This is in response to the thread further down. Kezz / Sam - the Zip Storm is a good chassis, but needs some setting up to get it to go well.
The dry settings (with a 2 stroke engine) that I have found that work for my lad are:
Front end: Loosen off the upper fixing points for the top bumper bar. Set your wheels parallel with approx. +1 to +2 degrees of camber (should be built into the chassis) using just the standard top hats (recheck with driver in seat to see that this sets at neutral - adjust if necessary). Set to middle front ride height. Use the inner tie rod mount points on the stub axles and middle hole on the steering column. Wheel offset 15mm.
Seat: Use a flexible Tillet or Iztec seat - set the bottom of the seat level with the bottom of the chassis rails, seat set evenly spaced between the rear supports with spacers if necessary. The rear lip position needs to be measured from the axle - check with Zip / Tillet / Iztec for the dimension (I can't remember off hand!). Adjust the pedal position to fit the driver, not the other way round as this will upset the front / rear weight balance. Use a flexible carbon floor tray if funds allow !
Rear: Use a soft or standard 970mm axle at the mid ride height. Short wheel hubs, set at the circlips. Make sure that the bearings move freely in the mountings. Uprated brake disc helps if funds allow - the black standard pads are fine. Engine sits evenly spaced straddling the rear offside sidebar mount.
Wheels / tyres: Use the Comer wheel rims. Tyre pressures at 24psi all round to start with. Increase 2-4 psi if very cold, decrease as the track temperature increases.
Side Pods / bumper: loosen off all bolts to get everything rattling - put some ties on to make sure the rear bumper doesn't fall off. Use nyloc nuts or tape around them to stop them undoing.
Balance: Adjust ballast to get approximately 60/40 balance rear to front weight using 4 bathroom scales (with driver fully kitted up in set) and 50/50 left to right balance - don't get too hung up on this though as it is virtually impossible to achieve exactly.
These karts tend to be a bit stiff and a bit less flexible as they get older, hence the settings above to help induce more flex and allow more rear flex. They tend to 'grip up' very easily as the track cleans up / rubbers up through the weekend, or the weather gets warmer. This causes the rear inside wheel to stay planted longer in the corner, resulting in the engine bogging down - losing corner exit speed and thus restricting the maximum speed that is achievable at the end of the following straight.
It sounds like you may have everything set up a bit 'stiff' resulting in your pace slowing over the weekend as everything grips up. If you have a mychron, use a computer to look at the rev traces from the beginning of the weekend compared to later on to see if the engine is dipping its revs more in the corners or failing to get to top revs by the end of the longest straight.
Also remember, you lad is only 8 yrs old. Karting is very physical and hard work for these small chaps over a long weekend. Make sure that he rests between sessions. Keep him fed and watered properly and early bed on Saturday night !!
I hope that this is of some help to you (or anyone else) or at least gives a basic neutral starting point to set up from. Make adjustments from there if necessary but only do one at a time.
If all else fails, take my lad's advice: ' DAD - LEAVE IT ALONE ' !!!!! (the kart that is before anyone says anything..) ;)
|
|