Cyzygy GT750 V Clockwork Orange H2 750

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Cyzygy
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Cyzygy GT750 V Clockwork Orange H2 750

Post by Cyzygy »

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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Craig380 »

Great sounds, there :up: :clap:

11.09 at 120mph is f*ck*ng quick for a GT750 too, especially as it doesn't look like it has been stripped of much weight apart from the stock exhaust system ....
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by titan performance »

Looked like the Suzuki was quicker....hard to tell.
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Craig380 »

Yes, the Suzi took it by a good few bike lengths. I bet the 60' time was good too.
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tz375
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by tz375 »

Congrats Bob. Good work by Flannery and you and your rider. Team work.

Watching the video, I see that the GT had the H2 in reaction time - half a second difference right out of the gate. The RT comes up on the big scoreboards after they leave and they post speed and ET after they cross the line.

I tried one of the online calculators and it said that to do 11 second ET at that speed with a basically stock weight bike would take about 110hp at the rear wheel and probably more than that to be honest. That's impressive power. Hmm. I have a set of those barrels here somewhere - just need a new liner to make is usable. Mine weighs 650 or so with fuel and with me on it. Bob's must be 50-100 pounds more than that.

My best was 12.8 at around 112MPH with stock BS40 carbs, mild tune and JEMCo pipes. Bob's bike is more stock and probably heavier than mine, and a whole lot cleaner and clearly makes more power. And his rider knows how to ride and is probably a whole lot lighter than I am.

When are we going to see 10s posted?
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Cyzygy
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Cyzygy »

GT v H2.jpg
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tz375
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by tz375 »

That's easier to read. So it was only .05 better reaction time and after that the GT just kept pulling away. For a heavy bike, those are impressive numbers. The H2 was slightly better than my PB and the GT is way better. Congrats.
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by jabcb »

Impressive. What mods does it take to make a GT750 that quick?
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tz375
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by tz375 »

Bob can best answer for his bike. I think he has porting and heads from Doug Flannery, stock carbs, probably a GS transmission and who knows what else.

Mine has moderate porting, stock head machined down, barrels decked, stock carbs, CrisinImage cast pistons, stock coils, Iridium plugs and JEMCo pipes. Jemco pipes work really well with a mild tune but are noisy and limit revs. They peak around 7000 to 7200. Mine used to have a home brewed DYNA S but I doubt that made much difference compared to any other ignition system. Mine used a stock early model wide ratio transmission with huge gap between first and second which encourages over revving in first but is fine on the street.

I'd also like to hear what else Bob has done to that beast.
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by D&D CHASSIS »

Bob, what does she weigh with the rider?
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Cyzygy
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Cyzygy »

Richard,
The best 60' time is 1.752, quick enough on the GT v H2 pass to have run a 10. The H2 was .038 sec quicker to the 60' but the GT powered on from there.

jabcb,
Engine mods include, STOCK BORE and STROKE, a Flannery Motorsports ported cylinder block and expansion chambers Dave Derrick was involved it the fabrication of the chambers too I believe, a welded and machined squish band head that I did, HPI self generating ignition, 40mm Lectron carbys.
Bike, without rider, weighs in at around 500lb race ready.
The rider, Brett Copping, extremely good. It is a real balancing act to hold traction with the 400 x 18 rear street tyre and not lift the front wheel excessively high. Brett is 23 years old and this is the first 2 stroke he has ridden at the drags. His own bike is an 8 second naturally aspirated Hayabusa A/SB (Street Bike)
Thanks for your interest Bob.
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Cyzygy
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Cyzygy »

D&D CHASSIS wrote:Bob, what does she weigh with the rider?
Dave,
Bike weighed 501lb race ready and bike and rider was 638lb, last time we raced it.
Bob.
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Alan H »

Cyzygy wrote:
D&D CHASSIS wrote:Bob, what does she weigh with the rider?
Dave,
Bike weighed 501lb race ready and bike and rider was 638lb, last time we raced it.
Bob.
:lol: I haven't weighed less than 140 lbs since about 1974! There again, I haven't been 23 since then either!!!
Think of how stupid the average person is, then realise that half of them are more stupid than that.
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Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Craig380 »

The timing gear doesn't lie, but I'm very surprised that the Kawa rider's reaction time was only 0.046 seconds slower, it looks a LOT longer than that from the video.

Is it possible to run a slick rear tyre in that class? Or might that actually make it harder to get off the line cleanly?
1976 GT380 - wounded by me, and sold on
2006 SV650S - killed by a patch of diesel and a kerb in Feb 2019
2017 SV650 AL7 - naked and unashamed
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Cyzygy
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Location: Over the hill in Fairfield NSW AU.

Re: Cyzygy GT750 V Clockwork Orange H2 750

Post by Cyzygy »

Craig,
The bike only competes at Nostalgia Meets, it runs at street meets and test & tunes for time only as well. The only rules at Nostalgia is "Classic Bike":- Pre 1985. Yes we could run a slick and wheelie bars but we just want a "Street Legal" (except for the loud pipes) GT 750 to run 10 seconds. It is registered for the road, I swap it back to stock pipes for the annual inspection, all lights and horn work. It is foot shifted, no air shifter or quick shifter (no ignition kill).
Alan,
I haven't weighed 140 lb since 1974 either:-(
Bob.
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