Never before has so little power been made from so much displacement! (Page 52 of 57)

that picture you posted is a cross-cut CV, not an Rzeppa. they only do 20-28 degrees or so. an Rzeppa will do 50 degrees.

you can tell the difference, an rzeppa has the races evenly spaced:

i know you guys are going to be shocked. but i went digging through my spare parts pile and came out with two twin turbo supra axle shafts.

the outboard joints are massive Rzeppa joints:

that just might work. they'll be at their max but otherwise happy.

alright, nothing exciting. i took the rest of the day to finish everything i could on the to-do list instead of trying to make another crazy contraption.

added the petty bar:

removed the broken glass to make way for the lexan:

at this point, it's almost ready to race again. here's where the list stands:
-fix 3000 GT box (or make alternative)
-redo oil lines with something that is actually oil safe (lines ordered)
-make rear window out of 1/4" lexan (material to be picked up tomorrow 54"x14")
-paint cage if i have time (the rust looks terrible, but it comes right off with a green scotchbrite pad.

I'll drop by the machine shop with the shaft that broke and my friend's opinion on it. if he thinks it's workable then i'll get the parts to fix it. otherwise i think we'll be using 3 Rzeppa joints to make it all work.

if i go that route i'll have to put a traditional spline interface in the middle. the vette inboard joint only allows 20-30degrees or so. not enough either.

it just came to me, a reason not to just use the shaft solution. the guibo would have to be removed which is doing a damn good job of removing killer vibrations from the system.

the 3000GT box stays. and i've got ideas on how to fix it to be much stronger.

there's just not enough length and the fact that the guibo isn't self aligning would add a degree of complexity i do not want at this point.

i did find a way to make the shaft coming out of the 3000GT have a weld diameter of 1.75" instead of the 1" I had previously. that almost doubles the weld and reduces the mechanical advantage on it by a fairly large factor.

given that the rest of the drivetrain survived the surging that broke that i feel quite good about everything otherwise holding together. the surging was caused by me forgetting to plug in the vacuum line on the ECU so megasquirt was hunting for idle between 500 and 1500RPM. the subaru flywheel loading from that probably caused the system to exert it's entire 600lb*ft of torque over and over in a high stress way.

Just in case the guibo issue comes back up:

https://www.pegasusautoracing.com/produ … RecID=5349

They should be easy to make.

got the lexan today and i learnt that it's just a fancy name for polycarbonate, about to go out and have some fun. but i wanted to show you guys something first.

my friend got the new shaft welded up and i wanted to demonstrate the difference between a rookie welder (me) and some guy that's been doing it since he's been in diapers. both were done on the exact same machine, likely the same piece of tungsten, same bottle of gas and both welds were prepared in a similar way on the exact same machinery.

so here's what happens when i use the tools:

and here's what happens when a pro uses the same tools:

I probably have to clarify, both welds used the assistance from a rotary table, but both were done by hand.

Oh, yes!   Those are both far better than I am capable of.   Color me green (with envy).

well, the other goldwing box did now show up yet so i'll make the mods to the current one tonight instead. not that big of a deal, just a little extra clean-up first.

also, i found this to help size the new driveshaft: http://www2.dana.com/pdf/IJ900-02.pdf

input torque: 600lb*ft
torque after 3000GT box: 736lb*ft
power factor: 1.2 (gas engine)
angle factor: 1.3 (about 8 degrees or so)
life factor: 1.0 (we could probably go to 0.5 without issue)

minimum torque capacity needed 1150lb*ft (1560Nm)

this says i really should use a much bigger joint than the 1310, i'm outside of it's ultimate limits.

the 1350 joint is the smallest joint that i don't exceed the absolute limits on. since i'm short on space that's what i will use. i suspect that the u-joints will be wore out after the first day if it make it through the entire day so i'll bring 2 spare joints in case it makes it past the first day.

Thanks,

it's going to be some long nights, but i should be able to get it done.

Caitlin works this weekend so that kinda shoots most of the weekend away since i will be watching Sebastian. but i gotta do what i gotta do.

the heat will also be an issue in the goldwing and the 3000gt box. i suspect that's what's going to take out the drivetrain in the end.

*edit* no, this car will only ever go to Joliet in this configuration. no matter how it finishes the motor is getting traded for a turboshaft after the june 9th/10th race.