LS V8-Swapping A Subaru BRZ Is One Way To Solve The Torque Dip

In the latest episode of The Smokin' Tyre's 'One Take' series, we get a closer look at a 500whp V8-swapped BRZ
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The problem a lot of people have with the stock first-generation Subaru BRZ‘s ‘FA20’ boxer engine isn’t necessarily the low torque figure, it’s more about the delivery. There’s an annoying low-to-mid-range dip, but the good news is there are things you can do about it, from N/A tuning to adding forced induction.

Adam, the owner of the BRZ you see here, wanted to do a little more than kill the torque dip, however. His aim was to extract 400whp from the boxer-four, something he tried to achieve first via turbocharging then supercharging. We say ‘tried’, as this resulted in more than one blown engine. And so, he came up with an even more invasive solution - drop in a V8.

LS V8-Swapping A Subaru BRZ Is One Way To Solve The Torque Dip

It should come as no surprise that the eight-pot of choice was a General Motors LS3. However, it’s not just a stock version of the pushrod V8 that’s merely mean shoved in and forgotten about. Built by Detroit-based Katech, it’s stroked to 6.8 litres and features a dry-sump system to keep the engine nicely lubricated on even the most demanding of race tracks.

This powers the rear wheels via a T56 Magnum XL manual gearbox and a Wavetrac limited-slip differential. The rear tyres (and the fronts too) now measure a reasonably meaty 275mm across, but as Zack Klapman found in this episode of One Take, care needs to be taken not to light them up with each hefty throttle application. Also, the cabin can get a little…fumey.

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The engine is good for just over 500whp, which will give a crank figure not too far off three times what a stock FA20 makes. The torque meanwhile sits at 516lb ft. In a car weighing relatively light 1360kg, that’s plenty.

See also: 10 Things You Need To Know Before Buying A Toyota GT86/Subaru BRZ

We’re not sure how much money was sunk into this project, but it’ll be many tens of thousands of dollars. So why, you might wonder, didn’t Adam merely buy a Corvette? It’s mostly down to the compact sizing of the BRZ, and the general feel of the car. He does seem keen to recoup a decent chunk of the build cost, though, as the car is currently for sale at a punchy $70,000. Think it’s worth it?



Why would a sober person choose push-rods over a DOHC/Modular? Might as well change out the fuel injection and go carburettor. Swap the discs for drums. 86 the shoulder belts and revert to lap-belts. Ditch the airbags altogether, and replace the HID/LEDS with candles, circa the early Neanderthal Period

11/04/2021 - 20:57 |
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