JA - KT100 vs. World Formula

Brian Garfield · Posted: Sun Sep 09, 2012 8:48 am Post subject: JA - KT100 vs. World Formula

For those that care, we had an opportunity at the SCCA Solo Nationals to do a true comparison between the the KT100 and Briggs World Formula in SCCA Solo JA class prep. Kevin Teague (2nd place at Nats) was nice enough to offer Julian Garfield a test run in his BWF and since Julian had never driven a 4 stroke before.

This was possibly the best opportunity we've ever had to do a side-by-side comparison. Here are the details:

Driver for both karts: Julian Garfield
Course: Solo Nationals Practice Course
Kart 1: National Championship winning Arrow AX-9/Sean Cook KT100
Kart 2: 2nd Place winning CRG/Briggs World Formula
Weights: 295lbs in BWF (10lbs over) / 310lbs in KT100 (5lbs over)

Process:
Julian ran his KT100 for two runs to set a bar and get used to the course. Unfortunately, the timer didn't work correctly, so we knew he'd have to come back to it. He then jumped into the BWF and ran two runs, the faster being a 28.8xx. He jumped back into his KT100 for one run and ran a nearly identical 28.8xx.

Of course this isn't perfect, but we knew it was possibly the best opportunity we'd ever have. Clearly, at the given weights, the karts are pretty well matched. Longer courses and different types of courses could change things, but at least this gives you an idea.

Brian

Joe Ricard · Posted: Sun Sep 09, 2012 10:45 am Post subject:

That's pretty interesting Brian. That's about as good of a comparision as possible.
Congrats on the JA win.

Blueprinted WF?

I guess it falls to the driver and tuner after that. Which is really where the differences are made.
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Arrow AX-8/ Rotax Sr.

Chris Teague · Joined: 03 Sep 2011 Posts: 6

Brian,

Thanks for having Julien try both karts. It's good having this data point. I talked to Julien afterwords about our kart, and it was good getting his feedback.

Joe, the WF motor in our kart was new in late 2004, and we ran it through the 2011 season including Nationals last year, where we realized we were down on power. In Jan 2012 we had Nash's Karts freshen the motor up, and he also found the clutch was shot, so that was replaced also. Both Kevin and Kencey noticed it was much improved after that. It already had the newer ignition upgrade back in early 2011 that comes standard on the newer BWF motors. Kevin being 16, and 5'10' weighed in at around 316lbs or so in our kart, so I'd say the BWF is better if you can be close to the 285 minimum.

Chris Teague · Joined: 03 Sep 2011 Posts: 6

A note on gearing: I think both karts were geared as they ran on the east course. So not optimum for the test and tune, but I think they were roughly equally not optimum, and probably not far off perfect for the test and tune.

Scott Boito · Posted: Sun Sep 09, 2012 5:24 pm Post subject:

Great data point. Looks like the weights are pretty close to where they should be for parity.
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BetterOffRacing
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Tom Reynolds · Posted: Mon Sep 10, 2012 2:02 pm Post subject:

Keep in mind parity might not be the objective from an SEB perspective. I do appreciate the data.

Joe Ricard · Posted: Tue Sep 11, 2012 4:40 am Post subject:

Tom Reynolds · Posted: Tue Sep 11, 2012 6:07 am Post subject:

Roll your eyes but that doesn't change people complain about 2 strokes.

Larry MacLeod · Posted: Tue Sep 11, 2012 7:14 am Post subject:

Can I lobby a complaint about the sound of a Dodge Neon with a straight pipe? I think they're way more offensive than 2 stroke engines.
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Old Birel/ hodgepodge Honda CR125
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Tim Walsh · Posted: Tue Sep 11, 2012 7:17 am Post subject:

Tom Reynolds · Posted: Tue Sep 11, 2012 7:25 am Post subject:

Jason Vehige · Posted: Tue Sep 11, 2012 8:20 am Post subject:

IMHO ... As in my personal opinion.. A 2 stroke shifter sounds great... a KT100 not so much.. But that is not a good reason to exclude the KT as long as FM is around Laughing

the one legit argument against the KT from a non parent perspective is their propensity to stall when spun and the fact this requires a starter to be taken out on course, worst case if a WF stalls is to have a worker pull start it (assuming it is not setup to TAG) and they rarely stall. I for one am happy parents still have a choice at all.

If .. Or should I say when I get my Nephews a kart for FJ it will be a WF .... I LOVE 2 strokes but the WF is the clear easy button for me. in B trim the clear choice performance wise and gets the job done in A as well.

thanks for the info Brian.... I appreciate the time and effort you and Chris took to make this happen.
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Jason Vehige

08 Gillard Charlotte / SGM sl204
05 Vanspeed Sirio / SGM sl204

Tim Walsh · Posted: Tue Sep 11, 2012 10:12 am Post subject:

Did Julian comment on left hand turns versus rights? I know the BMF is heavier, but is it heavy enough to affect the handling?
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Chris Teague · Joined: 03 Sep 2011 Posts: 6

Julian Garfield · Posted: Wed Sep 12, 2012 5:20 pm Post subject:

I hadn't noticed any handling changes linked to the direction of the turn when driving the WF. Since a lot was new to me when driving the kart, the only way I think you'd notice is if you put both motors on the same chassis. To answer your question, if there is a difference it wasn't big enough to feel immediately.
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Arrow AX9-4S/KT-100 - SCCA Solo