BRZ Rally Car

Nesegleh said:

Do you work a partial schedule at work or just never sleep?

Your progress on this car is insane lol

I've had a 4 on, 3 off schedule at work for a few years and it's awesome.  On top of that, I've been working from home since March so on work days I have around 2 hours that I don't have to spend commuting right now- that adds up fast too!

In reply to Nesegleh :

He also has a whiny co-driver that doesn't shut up about going rallying 

Welded some forward mounts for the light bar to the upper radiator support:

With matching holes in the bumper cover, this is all you see when nothing is installed:

The plan is to mount the Diode Dynamics bar and the little spot beams up as high as reasonably possible just ahead of the hood- I think I'm going to force myself to do wiring before making the mount itself, though.

In reply to kodachrome :

To be fair, she's a lot better looking than he is, so I can understand his desire to rally. 
 

I have been chipping away at the light wiring, I'm trying to do something a little more legit than my usual "bolt a relay to whatever and run wires" technique.  Using this little waterproof relay/fuse box:

Mounted it on the driver's side opposite the car's original fuse box, ran lots of wires through the annoying little waterproof thingies:

The smaller lights are wired in pairs and the Diode Dynamics bar has its' own relay, leaving 3 circuits open for future whatevers.  Diode Dynamics put a Deutsch connector on their wires so I made the assumption that that was a good choice and put them on the other lights- this will also potentially let me change them out later for something more serious:

The wiring all tests OK so next is mounting the long range lights up on some sort of bar.

I plugged all the lights in just to see, hit the highbeam switch, and am now posting this through a field of purple and green spots obscuring my vision.  They all work.  

In reply to ¯\_(ツ)_/¯ :

That's the way the pros do it!

¯\_(ツ)_/¯ said:

I plugged all the lights in just to see, hit the highbeam switch, and am now posting this through a field of purple and green spots obscuring my vision.  They all work.  

Thanks for posting that. I needed a laugh today.

I wanna hear the yoshi exhaust, when we gonna get a clip of you doing donuts? 

In reply to fidelity101 (Forum Supporter) :

I was thinking about sticking a gopro in there to watch the suspension, I'll be sure to put it on the same side as the exhaust if I do.

In regards to the wiring, that box looks like a nice solution, kinda similar to the bussman RTMR that all the tacoma guys use for aftermarket fuse/relay panels.  They compiled a whole big thread on it and all the wiring stuff to go along with it, might be worth a read.

https://www.tacomaworld.com/threads/diy-build-and-install-a-bussmann-rtmr-fuse-relay-block.399454/

Light bar!  It's basically just a piece of angle with some bungs welded into it, but the feet are wacky since I wanted them to slip under the front of the hood:

Painted and attached everything:

Feels extremely stable and is easy enough to take on and off, we'll have to see how much adjustment the lights need later.

It's noticeably warmer directly in front of the lights:

Stock projector vs all the business:

They're really quite good, no complaints although the Diode Dynamics bar blows everything else away so the very center is a bit brighter than the rest.  The only problem I have to solve is actually noise, this setup whistles like crazy above 66mph- it's probably something I can fix with a little foam or tape somewhere, we'll see.

¯\_(ツ)_/¯ said:

It's noticeably warmer directly in front of the lights:

 

Stock projector vs all the business:

They're really quite good, no complaints although the Diode Dynamics bar blows everything else away so the very center is a bit brighter than the rest.  The only problem I have to solve is actually noise, this setup whistles like crazy above 66mph- it's probably something I can fix with a little foam or tape somewhere, we'll see.

 

I mean, technically you'll never be going over 65mph on a transit, and you won't hear the whistling with helmets on so......

Lighting looks good (looks mean from the front :) )

Drove around with various configurations of painter's tape on the front to narrow it down before putting some foam in the bolt pockets and under the small LED bars:

This reduces the whistle from "steam train" down to "mild breeze" so that's good enough.

Found this out back talking to my Subaru about future recce strategies.

In reply to kodachrome :

See?!?! Even the car knows you like to rally!!!

Got a smelly present from TXratti!

For a quick refresher, this is a mk3 Supra LSD which I'm trying to stick in an IS300 housing with 4Runner gears and put in my BRZ.  Looks close:

Lexus ring gear fits:

And it all goes right back in the IS300 housing with the Supra races, although it would need different shims:

I don't know about you guys, but this is enough for me to be willing to start looking for a set of 4.88 gears and some shims.

That's so much differential cross-breeding that my head is spinning.  I'm guessing all the Japanese companies just use the same supplier.  But still.

Nice detective work there.

I think technically it's all Toyota diff stuff. I doubt Subaru had much to do with the BRZ/FRS differential. 

So the Lexus gears fit on the MK3 diff, which fits in the Lexus housing...what about the 4Runner gears you mentioned?

maschinenbau (I live here) said:

I think technically it's all Toyota diff stuff. I doubt Subaru had much to do with the BRZ/FRS differential. 

So the Lexus gears fit on the MK3 diff, which fits in the Lexus housing...what about the 4Runner gears you mentioned?

Toyota 4x4 guys back in the day were putting supra LSD centers in their trucks (all Toyota 7.5" stuff), and the rally folks have been using the truck ring and pinons for better gearing (even though you can get 4.3:1 from the supra stuff). 

http://www.4x4wire.com/toyota/tech/supra_lsd/

All the ratios, for cheeeeep: https://eastcoastgearsupply.com/c-284585-gears-install-kits-carriers-spider-gears-toyota-toyota-7-5-ring-and-pinions.html

In reply to ¯\_(ツ)_/¯ :

You waste NO time ha, I think I checked the tracking an hour ago because I was curious and it said delivered not 20 min before that!

I had planned to follow up with a post about how I got here but got distracted.  So:

Toyota has a whole bunch of differential outer housings, but it seems like they only use a few different sets of internals.  On the Frisbee twins, they use an outer housing that also appears in the Lexus IS300- which has open or Torsen options for the internals, and a couple of different ring and pinion ratios ranging from 3.9-4.3:1.  However, the guts of that diff have a 10 bolt/8" ring gear which is shared with various truck differentials as well as the mk3 Supra- that last one had an optional beefy clutch pack LSD which I rebuilt and stuck into my XR4Ti rally car, housing and all in this thread a while ago.  In addition, people have put that same Supra diff into the IS300, and have put various truck gears into the Supra housing, so there are a lot of arrows that point towards this all fitting together.  So when an IS300 diff appeared in my local junkyard, and TXratti offered me a Supra LSD, things were set in motion for me to figure out whether this all goes together the way I hope it does.

As far as gearing choices, the 4.88 gears typically found in a few 4runner models (although I will probably buy an aftermarket set) seem like the sweet spot to make 1st-5th usable for stage rally (5th topping out at somewhere in the 105-110mph range) with 6th still high enough to be a relatively pleasant cruising gear for transits.  Lower gears should also help keep me away from the dreaded "torque dip" everyone whines about.

Thank you for documenting all of this

In reply to maschinenbau (I live here) :

No problem!  If you, or anyone else, ever want me to elaborate on anything please feel free to ask, I know I skip through things too quickly sometimes.