Let's talk about Seat Position

(Liam Sergeant) #83

Hey Marin,

Thanks heaps for that!

I’m running Carrs Rd (Canterbury) and currently have a set of Vega (Open?) tyres on until they wear out and I’ll get the Dunlop’s. I definitely had issues getting the tyre pressures right the previous few sessions. Last time was pretty good and I felt a lot more confident.

I’m still 2 seconds off the pace so I know there’s lots and lots of improvement before I’m anywhere near the karts limits.

(Shawn O'Hara) #84

What cold pressure are you starting at with the vega’s? 9-10 is what I usually start mine at in the KZ.

Honestly the Canterbury track is bumpy as all hell and definitely the worst NZ track iv’e been on especially the section of turns that runs between track entry and track exit so i’d say expect to be loose through there

Come try Blenheim or Nelson. Much nicer…

(Liam Sergeant) #85

I’ve been struggling to go with the “correct” tyre pressures. I tried starting low and found I had no confidence/grip, then I put them up around 16 and they were better but also skittish.

Last time out I worked on getting the tyre pressure in the pits to down to 11psi after starting at 14psi. I found 12-13 to be grippy but my rear would get more over street towards the end of each session.

I have my front set to 15mm spacers inside hub (was previously 20mm) per side, and rear track to 1395mm. Is that what you mean by set up?

(Marin Vujcich) #86

15mm front ok.
1395mm too wide. 1380-1385mm. Your tyres getting worse in sessions suggests too high pressures. Unfortunately driving fast on cold tyres at correct pressure is an art in itself and took me a few years to be comfortable ragging to first couple of laps with a super loose kart.
Next time at track weigh your front and rear on weigh scales (if floor is level with scales) to get split weight. 58/38 is the starting point with these chassis.

(Noah Koenig) #87

Yes, that is what I mean. These measurements are standardish for the kart. I agree with Marin that your pressures are a little high at the moment. Driving with cold tires is a valuable skill that all the front runners have. It takes time to learn that though.

(Davin Roberts Sturdivant) #88

Seems like a little more seat time on cold tires might be more helpful too, just to get used to the kart in a wider envelope.

(Jonthan Stewart) #89

I really believe this is something that new drivers should be aware of. This is one of the biggest things I’ve been struggling with. At best I can be 0.5 seconds off the leaders, but the first few laps I am all over the place.

What do you mean here? 58 + 38 doesn’t add up to 100. My kart is 58% rear, which means 42% front.

(Dom Callan) #90

I.struggle with getting to Pace on cold tires too. I suspect experience will be the answer

(Marin Vujcich) #91

What do you mean here? 58 + 38 doesn’t add up to 100. My kart is 58% rear, which means 42% front.

Geez, and I’m a engineer. Scary aye.
Yes 58/42

(Andy Kutscher) #92

Gents, bumping this back up for a quick question.

Mounting a seat on my “new to me” Tony Kart 401. The seat placement guide for OTK is pretty good in my opinion.

If i went directly off the guide I’d place the seat at 625/630, and 5-10mm below the chassis rails. I even got an OTK seat to keep things simple and take as many variables out of the equation.

The question is in regards to a blurb in the OTK guide that says to move the seat back 10mm for “hard tires”

We run Bridgestone YLC’s which I believe is considered a pretty hard tire in the grand scheme of things. So should I go 635 /640 based on the hard tire?

I also almost got down to my target weight but not quite, I do fit in a size 3 seat vs. the 4 I thought I was going to have to be in. any additional considerations for being fat other than keep the seat low to minimize the effect of the weight on the kart?


(TJ Koyen) #93

The YLC would for sure be considered a hard tire in this case, so I would probably go for the 635 measurement, see how you feel in that, and adjust if you think you need to.