How much time is a KG worth?

Topic for discussion

In your experience how much time has a KG been worth to you.

Myself I am currently 15kg overweight in KZ and approx 6 tenths off the pace in the dry. In the wet I find no pace issues, if infact on my local track im usually the quickest in the wet.

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Depends on the usual conditions: track configuration, tire, etc., but here in the US we usually see a gap from KZ Pro to KZ Masters no closer than 1 second, and they are usually 15-20lbs different. Using that as a reference point, I’d say you’re doing a pretty good job. Time to cut some weight and win some races!


There’s no real linear relationship between a unit of weight\mass and time.
But, 15KG (33lbs) is a pretty big penalty on a typical kart track. If you happen to run on longer faster tracks, the penalty isn’t quite as severe as the power to drag ratio becomes a larger factor compared to power to weight

Time to unleash the beast!

Some positive feedback guys!!!

I’m really at a disadvantage so! I’ve 4 months before the season kicks off again so this looks like my best area for improvement!

You could always add 15kg and see how much that adds.

It does depends on where you add it though. I know my CG is too far rearward because my handling improves when I add 5lbs of gas. This doesn’t mean I’m faster because it’s heavier, it means I’d be fastest if I moved some of my ballast forward rather than running a full tank.

Compare Davide Fore’s laptimes in Pro Shifter to Davide Fore’s laptimes in Masters Shifter.

He’s on an ItalKart with a TM on Evinco Reds in both classes.

Unfortunately this year’s SuperNationals comparison is a bit off due to Cap’n Skusa’s Oops All Straightaways layout this year.

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Less affect being in a shifter kart compared to a cadet kart also with the horsepower.

You’ll have more stability with the extra weight, but no doubt acceleration will be hampered.

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Not a bad comparison. But Fore was on an R1 in Pro and an R2 in Masters. His primary focus was on winning Masters.

A well-prepared R1 and R2 are going to be nearly identical. Also, while I don’t know Fore personally, I highly doubt a multi-time world champion is going to enter into any race as a throw away. That dude wants to win whether it’s Pro or Masters.

The main counterpoint to Charles would be the difference in track conditions between Pro and Masters sessions. Otherwise the Fore comparison is about as apples to apples as what you’re going to get.

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There was an article on TKart that was about making the kart lighter with some carbon stuff…

They say something in this range… about 2-3 tenths more per 5 kg extra.
I guess that’s on an FIA/CIK track…
That’s on a single speed if I’m not mistaken…

My rule of thumb is 0.15 per lap for every 10 pounds you are overweight. But of course will vary on track length and layout. But generally that’s what I’ve found.

My jump between senior(360lbs/163kg) and masters(385lbs/174kg) weights on the same day during practice was 0.5-0.6 seconds on ~50 second laps. All of it lost mid-corner, Rotax is pretty punchy out of corners so I didn’t lose much on the straights.

That’s also about where I’d put it for KA & X30 from our own observations.