Cat SX3 grip roll and high speed instability

[Gavin Collingwood]

I've been on here before trying to sort this out and I'm still struggling, I race at bury metro which is very very high bite astro and I can't seem to fully get rid of grip roll. Mostly at high speed and sweepers. I've been running schumacher yellow mini spikes with the outside row cut on the rear and the inside and outside TWO rows cut on the front. My oils are 40 on front and 32.5 on rear I'm running a 4.5lbs spring on the front and 2.5 spring on rear and running 3 hole rounded pistons with the rears drilled to 1.6mm. The front shocks are on the middle hole on the tower and outside on the arm and inside on the rear tower and outside on the rear arm. I'm maybe thinking using 2wd fronts to take away the grip but I'm not sure if its just the front causing it to roll or rear aswell? It's very frustrating as otherwise the car feels good
Any help would be appreciated
Gav

[mark christopher]

Ride height?
Do others suffer same?
Using too much lock?

[Gavin Collingwood]

Well yes others were struggling a little but less so. Was running 19 mm so it was low, now the steering rack I would like to shorten the links as the Ackerman on the inside wheel turns further than the outside wheel too much in my opinion and may cause it to get snatchy anyone know of a trishbits/rude bits type of steering rack that shortens the steering turnbuckles that may help this?

[Chrislong]

Gavin, you know if you lower and stiffen the car so much the car can just snatch grip roll rather than chassis roll, especially if you are limiting droop by using outer hole on wishbones. See if you can find a Cockerill or Moss setup for Southport/Stotfold (also high bite Astro) and try that.

[Gavin Collingwood]

But surely if you have more roll you'll produce more grip and then roll even more...?

[robstanway]

Gavin,

I've got an SX3 setup that i used at Southport... I'll send it to you when i have chance over the next couple of days - If you PM me your email i'll attach it.

You will defiantly benefit from un-cut staggers on the front, it just doesn't look the best.

Depending on the oil... I used 32.5 losi in the back with 4 hole pistons and 45 oil in the front with 3 hole pistons, black roll bar on the front and possibly run the shocks on the outer hole on the front wishbones, I also found a slightly slower servo with the expo reduced helped a lot.

try using the core 4 lb springs on the front they are less aggressive and compact at a slower rate. I also found running the car lower helped me with the grip roll situation.

Hope this helps....

Rob