USPKS Southern GP | Practice - Ocala Gran Prix - T.J. Koyen | X30/Exprit


(TJ Koyen) #1

On-board of a few laps at Ocala in practice. I wasn’t particularly fast (actually I was particularly slow), but was still getting back into the groove of the soft tire and the X30 power and sorting some other issues. I feel like my driving was pretty much where it needed to be though! Maybe someone can see something I can’t!

Either way, was very refreshing to feel the difference between the MG Red and MG Yellow again. Sometimes you forget the subtle differences when it’s been a while, but I was really able to feel how different the Yellow was to drive at the limit.


(Jim Maier) #2

Here are some Mini Swift laps. Right up until the wreck and bent throttle pedal that stuck wide open.


(Dom Callan) #3

Looking good, I think. That series of concentric turns is brutal and it has a switchback with squared off corner. That looks intense.


(Davin Roberts Sturdivant) #4

Super interesting watching your steering work. I’ve been putting a ton of focus on improving my steering input to help the kart work better, so it’s interesting to watch someone else’s.

Question for you. Do you have a hub spacer on your steering wheel?


(Alan Dove) #5

How far off the pace?


(James Lundberg) #6

Out of curiosity, how different do the Reds and Yellows drive in your opinion? How does your driving style change between KA and X30?


(TJ Koyen) #7

Yeah, it’s the angled hub with an additional angled spacer in there. I can’t remember which one, I’ll check. Edit- I checked, it’s 20 degrees total.

About .5 in this session. I got within .3 in the final I think, but mostly it was .5+ off-pace.

The driving style with KA on Reds vs X30 on Yellows is similar actually, but the difference comes with the limit of the tire. The Red is more forgiving. You can over or under-drive a little bit without too much penalty. With the Yellow, the grip limit window is much narrower, so it’s easier to drive in too soft and set the inside rear down early or drive in too hard and get the kart out of shape. With the yellow you just have to be a little more precise.


(Noah Koenig) #8

Kart sounds tight in the hairpins. Especially the first hairpin. I bet that new patch doesn’t help you any. Overall, though kart looks pretty good.


(TJ Koyen) #9

Kart was flat all weekend. 4 axle changes, 2 seat changes, 2 ride height changes, 2 bar changes, 2 caster changes, and 1 entirely new chassis and couldn’t get rolling. Ocala be like dat sometimes.


(Dom Callan) #10

Engine makes a very weird noise at 1:07. Not sure if just distortion on audio.


(TJ Koyen) #11

I think you’re hearing the tires chirping from braking.


(Dom Callan) #12

You may be right, blends into the down shift noise, making it sound metallic.


(Davin Roberts Sturdivant) #13

Can’t really downshift on a single speed. :wink:


(Dom Callan) #14

The noise it makes under heavy braking as the clutch does its thing… you know what I mean. Awooogah.


(Nik Goodfellow) #15

Its probably better informed by the data you have but it looks like you have a gentle flick, then straighten up then have to turn again in the medium to slow speed corners. Probably indicative of the rear staying flat.

Could you drive harder into the corner and use the front more to slow it down and get it on the nose a little.


(James McMahon) #16

It’s rarely the clutch with these super low stall clutches. Its cadence of the wheel/axle speed changing with braking as the wheels scrub.


(TJ Koyen) #17

That’s a good observation I think. The kart for sure wasn’t lifting like I wanted, but it’s possible I wasn’t quite driving at the limit I needed to be to get it to work properly. Maybe I needed to charge corner entry a little more.

I think I was leery of that because I have a tendency to drive the front tires off when I start pushing too much like that.

I tried to watch my video compared to Norberg’s video from the Winter Series there and based on my quick frame-by-frame breakdown, our braking points and throttle points are almost identical, but he is apexing some of the tight stuff a little differently than me, and that could be where I needed to change something.

Ocala is just a track that hasn’t clicked with me yet. The surface isn’t what I’m used to and the track never feels grippy to me, so maybe being that it’s not a typical track for me, my usual “drive-under-the-rubber” technique just wasn’t quite working the way it does on other tracks.

The plus side of being a long-term friendly guy in the sport is that some guys who were faster that weekend are willing to share data with me so I’ll have some stuff to review this weekend.