LSR Rocket 3: The Beginning....

Howdy ya'll!!

This is the start of the beautiful adventure of turning an unsuspecting, early model Rocket 3 into a proper LSR (Land Speed Racing) machine. In true Spaz fashion, I've done this completely bas-ackwards and thrown together a rather ugly starter kit for Bonneville Speed Week 2020 to get her out there racing against a few open records. I figured I could pluck the low hanging fruit and see if this bike has what it takes to be a viable salt/dirt missile machine.

First, a couple snapshots. Now, when I say thrown together, I really mean it... this bike was completely stock 2 weeks before we left to race this year (well, stock for a racebike, anyway). First was the removal of.... stuff. All in all, about 160 lbs of stuff fell off the bike that I didn't need/want (yes, I weighed it all). Forward controls, bags, pipes, covers, guards, brackets, seats, sissy bar, handlebar, windshield.... the list goes on and on. I had to fab up some clip-ons, as no one makes an off the shelf 60mm clamp (!!) for 1" bars. After that was a lower gas tank with an aftermarket pump and 1:1 regulator (just to be safe...), and a quick and dirty turbo system to get it into the blown racing classes. Did it need that for the speeds I was planning on this year? Probably not, but I am a Spaz, and I do love me some forced induction, so that's what it got. The kit will change next year, but the G25-660 turbo and 40mm Tial WG will remain. Tuning/fueling was done by a PCV and a little bit of TuneECU (more on that later), some Carpenter clutch springs (blew through the stock clutch at about 65-70% throttle at 4psi), and a Pingel electric shifter. I had some, uh, issues with the shifter... namely not reading the instructions and setting it up right, so I had to hand shift it during the event, but it will go back on with better brackets and such this coming year.

The event went well... I would say better than expected, but I actually kinda expected it to be good for this bike. 4 records total for the R3, 3 that I rode and one that Mr. Josh Owens got the opportunity to ride as a rookie this year (Rookie year and a record, sweet deal there). The first big problem was tires, though. Without time to fit a proper 17" rear wheel, I was limited to "V" speed rated tires, which put me at 150mph or less, in theory. Turns out when I got there they put a 199 limit on my runs, but at that point I wasn't equipped to take advantage of that. First couple runs on the stock ECU setting saw an easy/on the rev limiter 150-ish MPH runs, and it was stable as a barn of horses. My new tank was a little tall in the front still, but it was manageable. Riding position was surprisingly good. The shifter adjustment we slapped together at the hardware store worked awesome for the first pass, but didn't hold up... so I flipped it over and hand shifted it for the rest of the event. My tuning cable showed up a little late, but I did get the chance to mess with it a bit.... still wary of my potential 150mph tire restriction I bumped up the rev limit a couple 100 RPM, and she immediately picked up MPH into the 160's. I wasn't really logging any data and didn't want to push my luck, so I left it there. It did start to push a little oil through the breather tube on the 3rd set of passes (after raising the rev limit), but the plugs looked good and nothing seemed hurt.... I guess it just didn't like being WFO for 2.5 miles. I changed tactics and would cruise the first 1.75 miles at about 100mph (out of boost), and then would turn on the last 60mph right before the beginning of the time traps to try and save some time at high rpm, and that helped a little.

Overall, I'm super impressed. This set-up is going to change quite a bit this year... I'm going to see if I can set some serious 200mph+ records with and without fairing for Speedweek 2021. I feel like the potential here is really awesome, and I'm looking forward to a non-rushed build and some of that 9000rpm Carpenter goodness with a little boost. I may need to have a longer 5th gear made in the transmission at this rate!

Technical tidbits:

Classes were 3000 M-BF/3000 M-BG, and 3000 MPS-BF/3000 MPS-BG. We made a little 'wind deflector' out of copper while we were in impound to qualify for the MPS class change (M=Modified class, PS=partially streamlined). That was more of a joke than anything else, but it got it done.

Bike made 150ish HP pre-mods, and made about 205 at 4-5psi (225+ fl/lb of torque). I certainly could have leaned on the wastegate more, but I probably didn't need the power I had to get to the 150's I thought I'd be limited to. I'll post some dyno graphs later, for reference. Intercooler was a tad on the small side, but it didn't seem to hurt much. The acceleration up to 150mph is absolutely effortless.... even at 70% throttle.

She's still technically street legal, at least here in AZ, so I may be riding it around a bit in the off season just for yuks. It gets -a lot- of attention from passers by, and almost no one has a clue what it is. Really fun bike, for sure.

Awesome. Well done.

Badass right there!

Very, very nice!

Cool !

Wow what a machine.

I'm surprised you didn't remove the starter -- that's a fair chunk of mass. Don't some of the race cars use external starters ?

Joesmoe said:

I'm surprised you didn't remove the starter -- that's a fair chunk of mass. Don't some of the race cars use external starters ?

Click to expand...

Mass isn't a bad thing out there, especially over/near the rear tire. Quite a few folks add ballast to the swing arm of higher powered bikes... some in excess of 40-60 lbs. Weight forward of the center is no bueno, though.