XRAY - Model racing cars

It all started out OK with my T2 but over the past few weeks, I'm finding my patiens with this car is starting to where thin, particularly after have some very expensive stacks while over driving the car to try and keep up.

Here is the current setup:
http://www.teamxray.com/xforum/xform/in ... 2&setup=t2

The only time the car is stable, is when it's under throttle (or stationary). The car feels like all it's weight is at the front, even at low speeds. When it's not trying to spin, it's 4 wheel sliding.

So, any comments on the setup, where have I gone wrong, what should I do to fix it.

Darren Campbell gave me an awesome setup for my FK05 last year, what I want to do is to get my T2 to drive like this.

Link to Darren's setup:
http://www.teamxray.com/xforum/xform/in ... tup=t1fk05

I would say increase the downstop/reduce droop. Try to see what other "mortal" drivers use (not the top pro´s as they tend to use very high droop which equals a very fast but harder to drive car). Replace the one-way for a diff and lower the car more. Also you don´t say which shell/body you use. Going for something neutral like the Protoform Stratus might help. Also foams for the dampers tend to make the car more aggressive so you might also try to remove those and make sure you do not have a lot of rebound in your shocks. If the car is 4-wheel sliding you need more grip and you are probably doing something wrong with the tires, if that is the case ignore all above and start there

Regards,
Emil

Emil gives some good pointers, especially the one about the tyres. Tyres are key, if you mess them up you won't have grip whatever you change in the setup.

Some things I noticed in the setup:

- You are running your rear diff relatively tight. I suggest you try running it medium-loose instead. This will help keep rear end grip during cornering as long as the inside rear wheel does not unload.

- You indicate you run foam on carpet. Emil is right in suggesting you run a normal diff at the front as this is the way most drivers run the car with foam.

- With foam it is also better to run harder springs, especially at the front. You may also want to close two holes in the front shocks instead of just one.

- Run a front anti-roll bar and make sure you have only 2mm uplift at the front and 1mm at the rear (i.e. how far you can lift the car before the tyres leave the ground).

- I am not sure what shore tyres such as the Jaco double pinks are, but 42 and 40 shore UFRA tyres sound a bit on the hard side. Try running softer tyres and increase the difference between front and rear to 5 shore.

- You are running a 9 turn motor timed 24 degrees. This is a lot of timing which will make the motor have a lot of drag brake. This will unsettle the car off power. I suggest you reduce the timing to about 12 degrees and gear up a bit. This will stop the car from braking too much off power.

- Run the chassis and top deck in their stiffest setting including all four posts.

- Run the front and rear ride height at 5mm. With the rear 1mm higher than the front the car will be much too aggressive, especially with a front one-way.

I think this will give you enough things to try for now. Perhaps TeamGP has some more suggestions.

Final suggestion, have a look at the setups posted by Paul Lemieux and Jilles Groskamp for foam carpet racing!

Emil/Tonyv,

Thankyou for taking the time to post answers to my post. It would be fair to say I was in the most posative mood when I started this thread.

I should mention that the carpet that we run on is really industrial nylon carpet tiles, not the stuff that IFMAR tracks use.

Front Diff - check

Tyres - check

Roll Bar - Ordered, the importer tells me that this should turn up next week.

Shocks - Foam removed and fronts rebuilt this two hole pistions (I don't use the adjustable pistions.

Chassis rebuilt to stiffest setting. I should point out that my T2 has been having a rough time lately and the chassis, left rear hub and rear shock tower need to be replaced, again, they are all on order. These parts are still operational, just far from optional. I have checked the chassis and it's n ot tweaked, it just as some additional/undesriable flex at the moment.

Motor, not yet but before the next race meeting (it's due for a rebuild). More advance causes more drag breaking? Wow!! I never knew!

Ride height 5mm front and rear. Will do.

I have rebuilt the car following these tips and have just tried it out on the street, not ideal but the car no longer seems to loose rear grip the moment the steerring is touched.

Once again, thanks, some of this is pretty obvious (like the diff) but I just would have not thought of it.

I won't get to run the car again until the 16th of May so I'll report how things go.

Mark.

Man I'm a putts.

Rebuilding the car I just happened to drop my toe gauge on the rear for the first time. Guess what. No rear toe!! All the parts were there, just not in the right place, the hubs were on the wrong sids, thus, cancelling out rear toe. A quick rebuild was ordered and soon the hubs were on the correct sides.

I still have not had a chance to run the car with the changes previously mentioned at my home track, but I have run it on Tarmac, in it's foam setup. The car was great!! Still very quick to turn in but this time with out the tail stepping out. As this track suited rubber tyres, changes were made as rubbers were installed. Whick give me an idea for anothr thread.

The track I was racing at suited Rubbers and I was also running stock.
Hears the setup I ran:
http://www.teamxray.com/xforum/xform/in ... 0&setup=t2

I'll be reverting the car back to it's foam setup and bolting in a 9t. I'll let you know what happens.

Any comments/thoughts?

you check your spring preloads? make sure the fronts are equal and the rears are equal, also , depending on the equipment used in yourcar, you may have to addweight to certain corners to balance the car out.

Thanks for your reply Cory but as I mentioned I have checked shock lengths, rebuilt shocks and I have removed ALL preload just to see if that would make a change on the corners, it did not. I even added 20g to each corner to help things out, (talk about being heavy!). It helped some but my guess is that I have a BAD chassis...but I could be wrong.

Please check

Thanks to everyone.

I finaly ran my T2 at racing last night sine starting this thread.

With all the usefull tips and having correctly reasembled the backend, I had a fast predictable car that was an absolute weapon.

thanks guys.

Go4iT, have a really close look at the bulkheads and Shock towers for damamge.

Nerdling that was an awesome 5 minute drive, your car looked dialed! Hey did you run a front one way or not?