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Carrera race prep
With all the recent discussion on the board about carrera cars lack of performance when run with out magnets I thought may be I should try to even things up a bit in the carrera camp.
As a comparison I have used a fly gt1 Porsche a good solid car to use as a yardstick to measure the performance against. The only mods on the Porsche was the addition of a slot it rear axle set up to make it reliable and a set of gom fronts to ensure good pickup contact
First thing that becomes obvious with the carrera is the weight of the thing the body is very heavy and doesn't allow any flexibility in the chassis the tyres aren't the best and the guide is a very sloppy fit
Initial tests on my track showed the fly car to be light years in front of the carrera. The fly running low 7s and the carrera almost in the 9s, although nice and smooth to drive I was unable to push the car and get a good feel for it.
Where to start?
Firstly we need to tackle the up top weight thing and get some body movement into the car. The carrera body posts sit inside cups which prevent any body rock first thing to do is to cut the lips off flush with the bottom of the cup and remove the centre mounts all together leaving only the front 2 mounts and the rear one. Enlarge the screw holes a little to allow some clearance for the body to move, next trim the rear diffuser a little to allow it to clear the sides of the body .The body will now be free to rock a little and damp out any vibration.
Next I turned my attention to the guide .The best cure is to replace this with a tsrf but you can get a cheaper cure by wrapping a little piece of copper tape around the shaft to take out the play.
The next step was to introduce some flex into the chassis this is to allow the chassis to generate some mechanical grip to replace the magnetic down force it has lost .To do this I chose to completely remove the section of chassis which held the front magnet this also lowers the c of g as there is a great chunk of plastic and metal high up in the front of the car when this is left in place cutting this out as shown in the pic will make the chassis quite flexible I have also trimmed the waste material at rear to reduce any pendulum effect generated by this .The chassis should now be sanded flat to remove any bits that hang down a to get the most out of this car we need to reduce the ground clearance quite drastically
Turning our attention to the wheels and tyres I glued the front tyres on and then turned them down to 20 mm on a hudy tyre truer, for the rears I fitted some slot it p2s in the same way.
Next I checked the motor for fastest direction which happened to be the opposite way to its normal rotation removed all the suppression and reversal paraphernalia and glued it into the bracket turned the axle over and fitted the wheels and wired up the guide and I had a rolling chassis.
I then turned my attention to the body this is where the major problem lies too heavy care full dremmel work reduced the body to a more reasonable weight. What you do is remove any excess plastic inside the shell very carefully and end up with a thin shell but be careful as its easy to go through I have left the interior out as I will be replacing it with a vac form.
Once reassembled the car was a different animal snappy acceleration and better brakes, weighing in at 75g against the 90g of the original
Onto the track
Hows it go,I added 2 g of lead under the axle and its great its great ,lap for lap it can now match the fly gt1 ok may be it wont live with the racer but add a quicker motor and It wont be disgraced either
Lap times 7.1 /7.2 against the flys 7.2/ 7.3
Pics to follow
With all the recent discussion on the board about carrera cars lack of performance when run with out magnets I thought may be I should try to even things up a bit in the carrera camp.
As a comparison I have used a fly gt1 Porsche a good solid car to use as a yardstick to measure the performance against. The only mods on the Porsche was the addition of a slot it rear axle set up to make it reliable and a set of gom fronts to ensure good pickup contact
First thing that becomes obvious with the carrera is the weight of the thing the body is very heavy and doesn't allow any flexibility in the chassis the tyres aren't the best and the guide is a very sloppy fit
Initial tests on my track showed the fly car to be light years in front of the carrera. The fly running low 7s and the carrera almost in the 9s, although nice and smooth to drive I was unable to push the car and get a good feel for it.
Where to start?
Firstly we need to tackle the up top weight thing and get some body movement into the car. The carrera body posts sit inside cups which prevent any body rock first thing to do is to cut the lips off flush with the bottom of the cup and remove the centre mounts all together leaving only the front 2 mounts and the rear one. Enlarge the screw holes a little to allow some clearance for the body to move, next trim the rear diffuser a little to allow it to clear the sides of the body .The body will now be free to rock a little and damp out any vibration.
Next I turned my attention to the guide .The best cure is to replace this with a tsrf but you can get a cheaper cure by wrapping a little piece of copper tape around the shaft to take out the play.
The next step was to introduce some flex into the chassis this is to allow the chassis to generate some mechanical grip to replace the magnetic down force it has lost .To do this I chose to completely remove the section of chassis which held the front magnet this also lowers the c of g as there is a great chunk of plastic and metal high up in the front of the car when this is left in place cutting this out as shown in the pic will make the chassis quite flexible I have also trimmed the waste material at rear to reduce any pendulum effect generated by this .The chassis should now be sanded flat to remove any bits that hang down a to get the most out of this car we need to reduce the ground clearance quite drastically
Turning our attention to the wheels and tyres I glued the front tyres on and then turned them down to 20 mm on a hudy tyre truer, for the rears I fitted some slot it p2s in the same way.
Next I checked the motor for fastest direction which happened to be the opposite way to its normal rotation removed all the suppression and reversal paraphernalia and glued it into the bracket turned the axle over and fitted the wheels and wired up the guide and I had a rolling chassis.
I then turned my attention to the body this is where the major problem lies too heavy care full dremmel work reduced the body to a more reasonable weight. What you do is remove any excess plastic inside the shell very carefully and end up with a thin shell but be careful as its easy to go through I have left the interior out as I will be replacing it with a vac form.
Once reassembled the car was a different animal snappy acceleration and better brakes, weighing in at 75g against the 90g of the original
Onto the track
Hows it go,I added 2 g of lead under the axle and its great its great ,lap for lap it can now match the fly gt1 ok may be it wont live with the racer but add a quicker motor and It wont be disgraced either
Lap times 7.1 /7.2 against the flys 7.2/ 7.3
Pics to follow
