This Monday was one of the first hotter days of the year at GoPro Motorplex and the track was didn’t have much grip. Even so, as I was dialing in grip, the kart began to bog on a few corner exits. So I’m looking for some set-up advice – essentially how to free up the kart on exit.
Some info on current set-up:
CRG Kalifornia, Bridgestone YKCs (stickers), Rotax SN
46″ front width, minimal castor, med-low front ride height, torsion bar flat.
55″ rear width, short hubs, 50mm M20 (Med) axle, highest ride height.
Things I tried:
– Front bar to vertical
– Rear bar in (flat)
– rear width to 55″ (was 54.5″) which helped settle the rear but possibly tightened the front on exit.
My turn in was mostly positive but a bit loose in the rear (track conditions that day I assume). Mid corner good with a little hop in some high speed corners, exit of the slower corners the kart felt good but would bind the engine.
Any help advice would be appreciated.
Did you try without the rear bar at all?
Typically things that will make the kart turn-in better will conversely hurt your exit. This is because inducing better turn-in requires quicker inside rear lifting action and therefore also quicker set-down of the inside rear after turn-in. This results in a flat kart on exit, giving you a bog.
Hopping results from too much lifting action too quickly. So your narrower rear track width might help the kart keep the inside rear wheel off the ground more easily, but would have increased the amount of hopping you were feeling if you narrowed it too much. In a fast corner, you have more force on the rear wheels so you can overload them more easily and get a hop.
My suggestion would be to split the difference on the rear track width to 54.75″. I’d also recommend a little negative camber. For me it usually helps the kart point into the corner and carry the inside wheel longer through the turn.
Thanks TJ. I was hoping to get someone like you to chime in on this. I’ll try the camber adjustment and then start narrowing the rear incrementally since I’m at the max now.
Good plan. Let us know how it goes.
Will do. I haven’t gotten back to the track, but I wanted to let you know something you said clicked.
“Typically things that will make the kart turn-in better will conversely hurt your exit”
That’s really good info. With the lack of grip on the track, I was really focused on entry. When I had the entry working well, the push on exit became an issue. I do think the rear was lifting too quickly – and therefore down to soon.
None the less, really valuable words there. Thanks again.
You must be logged in to reply to this topic.