View Single Post
Unread 04-12-2014, 02:35 PM
Fair!'s Avatar
Fair! Fair! is offline
I blame the internet
Join Date: Jul 2004
Posts: 6,077
Default Vorshlag Scion FR-S LSx Alpha Project

Project Introduction - April 12th, 2014: This is the first of many posts where we will document our first GM LSx based V8 swap into an "FT86" chassis, or just an "86". That's the Scion FR-S and Subaru BRZ rear wheel drive sports coupe, for those of you unfamiliar with the nickname. Also known as "the twins", these two-door coupes are a co-creation from Toyota (ne Scion) and Subaru, and a revolutionary design for them both. These are two companies normally making plebeian FWD econoboxes (Toyota) or plebeian AWD econoboxes (Subaru) - and together they made this completely different car!

This introductory post is a big one, so you might want to go grab a snack before you start reading...

Some call it the modern day Miata coupe, which it really is in some ways, but not in others. True, it is a relatively lightweight 2 seater (there is a faux back seat) with a hard top coupe chassis, which the Miata never got, but should have. The power-to-weight ratio is similar to the MX5 Miata, meaning pretty poor. But it does give those "pure" sports car feelings, and some would argue that a "pure" sports car is always a light RWD 2 seater with lower power but good handling and gearing.

Well, we beg to differ. An enjoyable sports car is anything with RWD, good handling, good brakes, and a GOOD power-to-weight ratio. The formula is simple: Lightweight, big power, rear drive, make it turn and stop. And the FR-S/BRZ chassis almost fits that bill, but it has a few glaring holes that we aim to fill.

What's Going in and Why?

Before you wonder what we are doing in this project, I will give you the quick summary: a customer brought us a 2013 Scion FR-S with a turbocharged FA20 motor, this car had several "major engine problems" previously, and now we are swapping in an all aluminum LSx GM V8 engine and a manual transmission strong enough to take it into this chassis. This LSx V8 swap will add a lot of engine displacement and horsepower, and some much needed powertrain reliability, yet still allow for affordable upgrade path for the future. This Alpha FR-S LSx will be used for both street driving and road course use, and already has some track oriented upgrades such as StopTech brakes, 17x9" wheels, racing seats, aftermarket axles, a roll bar, and a rear seat delete.

Out with the old 2.0L engine, in with the big honkin' V8!

Before we get to the "why a V8 swap?!?" question, let's look at this chassis as it comes from the factory. This Rear Wheel Drive coupe was introduced in 2012 as a '13 model year car and has been a popular car for people that liked the small, sporty handling of a RWD 2 seater like the Mazda MX5 but wanted a roomier interior, a much more rigid chassis via the hard top coupe design, and a nominal back seat. These cars are available as the Subaru BRZ and Scion FR-S (as well as the Toyota GT86 in other markets outside the USA).

This chassis was jointly designed by Subaru and Toyota, and it shows, with some of the quirkiness from both companies survived in this final design. And a lot of "parts bin" engineering solutions, but that is going to happen on most lower volume cars like this. Some bad ideas managed to stick around, which we will address in this build. Many more details of this new-for-2013 model chassis are well documented on the interweb and we've talked about it extensively on our 2013 BRZ Project Build Thread (linked here).

In that thread we document what we felt were many of the shortcomings on the OEM FT86 models and show our numerous fixes, updates and suggestions to make them better. We show parts we bought, built, or designed to make these cars stop, turn and go better. Things like replacing the underwhelming OEM tire and wheel package, upgrading the super soft springs and suspension bushings, and fitting some proper monotube coilover dampers and camber plates up front.

Many thousands of FT86 owners have agreed that these cars work better with a few mods and the aftermarket has grown quickly for this chassis, with many offerings available to upgrade the wheels, tires, brakes, dampers, spring rates, alignment settings, bushings, exhausts, and more. An entire aftermarket segment has sprung up in the past two years to support FT86 buyers. You see it is perfectly normal to want to modify a brand new car, and real gearheads understand that virtually no car is ever built 100% perfectly for everyone from the factory, especially in the first year. The motorsports and enthusiast aftermarket exists simply because the demand to upgrade and modify cars, and the FT86 owners are no different.

An LSx Swap Is Just Another Mod

We see the LSx V8 swap as "just another modification" that can make this car better. Sure, maybe we're just taking the "mods" thing a little further than some, but here at Vorshlag we have done so many LSx V8 swaps on many makes and models of cars that nothing phases us. Not the "its a brand new car!" nor the "How can you make electrical bits work?!". We have lots of happy customers to show for all of that work over the past 12 years that we've been doing these LSx transplants. Swapping motors is fundamentally not any different than folks adding superchargers, turbochargers, or built FA20 motors.

Will swapping in a Corvette V8 motor into an FT86 piss off some purists? Sure it will. Its not "JDM, yo". But we simply don't care about any of that. We are not brand loyalists in any way/shape/form; we simply use "the right tool for the job". Brand loyalty doesn't make a car faster, and ignoring this obvious engine upgrade prohibits 86 owners from these most affordable and reliable powerplant alternative on the market. Is this "brand loyalty snob" pushback something we've run across before? Of course. The BMW community was pretty cold to the idea of an LS1 V8 in a Bimmer when we first showed it in 2002, but many warmed up after they saw, heard and rode in the "hybrid" brand V8 powered cars we created and we are quickly approaching our 100th BMW LSx V8 swap sold this year.

This V8 powered BMW E36 M3 with a Vorshlag swap kit makes 420 whp on pump gas and 5.7 Liters of LS1 goodness

The simplicity, reliability, low weight, compact size, aftermarket support, power potential, and just RAW POWER of the OHV aluminum LSx V8 is hard to ignore. Since the early 2000s these "LS1 swaps" have become very popular in virtually any car it is stuck into: the 240SX, multiple generations of RX7, various Miatas, BMWs, classic muscle cars - you name it. And we've made a good dent in the BMW purists' armor, selling so many E36 and E46 LS1 swap kits over the past 12 years. Lots of folks with street or race prepped BMWs are running around on LSx power with help from Vorshlag.

So don't look at this project and think, "What drugs are these guys on?!" There is a method to our madness, and lots of proven V8 swap packages on the roads due to the hard work we've done to develop them. There are also millions of all aluminum LSx motors just sitting around in wrecked GM cars and trucks that we can pick these motors from. This makes the LSx engine prices affordable, and with tens of millions of this engine family produced since 1996 (and still being built to this day) the market for go-fast parts for this engine is MASSIVE.

There Are Many Things That Can Be Upgraded on the FT86

We've done a lot of work on this FT86 chassis here at Vorshlag, including: developing camber plates for it, co-developing the MCS coilovers using our in-house 2013 BRZ, as well as performed track and autocross upgrades on multiple examples of 86 coupes. We've done big brake kits (however - these cars usually don't need this), pad swaps, made our own stainless brake lines, brake cooling ducts, lots of different coilover installs, bushings, swaybars, exhausts, control arm swaps, tons of wheel and tire testing, and much more. We know this chassis inside and out.

We have tracked and autocrossed multiple examples of the FT86, including former Vorshlag employee Matt's blue BRZ, shown here. These cars are quite fun to drive in autocross or HPDE/Time Trial, once you perform a few basic modifications.

We feel that the OEM 7" wide wheels and 215mm Prius tires are extremely undersized and underwhelming, but after upgrading to a 17x9" wheel and aggressive 255/40/17 street tire these things can make huge grip. The stock ride heights are also a bit too tall and the spring rates too soft for any serious track use, so we tend to go straight to coilovers (like those from MCS) and firmer spring and damping rates, then add our spherical top mount camber plates up front for alignment and handling adjustments. We've also have had good results installing Whiteline bushings and swaybars, among other solutions.

Anyway, the 86 is a neat little chassis, which can be made to handle very well with the right parts, and with an upgrade to better track brake pads/lines/fluid they stop like a beast on track as well. Read our BRZ project build thread for more on our thoughts about the brakes and suspension, which we won't really cover in this thread.

This thread is not about: suspension, wheels, tires or handling. What we are covering here is a better choice of POWER PLANT for the 86

After those non-power things are addressed, our number one beef with the Scion FR-S and Subaru BRZ has to do with the goofy drivetrain it comes with. Yes, goofy is the only way to describe the flat-four engine in these cars. The engine that comes in these things is a giant headache with very limited potential and questionable reliability when modified.

What's So Wrong With The Subaru FA20 Boxer Engine?

We aren't picking on all Subaru engines, just this one. It isn't that much of a hindrance in low speed autocross competition (these cars are doing very well in C Street and STX classes!) but the deficiencies of the FA20 quickly becomes apparent on a road course. These cars are what you'd euphemistically call "momentum cars"... since they don't make nearly enough horsepower for the weight of the chassis, once you try to get going above about 30 mph. I say the same thing about all stock-engined Miatas, among other cars. These momentum cars are better suited running with the Miata run group on a road course, as the Mustangs, Corvettes, 911s and other powerful cars are going to be flying by your FT86 (if those other guys have a good driver, of course - no amount of power can make up for a lack of talent!)

The Subaru built FA20 / Toyota 4U-GSE 2.0L "flat-4" (aka: boxer) direct injected 200 hp engine that comes in these cars is a novel piece of engineering, I suppose. It has a "low center of gravity" layout and all that, but it is also a staggering 31" wide. This is really one big ass little engine. It is so wide that the frame rails had to be pushed way out there, but even so the clearance between the cylinder heads and the frame is tight. I suppose you can remove the spark plugs without pulling the engine, but it looked tight. This layout reminds me of Porsche 911 repair nightmares (which has a similarly wide flat-6 engine).

The engine block is short front-to-back (only 18" long) but it is placed in the engine bay way too far forward. So far, in fact, that more than 1/2 of the mass of the engine is in front of the front axle centerline. This is very strange, and I cannot say why the Subaru and Toyota engineers that designed this chassis and drivetrain placed the engine so far forward. They even had to use an extra long bellhousing and a crazy long shifter extension on back of the transmission to get the gear shift lever far enough rearward to mate up with the driver in the cockpit. My calibrated engineer's eyeball says this stock motor could be moved back by another ~10", which would help the front to rear weight balance significantly; in stock form we measured 56% of the weight on the front wheels, and our Alpha tester's modded FR-S has a 55%F/46%R weight bias.

Rick's FR-S came to us with a turbo kit, StopTech BBK, rear seat removed, a 4-point roll bar and racing seats installed, weighing 2682 lbs

So the engine is super wide, and fore-aft engine placement of this lump is not great - it could have been improved with just a little bit of effort. In my opinion this car was really built from a lot of older carryover Subaru parts and technology... Subaru GR design in the back, some Subaru GD front suspension design, a traditional forward biased engine layout (things like the starter, that sits way up high and would have interfered with the firewall if it was set back, would have had to be redesigned and moved down below), and all wrapped in some pretty new bodywork. Hey, it is economics, I get it... to totally design a 100% all new RWD coupe from scratch would have cost so much more, and that would have driven up the car's price. One of the saving graces of this chassis is the low cost: The FR-S starts at $24,500 sticker and the Subaru BRZ starts at $25,495.

The engineers did do a lot of things right: it is a proper Rear Wheel Drive car, it has a rigid coupe chassis, the interior is roomy for those of tall stature, the seats are excellent, visibility is pretty good, and driver ergonomics are excellent (placement and adjustabilty of the seat, steering wheel, pedals, shifter, and other controls). Still, the specific examples of engineering compromises are numerous and the FT86 chassis contains many examples of when "the bean counters win out over the engineers". We're here to fix some of those compromises, to make a great little sports car into an EXCELLENT sports car with some serious track credentials.

continued below

Last edited by Fair!; 04-12-2014 at 02:39 PM.
Reply With Quote