Safe Home! I am looking forward to reading your updates. Cool thread! Very cool project. Good luck.
Twin Engine GSXR Land Speed Racer
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
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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101 - 120 of 338 Posts
Speed Week was August 13th-19th...I've had a couple weeks to decompress and take care of a few home projects. I also wanted to tear back into the bike to be certain of what we managed to get right and what needs to be fixed for next time.
The bike passed tech inspection without any issues, other than they wanted us to mount the chain guard closer to the rear sprocket...a quick bracket took care of that.
The engines were new and other than a couple of heat cycles and re-torquing the heads, there was no run time on them. I decided to run on the "rookie" course, a 2 mile track intended for licensing runs and slower vehicles that don't need 3 miles to get up to speed. I decided that I would make 2 passes...take it through the gears easy and then we would change the oil and filters before taking it to the long course to see what it would really do.
The bike passed tech inspection without any issues, other than they wanted us to mount the chain guard closer to the rear sprocket...a quick bracket took care of that.
The engines were new and other than a couple of heat cycles and re-torquing the heads, there was no run time on them. I decided to run on the "rookie" course, a 2 mile track intended for licensing runs and slower vehicles that don't need 3 miles to get up to speed. I decided that I would make 2 passes...take it through the gears easy and then we would change the oil and filters before taking it to the long course to see what it would really do.
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I ran an easy 150mph and 175mph run...kept changing the rpm's and watching the GPS to keep the speeds down. It's pretty loud laying across the 2 engines...I don't know if I'd hear anything short of a rod coming out of the side of it.
We removed the coupler cover and were very pleased that everything was in good shape. We spent most of Sunday doing maintenance on the bike...the Double was never built to accept a 6" wide rim and the chain was rubbing on the 200 series rear tire.
There was an artist in the pit next to us painting pin stripes on a '53 Studebaker. I struck up a conversation and he came over to our trailer to look at our bikes. The Double now has some cool traditional pin stripes on the gas tank.
We removed the coupler cover and were very pleased that everything was in good shape. We spent most of Sunday doing maintenance on the bike...the Double was never built to accept a 6" wide rim and the chain was rubbing on the 200 series rear tire.
There was an artist in the pit next to us painting pin stripes on a '53 Studebaker. I struck up a conversation and he came over to our trailer to look at our bikes. The Double now has some cool traditional pin stripes on the gas tank.
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I've been doing this long enough that I know a naturally aspirated vehicle will go fastest early in the morning or late in the day. High temperature kills hp and during the heat of the day, the moisture in the salt is drawn up to the surface and the course becomes slippery. Part of my strategy then was not to get in line for a run until I was certain that we would make a run as late as possible and make the 7pm cut off. I rolled the bike off the trailer to warm up the engines and was disappointed to see the front engine's main oil cooler leaking oil...it appeared ok before and never leaked inside the trailer when we were working on it all day.
The next day, I sent my Dad & brother into Salt Lake City to try and get the oil cooler repaired at a radiator shop...it didn't pass the pressure test but they arranged to have a replacement delivered to our hotel for the next day. Although I paid for express shipping and we were promised that the cooler would be delivered by 9am on Tuesday, it would be 3pm before it arrived.
We mounted the new oil cooler and made certain that the oil lines were not pulling on it, causing stress etc. We managed to get up to the starting line on the long course before racing was done for the day. I've never run the Double on this course before as I couldn't trust the coupler. There are 2 miles to get up to speed and then you are measured from the 2-3 mile, 3-4 mile and 4-5 mile. You can qualify for a record on any of the measured miles, you are also given the exit speed at the 5 mile but it doesn't count for records.
I found the first 2 miles to be extremely rough...I thought the front end was coming apart...then it smoothed out and I was able to give it some more throttle...I could smell something burning but didn't see any fire...good enough for 185mph.
The next day, I sent my Dad & brother into Salt Lake City to try and get the oil cooler repaired at a radiator shop...it didn't pass the pressure test but they arranged to have a replacement delivered to our hotel for the next day. Although I paid for express shipping and we were promised that the cooler would be delivered by 9am on Tuesday, it would be 3pm before it arrived.
We mounted the new oil cooler and made certain that the oil lines were not pulling on it, causing stress etc. We managed to get up to the starting line on the long course before racing was done for the day. I've never run the Double on this course before as I couldn't trust the coupler. There are 2 miles to get up to speed and then you are measured from the 2-3 mile, 3-4 mile and 4-5 mile. You can qualify for a record on any of the measured miles, you are also given the exit speed at the 5 mile but it doesn't count for records.
I found the first 2 miles to be extremely rough...I thought the front end was coming apart...then it smoothed out and I was able to give it some more throttle...I could smell something burning but didn't see any fire...good enough for 185mph.
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We got back to the pits and I pulled the bike out to wash the salt off. I noticed the right side front fender bracket had broken off, which allowed the fender to rub on the tire and explained what I smelled burning during the run. Then I noticed green Motul engine oil leaking out of the front engine's new main oil cooler...it was dented and it appeared the fender bracket had struck it. No choice but to laugh now and throw some more money at it.
The next morning, we ordered another another oil cooler. I paid for over night shipping, promised that it would be at our hotel by 8am on Thursday.
I had brought my Hayabusa in case we wrecked the Double early in the week. I had left the fairings at home because I planned on running it in the "open" class, where streamlining forward of the rider is prohibited. This was also the first year that I had run the Busa in the 2000cc class and I had to run over 175mph on the short course before I could qualify to run it on the long course. I ran 184mph on the 3 mile short course and then we moved over to the 5 mile long course. I had a great pass and ran 195mph against a 197mph record and was excited to get back to the start line as quickly as possible and make another run, however I was covered in coolant...the head gasket had popped...even with the block and head o-ringed, the cylinder walls are only .070" thick with the Muzzy big block...oh well back to the Double...
It was early afternoon before the oil cooler showed up. Again, we found ourselves at the start line on the long course. I found the first mile really rough...chewed up from everyone spinning. As I was coming into the 2nd mile, I saw 200mph on the GPS and thought for sure that I could gain enough speed over the next 3 miles to grab the record. I gave the bike more throttle and could feel the rear wheel spin...I'd back the throttle off and see the GPS read mid 190's...more throttle and more wheel spin...off & on over the rest of the run with a 201mph exit speed. Regardless, I was happy that the bike was holding up and figured we would just get back in line again for another run, I didn't even plan on getting out of my gear. Unfortunately it was soon discovered that the oil cooler(replacement #2) was leaking! With only one more day of Speed Week left, we were out of time so we decided to pack everything up, have an early evening and depart Wendover at 3am for the 20 hour drive back to Alberta.
I'm pleased that the coupler issues appear to have been solved...that was previously a bit of a deal breaker and now we can go forward. I'm not sure why we were so hard on oil coolers this year, its the same set up that made multiple runs in 2009...nothing that we can't sort out now that the bike is back home. I always get asked during tech inspection where have we mounted our ballast and I tell them that I figured the 2nd engine was enough...apparently not enough. We will replace the swingarm...either adapt one from another bike or get a custom one made...I will fill it with lead shot and have brackets for adding lead plates if needed...for comparison the Busa has 200 # of lead shot in the swingarm and lower frame. I'm headed to Kenya next weekend, I'll give the bike back to my mechanic, Richard Bak, before I leave. Richard will fab up some mounts for the new body and will likely have to reposition the oil coolers during the process. I have a hydraulic shop sponsor so we will replumb everything.
Thanks for your interest.
Cheers,
Scott
The next morning, we ordered another another oil cooler. I paid for over night shipping, promised that it would be at our hotel by 8am on Thursday.
I had brought my Hayabusa in case we wrecked the Double early in the week. I had left the fairings at home because I planned on running it in the "open" class, where streamlining forward of the rider is prohibited. This was also the first year that I had run the Busa in the 2000cc class and I had to run over 175mph on the short course before I could qualify to run it on the long course. I ran 184mph on the 3 mile short course and then we moved over to the 5 mile long course. I had a great pass and ran 195mph against a 197mph record and was excited to get back to the start line as quickly as possible and make another run, however I was covered in coolant...the head gasket had popped...even with the block and head o-ringed, the cylinder walls are only .070" thick with the Muzzy big block...oh well back to the Double...
It was early afternoon before the oil cooler showed up. Again, we found ourselves at the start line on the long course. I found the first mile really rough...chewed up from everyone spinning. As I was coming into the 2nd mile, I saw 200mph on the GPS and thought for sure that I could gain enough speed over the next 3 miles to grab the record. I gave the bike more throttle and could feel the rear wheel spin...I'd back the throttle off and see the GPS read mid 190's...more throttle and more wheel spin...off & on over the rest of the run with a 201mph exit speed. Regardless, I was happy that the bike was holding up and figured we would just get back in line again for another run, I didn't even plan on getting out of my gear. Unfortunately it was soon discovered that the oil cooler(replacement #2) was leaking! With only one more day of Speed Week left, we were out of time so we decided to pack everything up, have an early evening and depart Wendover at 3am for the 20 hour drive back to Alberta.
I'm pleased that the coupler issues appear to have been solved...that was previously a bit of a deal breaker and now we can go forward. I'm not sure why we were so hard on oil coolers this year, its the same set up that made multiple runs in 2009...nothing that we can't sort out now that the bike is back home. I always get asked during tech inspection where have we mounted our ballast and I tell them that I figured the 2nd engine was enough...apparently not enough. We will replace the swingarm...either adapt one from another bike or get a custom one made...I will fill it with lead shot and have brackets for adding lead plates if needed...for comparison the Busa has 200 # of lead shot in the swingarm and lower frame. I'm headed to Kenya next weekend, I'll give the bike back to my mechanic, Richard Bak, before I leave. Richard will fab up some mounts for the new body and will likely have to reposition the oil coolers during the process. I have a hydraulic shop sponsor so we will replumb everything.
Thanks for your interest.
Cheers,
Scott
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Time for another update...
While I've been enjoying my adventures in Kenya, Richard has been making some progress with the Double.
What was supposed to just be some simple brackets for the body and trying to find a used swingarm to fit the bike has become a little more complicated.
I didn't want to mess up the powder coating on the frame by welding on the body mounts, so Richard designed a clamp style that has alot of adjustability and can be easily removed. We will need plenty of mounting options when we try and fit the body and manage to keep it legal within the rules.
I'm still amazed to see the process from a drawing to custom parts.
While I've been enjoying my adventures in Kenya, Richard has been making some progress with the Double.
What was supposed to just be some simple brackets for the body and trying to find a used swingarm to fit the bike has become a little more complicated.
I didn't want to mess up the powder coating on the frame by welding on the body mounts, so Richard designed a clamp style that has alot of adjustability and can be easily removed. We will need plenty of mounting options when we try and fit the body and manage to keep it legal within the rules.
I'm still amazed to see the process from a drawing to custom parts.
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I had an extra '04 Honda 600RR front end collecting dust, although they are just conventional forks, they have lots of adjustments. The original forks on the Double are Honda as well but are likely from the early 80's. They really sucked over the rough sections so it's time for an upgrade. I had an extra Busa front end too but it required too much machine work to fit USD forks, no need to reinvent the wheel everytime.
The Double was never designed to run a 200mm rear tire and was built with skinny 18" wheels. Current rules require 17" race rubber if you run over 200mph and that means a fat rear tire. I knew clearance was tight but with a little tire growth, I actually ended up shaving over 1/4" off the left side of the rear tire as it rubbed...that's not helping me go faster.
We looked at several used swingarms at a bike wreckers but didn't have any success. I also want to be able to fill the arm with lead shot and mount lead plate on the outside if needed. Once Richard got measuring, it was apparent that in order to keep the wheel aligned with adequate clearance, a jackshaft would be required to keep the sprockets lined up. I'm not a fan of swingarms with jackshafts as you only see them on bastardized sportbikes with beach ball sized rear tires...but this is the direction we need to go in. The pictures are just a draft but you get the idea, it will be made out of 2" tubing and will be heavily braced.
The Double was never designed to run a 200mm rear tire and was built with skinny 18" wheels. Current rules require 17" race rubber if you run over 200mph and that means a fat rear tire. I knew clearance was tight but with a little tire growth, I actually ended up shaving over 1/4" off the left side of the rear tire as it rubbed...that's not helping me go faster.
We looked at several used swingarms at a bike wreckers but didn't have any success. I also want to be able to fill the arm with lead shot and mount lead plate on the outside if needed. Once Richard got measuring, it was apparent that in order to keep the wheel aligned with adequate clearance, a jackshaft would be required to keep the sprockets lined up. I'm not a fan of swingarms with jackshafts as you only see them on bastardized sportbikes with beach ball sized rear tires...but this is the direction we need to go in. The pictures are just a draft but you get the idea, it will be made out of 2" tubing and will be heavily braced.
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I never had any issues with the mounts that Richard has previously fabbed up for the 2 ignition boxes, but he hated them and didn't feel they belonged on the bike, so I gave him a little artistic freedom.
The bike currently has a pair of Trailtech Vapor digital guages, they were the cheap and dirty fix to give me tachometers. However, the bar graph is hard to make out and I can't tell if the engines are revving at 9 or 10 grand once I'm underway. We found this tach, it's a little busy with all of the smaller needles but I'll probably buy a couple...plus it gives me oil pressure and oil temperature.
Well that's it for now until the swingarm design is finalized.
The bike currently has a pair of Trailtech Vapor digital guages, they were the cheap and dirty fix to give me tachometers. However, the bar graph is hard to make out and I can't tell if the engines are revving at 9 or 10 grand once I'm underway. We found this tach, it's a little busy with all of the smaller needles but I'll probably buy a couple...plus it gives me oil pressure and oil temperature.
Well that's it for now until the swingarm design is finalized.
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A few more pictures of the new swingarm design. The jackshaft sprockets will be 18 tooth, to match what is on the rear countershaft.
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101 - 120 of 338 Posts
