XRAY - Model racing cars

With rubber tyres I generally run a one-way <<<<edit: meant to say one-way here off course! must be old age.>>>> to get the aggressive steering necessary to be fast. However this can be tough to handle resulting in many mistakes. This is especially true in low and sometimes medium grip situations so it is definitely worth trying a spool under these circumstances. You will have less steering which will require a more aggressive driving style, but you will also have an easier time keeping the car on the racing line without making errors. Slightly slower cornering usually though.

Tony, when you run a spool in a low grip environment, what areas of setup would you alter over that for a standard front diff setup?. Would you run softer front springs/damping to allow for the difficulty on initial turn in?.
Thanks
Phil

With more droop I mean a lower number on the downstop measurement. I.e. the arms drop lower than before (more chassis uptravel). Confused? I am...

The reason I suggest to run more droop with the spool is twofold. More droop at the rear will allow more weight transfer to the front off power which you'll need to help the car turn in. More front droop will help increase front-end grip mid corner by allowing more chassis roll at the front. On power it will allow a bit more weight transfer to the rear which will help settle the car down.

Tony i understand thta spool is quite better than one-way especially on low grip tracks, so does one-way should be better on high grip tracks? what are the main,particular,differences between these? i know that one-way could makes car more aggressive exiting corners is that right?i know also that spool is quite lighter than one-way,do you know how much ?

Actually on power a spool and one-way work exactly the same way. It is off power when entering the corner through mid corner that the one-way gives more aggressive steering. Moreover with a one-way only the rear wheels will be used when braking making it very easy to oversteer the car while with the spool all four wheels are used making the car much more stable under braking.

One other thing of note for the one-way is that you can get away with using any ackerman angle setting to increase/decrease steering without scrubbing speed in any corner, regardless of their different turning radiuses. With a one-way either wheel is free to rotate faster than the other as the road surface pulls it. This has helped me maintain speed through the fast sweeper at our local track and when used in conjunction with a stiff front roll bar (which helps keep the front inside wheel planted with traction during cornering) you are assured that there is no loss of acceleration when exiting corners. In contrast a front diff that is even slightly loose will give more acceleration to the slipping wheel on corner entry and exit and thus you may lose some cornering speed and acceleration out of corners.