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Slot It Warsteiner Porsche Race Preparation And Tuning

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  • Slot It Warsteiner Porsche Race Preparation And Tuning

    The Slot it 956 KH Warsteiner Porsche has their usual excellent quality, with a colorful, well done paint scheme.

    The car weighs 75 grams, front 31 grams, rear 44 grams, and a total magnetic weight of 245 grams.

    I totally disassembled the car and inspected all the parts.

    The front wheels wouldn’t spin, and the motor pod wasn’t installed correctly.(photo # 1 )

    The front wheels were trued up using a Dremel, and a radius was filed on both sides of the ridge, and on the edge of the hub. (photo # 2)

    The mounting pins for the front axle adjusters were filed down 0.010” to free up the axle.
    The outer edges of the front axle supports were filed smooth and polished with a rotary brush. (photo # 3)

    The sides of the chassis had the runner attaching points filed smooth and the opening for the motor pod had material removed for clearance, so the pod could float easily. ( photo # 4)

    The crown gear groove was widened for armature shaft clearance.
    Spacers and thrust washers were installed to locate the rear axle.
    The S2 rear tires were trued up on the sanding fixture. ( photo # 5)

    The car was assembled using SISP05 soft pickup braids, and the motor pod screws were loosened a half turn.
    The car was run on the sanding skid pad to true up the front and rear tires.
    This also puts a radius on the edge of the tires. (photo # 6)

    These are the results of the motor performance test @12 volts.

    177 g/cm Ts, 23076 max rpm, 10.2 watts, 4.65 amps @ stall, 0° advance.

    These are the average lap times @ 10 volts.


    9/28, 3.11:1.…..7.150 sec…………………7.134 sec………..18.1 f/sec..12.3mph

    9/24, 2.67:1.…..6.800 sec…………………6.783 sec………..20.9 f/sec..14.2mph

    The car was smooth and fast after the tune up. With the 3.11:1 gear ratio, the slower speeds on the straights reduced the lap times.
    With the 2.67:1 gear ratio the car had more top speed and was a little smoother in the transitions to the turns.

    The car's overall performance, top speed, cornering, and lap times are comparable to the Schiesser Porsche with the same setup.

    Last edited by davejr; 09-09-2008, 06:38 AM.

  • #2
    Nice basic setup article!



    • #3
      Man, your tuning threads put mine to shame!!!!!! How do you find the time! Great thread as usual Dave.
      Maybe you should open a mini garage for Slot-Cars!!!! Dave's Tune-up shop! Take in guys cars and tune them to the max!!!!
      Thanks PS I need this car too.


      • #4
        I just got mine today and when I saw your green crown I had to open it up to see what the deal was... standard yellow crown. Then I read the article a little deeper .

        I find all Slot.its need a pod and pod hole trimming before they are good to go. The front motor mounting bracket on the pod is often bent forward because the hole has not been trimmed well enough to fit around the motor mount.

        Still the best bang for the buck in slot racing. Just load up the proper tires for the track and go!



        • #5
          I didn’t keep track of the time I spent on this car, but it was no more than an hour to prepare the car for it’s first laps on the track.

          The motor test was done afterwards, and a little more time was spent tuning the car for its best performance.

          I normally don’t use S2s on my track, so it took a little longer to find the best setup.

          Of all the cars I own and race on my track, the Slot it cars are still the best performers and the “best bang for the buck“.



          • #6
            "Still the best bang for the buck in slot racing" - Lord knows I could NOT have said it better than Pete!! SCI and our members have long been accused of being Slot.It lovers. Well? I, for one, am darned proud of that name.

            Dave, once again you have done a fantastic article. I was surprised how the motor pod was twisted OTB though. That is unlike the usual Slot.It quality control. Most Slot.It cars need wheel adjustments and some trimming/tuning of the chassis. What I read into your thread here is the ease in which these tasks are accomplished with a Slot.It car. Slot.It cars are predictable which is generally accepted as a bad connotation except when it comes to a race car no matter the scale.

            Now a question for you Dave: Do you (in general) remove the blocks under the axles to allow vertical free play of the front axle?

            For the longest time, I never removed the blocks. Now as I find myself making the transition to no-mag racing, I like the way the 956's, 956 KH's and the 962C's handle without the blocks. I suppose it is a matter more of personal preference. I really want to hear how an accomplished car tuner feels about the front axle and whether or not vertical play is good.

            Thank you as always Dave. Even with all of your answers, you still make us ask MORE questions. And with more questions come more answers and understanding. You are one of the best there is Dave .

            BTW, got any cars for sale?



            • #7

              I have always liked to keep the weight at it’s maximum on the front wheels, allowing the axle free movement reduces the nose weight under acceleration.

              This slight reduction of weight allows the front of the car to lift faster during weight transfer, which will make it harder to control, causing the front of the car to lift further than it normally would.

              This is also the reason I use the SISP05 pickup braids, they have a lot less tension on the track, further reducing the lifting forces under weight transfer. I also adjust them as flat and close to the bottom of the pickup with a slight arc, this will also act as a governor and help to keep the car from wheel standing.

              An offer of proof that this method works is my R&D Jaguar, it has a 20 plus watt motor, 3.75:1 gear ratio, weighs 71 grams, 31/40 split, and has never come out of the slot due to a wheel stand.


              Now if you are drag racing it’s another story.


              • #8
                Wow! A 375 gear ratio and it does not do a tail stand? I KNEW there were aerodynamic effects on these cars !!!

                This is off topic Dave.....Did I read correctly that your test Jag has a paper stock rear wing assembly? Just curious.

                kind of. AS far as your "sanding" skid pad is a terrific idea! Does it work as well as it appears to? And lastly, have you found a big difference in how you tune the Slot.It 956 vs the 956 KH? These questions are directed at Dave but anyone please feel fre to answer.



                • #9

                  I have made wings from decal paper for a few cars, it made an improvement on the Jag, not on the C9. This was done just to reduce weight and retain the appearance.

                  The sanding skid pad works, but the tires should be trued up first. This will slightly true up the front and rear tires at the same time, while it puts a running radius on the edge.

                  The KH has a little more weight on the tail, the only improvement I know of is to remove some of the weight.



                  • #10
                    Originally posted by davejr View Post
                    ...Of all the cars I own and race on my track, the Slot it cars are still the best performers and the “best bang for the buck“.

                    Copy that.


                    • #11
                      Is there a part number for that green crown gear? I would like to try one in my Schiesser 956.


                      • #12
                        Looks like a SIGI24 BZ to me.

                        You can find all of the parts 'n stuff here: