Suzuki GSX-R Motorcycle Forums banner

Twin Engine GSXR Land Speed Racer

55869 Views 337 Replies 83 Participants Last post by  Beairsto Racing
Hi everyone,
This my first post. I was slacking off and surfing the net hoping to find race parts for early GSXR's and ended up on this site and then was surprised to see a recent thread on one of my race bikes. I just enjoyed my 8th year competing at the Bonneville Salt Flats, I've had some success with very large displacement Hayabusa's. I still own my first race bike, a 1986 GSXR 1100 built as a period endurance racer.

One of my mentors, Larry Forstall built my twin engine GSXR back in the early 90's. Larry built it to run in the "naked" classes without any bodywork. Other than a couple of shake down passes which were aborted due to vision problems and salt conditions, the bike has never run. The Double sat for over a decade in Pennsylvania. I met Larry in 2002, the year that I got inducted into the Bonneville 200 MPH Club and he mentioned having a twin engine GSXR in storage. I was after Larry for several years to either sell it to me or let me fix it up and race it. Bonneville has such a rich history of multi-engine vehicles, I thought the Double was very cool. I was teased with pictures at first but Larry finally agreed to sell it to me and I had it shipped up to Alberta, Canada. I will always run it as a "Beairsto & Forstall" entry. Larry is an innovator and I'm proud to own a piece of his work.

The Double uses a pair of 1986 GSXR 1100 engines, they are now 1255cc with Cosworth pistons, ported heads, Carrillo rods, Falicon cranks, Megacycle cams, 40mm flat slide Mikuni's, all the good stuff that was available at the time. Older technology for sure but horsepower is horsepower. The engines are coupled together, both transmissions are engaged.

I work overseas in the middle east and Africa, I'm not home much and it was hard trying to get 3 other race bikes ready for Bonneville. As anyone who has run at Bonneville knows, corrosion is a bitch. It doesn't seem to matter how much you clean up afterwards, it ruins everything. Having sat for so long, the bike needed some attention. I also wanted to be able to run the bike with bodywork and decided that an early GSXR competition fairing was the right choice. We replaced the wiring harness, spark plug wires, cleaned the carbs and got the front engine running fairly quickly. The rear engine gave us a little more grief but we sorted through the electrical gremlins. A seized rear custom clutch slave cylinder almost kept the bike at home, we fixed that the night before we left.

I had never driven the bike until I let the clutch out for the first time on the salt. Its very stable at speed but it is a bit of a stretch even laid out over it and the gear shift pattern is backwards.
The front engine is started using a battery cart, with the bike on a stand, I shift into 1st gear, rev it up a little and drop the clutch. The rear engine fires up and the bike gets alot of attention. I put it back into neutral, the stand is removed and I wait for the starter to give me the ok to run on the course.

I did a couple of passes on the short course to get familiar with the bike but we soon discovered a weak link in the engine's coupler. I knew with the weak idler gear that I would only be able to make a few runs. My top speed was 203mph @ only 7000rpm, the bike has alot of potential in it. I like it because its different, my Hayabusa disappears in a sea of other 'Busas at Bonneville. On my last run, we actually broke the coupler's idler gear and the loose chain caused a bit of damage but nothing that can't be repaired. There's nothing like running 200 mph and hearing bad crunchy noises coming from the coupler.

I hope to be able to run it again this year at Bonneville or El Mirage, work permitting. The bike is in a shop right now getting the coupler modified. I also need to improve the rear suspension and add some ballast for traction. It just spins the tire hopelessly at anything over 3/4 throttle. Over the winter I'd like to throw some more power at it and upgrade the 1255's, its a shame they stopped making the big blocks. We are entertaining the idea of adding fuel injection as well.

Well I should get back to work.



See less See more
81 - 100 of 338 Posts
what an amazing machine
i'm late to work because of this thread
stay with it B.R.,
and how bout that vid with SOUND?!

Ok, here's a crappy youtube video. I've got some better ones but I don't know how to resize videos.

The salt only has about 70% of the traction that pavement offers so everyone has to take it easy off the start. I pull away harder on my Busa but I'm still usually half way through 6th before I can ever open it all the way up. One of the secrets to going fast on the salt is by adding ballast..theres 200 # of lead shot in the Busa swingarm and frame. When I ran the Double through tech inspection, they wanted to know where I'd put the ballast..I replied that I figured the 2nd engine was enough.

The first time I ever put the bike in gear and let the clutches out was at the starting line...not very graceful...granny shifted...ran @180mph...took forever to slow it down as I was unsure how it would act with 2 engines braking on compression...the track officials gave me shit for holding up the course, I said "WTF? Its a shake down pass, I've never driven the damn thing before".

The next morning I ran @190mph..again just checking things out..the rear tire went local shop had put a tube in a tubeless rim and I sheared off the valve stem..WTF?? I lost a day getting the wheel and tire checked out in Salt Lake City.

After that, I made several passes in the low 200's but we knew the coupler was eating itself up and that we'd have to come up with a better solution for next time.
See less See more
Very cool to see the beast alive. I hope you have more success this year with all of the coupler mods!!

If you remember, did you wire the vaypor tachs to the coil wire or did you do the coils around a plug wire?
Very cool to see the beast alive. I hope you have more success this year with all of the coupler mods!!

If you remember, did you wire the vaypor tachs to the coil wire or did you do the coils around a plug wire?
Thanks for the encouragement.
Yes, we wired the tachs to the coil wires...wrapping around the plug wire works too.
The bike looked alot cleaner when it was just a pair of engines in the frame.

Unfortunately we had to cut Mario's carb heat shields in half, the rear engine's headers would have melted the front one, we also need to be able to frequently change the main jets without removing the carbs every time.

The clutches need to be bled, the new Dynatech 2000 ignitions go on next, then its on to the coupler installation.

The Double is too long for a bike dyno, we are going to see if we can rent a car chassis dyno just to break the engines in and check the timing and jetting.

Calgary is at 3400 feet above sea level, the salt flats are at 4200. The bigger issues for jetting is the dramatic changes in air density through out the day. Early morning runs might occur at 65 degrees, 110 degree heat later in the day brings the moisture up out of the salt and affects the humidity, it can cool off to 90 during the last runs of the day. When I went to the Busa in '01, and saw how easy it was to tune EFI, I swore I'd never go back to carbs... now we have 8 of them!


See less See more
Damn! , what a shame about the heat shields. But for sure it would have been a PITA to do the jetting with them on.
The new pair of Dyna 2000 ignitions have been installed.

Both clutch cylinders have been bled.

New RaceTech shocks should arrive tomorrow.

The coupler plate is getting drilled and tapped for the new cover. Now that we have an oil bath, seals are getting installed on the back side of the coupler countershaft bearings. The coupler guts will be installed right away.
It should be running in another day or two.

Now that the postal strike in Canada is over, my PM front wheel might show up.


See less See more
The coupler is finished and filled with oil.
Here you can see what the back side of the coupler looks like, the coupler shafts just fit over the countershaft splines and secure with a nut on the inside.
Just some minor jobs to finish like a new chain guard etc.

The salt flats are currently flooded, several inches deep in some areas. A couple weeks ago, they were dry and everything looked promising. Speed Week isn't for another month, the salt may still dry out in time but the SCTA were supposed to start surveying the courses this week and do some grading, but that got we'll see what happens. We can only move forwards at this point. Although far from optimum conditions, I've driven on wet salt before, its like driving in slush. Given the choice of staying home and not running this year or running on crappy wet salt..I'd rather make the trip and atleast make some more test runs as long as the SCTA will host the event.


See less See more
Seeing the flats flooded like that is quite a remarkable sight! I hope things really start to fall in place for you to make a run at the record this year. I dont know anything about land speed records or how the classes work but it is pretty damn remarkable that the record you are going after has lasted for 32 years! Big ups to Tom Elrod, but it would be nice to see suzuki atop the heap! ;)

Do you have any major sponsors? seriously, you or someone needs to be making a documentary! I'd pay to watch that... Good luck! I hope you obliterate the old record. :cheers
Wow, you sure took the bull by the horns with that new coupler setup! The sophistication level is up a few notches, eh? That should be a great durability improvement. Good luck with your runs. I'm rooting for ya.
Great Scott Scott, What a fantastic job of engineering and fabrication on a fantastic machine. Hope you get a decent run when you get to the salt and the bike performs to the potential it looks like it has (Soggy salt or not). All the best, Mike
Thanks for the positive comments!

12 years ago we were building our own stuff in my garage and happy as shit to compete against a Muzzy backed race team and take the record. Now I send alot of it out, however I entrust most of it to my mechanic / engine builder / machinist, Richard Bak of 12 O'clock Performance. Richard is pretty switched on, he invented a planetary drive that replaces the cush drive on several late model sport bikes and allows weekend bracket racers and stunt riders to change their gearing with a push of a will be on the market fairly soon. He considers the Double to be one of his most challenging projects to's an eclectic mix of farm repair and modern tech.

Larry Forstall, the original builder is thrilled with our modifications and updates. Larry built alot of the original brackets by drilling hundreds of holes on a drill press to cut out a pattern and then finishing them by hand with a file...there is alot of blood, sweat & tears in this project..that's what makes it so cool. Today, we can do a drawing of the it to the factory we use and have the parts done by CNC and back to us within a few weeks.

The Bonneville Salt Flats are actually flooded most of the year, however they ususally start drying up in late Spring. The water table is actually quite high, it doesn't take too much rain to flood it and a storm far away on the other side of the mountains can still send water towards the courses. It is what it is...I'm in Oman for another couple weeks but am trying to get home. If the event gets cancelled at the last minute, I'll load up my KLR and ride to Alaska.

After a couple of shake down passes to check out the coupler and tune, we will run against two records:
3000 APS/G - 208.450mph - Dave Campos - H/D - 08/74 (with the fairing)
3000 A/G - 200.022mph - Tom Elrod - Kawasaki - 08/79 (no front faring)

I don't know the details on the Campos machine but he later drove the Easy Rider streamliner to 322mph in 1990, which held the absolute motorcycle record for 16 years. Today, Harleys and older British stuff etc run in a separate "push rod" category..this is likely one of the last HD records before they were given their own class.

Elrod ran a pair of Kawasaki Z-1's, I'd like to find a picture of that. I have quite a file of twin engine drag bikes.

Nobody is building twin engine bikes anymore, that's why the records have stood so long. The Double is a dinosaur. If I'm fortunate enough to get the bike dialled in, I won't take alot of satisfaction in bumping these current records. Lots of smaller bikes have run faster. However, I'm pretty optimistic that next year with the new body, the bike is capable of over 250mph..that's my goal.

Here's a few more photos...
We had clearance issues with the coupler chain so Richard machined the coupler plate to allow the bearings to sit a little deeper in order to steal the clearance needed.

The custom RaceTech shocks didn't fit as promised but some spacers were machined to allow them to fit on the outside of the original mounts, now they don't foul the rear caliper or sprocket. I think they are pretty sexy for twin shocks, might have to get a pair for my H1.

Lots of little projects need to be completed to finish the bike but a new chain guard was fabbed up and that's one less item on the list now.

It's alive!! Both engines have been heat cycled and the heads were re-torqued.



See less See more
Found a picture of Tom Elrod's bike with twin Kawasaki Z1's
Pretty cool! It probably sounded awesome howling down the course with a pair of megaphones.


See less See more
What a difference that a couple weeks makes...lots of sun and wind has dried up what was under water recently. There is no more standing water, 3 courses have been surveyed and grading is underway.

I'm leaving Oman tomorrow, back to Dubai for a day and then flying home to Alberta on Saturday. I'll spend a week playing in the garage and then load the trailer. Only 16 more days to Speed Week!


See less See more
81 - 100 of 338 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.