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Twin Engine GSXR Land Speed Racer

55863 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.

-Scott

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Although we are still a long way from having to worry about paint, I am entertaining the idea of a vinyl wrap with a first gen blue / white theme.
^^^^^^^^
And finally put an end to the debate about which colour is faster :cursing.

Great project Scott; always like reading the updates. Regards, Mike
^^^^^^^^
And finally put an end to the debate about which colour is faster :cursing.

Great project Scott; always like reading the updates. Regards, Mike
Not fair... That bike used to be red/black :lmao
159 days to go until Speed Week!

The swing arm components are finished and have been shipped. The arm itself wil be checked on the chassis and then welded together.

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The front mount for the fairing was fabricated and the sides use the new mounts that were machined last fall.

Now it's on to the oil coolers...as we are trying to reduce the frontal area and don't want them hanging off the sides of the bike like before, there is alot less room to package 4 of them within the body...we may try stacking them together in pairs...or find some sort of creative solution and stuff 2 in the tail etc.

The clip-ons and controls are going to have to be redesigned as well. It's a good thing the rules limit steering to only 15 degrees each way, because it's tight in there. My only concern is that they need to be angled enough to give me some leverage at low speeds.

The tail section will have to wait until the new swing arm is installed. Then a new fuel cell, fuel pump etc will get mounted in the rear.

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This project is gaining some momentum again!!

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thanks for the pics and updates Scott -keep em coming
I love seeing these updates, great job on all of the special parts.
+1^

Thanks Scott!
Looking good Scott! That's gotta be the beefiest front mount I've ever seen. Some guys use and inverted U-shape handlebar mounted to superbike clamps, real narrow and tucks the elbows in. Are you going to make some downturn bars to slip into those clip ons?
Last weekend, I visited Richard's shop and we sorted out how I'm going to steer the Double. I stretched across it and made appropriate engine noises, I think I'll have enough leverage to steer it at low speed...gyroscopic effect should keep it upright from there on.

The big beefy front fairing mount grew a little more and now ties the fairing in at two more points. I'm looking forward to getting the windscreen fitted, it looks like a fighter jet canopy.

What to do with the exhaust has been debated...do we try to run them out the back?...do we make some "blisters" to cover most of them up?...I think the quick fix for now will be to water-jet some stainless trim to fit around them and use lots of heat shield on the inside of the fairing, the header tubes might get wrapped too.

We have a game plan for the oil coolers now too, I'm pleased that everything is falling into place.

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Richard has started aligning the swingarm pieces and tig welding it together.
The jackshaft sprocket will get sent out for surface hardening.

This chapter of the project has proven to be very effective in quickly converting money into shiny one-off bits of steel and aluminium.

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Thanks for posting more M/C Porn... That is beautiful :punk
WOW Just found this thread....
SWEET bike and hang on!

Do you have a link to all the crazy rules for this mess?

I was wondering (probably against the rules) about putting both engines behind the driver and have him sit way low in the frame (possibly level or below the top triple tree when tucked ?

I guess at speed you hide behind the fairing and just watch the GPS?
That takes big coconuts even on a known clear track!!

Shame you can't make a small THICK polycarbonate window like I see in the battle bot arenas LOL or a camera just above the front wheel and a tiny screen inside the faring.... (Then you could tuck all the way in).

Make uncoordinated butt would probably have to put a lean gauge down under the bonnet to tell if I was falling over.

I just gotta say WOW my ADD is in full turbo mode and loving every imaginary minute of what I would do.......
JC
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The Southern California Timing Association has been hosting Speed Week in August since 1949, more info can be found on their site below:
http://www.scta-bni.org/#

BUB offers a motorcycle only event in September and run under AMA and FIM rules ...pick your poison.:cheers

As I compete with the SCTA, I run under their rules and sanctioning body. The Double's class is 3000 APS/G...engine displacement is 3000cc or less, but more than the previous class of 2000cc(big jump!)...the "A" is for Altered Frame / Special Construction..."PS" is Partial Streamlining and there are lots of rules concerning how much the body work can cover the bike and rider..."G" is a gas class, it is still race fuel but ERC provides the event fuel and I have a choice of several approved ERC race fuels. Gas tanks have to be sealed by an official after being filled in the "gas" class. If the bike qualifies for a record and is impounded, fuel samples are taken before and after the record return run. Displacements are also measured, so you have to be able to tear down the engine(s) and reassemble if you want to keep running. Inspections, qualifiers, records etc are all detailed in the vehicle's log book.

Yes, you can build a recumbant style chassis and have the engines behind you but you still have to meet chassis and body rules / restrictions. The ultimate land speed racer is a streamliner that completely encloses the rider and engines...2 or 4 wheeled, you have to have roll cages, parachutes, fire suits, fire systems, fire walls etc.

Human powered bicycle streamliners are very efficient. Here you can get away without a windshield and just use a camera.

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This is Airtech's / MDR Racing electric bike that Kent Riches rides.
The Double's new body is based on this design.
I will have good visibility once I'm tucked down inside the fairing.

I'm off to Calgary to get a pair of tachs, oil pressure and oil temp gauges for it...2 of everything pretty much always!

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Great build... I am building a double also but in a different class. Would you be willing to share any info on the bearings that you used for the outer bearing support for you trans output shafts? It looks to be 1.5-2 inch ID? Thanks
Same class...different class...no worries, I'd be glad to share with you what we have learned.
Shoot me a PM with your email address and I can send you info, pictures etc.
Just read this thread real like what your doing nice engineering indeed.
Ive always wanted to come over to speed week for holiday got nothing like that over here.
Got quite few hot rod mates that always go over.
Good luck.
How are the engines timed? I am curious why you are running 14.1 in the lead engine and 13.1 in the rear engine?
Awesome project btw!!:cheers
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