Last updated: March 5, 2019

2012 Radical SR8-RX Intro & Photos
The fastest 'production' sportscar around the Nurburgring until 2017

 

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2012 Radical SR8 RX Project Photos
2012 Radical SR8 RX Project Videos
Radical SR3 & SR8 Technical Documents
My Automotive overview and history
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Ever since I first laid my eyes on a Radical SR3-RX at Vancouver Island Motorsports Circuit (VIMC) in 2016 I have wanted to own a Radical sportscar. When I learned of its more powerful V8 brother, the SR8-RX, I thought, well maybe that could be my future track car? Was it too much for me,performance potential wise? Was it too much to maintain and support without a partner and dedicated mechanics around to help out?

After running my little GTI around VIMC as a member for the 2017-2018 period I started to feel that there are natural limits to what a street car can/should do on a dedicated track and felt more and more that if I wanted to go further into the sport, a dedicated track car like the SR3 or SR8 would be a better investment than say a Porsche Clubsport or similar GT car would be - mid-engined, light-weight, relatively simple layout and ease of maintenance, downforce, ultra-high performance potential ... it all added up to the SR8 in the end. And with 2 seats entertaining my friends was a reality ...

 

Background on the Radical SR8-RX

The SR8 is basically the same car as the SR3 with the addition of 4 more cylinders and 2x the power at a cost of 150lbs of increased weight (as a result of the engine, transmission, oiling, cooling system and brake upgrades). The SR8 uses the same body/frame/electronics/suspension but with larger brakes and a Quaife transmission to mate up to the V8, which itself is a combination of 2 SR3 engines with a custom block, crank, and dry sump oiling system. The engine is based on the Suzuki 1340cc Hayabusa motorcycle engine, using its cylinder heads and rods with different pistons that bump compression from 12.5 to 14:1, upgraded cams, ported cylinder hears and a custom intake and exhaust system - these changes move up the Hayabusa spec power from 190hp to 220hp for the SR3 and 430hp for the 2680cc SR8 V8. The torque curve is very flat making this engine superbly linear. The additional cooling requirements add a second sidepod mounted radiator, a transmission cooler, and 300mm brake rotors (up from 260mm).

On a short/tight race circuit the SR8 is usually good for 2-3 seconds over an SR3 and on longer circuits the difference can be more significant, in the range of 5-6 seconds. But a hot-shoe SR3 driver can easily beat a less competent SR8 driver on many courses due to the more neutral handling balance and ability to late brake and typically carry more speed around the apex in an SR3. It is not that the SR8 cannot corner effectively, but it is a more intimidating driving experience that requires more care and attention on many levels: speeds are considerably higher on the straights; the rear-weight bias making trailing throttle oversteer an obvious issue; and the general agility reduction from carrying around 10% more mass.

For more background on the development of the RPE 2.7L V8, please read this 2009 article published in Engine Tech Magazine on Steve Prentice of SPD Ltd's sub-contract development work for PowerTec/RPE on this engine...

Engine Tech Magazine 2009 - PowerTec/RPE V8 Engine

 

Here are the full specs for the 2012 Radical SR8-RX ...

Engine

Transmission

Chassis

Body

Cockpit

Electronics

Suspension

Brakes, Wheels & Tires

Dimensions & Weight

 

Index of Project web pages

2012 Radical SR8 RX Project Photos
2012 Radical SR8 RX Project Videos
Radical SR3 & SR8 Technical Documents
My Automotive overview and history
Exit to Home Page

 

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