So who knows F104 setup?
 

First of forgive me I'm new at the F-104 class and I gave up finding this in the 294 page F104 thread I did scan it bit but after about 75 pages I gave up.

I am running rubber tires on asphalt. I have the soft T-Bar and I am using all Tamiya parts and most blue hop ups.

The problem I am running into is rear traction. Right now I have Medium tires in front and soft in the rear. When coming off of speed or into a turn the rear end comes around bad. I mean real bad In fact I can come down a straight away and barely let off the throttle with no turn and the rear will come around. Its like the rear end is on ice.

I have adjusted springs, ride height front and rear. I have tried new tires. I have used Paragon II traction compound and etc. And I have loosened up the diff to almost nothing.

The weird thing is a couple of times it seem dialed in ran pretty good then next heat or later in the day it was all gone.

Could I be causing a problem with the traction compound? It does seem like the tires are stickier at first then they pick up all the usual crap off the track and then it worse. But this is only for about the first lap. Its all downhill after that.

I bought this car and ran it last season. the car was almost new. I am going to break it down and rebuild it. Anything i should look for?

Any helpful comments would be appreciated. I am at a loss here.

I don't have a F104, but I've seen someone at our track working on setup. I don't know how much tuning experience you have, so I don't want to setp on your toes, but I can give you some ideas.

Try stiffening the front up, and find ways to slow weight transfer. When you get off the gas the rear end will get light and come around on you. Use traction compound on the entire rear and half of inner tire or less on the front. Get the car on scales at each corner and try make sure the weight balance is even left to right. Also see what the current weight distribution is. Try shifting more weight to the back and make sure if you have any more aero adjustments to get the back planted more.

Usually as the day goes on traction goes up and the car oversteers badly, but I don't know why your car just snaps around when you get off the throttle going straight. Sounds like the chassis is very upset. My friends at the local track are switching to the lightest springs because the stock springs are way to stiff for the light lipo's they are using in the car.

You may want to try a hard compound front tire. I'm not super familiar with running the F104 on asphalt (we race on carpet), but you may have too much bite with the medium compound up front. Also try only putting compound on the rear tires. You could also try to reduce the preload on the on the damper shock (not the pressure plate/disc, but the shock itself) to help make the car more "compliant" to the track surface. If the rear axle isn't planted and the wheels lose contact with the track for even a split second, it will spin out. These cars respond hugely to the smallest adjustments.

These changes helped me immensely on carpet (with rubber tires) so maybe some of it applies to asphalt?

Jeff

Post this on f104 thread. Also look up uf1 series. Pit shimizu tires?

Make sure that there is nothing binding the axel or bearings. I had the same thing happen to me with my 103. The diff back plate was rubbing the height adjuster and made the car want to snap into a 180° turn. It was a simple fix, but the bearing went bad because of that.