24V AWD Swap Knowledge Base

[nando]

"slow" setup, hahaha. :)

looks great! so you are able to keep the stock booster no problem huh? it looks like there's lots of room.

[Nisse Järnet]

Finally time for the new engine setup :D



And one more video of the slow engine setup:

https://www.youtube.com/watch?v=J6F-3WWXNbQ

[The Dark Side of Will]

Data package on the RWD crossmember is complete, but I haven't picked it up yet.

[Nisse Järnet]

Yeah its ok :)

Did some street racing tonight just for fun with the test engine :) Promising!

https://www.youtube.com/watch?v=XePQMN5p74g

[stonea]

^Car sounds fantastic

[Nisse Järnet]

Another test video with turbo ix, 0-230kmh (140mph)

https://www.youtube.com/watch?v=AfeKc89mY6M&feature=youtu.be

[Nisse Järnet]

0-62mph (0-100kmh) times with current power (~300hp) is pretty consistent 4.8-5s with a best of 4.6 :)

[Nisse Järnet]

Did 10 more 5500 rpm launches last night, visited a small local street race and had to try some runs :)

https://youtu.be/IUAQTBc3Abg

https://youtu.be/dJmhnpAJuLw

[The Dark Side of Will]

Like he said... knowing how BMW changed the RWD front end to allow for AWD can help me understand WHY they made specific change and what I have to track on my unit.

Also, it would be interesting to have a pseudo-bolt-in unit to convert a RWD car (like, say... an M3) to AWD.

[stonea]

Looks like this thread is becoming an ix knowledge base in general. Some interesting stuff going on for sure, however.

What are your intentions with the rwd subframe?

He just wanted to take some measurements and see what BMW did different, and if he can, maybe figure out why they made it different.

[iXguido]

Looks like this thread is becoming an ix knowledge base in general. Some interesting stuff going on for sure, however.

What are your intentions with the rwd subframe?

[The Dark Side of Will]

Stonea lent me a RWD crossmember and control arm for research purposes. Here are some pics:

Crossmembers overlapped with the front mounting holes of the RWD unit lined up on the rear holes of the AWD unit:

You can see that the AWD cars have the rack something like SIX INCHES further forward than the RWD cars, which combined with the packaging constraints of the AWD knuckle results in the weird ackerman geometry in the AWD cars.




Adjacent ball joint bosses:



More Adjacent ball joint bosses:




Adjacent engine mount locations:







Ball joint "disassembled"

[The Dark Side of Will]

And a much heavier car.
My dad snagged an e53 driveshaft... the splines are a bit bigger and aren't made on a 90 degree valley angle like the E30 splines are... but they only a little bit larger, so the loading on the splines is actually greater.

Trivia: E53's, even the 4.4's, use 188mm rear diffs and 86mm CV joints... so BMW expects the fraction of the 4.4's power that gets to the rear to be about what an M50 automatic belts out.

[nando]

they might have it worse though, since the motors in the E53 have significantly more torque while the spline design is basically the same.

[The Dark Side of Will]

E53's have *EXACTLY* the same problem with front driveshaft splines as E30's.