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Post by keitheroonie on Sept 6, 2008 15:16:07 GMT
Everyone seems to be enjoying the voting so here's another.
This poll should give an idea of what motors people own or will own.
You can choose up to 3 options
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Post by mattsedgley on Sept 6, 2008 15:51:03 GMT
17.5 and 13.5
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Post by issac on Sept 6, 2008 16:04:30 GMT
keith
why only 3 choices
i have 10.5 13.5 17.5 and 27t for when its wet
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Post by Robin Howett on Sept 6, 2008 16:48:33 GMT
for winter club running i think a 17.5 may have to appear in my tool box, easier on the tyres, close on speed (i hope) to give close racing, good on cold days when the grip is low. But if i was going to do any competitions i'd need 13.5 or 10.5... too many options!
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Post by Mark Townsend on Sept 6, 2008 18:20:53 GMT
Great poll Keith. My vote goes for 10.5, as that's what I like running but as Rob says a 17.5 may find it's way into the toolbox. Just so i've got people to race against and can have chat while the car ambles down the straight  |
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Post by keitheroonie on Sept 6, 2008 18:30:28 GMT
Yea! I voted 17.5, 13.5 as I'm going to go 17.5 for the winter.
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Post by keitheroonie on Sept 6, 2008 22:24:31 GMT
keith why only 3 choices i have 10.5 13.5 17.5 and 27t for when its wet This poll is only to see what people will use in club racing, we don't generally run in the rain, so I figured 3 votes would cover it. I know what you mean though a wet option for bigger championships does need considering. |
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Kev
Hitting the Tyre
Posts: 63
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Post by Kev on Sept 6, 2008 22:31:33 GMT
13.5 & 17.5, no plans to run that old stuff 27T
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Post by TryHard on Sept 7, 2008 0:57:20 GMT
guess who voted for the mod...  Having said that, I'm gonna be needing 13.5 at some point to do Carpet Wars... yes I'm going pot hunting  |
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Post by Barry Staples on Sept 7, 2008 11:35:59 GMT
i have a 17.5 on order and i have a 13.5.i wont own a 27t for wet days as i'll properly waterproof my brushless!!! ;D
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Post by Graham Staples on Sept 7, 2008 11:44:14 GMT
I have voted for 13.5 and 17.5. 13.5 being my preferred choice but 17.5 maybe being a good club allrounder
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Post by Mark Townsend on Sept 7, 2008 14:24:22 GMT
I'm ordering a 17.5 just so I can guarantee a race come Sundays. Trouble is if Nobby and Gray do the same I'd need a 15.5 to keep up!
Who fancies a 15.5 class?.........
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Post by lesbaldry on Sept 7, 2008 16:10:52 GMT
Good for you Mark trust me it will be a good fun winter class with plenty of close quarter paint swoping ;D...Even Rob was chating to me today about one!...we've just got to get Pete on the boat now  ..Hi Pete..you pedantic old so "n" so!! |
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Post by yellowshark on Sept 7, 2008 16:39:21 GMT
Good for you Mark trust me it will be a good fun winter class with plenty of close quarter paint swoping ;D...Even Rob was chating to me today about one!...we've just got to get Pete on the boat now ..Hi Pete..you pedantic old so "n" so!! Sorry Les I just got up from the floor rolling around and laughing at Mark's suggestion it should be me that proposes a brushless motor to the BRCA ;D  ;D |
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Post by yellowshark on Sept 8, 2008 14:31:39 GMT
Have you got your 9.5s on order? The forthcoming European TC championship is using 9.5 brushless. I do't think we will enter after all  |
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Post by keitheroonie on Sept 8, 2008 16:55:11 GMT
Why wouldn't you enter Pete, motors are only £39.99, the exact same price as a brushed motor and a set of brushes ;D |
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Post by yellowshark on Sept 8, 2008 17:16:18 GMT
Well Keith a. we are not good enough ;D b. far too expensive to go to Poland, Germany, Austria etc But its a good example of the trouble with all forums; what you are thinking often does not get clearly articulated. What I was thinking was here we are amid major discussions on engine class directions and the Europeans come up with one we have never mentioned. Does that mean the BRCA are not aligned with their EFRA colleagues or have the people organising the championship gone of their strudel? |
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Post by issac on Sept 8, 2008 17:46:17 GMT
pete
i could be wrong on this but i believe the original brushless motor for the pro stock class was the 9.5 turn ( half of 19 ) but the brca in testing found the 10.5 to be closer and this was adopted as the norm.
becouse the brca doesn't or hasn't approved any stock brushless class we are in the situation of the old figure ( 27 devided by 2 equals 13.5 ) now we know they are too fast for the 27t at some tracks and perhaps a 15.5 or 14.5 would be more equal but the only 15.5's on the market at the moment are the lrp/nosrams and they are bonded so don't even give the same power as the sintered 17.5's and the 14.5 don't exist. in all its a mess the brca has washed its hands of and left it to the clubs hence the difference in rules.
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Post by keitheroonie on Sept 8, 2008 17:56:43 GMT
It certainly looks that way Pete, It looks like 9.5's have been around as a modified motor for a couple of years, maybe they've been using them around Europe without our knowledge. It does seem a bit strange though making a 9.5 class. Something I've never heard of  I think we can safely leave it out of this poll, Ed or Mark might like a play though |
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Post by yellowshark on Sept 8, 2008 18:39:57 GMT
Thank goodness, adding 9.5 to the mix would be almost as crazy as thinking the FIA were impartial and Ferrari did not regulalry bung them a large wedge  |
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Post by keitheroonie on Sept 8, 2008 18:51:02 GMT
Just to elaborate on what Ian was saying
The main factor that produces the huge difference between the brushed and brushless motor powers is in the way the coils are wound (ie 27t brushed vs 27t brushless). in most brushless motors the coils are star wound (all 3 coils have 1 end linked together), brushed motors on the other hand are delta wound (coils connected in series (imagine a triangle where each side is a coil)).
To power the coils in brushless or star wound motors two coils need to be powered simultaneously as there are 3 external connections to the coils from the speedo, 1 to each coil. the current then flows in through 1 coil across the linked ends and out through another, with your fancy speedo working out which ones to use. this system works very efficiently as the 2 simultaneously powered coils push and pull on the Rotor making it more powerful but slower than a brushed or delta wound motor.
The brushed or delta wound motor on the other hand has only 2 connections from the speedo, these power brushes that connect to the Commutator, the commutator then powers each coil individually, giving a less powerfull but faster motor.
To get the same speed out of a star wound motor you need to divide the amount of turns in the delta wound motor by 1.73, ie. 27 / 1.73 = 15.6, so 15.5 is the closest you'll get.
The star/delta motor is something that has been in use for decades within heavy machinery, it uses the star wind to get it going then switches to the delta wind when up to speed.
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Post by keitheroonie on Sept 8, 2008 18:53:19 GMT
Thank goodness, adding 9.5 to the mix would be almost as crazy as thinking the FIA were impartial and Ferrari did not regulalry bung them a large wedge One word on that Pete. [glow=black,2,300][shadow=blue,left,3000]GITS!!!!!!!!!!![/shadow][/glow] |
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Post by Simon Crabb on Sept 8, 2008 21:31:24 GMT
To get the same speed out of a star wound motor you need to divide the amount of turns in the delta wound motor by 1.73, ie. 27 / 1.73 = 15.6, so 15.5 is the closest you'll get. Fascinating stuff Keith! Where does the 1.73 come from? |
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Post by mattsedgley on Sept 8, 2008 22:32:10 GMT
i expect its the difference in lengths of wire from one wind to the other simon, interesting stuff Keith - it'd be cool to see one actually doing it in slow motion!
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Post by Martin S on Sept 9, 2008 7:45:43 GMT
The 1.73 comes from the 120 degrees phase shift between the 3 lines.
1.73 is the square root of 3.
Comes from cos(alpha+ 0) + cos(alpha+120) + cos(alpha+240).
I don't understand either, but I 'm sure it makes sense to someone
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Post by Simon Crabb on Sept 9, 2008 11:07:55 GMT
Ahh root 3. Yes, of course.
It's been a long while since I studied that sort of stuff!
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Post by saintroeer on Sept 9, 2008 14:23:09 GMT
The 1.73 comes from the 120 degrees phase shift between the 3 lines. 1.73 is the square root of 3. Comes from cos(alpha+ 0) + cos(alpha+120) + cos(alpha+240). I don't understand either, but I 'm sure it makes sense to someone its been a long time since i cared |
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Post by keitheroonie on Sept 9, 2008 16:30:22 GMT
The 1.73 comes from the 120 degrees phase shift between the 3 lines. 1.73 is the square root of 3. Comes from cos(alpha+ 0) + cos(alpha+120) + cos(alpha+240). I don't understand either, but I 'm sure it makes sense to someone Well answered Martin (A+) ;D The simultainiously powered coils are 120 deg. and 240 deg. apart at any given time, 120 clockwise and 240 anti-clockwise or vise versa, |
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Post by Martin S on Sept 9, 2008 18:14:04 GMT
The 1.73 comes from the 120 degrees phase shift between the 3 lines. 1.73 is the square root of 3. Comes from cos(alpha+ 0) + cos(alpha+120) + cos(alpha+240). I don't understand either, but I 'm sure it makes sense to someone Well answered Martin (A+) ;D The simultainiously powered coils are 120 deg. and 240 deg. apart at any given time, 120 clockwise and 240 anti-clockwise or vise versa, That's what comes of helping your son do A level electronics. And when your kids think they know more than their parents, they're probably right. |
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Post by keitheroonie on Sept 9, 2008 19:30:20 GMT
I've got a city and guilds and NVQ 3 in electronics and electrical principles but I wouldn't fancy trying an A level in it now. It's been a while since I've had to study text books. I need instructions to scratch my own......er.. head |
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..Hi Pete..you pedantic old so "n" so!! 
;D 
