Tight or loose??

[Jean Stafford]

I'd like some feedback on what people mean when they say a Kart is loose or tight.

I've understood that loose is fast, but my idea of loose seems to differ from others.

What's your take on this subject.

[Mike Walpole]

Seeing how your kart handles great at night races I'd say it's generally too tight.

The problem I believe is tight can mean two different things. Tight can mean understeering or it can mean too stuck to the track. I believe most karters mean tight is too stuck to the track. Opposite of that kind of tight is free.

Loose usually means oversteering, which too much of is not a good thing. The tires we run don't like a lot of slip angle, even the SL4s. I got my kart too loose the race before last, it was not fast and it was a handful to hang onto. I know Jean got a good look at that too.

I think what we are looking for is to have the kart run free through and off the corners. Personally, I want a neutral kart. I want it to turn in and I want it to hold on exit and carry speed off the corner onto the straight. Unfortunately, I haven't found it yet either as I am generally too tight also.

I got a good education of how far off my kart is this last Sat. night when following another kart through the barn turn at Camden. The other kart was in the wrong position to make the RH kink onto the back straight and I was on the right line. I should have been able to roll on the kark since he had to pinch the right hander. What happened is he went through on a bad line and still pulled away from me. His kart was more free than mine and the difference was dramatic!

[John Valerio]

Jean,
I have found the best results with my chassis being neutral(Invader Proworks). I have drivin loose and tight and in either application the karts handling seems to change during a race. My definition of tight is when the chassis binds up or bounces in the corners both entering and exiting. and loose would be mostly talking about the rear end and lack of grip both entering and exiting corners. The nuetral set up I have seems to be very predictable and consistant through the whole race. By the way we run on YDS tires.

just my 2 cents:-)

John Valerio

[S. Clark]

We just had this discussion in our shop and we dicovered that when some people were saying loose or tight - they were refering to the chassis set-up (bumpers loose ,soft axles,chassis bolts loose etc.)and so it was confusing the people that meant loose or tight in regards to over/under steer . So now we are trying to to use "loose or tight" for handling and "soft to stiff" for chassis .Anyway, helps me understand what people are trying to explain a little better .

[Mike Walpole]

S Clark: That's a hoot - "I made my kart loose and I 2-wheeled!"

I look at loose & tight as oversteer and understeer. I still catch myself saying the kart's too tight when I mean its too stuck to the track.

[Mike Walpole]

Bob - I'm with you. However , tight is used as understeer and too stuck to the track.

IMHO - neither is good. Understeer means you get to see what you'll hit and too stuck means hopping, 2 wheeling and not getting off the corner.

Loose is generally faster than tight since it lets the kart run free off the corner, but I don't believe it's optimum because the kart isn't balanced.

Having said that - I think it's better to try to tighten up a loose kart than to try and free up a tight kart.

[Bob Chiras]

Try two simple definitions:

Tight -- the front of the kart hits the barrier first

Loose- the back of the kart hits the barrier first

Now adjust the vocabulatory with these in mind.

[Vernon Head]

Can someone explain what too stuck to the track means?

[Mike Walpole]

Vernon - my understanding is that being too stuck to the track means the kart has the wrong kind of traction. This kind of traction robs power from the kart and makes it slower off the corners. Sometimes a driver will say the kart feels all bound up. Some drivers will say the kart feels too tight because sometimes a kart that is doing this takes a lot of effort to turn the steering wheel and it may feel like the driver is fighting the kart. (With the kart winning ) Other symptoms are hopping and 2-wheeling.

I believe this has a lot to do with the way the kart picks up and carries the inside rear tire around a corner. If, for example, you can't get the inside rear off the ground on corner exit, the drag of the rear wheels fighting each other will not allow the kart to accelerate as a kart that can get the inside rear off the ground. I'm sure there are other ways this can happen also.

IMO, I believe a kart that is neutral and free is the best. The kart needs to be quick all the way through a corner to be really fast. An understeering kart won't be free because of more drag off the front tires. A kart that is loose is better, but the rear sliding around too much will scrub speed too.

I know the kart I've raced all year is too tight coming off the corners because it understeers a little. When I move the seat forward to make it turn, it hops badly and 2 wheels. Not fun. I'm looking for another kart that will work.

[Alex Williamson]

Mike,

I know where you can get one!!

[Mike Walpole]

Alex - then you know I'm driving the wheels off what I got to finish where I'm at. And yes, I do want to try the kart you are talking about.

[Vernon Head]

How can a racing vehicle be gripping the track too much? Isn't that why we use such soft rubber? I can see hopping being a bad side effect of grip, but if the kart is gripping really well, why would you want to make it grip less?

It would seem to me that the higher the grip the faster you can go, barring any oversteer/understeer problems.

[Rick Crow]

Vernon, too much grip is more of an issue with a single gear kart. When the grip is too high the engine looses alot of RPM in the turn and slows your exit(AKA Binding), In a shifter kart you have the mechanical advantage of the gear box to help overcome the high grip of the tires

Rick

[Mike Walpole]

It's not that the kart is gripping the track too much, it more that the kart is gripping the track incorrectly. In a low HP/weight kart this condition robs speed off the corner exit.

All things being equal, except handling, a kart that is tight or bound up coming off the corner is not going to have as much speed down the next straight.

Let's back up and say we both have karts that will run 30 mph through the middle of the corner. However, my kart is free on exit and your kart is tight. I exit the corner at 35 mph and you exit at 30 because your kart is so stuck to the track that it takes all the available power to keep it moving at 30 mph while turning the corner. That's a lot to give up, bit I can guarantee it happens.

That example is a little extreme, but the reality is 1 - 2 mph difference coming off a corner is a lot. If you have data aquisition and can do splits, you will really see the difference. It can make .2-.3 sec on a long straight. Do that in a couple of places and you are .5 - 1.0 sec a lap faster. Using the average speeds of more sprint tracks, .1 sec is 6 to 10 ft. per lap.

Back to the original subject, being too stuck to the track is slow - in any kart. More horsepower can mask it, but it's still slower because it's harder to drive.

[Scott Davis]

Vernon, it means your kart is not sliding like it should. Instead of sliding it is gripping to the track too much causing more friction.