Siren Song: Turbo GSX-R600 SRAD

Turbo SRAD: Turbocharged Suzuki GSX-R600 from the UK… 

In 1996, Suzuki introduced the GSX-R750 SRAD, which would revolutionize the sportbike world just as the original GSX-R had done a decade previously. Gixxers has been gaining size and weight every year since ’85, but the SRAD stopped that trend dead in its tracks, jettisoning the traditional cradle frame for a lightweight, GP-bred twin-spar aluminum frame derived directly from Kevin Schwantz’s RG500 Grand Prix machine.

Meanwhile, the new SRAD (“Suzuki Ram Air Direct”) WT engine was not only narrower and more powerful, but nearly 20 lbs lighter than the WS mill it replaced. The result was a bike that could punch well above its weight class.

“The new GSX-R’s biggest performance gains were its 50-pound weight reduction (422 pounds with an empty tank and 453 pounds full of fuel and ready to ride) from the previous GSX-R, and its approximately 116 horsepower at the rear tire. This put it in the same weight category as most 600s at the time, while having near-900cc horsepower.” –Cycle World

Embarrassingly enough for Honda, the SRAD 750 actually bested the CBR900RR in horsepower and top speed! The GSX-R600 SRAD followed a year later — a bike that could not only win supersport races nearly right out of the box, but was one hell of a hoot on the roads:

“Ridiculous, dangerous fun, it’s a raw, involving, lunatic on wheels.” –MCN

Enter our new friend Adam Richardson (@Adam.p.built ), a UK-based mechanical engineer who’s been tuning 90s Gixxers for most of his life. His first-ever big bike — a water-cooled GSX-R750WN with a 907cc big bore and one-off Yoshimura Japan development head — ended up as a magazine feature bike. Adam’s WN was as fast as it looked, too, running 10s at Santa Pod Raceway.

Today, Adam works out of his small home workshop, where he does porting work, machining jobs, and works on builds like the turbo SRAD 600 you see here.

“Usually disappear into the workshop for hours making bits for the bike or planning my next modification kinda like my church tbh :)”

This bike began life as a 1998 Suzuki GSX-R750 SRAD — the first of the fuel-injected 750s. Originally a lockdown project, the SRAD received a big-bore kit and big brakes, but Adam had begun hearing the siren song of forced induction and decided it was time for his first turbo build.

“I decided on a mix between a Yoshi endurance XRO bike and a Lucky Strike race rep, then came up with this design. And then thought that mixed with a turbocharged bolted on the side would be epic!”

Epic indeed. Little of the original SRAD 750 is left. The engine has been swapped for a GSX-R600 lump with a thicker head gasket, Kent cams, and Adam’s own custom porting…just to name a few highlights. The turbo is a modified IHI unit with ported housing and a one-off stainless steel plenum and manifold, matched with a pie-cut titanium slash exhaust.

An electronic quickshifter handles the gear changes, and the suspension and brakes have been brought up to par with the boost. The swingarm is a GSX-R1000 K4 unit with a Nitron spring and Technoflex rear shock, and stock GSX-R600 forks have been revalved and resprung to suit Adam’s weight and needs.

The wheels are Brembo, powder-coated Sony PlayStation 1 gray with ceramic bearings and custom spacers, and the brakes are a combination of Brembo and PFM goodies with HEL lines, with a billet thumb brake for when the front wheel takes flight.

Ex-F1 titanium bolts can be found throughout the build, and the quick-action throttle is an ex-factory Yoshimura billet unit. We could go on and on, but Adam has a full list of mods below.

So how does all of this work translate to the rear wheel?

“It’s running at just over 200bhp at 15psi but I expect it to make around 250 once I have made a few upgrades over the winter, which will include an intercooler and making the engine stronger —  it’s around 170kg dry weight.”

That’s more than double the horsepower of the stock SRAD 600. As you can imagine, the riding experience is nothing short of epic:

“It’s honestly the most fun bike I think I’ve even ridden due to the sound the turbo makes, and also with the amount of pops and bangs the exhaust will make at will — also it has zero turbo lag. Knowing I put the bike together myself makes it all that bit more special :)”

The sound of the exhaust — and its tendency to spit the occasional flame — has helped the bike earn the nickname the “ASBO SRAD.” ASBO means “Anti-Social Behavior Order,” a British civil order for a person to stop behaving in a way that causes alarm or distress, ha! A fine moniker indeed.

Below, we talk to Adam for the full story on his turbocharged GSX-R and the complete parts list. Also, a big thanks goes out to Dave Elliott at Moto Dave Photography for the stunning shots and putting us in touch with Adam. Thanks, Dave!

Turbo GSX-R: Builder Interview

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

Mechanical engineer by trade, have always had a passion for motorcycles since I can remember. I’ve been riding since a young age, been tinkering about with motorcycles for as long as I can remember, too. It was dirt bikes when younger then road bikes; my first road bike (scooter) being a Peugeot Speedfight that I heavily modified and managed to get it to do a genuine 90 mph and then the need for speed just grew.

My first bigger bike was a Suzuki GSX-R750WN, first of the water-cooled models. Again I heavily tuned it by fitting a big bore kit, managed to get hold of a few extra factory parts for it and it absolutely flew. Ended up being a magazine feature bike and would run in the 10’s at Santa Pod. And from there I’ve owned various 1000’s and other GSXR’s, which I’ve always tinkered with.

I’m also known for my cylinder head porting work and have done quite a few porting jobs over the years.

I have my own little workshop at home consisting of a 100-year-old metal lathe, also TIG welder and various other machining equipment. Usually disappear into the workshop for hours making bits for the bike or planning my next modification kinda like my church tbh 🙂 I have a little Instagram page showing some of my work: @BarryAlanRacing.

• What’s the make, model, and year of the donor bike?

The bike is a 1998 Suzuki GSX-R750fi SRAD.

• Why was this bike built? (Customer project, company promotion, personal, etc.)

I built it as I’ve always love the look and shape of the SRAD model GSXR’s and thought what better bike for a custom build. It was firstly built as an SRAD with a big bore and mildly tuned motor and big brakes (which was a lockdown build), but I soon got bored and always longed to build a turbo so got to work on building the turbo SRAD.

• What was the design concept and what influenced the build?

I’ve always liked the look of the SRAD’s that ran full-on factory fairings like in the old Yoshi endurance bikes; I would see photos of the bottom part of the fairings removed showing off all the factory radiator and dry clutch kits, etc. that they would run, and thought how trick do they look!

Kinda got the idea of running the half fairings from that and then loved the look of the old Lucky Strike race bikes from back in the day, I decided on a mix between a Yoshi endurance XRO bike and a Lucky Strike race rep, then came up with this design. And then thought that mixed with a turbocharged bolted on the side would be epic!

• What custom work was done to the bike?

The mods on the bike are:

• Suzuki GSX-R1000 K4 swingarm
• Custom-made 2mm offset billet eccentric frame swingarm inserts
• 3D 525 drive chain with Talon 47 tooth rear alloy sprocket, JT 16T front sprocket which is offset by 5mm.
• Standard SRAD 600 forks with Abe Engineering stanchions, binitride-coated by Factory Coating
• Harris 45mm clip-ons
• Toby side-mounted steering damper
• Forks revalved by K Tech, also resprung to suit my weight.
• Fork bottoms and fork tops ceracoated burnt brown by Stopping Power Coatings
• Rear shock is a billet Technoflex item with a Nitron spring to suit my weight, custom dog bones, billet ride height adjuster — also every linkage bolt is titanium.
• Custom billet top yoke made to my design, which also makes the front end more rigid.
• Brembo wheels modified to fit with custom spacers and aftermarket ceramic bearings, painted in Sony PlayStation 1 grey by CSP Powder Coating
• Pull cup axles with 3D-printed centre nuts.
• She wears Pirelli Supercorsa SP v3 tyres.
• Crash bobbins which I spin up in the lathe
• Loads of titanium bolts some which are ex Honda F1
• Custom made switchgear buttons by Bike Sport Developments
• Ex factory Yoshi billet quick action throttle

Front Brake:

Brembo RCS 19 Corta Corsa master cylinder with ten short lever, ex Harris Suzuki factory front fluid res, Tygon 2375 res hose. PFM 320 front narrow track stainless rotors fitted with titanium bolts, PFM 6-pit billet calipers with SBS ceramic pads. Custom caliper spacers to suit.

Rear Brake:

PFM 84mm billet caliper with SBS ceramic pads, narrow track rear stainless race disc, titanium dry brake connector, Ducati Panigale V4 S Brembo master cylinder on the foot pedal, which also has pushrod spring and level stop made by @racecomponentdevelopment — also Titanium Racetorx master cylinder adapter.

Also rear has an SES billet thumb brake fitting with a 14mm Brembo mc titanium pushrod and adjuster Brembo fluid res. HEL brake lines throughout made by @lightenUPgrade.

Engine:

• Suzuki GSX-R600 ’98 carbed motor
• Running a custom Cometic thicker head gasket from the USA.
• Kent cam, billet manual cam chain tensioner.
• Cylinder head ported by myself.
• Suzuki TLR’s clutch with custom-made basket springs and Barnett clutch plates
• Modified engine oil pan to accept the turbo’s oil return.
• Oversized radiator with HRC expansion bottle & one-off carbon fibre bottle holder.
• Ex factory Yoshi XRO SRAD gear shift linkage.
• Modified Suzuki ignition.
• Racegadgets quickshifter
• 5mm offset front sprocket to suit the GSX-R1000 K4 rear swingarm.
• Malpassi fuel pressure regulator & Bosch fuel pump.
• Modified 1998 Suzuki GSX-R600 carbs
• Aftermarket oil catch can modified internally, ITG breather filter.

Stainless steel one-off turbo manifold made by myself along with a highly modified IHI turbocharger which has aftermarket rotors. Turbocharger housing is also ported and profile altered. Has a Turbosmart wastegate actuator with custom spring. Turbo exhaust is bespoke by myself, which is stainless then has a pie-cut titanium slash exhaust. Ramair turbo air filter.

The plenum is also a one-off bespoke unit to suit the bike with a Turbosmart supersonic dump valve, which runs between the turbocharger and the plenum.

Electrics:

• One-off loom
• 1998 Suzuki GSXR SRAD 750fi clocks modified and slightly rewired internally.
• Yoshi oil temp gauge & AEM air/fuel ratio gauge both mounted to the dash on carbon fibre.
• Stack boost gauge which is mounted in a titanium bracket which has a one off carbon fibre shrouding on the back.
• Modified ignition which runs slightly retarded in places.
• Racegadgets quickshifter which is activated by the switch gear.
• Noco lithium battery.

Bodywork:

• Standard nose cone and cut-down front fairings, Yoshi two-piece factory ram air air tubes.
• Motogadget LED recessed front indicators
• Carbon fibre front mudguard.
• Quick release titanium screen brace, which I designed and made — mounted via a nylon bushing in the steering stem.
• Airblade clear double bubble screen with Bob Heath air hump.
• Standard seat unit with Bike Style undertray and Demon Tweeks LED rain lights modified to work on the road. R1 mini LED rear indicators.
• Modified standard petrol tank to fit over the plenum with one-off fuel pump feed and return fitting plate. Tank also runs a breather with an HRC catch bottle with one-way feed system and carbon fibre bottle holder. Newton Equipment fuel cap. Titanium quick release tank pins which I also made.
• Modified standard seat to suit reprofiled petrol tank.
• The bike is also vinyl wrapped which was done by @motowraps.

• Does the bike have a nickname?

It’s kind of been named by my friends as project ASBO SRAD due to how loud it is and how it will produce the odd 3-foot flame lol, so it’s unofficially ASBO SRAD 🙂

• Any idea of horsepower, weight, and/or performance numbers?

It’s running at just over 200bhp at 15psi but I expect it to make around 250 once I have made a few upgrades over the winter, which will include an intercooler and making the engine stronger —  it’s around 170kg dry weight.

• Can you tell us what it’s like to ride this bike?

It’s honestly the most fun bike I think I’ve even ridden due to the sound the turbo makes, and also with the amount of pops and bangs the exhaust will make at will — also it has zero turbo lag. Knowing I put the bike together myself makes it all that bit more special 🙂

Although it’s an older superbike you can still really enjoy the twisties, especially with modern rubber, so in a word it’s pretty epic 🙂

• Was there anything done during this build that you are particularly proud of?

Considering this is my first turbo build when it started first time that was a pretty proud moment for me.

• Is there anyone you’d like to thank?

Would like to thank Dave Dunlop at Fastbyme Turbo Systems for all the help and tips and countless questions when building the turbo kit.

Also a massive thanks to Tim at Metal Prefabrications Dartford LTD for helping me with all the welding jobs that I wasn’t able to do myself. Also big thanks to Dave Elliott at Moto Dave Photography for all the epic pics.

Follow the Builder

Instagram: @Adam.p.built | @BarryAlanRacing