Toyota‘s legendary Supra has the distinction among modern sports cars of being every bit the indomitable performer as it is an epic cultural icon. From seasoned JGTC/Super GT and LeMans veteran, to one of the most fabled automotive presences in both movies and video games, Supras are the epitome of Japanese high performance.
It’s easy to understand, therefore, why aftermarket parts manufacturers are anxious to put their stamp on the 5th-generation A90 Supra’s high performance legacy. With their fast-spooling turbocharged BMW powerplants, A90s are arguably the most potent factory-direct Supras ever offered. And that makes them an especially appealing project for high performance exhaust manufacturers like Australia’s XForce that are committed to the smoothest possible exhaust flow.
XForce Exhausts Guarantee A90 Supras the Smoothest Flow
source: xforce.com.au
For more than 20 years, XForce has been on the leading edge of Australian exhaust design and tuning, and they’re responsible for some of the most innovative systems ever manufactured in Oz. They’re especially proud, however, of their lineup of high flow A90 Supra exhaust system components and accessories.
With its solid 285kW output and effortless 1 -100 km/h times under 4 seconds, the A90 is a once-in-a-generation pairing of brutish BMW power with the precision of Toyota’s own Gazoo Racing pedigree. Only the best-engineered aftermarket parts are capable of taking these class-leading sports cars to the next level of street legal performance, and XForce delivers with a specially engineered, straight-through exhaust system that consists of:
- A 3⅜” front pipe into a dual 2½” centre pipe section;
- A dual 2½” centre pipe section into a dual tail section; and,
- A dual 2½” tail section into a single 3″ muffler inlet.
These free-flowing, mandrel bent components are the core of a complete XForce Supra system that’s designed to increase output and torque, and dyno-tested for maximum scavenging and exhaust gas velocity. High strength 304 stainless steel tubing and fully TIG welded joints also offer a significant weight saving while guaranteeing the smoothest flow and highest velocity behind the B58 BMW’s big single twin-scrolling turbo.
Unlike ordinary twin-turbo setups, there’s no bottom end lag with the Supra’s dual-chambered twin-scrolling turbos. They spool up quickly and deliver boost instantly, which means they need downpipes that can handle the added draw. Not surprisingly, XForce manufactures its own bolt-on replacement for the A90’s heavyweight OE downpipe – one that allows the B58’s turbo to enjoy the smooth flow they need, and to shed a few kilos along the way.
Low Restriction A90 Downpipes For Optimum Turbo Performance
Make no mistake: while it’s easy to get lost in the details of main tube diameters when discussing exhaust systems, exhaust engineers know that when it comes to turbocharged engines, it’s downpipe design that makes all the difference. And this is especially true with fast spooling twin-scroll turbos like the A90’s, where even minor airflow restrictions and disruptions in pulse management can be major contributors to turbo lag and costly turbo wear.
XForce’s catted, high flow A90/BMW downpipe is a masterpiece of bolt-on engineering that’s manufactured specifically for the twin-scroll fed straight-through Supra system, and boasts build specs that include:
- A 4″ inlet flange, to a 3⅜” front outlet pipe;
- A high flow, 200 cell cat with O2 sensor port; and,
- A braided flex bellow for optimal fit.
With a 21% increase in flow capacity over the Supra’s OE downpipe, XForce’s A90/BMW replacement is perfect for reducing turbo lag, improving throttle response and even enriching the B58’s exhaust note. These high flowing A90 downpipes also deserve as much credit for their visual appeal as they do for engineering excellence. With their welded joints and matte finished stainless steel bodies, these A90 Supra downpipes are good looking components. That makes them a perfect complement for XForce’s most impressive Supra component: their custom-fitting, electronically controlled VAREX muffler.
Electronic VAREX Mufflers Give A90s Maximum Adjustable Flow
source: facebook.com
If exhaust gas flow and velocity are the main points of exhaust engineering, then muffler design is possibly its most overlooked topic. A muffler’s core function may be to absorb nuisance noise, but the fact is the buffering and chambering materials used to filter noise are also a major cause of power-robbing backpressure. The Supra’s OE mufflers are no different, making XForce’s mandrel bent, stainless steel VAREX an exceptional high performance option.
The VAREX is a 3-mode, electronically controlled muffler that allows drivers to regulate both the noise level, and the amount of backpressure passing through the muffler. The A90’s VAREX is designed specifically to fit XForce’s low restriction Supra exhaust system, going from a dual 2½” centre-plumbed pipe to a single 3″ muffler inlet, with butterfly-valve actuated functionality offering three functioning modes:
- Street Mode. In street mode, the VAREX’s butterfly valve is closed, routing spent exhaust gases through the system as they would through an OE muffler, absorbing the most sound.
- In-between Mode. In-between mode allows for a partial opening of the butterfly valve, resulting in a 50% reduction in backpressure with a corresponding increase in the exhaust note.
- Race Mode. In race mode, the VAREX’s butterfly valve is wide open, allowing totally unrestricted exhaust gas flow with an absolute minimum of backpressure, along with the healthiest exhaust note.
The A90 VAREX offers optimal tuning for the Supra’s turbocharged B58 and is controllable through either by remote control or smartphone via Xforce’s SmartBox Bluetooth® app. Xforce also offers a choice of 4“ black-coated, or burnt blue stainless steel muffler tips for their Supra mufflers, ensuring that their looks continue to match their performance at all times.
The Final Word
At the end of the day, whether it’s the Ferrari-beating power-to-weight ratio of the 1st-generation Celica Supras, or the violently powerful 4th-generation 2JZ powerplants that continue to defy the rules for 6-cylinder performance, the Supra is one of the most formidable sports car ever marketing by Japan. The 5th-generation’s BMW-powered A90 solidifies that position, while retaining the Supra’s decades-old legacy for readily accepting high performance aftermarket parts.
XForce has been a part of that legacy for more than two decades, and the Supra high flow A90 exhaust system is the latest contribution to continuing to shape that legacy. Theirs is a legendary exhaust system, for a truly legendary sports car.