XRAY - Model racing cars

I recently lowered my rear roll center with the Xray Quick Roll Center on the shock tower to the inner lower position. To increase the upward angle of the link. Also took 1mm off the standard 4mm of shims between the hub and link. It worked well and gave me much better cornering ability. It certainly worked a treat to give the rear more grip. The car is much much better but it still turns a wider arc (or pushes/understeers) coming off power on entry and mid corner in the high speed sweepers on a high grip hot ashphalt track. I do like how it works now on the slower corners!

The car is an 011 T3 and basically a standard Xray set up except with Xray gear diff with 1000wt oil and ECS drive shafts on the front and 1mm ackermann. Is there any way I can fix this problem without sacrificing the rear end set up I currently have? Should I try lowering the front roll center now? Is putting a stiff gear diff in the front the best option? Heavier rear diff oil maybe? Laying the shocks over or standing them up doesn't seem to help much. I get alot of conflicting advice at the track and Im usually left scratching my head thinking wtf

I found that adding bump steer helped with mid corner, but I don't think that will help with the corner entry.

Skiddins

Hello,

do I understand that right when I say that you enter the sweeper full throttle and between you have to lift a little for getting rid of understeer?
If you feel that your car has really plenty of traction and grip in the rear you should try a harder rear ARB. But, how ever, if it's understeering hardly on power in mid corner and corner exit you are probably too hard with your front ARB as well. I would start with a stiffer rear ARB and add a softer front ARB (if still needed). Also you can try a little less front droop.

Whether you select a harder or softer front or rear ARB depends mostly whether you have on- or off power issues.

Thanx guys, I think the issue is off power push just after corner entry of high speed sweepers. If I go through the corner fractionally slower but stay slightly on power the car will steer the arc of the corner nicely, but it is too slow. The sweepers are at the end of a full throttle straight and If I attack the corner more aggressively, as soon as I'm coming off the power just after corner entry - mid corner the car won't quite hold the arc I want it to turn in at. It has a tendency to want to go wide. The corner is shaped like the number 6. As I said the car is fine on the rest of the track which is slower and more technical.

I've never used different arb but will try what you say and also bump steer is definetly something iv'e overlooked and will make sure its eliminated. Downstops Ive been using 6mm front 5mm rear and will try less in the front. Is ackermann also an issue? I'm using a 1mm shim but thinking I should try 2mm but I don't want to mess with the cars abilty on the rest of the track.

Better try Skiddins advice with the elimination of the bump steer first and try different ARB. Just don't try too much different things at once so you better can point out which change(s) helped and which not. Especially when the car is all right basically for the rest of the track.

Sorry, I don't get the point with the ON ON ON. Do you mean throttle pumping by that? Now this is not normal and you should get rid of that off throttle understeer.

The best is always a car very neutral on- and off-power. But that's almost impossible as a setup always is a compromise for the best and most consistant lap times. But if you don't feel comfortable by always hitting the corner perfectly with some throttle applied then you should get rid of that off-power understeer.

Just had a thought as this in a T3'11 do you have the stiffening posts in that bolt the dual steering arms to the top deck? As those posts can affect how the cars works on steering and front end flex.

But we aren't talking about a T4... JPS is running a T3'11 so his car will have the posts depending on his set up!

Oh, I forgot about that for a short time. Sorry. But with off-power understeer it's not common to add stiffness to the front but to the rear if this setup option should be used.