Weight's effect on go karting lap times.

[Tim.Wright]

I think the main variable in hire karts is the engine performance. Since you are power limited practically all the time, any disadvantage you have in weight or engine tune will be quite significant.

[jz11]

front setup has huge impact too, I would say even more than 5-10% difference on the engine power (subjective), I once was given a cart that was 1,5sec slower on 50sec lap than the cart I was in just before that, and it noticeably wouldn't turn in to one side, got out, and noticed that there was almost zero caster angle on one side in the front, which pretty much explains why it handled like crap, no caster angle = no wheel height change at the front on turn = no jacking at the rear = no turn in into tight/medium corners

turned out, after talking to a mechanic there, the crap cart had an accident the day before, and they didn't have the right spares to fix it, so it had some odd steering arm that wasn't the right length, or the knuckle itself was from something else, can't remember, and it was impossible to align the front with proper caster/camber on both sides

after that I gave up on rental carts altogether

[Manoah2u]

+2 on the rentals.

Offcourse for a fun day of karting, it's not done to have to buy your own race kart in perfect shape.
Unfortunately, your fun day in karting gets trashed because of the seriously inferior and mangled material at hand
at most indoor centres.

I've been to a indoor centre in Delft, Netherlands, its quite 'popular' but the material provided there is absolutely
below acceptable. Leaking fluids (over the tires actually), damaged steering racks, half-functioning clutches,
and the personnel is even more below acceptable. Heat got underway and 3 karts stalled instantly because they had
NO FUEL!

I went to Zoetermeer after that, as i've read they had the newest material, and indeed - that was a huge difference.
However, these things get 'trashed' just the same because there are enough people around that simply do not know what the hell they're doing. Atleast in Zoetermeer (NL) the maintainance level is higher than in Delft (NL). I'm never ever going back to Delft, even though i really enjoyed the track. Shame.

I've come to the experience though that you haven't really felt like karting untill you actually went out karting outdoors in a 'real' kart [not such a half-assed rental kart]. You don't neccesarily have to buy one, there is enough market available to find a way to not having to pay thousands on a 'decent' kart, it'll offcourse be a lot more expenseive compared to indoor trashing though.

[PlatinumZealot]

Doesn't this thread belong in the other automotive news and technology forum? Massively off topic.

[allsmiles]

weight in karting has a massive difference especially on the arrive and drive karts

i started out doing the indoor arrive and drive karts which are about 6hp and i got pretty good on the corners but i found as soon as i got on the straight i would get overtaken by the lighter drivers(i weigh 125kg, other guys i have raced weigh around 70-80kg) altho i find myself catching them effortlessly around the turns and under braking

acceleration is affected mostly, if a track has a slow corner then you basically have no chance due to having to accelerate out of the slow corner, you end up having to take odd lines to try keep the momentum up which leaves you exposed for a overtake on the inside, even worse are the indoor tracks that have steep hills, the karts near enough cut out when you get to the top while the lighter drivers fly up them

indoor karts are overgripped and underpowered and do not test a drivers ability much, and any sliding will just destroy your momentum, indoor karting to me is just for giggles and banter tbh and the karts are never equal, i can usually still do very well for my weight with my fastest lap usually just being over a second slower, obviously it depends on track

i ended up buying my own kart with around 20hp, much faster and better maintained and they actually have the power to move you quickly even if you are very heavy like me, i found the lighter people who have beaten me on the indoor tracks cant keep up with me on the faster karts on the outdoor tracks

[Tim.Wright]

The general equation is this:

The less power you have, then the more often you will be power limited on a given track.

The more you are power limited, the higher your mass sensitivity on laptime.

[CapitalKarts]

Weight plays a big role, especially when you say you've already got the cornering down. Most time is made up in the corners so if you are already doing that optimally then it's going to be difficult. Just wondering, who in the end had the quickest time.

[The Chairman]

I have found in the past that any hire karts are more dependent on the tune of the engine, the quality of the fuel and state of repair of the kart than driver weight or ability.

I am one of the owners of Hi Voltage Karts in Melbourne, and we run electric karts. These karts weigh roughly 275kg before the driver gets in, and they also run a differential. They run a 4kW electric motor. As electric motors have torque from 0 rpm and they are very even between karts in the output, there is little performance difference in the karts themselves.

The weight of a driver does not have a huge effect on the performance of these karts. We have had drivers around 130kg outperforming drivers of 80kg. Our track is roughly 300m and I have a pb of 28.540 sec and I weigh roughly 105kg. We have a female racer who is one of our fastest customers that weighs roughly 50kg. She has done over 50 races at our track, so she is proficient in the karts and on the track. Her best lap time is 28.617 sec.

The differential means that there is no longer the requirement to lift the inside wheel to get around the corners, and these karts actually promote smooth, but fast, driving. They handle more like a race car, than a kart.

The electric motor having torque on tap from standstill means that there is not as much of an emphasis on keeping speed up into the corners. These karts are also direct drive, so there is no clutch to worry about. If you put your foot down, the karts go. With the direct drive and the torque, the karts can spin the wheels in the corners, so being patient on the throttle is the fast way to go. Slow in, fast out is the way to get a fast lap time here!

[munudeges]

Let's just say, extreme weight loss, borderline anorexia and bulimia and balancing that against being physically strong enough are a huge part of karting competitively, they have been forever and they will continue to be. Even when you have minimum weight limits a low centre of gravity is vitally important.

[V12-POWER]

Lighter = faster

In real karting you don’t need to be 80kg to move the kart around. You can change how much inner rear lift you get by adjusting the caster or widths.

This is why the 15 year olds are straight away quick in the transition between OKj and OK they run very close to the minimum weight, heavier drivers while still as fast as them, have extra unnecessary weight and often have a plus of 5 or 6 kg above the min weight at the end of a race

[kebab]

Weight is very important in any form of racing including kart so that's why in competition there is minimum weight applied for each category.

More weight would cause you to brake earlier and hamper your exit....and yes weight affect cornering ability as it affect frame flexibility which is very important for cornering.

There are many ways to play with the frame flexibility which some of you have mentioned above but don't forget that changing the stiffness of the rear axle would help and event the stiffness of the seat plays its part too, and of course many more.

[lederpina]

actually, if you are heavier your kart will be faster.. its called momentum.. ask any junior high school child to explain.. ever wondered why a stone drops faster than a piece of paper even though they have the same force of gravity propelling them? its called MOMENTUM. i literally smoke everyone at my local track and i'm 180 KG

[NathanOlder]

actually, if you are heavier your kart will be faster.. its called momentum.. ask any junior high school child to explain.. ever wondered why a stone drops faster than a piece of paper even though they have the same force of gravity propelling them? its called MOMENTUM. i literally smoke everyone at my local track and i'm 180 KG

Thank you.

[Rodak]

actually, if you are heavier your kart will be faster.. its called momentum.. ask any junior high school child to explain.. ever wondered why a stone drops faster than a piece of paper even though they have the same force of gravity propelling them? its called MOMENTUM. i literally smoke everyone at my local track and i'm 180 KG

Momentum has nothing to do with it. In a vacuum the paper and the rock would drop at exactly the same speed; air resistance, which is effectively mass density, is the deciding factor in an atmosphere. The rock would have more momentum (p = mv) and more kinetic energy (KE = 1/2mv²) but they would have the same velocity. While it's true you at 180 kg will have more momentum than a lighter person at the same speed you will also accelerate more slowly (v = at) for the same power.

[lederpina]

Ok so the acceleration is slower but that is very small difference.. the key factor it reduces down to is this: [/list]the ice ball reaction.. which demonstrates that once things start moving they are hard to stop and I plough through them