Go Back   oOple.com Forums > General > Electrics

Reply
 
Thread Tools Display Modes
  #1  
Old 28-03-2012
Dr_UpGrade's Avatar
Dr_UpGrade Dr_UpGrade is offline
Senior Member
 
Join Date: Jun 2010
Location: Wokingham
Posts: 498
Default LRP 8.5t motor 'final' ratio question?

Hi Guys,
This 'may' be a silly question, and if so I'm sorry... However, here goes:

I've recently bought an 8.5t LRP to go in DEX210. The blurb that comes with the moter suggests that this motor works best in a 2wd offroad with a final ratio of 8.5:1... No problems there, I can use a 26tooth pinion on the std 87 spur on the dex to give a final ratio of 8.7:1.
I'm using a hobbywing/bullistorm controller with the settings RogerM suggested a while back of:

boost timing =10
TURBO timing = 18
Turbo delay = off
Turbo ramp rate 3deg/1000rpm
Turbo start revs = lowest

Now my question is with these type of settings is the LRP suggested final gear ratio still valid? Is the moter 'still' behaving like an 8.5t or is it now more like a 7.5 or 6.5? I'm swapping out from a 6.5t where I was running 21:87... I'm a bit concerned that 21 to 26 is a big no' of teeth and I dont want to cook my speedo and/or motor..

Sorry this is a bit long, but all opinions gratefully received...

Cheers!!
__________________
www.shrccc.co.uk
surrey and hants radio control car club
Reply With Quote
  #2  
Old 28-03-2012
SLEENAD's Avatar
SLEENAD SLEENAD is offline
Member
 
Join Date: Sep 2010
Location: Olen, Belgium
Posts: 230
Default

IMHO there 's just three things to look at.
TOPSPEED=bigger pinion and/or smaller spur
ACCELERATION=smaller pinion and/or bigger spur
TEMP=THE MOST IMPORTANT SO MEASURE MEASURE MEASURE!!!

Start with the recommend gearratio and check the temp after 2min then 4min and 6min (so you can avoid cooking speedo/motor).

TEMP= OK? Then go can up a tooth and recheck and repeat if possible.

TEMP TOO HIGH? Almost always go down a tooth (but it isn't always true) and repeat if necessary.
Reply With Quote
  #3  
Old 28-03-2012
Dr_UpGrade's Avatar
Dr_UpGrade Dr_UpGrade is offline
Senior Member
 
Join Date: Jun 2010
Location: Wokingham
Posts: 498
Default

Thanks for that!

I did try the car with the previous 21t pinion and it seemed 'ok' (and motor not warm, but this means its 'the same' as the 6.5t I had in it before... but does that mean that all the turbo boosting etc no longer means I should take no notice of the LRP suggested final ratio for their motor?

-just trying to get my head round it!
__________________
www.shrccc.co.uk
surrey and hants radio control car club
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 05:15 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
oOple.com