Suzuki GT750 Phat Trakka Drag Race fun


This bike was conceived and built as a mild fun street bike.  There was never any intention to race it in any form whatsoever.  I made the mistake of encouraging a fellow GT750 owner in his race efforts with his full on GT750 Drag race bike, and I was seduced into taking it to the drag strip for a fun run in the sun.  Pipes were changed to a set of Jemcos and that was as far as changes went.  The bike was still high and wide - the polar opposite of a drag race bike. 



By 2015, the forks were replaced with a spare set that were lowered a little - maybe 3 inches and bars were changed first with drag bars which were incredibly uncomfortable and then with a set of clubman's bars which are marginally less uncomfortable. Still with full lights horn, charging system etc but now fitted with CO2 cylinder in the tail and air shift/ignition kill system that usually reduced shifting issues. 

Carbs now had SteelDragon velocity stacks which looke wicked but didn't make much difference to ET or MPH, but looks count.

Launch was still closer to a supertanker than a rocket launch but getting there - slowly.


Nice new Vanson leathers in 2016 make race days more comfortable, but they don't make the bike any faster.

By 2017, another poofteenth had been shaved off MPH was down a few with the different transmission.  Carbs now had custom made shorty bellmouths, to try to get a few more HP at the very peak of the rev range. Forks were shortened a little more, and shorter rear shocks were added along with a swingarm pinched off a late model GT750B.  It looks almost like a GS750, which was in production at the same time, but with a brake torque arm mount for the old drum brake.

Before the race, the motor was stripped and inspected and all was OK but some of the gear dogs were worn, so the whole transmission was replaced with a suitably modified GS750 with higher first and lower top gears. The higher first gear was better for the 1-2 shift but made it a little harder to launch and the lower top gear set killed top end by 3-4mph. While it was apart, the ports were cleaned up a little but still left as a very streetable set up.

Unfortunately the CO2 high pressure regulator had decided it was hot and bothered and didn't want to play nice.  It caused a lot of missed shifts and much frustration. That will be added to the "to do" list for 2018


For 2018, the carbs have been replaced with a set of 72-3 model slide type carbs to see if that improves throttle response. Stock 74 on carbs are really amazing and are so smooth but maybe they are holding things back - always need a new excuse. The custom DYNA Ignition has been replaced with a fully programmable Ignitech so we'll see how that changes things. It is small and light and easy to program.  With a little cheating, it was able to have a rev limiter, two step launch rev control using the clutch switch, push button shifting with programmable kill time off the horn button and programmable ignition timing.

Given that the limiting factor is the rider those changes may not be enough to make much of a difference, but it's always fun to explore new ideas.