¯\_(ツ)_/¯ said:
In reply to fidelity101 :
Does it? I thought u-joint angles at both ends of the driveshaft were supposed to be within .5deg as a general rule, but I am willing to learn otherwise.
Within .5 but also less than 2-3 degrees absolute angle. depending on how fast you are spinning it.
I shoot for zero degrees in the black RX-7 because that sucker is spinning hard and you can feel 1 degree even if the two joints are complementary. It's more an issue under cruise or coast and not heavy load.
¯\_(ツ)_/¯ said:
In reply to GladlyTheCrossEyedBear :
Yep, planning on a single piece- critical speed for a 3" steel driveshaft at this length will still be well past the top of 5th gear, so we should be ok. If I have issues I could return to a 2 piece design but it hopefully won't be necessary.
You're shortening it by 8" on an already short wheelbase car, a 1 piece shaft will definitely be everything you need. Plus less spinny bits to break
i love what you're doing, keep it up.
With a bit more trimming, the tunnel was ready for another fitup:
And then I just decided it wasn't going to get any closer to perfect so I zapped the transmission and support bearing mounts to the car:
Pulled the engine/transmission out again (really tight with the cross support welded under the car but it worked):
Did a bunch more welding until I was nearly out of argon, ending up here:
Then set about making templates for when I get a refill- a giant roll of this white paper was pretty cheap and it's way nicer than hoarding and chopping up cardboard:
And the driveshaft showed up already! Axle Exchange in NJ was easy to work with and very prompt, it was just "BRZ? What length? OK, you'll have it this week" and it uses normal 1310 u-joints so I can have a spare easily. Despite the larger diameter and steel construction, it's still 5lbs lighter than the stock 2-piece:
why not an aluminum shaft?
Hopefully you don't need the center support bearing. With the Kpower kit it was 5.5" shorter and had lots of vibration but that was aluminum. I think steel is more forgiving with harmonics?
In reply to fidelity101 :
Rocks. Might do one if I'm chasing tenths later and keep the steel one as a spare.
In reply to captainawesome :
Did you check drivetrain angles with the Kpower stuff? Wouldn't be the first kit that failed to account for something like that.
In reply to ¯\_(ツ)_/¯ :
Never did, but when I shortened the stock one I had to use a spacer to get proper driveline angles, so you may be on to something with that. It was roughly a 1/2" drop if I remember correctly.
In reply to captainawesome :
That's a LOT, at least based on the pretty mild shimming I've been doing to place this tunnel- hopefully that was it, and if not I'll find out the fun way.
In reply to ¯\_(ツ)_/¯ :
It sounds like you are going through more rigorous planning in this aspect than Kpower did, so I bet you are going to be fine. They did a great job with some of the kit and other parts were not well thought out. The shifter setup, driveshaft, and cooling system were the most egregious offenders.
Why not a carbon fiber driveshaft like Jesus 02wd intended?
In reply to paperpaper :
Carbon fiber has less than phenomenal impact strength...
In reply to Pete. (l33t FS) :
berkeley yeah
And he just left the course mid run after coming through sounding like it was running less than stellar 
In reply to fidelity101 :
I know. we are poking fun at another car we compete against.
Welding, lots of it:
The underside has several pieces of the OEM floor structure folded over each other and then capped with what used to be the front of the lower tunnel- not the prettiest but it's really strong, don't want a rock coming through there:
Paint- this will get sealer at a later time and more paint but have to keep it from rusting:
Engine and transmission back in to check things again:
Plenty more sheet metal fun ahead for me:
And hey, the driveshaft fits! I'll need to clearance the shift rod a bit, the larger u-joint is too close for comfort:
Does the fuel tank go over or under the driveshaft?
In reply to Pete. (l33t FS) :
Over. Stock saddle tank has its' downsides but low and back seems like the right place for sloshy fuel to live.
