2018 Subaru BRZ build + planning

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WolfWings

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So first: Thanks to my friend @Nanuka for the much-needed prodding after too many months of spinning my proverbial wheels listlessly.

Starting on this Overland Bound adventure of sorts has given a lot of the vague notions and ideas I had for my car much more concrete tasks to target, and goals to achieve.

I figured starting a thread on the build plan for the car would be a good place to start, as much to get my ideas in the open where others and chime in as anything else.

I purposefully bought a stick-shift and more stripped-down model of the BRZ so I'd have a base to build something unique on, and inspired in part by DT_FRS on InstaGram but aiming for a less extreme build since I want adventure, not racecar. :) The year I purchased them they changed the rear diff to a higher ratio for the stick-shift, so there's a bit of extra torque to work with as a result. This leads to my current plans, in order of what they allow for:
  1. 2" Lift (front and rear), for obvious reasons but allowing the next step without needing to cut and fabricate around the front strut tower mounts:
  2. A "Mantis" high-angle turning kit (same vendor), in part for the added turning angle and MUCH tighter turning radius, but primarily the additional 2.5-3" of track width in the front it adds and making the front suspension have parts that are more feasible to swap trail-side and with designed-in failure points in case of common mishaps.
  3. This should (in theory and from initial measurements) allow for a small tire size increase (from factory stock 25" to 27") to allow moving to 215/65R16 tires for off-road use, which is available in a wide range of heavy-duty options. Including a very solid KO2 heavy-duty choice.

That's the extent of the planned 'powertrain/suspension' changes, with most of the rest being where I'm wide open for suggestions:

Lights, LEDs obviously but are there certain types which are more popular or "I wish I knew about those when I started!" that people can suggest? I'm holding off somewhat on this until I have more experience with Mon (the nickname of the car) as well, so I'd love suggestions that would fit on a BRZ.

Interior storage is one place the BRZ shines quite brightly, and shockingly so. I have plenty of space for a week of supplies for one person with room for modest luggage and clothing, it's worked well for such trips 3-4 times already. But one obstacle I have is limited height for that storage space, so many common packaging approaches don't quite fit. Like the ubiquitous "5 gallon bucket" option for some things doesn't quite work, so I'm having to pick over ultralight backpacking forums for suggestions for tools and the like.

One of the few true failings is the roof sheetmetal can't support a long-term roof rack (almost all makers of them pulled the products from market) so I'm limited to rear-hitch storage shelves. Any particular good/bad brands of those out there these days? There's so many options that it's hard to research them because every single one has good and bad reviews but it's all spotty and spread about.

Anyways, here's to the start of what I hope will be a longer build thread with time.
 
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Tupenny

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Can't wait to see this happen. I had a fully tuned FG2 that I used for everything from carving mountain passes to country exploring. It worked well although it was low.
 
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Sasquatch SC

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As a Subaru guy, I love this. I was thinking of trading in my motorcycles in exchange for a BRZ a year or two ago. I test drove one and it made me feel like a freaking giant. Yeah, it was low on power. No, it doesn't have the amazing symmetrical AWD that graces every other Subaru. But it is crazy light, agile and fun to drive. I didn't go through with it, but they are still pretty cool. Obviously, you won't be able to get on any technical trails where you really need all 4 wheels powered - but it would make a pretty bad ass pre-runner type rig. It would have no problem with most forestry roads and some lighter trails. They weigh less than 3k lbs. It would be like one of those battle-Miata's we've all seen photos of.

I think to really get the most out of a lift and tire size you are going to have to trim the front bumper or replace it with a fabricated one and you are probably going to have to roll some of the wheel well back. Because it is a RWD and with the lift I would put some seriously stiffer springs on the rear or you are going to be dragging ass with any kind of rear hitch tray. I would go with the heavy King springs on the rear and something like the RalliTek springs on the front. The OEM stuff on there with it's roadster setup isn't going to have the spring rate needed for offroad. I'd even go as far to just get one of the pre-assembled strut kits from RalliTek. You can make up for the weak stock roof and help stiffen up your chassis by getting some external rollbars fabricated. Think of the racks you see on Wranglers, but adapted for a much smaller vehicle.
 

Sasquatch SC

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Another thing I just thought of... weigh your stock wheels and tires. When you get ready to put a more aggressive set on, you will want to go with a wheel and tire package that is as close as possible to the same weight or you are going to really feel the difference. If you add a lot of weight to the shoes you are going to put a lot of undue stress on your steering components.
 
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WolfWings

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As a Subaru guy, I love this. I was thinking of trading in my motorcycles in exchange for a BRZ a year or two ago. I test drove one and it made me feel like a freaking giant. Yeah, it was low on power. No, it doesn't have the amazing symmetrical AWD that graces every other Subaru. But it is crazy light, agile and fun to drive. I didn't go through with it, but they are still pretty cool. Obviously, you won't be able to get on any technical trails where you really need all 4 wheels powered - but it would make a pretty bad ass pre-runner type rig. It would have no problem with most forestry roads and some lighter trails. They weigh less than 3k lbs. It would be like one of those battle-Miata's we've all seen photos of.
Oddly the Rally Fighter gave me a lot of inspiration for this build once I set my heart on it; it's not for complex technical trails, you're right there! But for getting to/from some beautiful, amazing campsights and being made highly dirt-capable for low-speed exploring tempos? Seems ideal. So yeah, pre-running is a good description; I'll be the guy wielding a camera at the side of the technical trails and cheering ya'all on with all my heart and soul!

Also very much yes on forestry roads/dirt trails being the target minimum; stuff where old RWD subcompact Toyota pickup trucks and Jeep Comanche's would fit but modern Wranglers and their ilk feel crowded. Heck if I win the lottery I'd go with a wooly bear trailer instead of the simple shelf TBH.

I think to really get the most out of a lift and tire size you are going to have to trim the front bumper or replace it with a fabricated one and you are probably going to have to roll some of the wheel well back. Because it is a RWD and with the lift I would put some seriously stiffer springs on the rear or you are going to be dragging ass with any kind of rear hitch tray. I would go with the heavy King springs on the rear and something like the RalliTek springs on the front. The OEM stuff on there with it's roadster setup isn't going to have the spring rate needed for offroad. I'd even go as far to just get one of the pre-assembled strut kits from RalliTek. You can make up for the weak stock roof and help stiffen up your chassis by getting some external rollbars fabricated. Think of the racks you see on Wranglers, but adapted for a much smaller vehicle.
Several folks have fit 245/50R17's on with OEM setups for winter use to slap their other subbie winter wheels on the BRZ in a pinch, but as they say the proof's in the pudding in the end. If it rubs, things get modified until it doesn't rub anymore! I'm hopeful I can avoid cutting sheetmetal I admit since then I'd need to refabricate a LOT of safety equipment that they decided to build into the literal edge of the front wheel fender. :C I'd especially like to avoid modifying the front bumper as they're rather infamous for never re-attaching right once you take one off ever. If I found someone capable I'd look into outright removing the front bumper and crash-bar, replacing the entire assembly with a fabricated steel one, but that's $$$$$ so relegated to future-dream status for the moment.

Good thoughts on the springs though, especially with my plan to have some kind of hitch used I almost forgot to account for that in my math. But you're very spot on there, and since I'll need to take the suspension apart to put the lifts in, that's an ideal time to replace it with better parts. If you have to take something off anyways while doing other maintenance, upgrade it if you can!

One option I was looking into is the RS-R Sport-i coilovers; they're one of the only ones that targets stock plus-or-minus an inch instead of purely lowering. I'll check into RalliTek's offerings since they hadn't been mentioned on any of the lists of spring rates/heights for the BRZ I'd come across yet.

Another thing I just thought of... weigh your stock wheels and tires. When you get ready to put a more aggressive set on, you will want to go with a wheel and tire package that is as close as possible to the same weight or you are going to really feel the difference. If you add a lot of weight to the shoes you are going to put a lot of undue stress on your steering components.
That's actually one of the primary reasons I changed down to 16" wheels currently! The stock 17" wheels are almost 21lbs each, while the 16" Torq Thrust M's I changed to are only a hair over 17lbs, so over 3.5lbs lighter for the rims alone with the tires I'm running equally being 17lbs versus the factory 20lbs tires so each assembly is a bit under 35lbs versus almost 42lbs each stock.

You are right though that switching to 215/65R16 KO2's for off-highway use would overtake that since that particular size weighs almost 35lbs each for the tire alone as they're heavier-duty tires. I'm looking into replacing the steering rack (there's a few heavier duty options, due to the same market of drifting where they tend to torture the steering components) when I get the Mantis kit as that will also let me relocate it to free up space around the wheels.
 
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WolfWings

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Oh certainly, you're all quite right @DividedSky and @chuckoverland I hadn't posted pictures of the car here on this thread, only in the big "Hi, I'm new here!" thread where it gets quickly buried six pages deep!

Subaru BRZ - Freshly Washed.jpg

I'm hoping to take a lot more photos this next week during my road trip, and the photo is about 5000 miles and ~30 days after first buying the car when I got back from a Kansas City <-> Irvine expedition. I bought the car with literally 4 miles on the odometer; 500 miles later I got new tires (but not the final rims, they ended up back-ordered, so steelies it was for now!) and another 500 miles to break in the new tires and finish breaking in the car before I set off on that 4000 mile week-long round trip last November.

Subaru BRZ - Freshly Home.jpg

The tires currently are 205/55R16 (the winter -1" wheel option), Vredestein Quatrac 5's, and the rims are American Racing actually; I get some odd looks when people realize it's an import wearing what are normally considered classic 'American Muscle Car' wheels, but they add a nice 'cats claws' finishing touch to the tribal margay decals I commissioned across the side of the car instead of just doing basic stripes. They're retroreflective safety blue material, the third photo shows what it looks like at night when the light catches it but in the daytime it's a very subtle near-match for the car's normal color. Why just be functional when you can look decent while still being functional? :)

Subaru BRZ at night.jpeg
 
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Billiebob

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which is available in a wide range of heavy-duty options. Including a very solid KO2 heavy-duty choice.
Keep the tires light, KO2s are way too heavy for a sports car suspension, unsprung weight is far more important.

For this whole project, try to make every mod a weight saver. And if you must add weight, make it minimal, don't build it like it is an F550, use light gauge metal, use Baltic Birch. Yes, the light weight bacpacker stores should be your favourite shop.
 
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Billiebob

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I'd look into outright removing the front bumper and crash-bar, replacing the entire assembly with a fabricated steel one
As already mentioned, weigh what comes off and stick with the goal of not adding more weight.
 

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Keep the tires light, KO2s are way too heavy for a sports car suspension, unsprung weight is far more important.

For this whole project, try to make every mod a weight saver. And if you must add weight, make it minimal, don't build it like it is an F550, use light gauge metal, use Baltic Birch. Yes, the light weight bacpacker stores should be your favourite shop.
I run Kuhmo AT51s on my Outback wrapped around a lightweight & inexpensive wheel (didn’t want to drop hard dollars on parts that are going to be taking a shit ton of abuse). The Kuhmos actually had pretty comparable performance scores to the KO2s with the added benefit of them being lighter & coming w/ free road hazard protection. They have worked out really well for me. No complaints.
 
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Billiebob

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there is the option of a single tire trailer with a 2 point hitch..... keep it aluminium and very light.
I had one like this behind my TA in the 1970s.... but way smaller.

SWECO3.jpg

or, just to get the imagination rolling..

Motorcycle-Trailer-SEMA-2011.jpg
 

Sasquatch SC

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there is the option of a single tire trailer with a 2 point hitch..... keep it aluminium and very light.
I had one like this behind my TA in the 1970s.... but way smaller.

View attachment 116434

or, just to get the imagination rolling..

View attachment 116435
That would definitely slow you down & limit maneuverability. I still vote for the exoskeleton to utilize roof top storage.
 

Billiebob

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think small, like aback pack, maybe only 20" deep x the tapering width of the BRZ and matching the profile with maybe a Porsche ducktail, carbon fibre??? lol
 

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think small, like aback pack, maybe only 20" deep x the tapering width of the BRZ and matching the profile with maybe a Porsche ducktail, carbon fibre??? lol
That still sounds awful in my opinion. I’d rather have weight between the axles than in front of or behind them - even w/ a RWD.
 
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WolfWings

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TL;DR: This is why this is VERY much a planning thread and not just a raw build thread. I'm quite happy to tap into ya'all's collective knowledge and ideas to help tune this and avoid mis-steps along the way! Thank you everyone!

Upside of starting from what is often marketed as a "bolt on everything racecar" after the platform has matured enough there's a "Spec" cup for the model I suppose is there's a literal smorgasboard of additional structural mounting points on the body sheetmetal near all major suspension points I'm learning about!

Keep the tires light, KO2s are way too heavy for a sports car suspension, unsprung weight is far more important.

For this whole project, try to make every mod a weight saver. And if you must add weight, make it minimal, don't build it like it is an F550, use light gauge metal, use Baltic Birch. Yes, the light weight bacpacker stores should be your favourite shop.
By and large I'm aiming for that, and you're 100% right that birch and lighter gauges and aluminum at times instead of steel are the name of the game here for things being fabricated. I'm thankful that there's a LOT of ultralight backpacking type stores in my area, but doubly thankful that the car seats in the BRZ are very comfortable to sleep in for me already, so I can focus on cold storage, food prep, etc.

Good thought on the overall wheel package weight though, I'll look into other tire options. General Grabber's in the same size would be only 25lbs, which on the lighter wheels I already have would still be 1lb lighter than stock at least, I'm starting to get really curious why the KO2's for that particular size are so many extra plies and thus so much heavier. Niche construction/mining use case size I guess? Hard to say, but thanks for the reality check there! Also only ~$140/tire instead of ~$190.

This project screams for an exocage rack off the a-pillar and rear hatch hinges.
Honestly something like an Exo Cage would be ideal now I've realized. It turns out I actually have a strong mounting option just in front of the A pillars without having to cut sheet metal on the body, and possibly not at all.

The silly looking slashes on the upper edge of the fender panels are a trim piece that has half a dozen mounting smaller holes underneath it through the front quarter panel, or notch the fender (removable sheet metal I'm not concerned with) there and there's dedicated threaded mounting points on the body sheetmetal that are intended for three-point fender braces Toyota offers as a racing upgrade, which would be more than sufficient for a rooftop storage oriented exocage bolt-on bracket.

For the rear point (as sadly it's a sedan-style trunk not a 944-style rear full window hatch) there's a number of rear louvers including "official" ones from Toyota all of which use a bracket that slips underneath the rear trunk hinges and runs along either side of the rear glass so there's an engineered gap there for a 1/4" metal bracket to fit through there and the hood hinges are perfectly flat and designed to have a bracket bolted on top of them reusing the stock screws.

So with some custom brackets an exo cage style shelf that chases the front A-pillar in front and stops just shy of where the rear trunk hatch swings when opened would be very straight-forward to do, thank you all very much for the suggestions there! Bonus: Adds some nice shade to the rear window for sleeping in the car during the day. It'd also give me a good reason to remove the rear faux-wing the car came with and constantly bites your fingers whenever you go to close the trunk. :P
 

Billiebob

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That still sounds awful in my opinion. I’d rather have weight between the axles than in front of or behind them - even w/ a RWD.
depends on what you put in the box, I'd use it for sleeping bags & clothes not tools sets and spare car parts...
actually I leave the tools & parts at home and rely on AAA & VISA if something breaks.