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Old 09-12-2011, 06:14 AM   #1
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Default Gear ratio 13.5t non boosted

Hi Guys,

Running in a 13.5t non boosted event next weekend. What sort of FDR should I be running?

Thanks

Mark
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Old 09-12-2011, 08:36 AM   #2
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Hi Guys,

Running in a 13.5t non boosted event next weekend. What sort of FDR should I be running?

Thanks

Mark
depends on track size , huge track 3.5 , normal size 4.0 , indoor carpet 4.5

this is a rough sizing , 3.5 be carfull of heat !!!
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Old 09-12-2011, 09:28 AM   #3
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3.5fdr to 4.0fdr is 17.5t territory !!! I would recommend 4.5fdr to 5.0fdr !!!!
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Old 09-12-2011, 10:04 AM   #4
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3.5fdr to 4.0fdr is 17.5t territory !!! I would recommend 4.5fdr to 5.0fdr !!!!
Really ??? We ran 3.5 at MACH last year with 13.5 0 timing , and at my local club we run 4.0 now !!!
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Old 09-12-2011, 10:08 AM   #5
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There is always a way to keep cooking motors (3.5fdr), and there is a way to run them (4.5fdr) !!!!!!!!!!
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Old 09-12-2011, 10:13 AM   #6
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There is always a way to keep cooking motors (3.5fdr), and there is a way to run them (4.5fdr) !!!!!!!!!!
what motor temps do you get when running at 3.5 ???

We ran all weekend at 32 DegreesC and my motor was only 65 degrees C after 5 mins of driving

With my club at 4.0 we run 7 mins and my motor is less then 60 degrees C

It is all dependant on track size , MACH has a 70m straight and a long fast corner on to the straight that is why we needed 3.5 , my club has the same set up but only a 50m straight and a couple of chicanes , so we decided 4.0 was better
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Old 09-12-2011, 10:56 AM   #7
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I know it depends on track length, but if you are giving advice you need to consider that most tracks are small, not 70m or 50m ! In most cases you will want to start at 4.5fdr to 5.0fdr , and go up or down as necessary, but not 4.0fdr start !
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Old 09-12-2011, 11:01 AM   #8
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I know it depends on track length, but if you are giving advice you need to consider that most tracks are small, not 70m or 50m ! In most cases you will want to start at 4.5fdr to 5.0fdr , and go up or down as necessary, but not 4.0fdr start !
HELLO .... READ MY 1ST MESSAGE !!!!!!!!!!!!!!!!!!!!!!

I guess you know best ........ I have only been racing 0 timing 2 years , what do I know !!!
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Old 09-12-2011, 11:07 AM   #9
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First message is still wrong, no 5.0fdr !!!!!! CALM DOWN !!!! Go wrench or something, and leave the advice for those who know !!! End of discussion .........
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Old 09-12-2011, 11:14 AM   #10
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First message is still wrong, no 5.0fdr !!!!!! CALM DOWN !!!! Go wrench or something, and leave the advice for those who know !!! End of discussion .........
hahaha i will leave the advice to those who THINK they know ..

Hey Mb3195 let us know how it goes with the 0 timing
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Old 09-12-2011, 01:23 PM   #11
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Also depends on whether your motor timing is locked or advanced.

I would say start with 4.0 with no motor timing and temp the motor after your full run.

Track size,layout, driving style, type of motor and physical timing all play a part in the FDR.

I used to run 3.5-4.0 for my older 17.5 motor (fixed timing) at my local track, as I get better and with newer 17.5 motor (max advanced timing), I start to use 4.0. Then the track becomes technical I use anywhere between 4.0-4.5.

In terms of KV value, a fully timing-advanced 17.5 is pretty close to a non-timing 13.5 so I think 4.0 FDR is a good starting point.
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Old 09-12-2011, 01:56 PM   #12
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4.0
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Old 09-13-2011, 12:23 AM   #13
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depends on track size , huge track 3.5 , normal size 4.0 , indoor carpet 4.5

this is a rough sizing , 3.5 be carfull of heat !!!
+1
People ran 3.5-4.0 outdoors here in Denmark with 13.5T no-boost, and we have 7min heats.
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Old 09-13-2011, 02:32 AM   #14
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hahaha i will leave the advice to those who THINK they know ..

Hey Mb3195 let us know how it goes with the 0 timing
He normally runs 13.5 boosted but is doing a charity event (http://www.rctech.net/forum/electric...-im-crazy.html) where he will race in every class in last of the summer indoor series.

I have been speaking to him and have offerd my support as part of his pit crew, while it is unrealistic for him to be competetive in all the classes (most of which he has never raced before) he does not want to get in the way of those who are racing for series points, hence the FDR question.

I wish him all the best in what (I am sure you will all agree) is a tough challage for a worthy cause

Bb

Last edited by bucketboy; 09-13-2011 at 02:47 AM.
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Old 09-13-2011, 10:30 AM   #15
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This is a little off topic but what starting FDR range do you recommend for 10.5t non-boosted?
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