Source: Bike Bound
Custom-Frame, Big-Tube 1216cc Turbo Suzuki from Dave Young…
Of the early aluminum-framed superbikes, few can rival the mythic power and tuning potential of the mighty Suzuki GSX-R1100, which combined the light weight and sophistication of the GSX-R750 with big-bore power. In 1989, the K model “Slingshot” appeared with the now-legendary 1127cc air/oil-cooled engine, which would earn a reputation as one of the strongest, most tunable motorcycle powerplants of the era.
Unfortunately, the Slingshot 1100K faced handling problems straight off, and a fatal crash at the ’89 Isle of Man TT only reinforced concerns about the bike’s geometry and suspension setup. But what if you could put that brutish air/oil-cooled 1100 Slingshot engine into a chassis with better geometry…and then add boost?
That was the vision of our new friend David Young (@SRAD_1216), who spent his teens and twenties in the engineering trade, working as a manual and CNC milling and turning engineer in a company machine shop. There he met a friend and kindred spirit, Chris, who was just as mad about bikes as he was, and whose custom-frame bike project was an inspiration to him. Unfortunately, Chris passed away when Dave was just 25.
“He unfortunately died in a road traffic accident on his way to work, and in the book of condolences to his family I wrote that one day I would make my own frame the way he made his as a tribute to him.”
Fast forward 15 years, and Dave owns and runs a small gym / fitness business, which gives him more time to work on bike-building projects out of his home garage. The time had come for Dave to carry through on that custom-framed tribute build. The design concept was simple enough:
“Loud as fuck, expensive, and too much for the road.”
Sounds like our kind of machine! Many of you taking a first look at the bike might mistake the frame for a Spondon or Martek, but in reality it’s a completely one-off frame that Dave built in his home garage based on the geometry of the Suzuki GSX-R750 SRAD, itself based on the dimensions of Suzuki’s RGV500 GP racer.
“The work on the frame is never fully appreciated and every part has been carefully placed to make it look like it belongs on the bike rather than some mates attempting to do a bit of welding on a frame someone has bought.”
To this handsome and impeccably executed frame, Dave added a modified Triumph swingarm, GSX-R750 K5 forks with K-Tech internals, Dymag wheels, HEL brakes, and last but not least…one turbocharged monster of an engine.
The ’89 GSX-R1100 mill boasts 1216cc MTC big bore turbo pistons, an S&S Super G carb machined to take an additional power jet, and a heavily modified Garrett 2860R ball-bearing turbo currently running 12 psi. Dave did all of the turbo work himself, including a one-off oil feed and restrictor system and modifying the turbo itself:
“The compressor side has had the inlet air passage undercut removed so the carb now directs fuel directly onto the compressor wheel. This ended up being so close that I had to reduce the height of the compressor collar and shaft assembly which meant having the turbo rebuilt and balanced. I believe that this modification is what gives the bike its low down boost pick up, which typically you don’t see on a draw-through turbo system.”
Aptly nicknamed “Waking Godzilla,” the bike has been dynoed at 202 horsepower at 12 psi, but Dave has it dialed back to a 185-hp tune that offers more midrange punch for street riding.
He has about 300 miles on the bike so far, and he says “it absolutely scares the shit out of you” as it comes on boost — mission accomplished!
Dave has shown the bike at three of the UK’s top shows — Kickback, The Bike Shed, and most recently the Worship Moto Show. At the latter, Dave’s build caught the attention of none other than Guy Martin, who had a chat with Dave about the build, and “Waking Godzilla” was recognized as “Bike of the Event.”
After some winter tuning, Dave hopes to take the bike on a track day next riding season. This is simply one of the coolest, baddest, and best executed turbo builds we’ve seen in some time. Dave, good on you for building such an incredible tribute to your lost friend — we’re sure Chris would be proud…and be giddy for a go himself on “Waking Godzilla.”
Below is our full uncut interview with Chris, chock-full of more technical details. Enjoy!
SRAD 1217 Turbo: Builder Interview
• Please tell us a bit about yourself, your history with motorcycles, and your workshop.
I originally started out as a machining apprentice and completed a city & guilds 228 PT 1&2 in mechanical engineering at an engineering college and then went on to continue to work within a machine shop (as an apprentice first) at an engineering company, where I worked as a manual and CNC milling and turning engineer. I probably stayed and worked there for around 10 years until my late 20’s. This alone set me up with the background I needed to transfer my engineering knowledge into my hobbies and bike building interests.
Over the years I’ve modified various bikes and cars to different standards and have always maintained a background in engineering; however, I left the engineering trade over 10 years ago and I now run and own a small gym / fitness business, which allows me to have a bit more flexibility with my time to concentrate on bike building and similar engineering projects.
I work from my home in a single garage where I have a very simple conventional milling machine and an old imperial lathe along with a AC/DC TIG welder. These have provided me with everything I need for bike building. Albeit at times the machinery is a little underpowered they have done everything I have ever needed them to do and I feel that my experience and background makes up for the under capacity / age of the equipment.
• What’s the make, model, and year of the donor bike?
1989 GSXR 1100.
• Why was this bike built?
When I was in the engineering company I had a work friend who was just as mad about bikes as I was. I started work and met him as he was just finishing a similar bike project, which always inspired and stood out to me. He unfortunately died in a road traffic accident on his way to work, and in the book of condolences to his family I wrote that one day I would make my own frame the way he made his as a tribute to him. (I think I was around 25 at the time of his passing and I turned 40 this year.)
• What was the design concept and what influenced the build?
Loud as fuck, expensive, and too much for the road. A lot of people mistake the frame for a Spondon or a Martek, which at times is both a compliment and a curse. The work on the frame is never fully appreciated and every part has been carefully placed to make it look like it belongs on the bike rather than some mates attempting to do a bit of welding on a frame someone has bought. If anything the influence of the bike would go to my friend Chris who sadly passed away.
• What custom work was done to the bike?
All the turbo mounting, inlet, and exhaust were all done by myself. The swingarm was originally designed for a Triumph but I hacked all the front spindle and suspension mountings out of it and grafted in something in between which helps mate it to something more suitable for a Suzuki.
The geometry of the frame is based on the 750 SRAD, and in very basic terms if you were to fit the GSXR 1100 engine into the SRAD frame, the ride quality and characteristics would be that of the SRAD.
- DYMAG CA5 Wheels
- Full HEL brakes and controls
- Brembo rotors
- Custom Nitron NTR 2 rear shock
- KTECH front damper kit and springs in K5 750 forks
- Yokes came with the streetfighter front end I picked up for the bike.
Garrett 2860R ball-bearing turbo. The turbo has been heavily modified and the compressor side has had the inlet air passage undercut removed so the carb now directs fuel directly onto the compressor wheel. This ended up being so close that I had to reduce the height of the compressor collar and shaft assembly which meant having the turbo rebuilt and balanced. I believe that this modification is what gives the bike its low down boost pick up, which typically you don’t see on a draw-through turbo system.
The engine has the MTC turbo pistons installed and has a good general strip down and overhaul where no part wasn’t inspected. All the engine was aqua blasted and then any external parts painted with armour black cerakote.
I run and have developed my own turbo oil feed and restrictor system which up to now has worked without fault and I am very pleased about that.
- S&S Super G big bore carb machined and altered to take an additional power jet (3rd fuel circuit).
- MTC lock up clutch spacer and lock up.
- Full DYNA 2000 ignition with 3ohm mini coils installed with a custom-built wiring loom by myself.
- Boost sensitive pressure switch to activate a retard ignition curve if needed.
- Turbosmart compgate 40 Blow off valve set to a sprint rate of 12psi boost pressure
• Does the bike have a nickname?
The first time I ever fired the bike up, I sent a video to my mate and said it was like “Waking Godzilla!” That name stuck and every show I have showed the bike at (Kickback, Bike Shed, Worship) I have always displayed it under that name.
• Any idea of horsepower, weight, and/or performance numbers?
The bike was dyno’d at the beginning of September and made 202 HP at 12 psi. I ride the bike round at 185 HP at 12 psi, as it was decided that what HP the bike lost at the top end it gained at a more mid range RPM so that’s what power output we left it on.
• Can you tell us what it’s like to ride this bike?
The bike is registered and on the road, and while it’s an absolute nightmare to ride round town and in traffic as it absolutely scares the shit out of you, on the move is a different story. Low rpms and gear changes see cars on motorway slip roads appear quickly and when the bike comes on boost it feels like you are being pushed forward at a rate that doesn’t seem to match the rpm. Which takes some getting used to at first.
I would say I’m still in the shakedown stages of the build, and even though I am a dyno session and 300+ miles into riding it, I have now found out that the clutch lock up doesn’t have enough weight on it and is slipping under heavy load and the ignition needs altering slightly (all jobs for winter).
Next year I’ll have the bike on the road for the start of the biking season for any test rides and I would also like to be able to attend Suzuki Live at Cadwell Park and take it on a track day.
• Was there anything done during this build that you are particularly proud of?
The finishing of the bike is what makes it what it is for me, and while at times it was very frustrating to build the bike I feel it’s given the drive to possibly make another frame or design and build another bike altogether.
Follow the Builder: @SRAD_1216
