertical lever directly to the coupler, and the 1-2 cable can attach directly to this via ball stud.
Step 7: Proof of Concept. what can I scavenge and hack together quickly, to verify the MATHS and lock down the geometry? i've got some scraps of garage door track angle, a used circular saw blade, and a bunch of 10mm ball studs and sockets from my buddy Andreas at Redline Tuning
With this mess of scrap, i was able to make the neutral cable move the shift shaft through the full neutral travel from R to 5-6. Hooray! I also learned that just scabbing attachment points on to the existing coupler would be both ugly and flimsy, and my MATHS were a little off on bell crank lever ratio. I was using too much cable travel, so i needed to extend the forward length of the bell crank. it would have been lighter to shorten the cable attachment length, but that would have put the cable in a less favorable orientation and required fabbing cable bracket mods. and i really was trying to get this done faster, i swear.
so, how to make a dedicated coupler, at near-zero cost? first, take a close look at OE coupler:
the shift shaft is about 14mm dia with a flat on the bottom. it has an axial thread that holds the coupler in place, and figuring out how to use that axial thread was really making my brain hurt. so I said berkeley it, for the level of forces involved I think a radial set screw will do the job. now i just need something with an inside diameter that's a close fit to the shift shaft. WTF, i don't have ability to bore holes and don't have drill bit larger than 1/2". but what i do have is a box of random Craftsman sockets. turns out a 15mm 12-point is a halfway decent fit, so I drilled and tapped it for a 6mm set screw (really another small bolt scavenged from the Red Solo Cup of C4 Fasteners). Then I'm thinking "can i even weld to this thing?" because it's not long enough to attach anything to it. looking through my random material stash, i see a piece of cattle fence gate, and the lightbulb goes on. ID is a little smaller than the OD of the 15mm socket, so a little ID cleanup with a carbide burr and the socket slips right in! so i grind the chrome off the edge of the socket and tack them together:
and drilled through at a different spot for the set screw. i left the fence piece a bit long so i could experiment with different cable and neutral link attachment schemes. since i needed to change the bell crank lever ratio, i scrounged around a bit longer and found the scraps of Audi shift rods that were still on the trans when i got it. measured, cut, and laid out for your viewing pleasure:
shout out to Trent (generally supportive dude) for the NICE bearings he included in my NYG 2020 box. With a small slice in one of the Audi shift rod bits, i was able to use this NICE bearing for the pivot. yes, i know it's not the right application for a roller bearing, but IDGAF. sealed roller bearings are cool, and now another forum member has contributed to the effort. thanks Trent! i also machined a neat little aluminum spacer to provide some stand-off height and keep the 1/2" ID bearing centered on the M10 pivot bolt. it's these little things that add up to a lot of time lost.
so here's what it looks like with functional neutral travel:
at this point i could start working on the 1-2 cable attachment. i took a short length of 5/8" OD x 1/8" wall steel tubing and drilled holes at six different lengths, so i'd have some "gross adjustment" capability. fine adjustment can be achieved with ball stud threads. turned one end down to about .505" to match the 1/2" step bit hole and pressed them together with my mechanical horizontal press aka bench vise. put it on the shift shaft, connected the 1-2 cable, and for the first time i could "remotely" click the trans through all gears.
kinda.
only kinda because the side-to-side movement through neutral made the 1-2 cable bind up. so that's why Porsche has the neutral cable act directly on the shift shaft but uses a bell crank on the 1-2. the bell crank decouples the shift cable from the side-to-side motion of the shift shaft. berkeley. there's nowhere good to put a bell crank on the left side of the trans, so i'm going to mount it to the C5 frame rail. with the solid motor mounts, there should be no risk of binding or lost travel due to relative motion between powertrain and frame.
so now i have to make a 1:1 ratio, 180-degree bell crank. easy peasy, right? LOL, not when you're first name is Angry and your last name is Corvair. i was able to scrounge up the required scraps of material, but the lathe took a E36 M3 and i had to disassemble / clean / lube whatever the parts are called that allow left-right and fore-aft movement of the tool holder:
on a positive note, the machine didn't fight me through this process and it now works better than ever. on a negative note, after multiple machining operations on each piece, plus welding, plus attaching to frame, this new bell crank didn't work. because i'm a dumb ass. i put the lower ball stud (right side in pic below) in vertical orientation, which made it bind before full travel. so i cut that insert out, machined a new insert to put the ball stud in horizontal orientation, welded, and now it works a treat. lowercase yay.
old crap:
new hotness:
i also went through a few iterations of pivot bearing for this bell crank. first i tried using an old skate wheel bearing pressed into a short section of cattle gate. no bueno, for several reasons. then i had a flash of brilliance when i remembered i bought a usable drop of oil-impregnated UHMW a while back. i forgot about it because i didn't have a dead center for my lathe tailstock, so couldn't keep it centered for turning. i recently unearthed the dead center, so i decided to take a swing at making bushings. sleeve turned and ready for fitment:
first attempt no bueno, parted before checking OD and it was too tight. second attempt no bueno, cut too short so tightening the through bolt bound it up. third attempt muy bueno. made lots of UHMW worms in the process. had a fun moment with the UHMW worms though, gave one to the 9YO kid next door and told him to stretch it until it broke. it elongated a ridiculous amount but he wasn't strong enough to break it. he runs over and starts telling his Dad about tensile strength, plastic deformation, etc. his Dad tells him "that cat next door, that's Tony Stark right there."
i still need a link from the bottom of this bell crank to the shift coupler. to the scrap pile again, this time i came away with the pickup tube from the boat gas tank. aluminum tube, about .525" OD and .360 ID. to the Red Solo Cup of C4 Fasteners again, came up with a couple of M6 bolts with about 1" of thread. grabbed the death wheel, and off with their heads! in the not-scrap bin i have a usable drop of 3/4" dia 6061. tired of do-overs from trying to work by memory, i drew up a quick sketch and even took notes during the machining process:
diameters cut:
parted, drilled, and tapped:
and loosely assembled:
and now we're all caught up. i'll cut the tube and weld the inserts tonight, then it's down to securing the cable housings to the C5 frame rails and i'll have a functional shifter. it's about berkeleying time.
2022
In reply to barefootskater :
I admire your optimism!
AngryCorvair (Forum Supporter) said:
Barefootskater meet Barefootdriver.
In reply to Indy "Nub" Guy :
Distant cousin, I'm sure.
AngryCorvair (Forum Supporter) said:so, how to make a dedicated coupler, at near-zero cost?
random Craftsman sockets.
a piece of cattle fence gate
sealed roller bearings
a short length of 5/8" OD x 1/8" wall steel tubing
an old skate wheel bearing pressed into a short section of cattle gate. no bueno
oil-impregnated UHMW
the pickup tube from the boat gas tank
Now you're just berkeleying with us.
RandolphCarter said:AngryCorvair (Forum Supporter) said:so, how to make a dedicated coupler, at near-zero cost?
random Craftsman sockets.
a piece of cattle fence gate
sealed roller bearings
a short length of 5/8" OD x 1/8" wall steel tubing
an old skate wheel bearing pressed into a short section of cattle gate. no bueno
oil-impregnated UHMW
the pickup tube from the boat gas tank
Now you're just berkeleying with us.
When I send the shift knob, do you want me to use metal trash as packing material?
Edit: Shipped the shift knob in a Medium Flat Rate box. It's heavy.
In reply to AAZCD (Forum Supporter) :
This is a great idea! I'm going to send Angry a crate of scrap pieces and stuff I don't want. As long as shipping is cheaper than a month of storage locker rent it's a win!
In reply to RandolphCarter :
Your comment is for sure in my top-3 favorites in this thread. And I assure you I am not. 
In reply to AAZCD and RacetruckRon :
as long as I don't have to pay shipping, I'll figure out a way to use something from your junk piles. 
I dont think I've ever seen a circular saw blade used quite that way before...
03Panther said:I dont think I've ever seen a circular saw blade used quite that way before...
i wanted to use a big chainring from a road bike but i didn't have one laying around. circ saw blade was right there...
Did some work on shift cable brackets at lunchtime today. They are routed together and share a bracket on the Boxster, which doesn't work on MonZora.
old crap:
new hotness:
just need to drill a couple holes and mount 'em up.
AngryCorvair (Forum Supporter) said:03Panther said:I dont think I've ever seen a circular saw blade used quite that way before...
i wanted to use a big chainring from a road bike but i didn't have one laying around. circ saw blade was right there...
I have a few.
We've been having a Shimano 39T Christmas for several years now:
I could send you a box of laughably unusable bike parts to further your quest for improbable build components.
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