86LikesHpi Pro 4
02-12-2006, 02:35 PM
Originally Posted by Greg45231
micrors4guy ,
I don't know much about setting up for asphault but the HPI site has a lot of setup sheets on there and the majority are for outdoors with rubber tires so that may be a good starting point.
For the Integy motor you will want to gear high like around a 1.3 on roll out. 19's like it tall, just keep and eye on the color of the comm and and brush spring tension.
Greg
I don't know much about setting up for asphault but the HPI site has a lot of setup sheets on there and the majority are for outdoors with rubber tires so that may be a good starting point.
For the Integy motor you will want to gear high like around a 1.3 on roll out. 19's like it tall, just keep and eye on the color of the comm and and brush spring tension.
Greg
Nice little snow shower here.
02-12-2006, 03:06 PM
Originally Posted by micrors4guy
im starting to see the term rollout alot for setup reasons with the on road stuff. can you tell me how to measure this?
from te sounds of it it seem as roll out is how far the car travels b4 the motor makes one revoloution?
from te sounds of it it seem as roll out is how far the car travels b4 the motor makes one revoloution?
Generally used with foam tyred cars as the tire diameter is always changing (reducing).
02-12-2006, 04:25 PM
Tech Adept
pinion help
what pinion is best for a 13 turn motor.
does some one have a good setup for asphalt.
http://www.htufrederickmd.com/RCraces.htm
does some one have a good setup for asphalt.
http://www.htufrederickmd.com/RCraces.htm
02-12-2006, 05:04 PM
What's a good starting point for a 19 turn in a PRO4? I will be running outdoor asphalt on rubber. Motor will either be a Atlas 19 or a C2. Track size about 60x110. I have heard 6.0FDR??????
Thanks for any tips
Thanks for any tips
02-12-2006, 05:10 PM
Originally Posted by LORD SHADO
does some one have a good setup for asphalt.
02-12-2006, 06:24 PM
Tech Apprentice
dodgeguy,
I wish I could have run today but we had a birthday party for my daughter. I am going to try next week and maybe run 19t or mod if there are enough guys. I just want to run something other than stock and since most of the guys have switched to brushless we don't have a stock turnout anymore.
For those guys that are looking for roll out here is the formula.
(tire dia x 3.14) / ((Spur/pinion) x 2.4375)
Note that the 2.4375 is the internal Pro 4 gear ratio per the manual.
Here is sample so you can check your math.
Tire dia 2.25 inches x 3.14 = 7.065 save this in memory in your calculator.
100 tooth spur divided by 33 tooth pinion = 3.030
3.030 x 2.4375 = 7.39 rounded up. Write this down
Hit memory recall and divide the 7.065 by 7.39 to get .956 which is how far the car will move in inches with one rotation of the motor. This happens to be my rollout for a monster stock last time out at my track.
Greg
I wish I could have run today but we had a birthday party for my daughter. I am going to try next week and maybe run 19t or mod if there are enough guys. I just want to run something other than stock and since most of the guys have switched to brushless we don't have a stock turnout anymore.
For those guys that are looking for roll out here is the formula.
(tire dia x 3.14) / ((Spur/pinion) x 2.4375)
Note that the 2.4375 is the internal Pro 4 gear ratio per the manual.
Here is sample so you can check your math.
Tire dia 2.25 inches x 3.14 = 7.065 save this in memory in your calculator.
100 tooth spur divided by 33 tooth pinion = 3.030
3.030 x 2.4375 = 7.39 rounded up. Write this down
Hit memory recall and divide the 7.065 by 7.39 to get .956 which is how far the car will move in inches with one rotation of the motor. This happens to be my rollout for a monster stock last time out at my track.
Greg
02-12-2006, 07:11 PM
Greg, I know what you mean about family. My in-laws are here for the weekend. I really like them so it is not a bad time here.
I am thinking of running something other than brushless next Sunday. I now have a motor sponsor so I will be running more brushed classes. I am also thinking of racing at other tracks to get some more runs with brushed fast guys. Our track seems to be the only one around with a brushless class as big as it is.
So 19 turn may work next weekend.
I am thinking of running something other than brushless next Sunday. I now have a motor sponsor so I will be running more brushed classes. I am also thinking of racing at other tracks to get some more runs with brushed fast guys. Our track seems to be the only one around with a brushless class as big as it is.
So 19 turn may work next weekend.
02-12-2006, 07:19 PM
Tech Adept
thanks work
hey work kill that monkey its driving me crazy! 
02-12-2006, 08:23 PM
Originally Posted by SOuthernFRIED
What's a good starting point for a 19 turn in a PRO4? I will be running outdoor asphalt on rubber. Motor will either be a Atlas 19 or a C2. Track size about 60x110. I have heard 6.0FDR??????
Thanks for any tips
Thanks for any tips
With C2, yup.
Here's a tip I got from my buddy who got it from team HPI. Gear your car up until the motor tops out at 200deg F.. When you pull it off the track after a 5 minute run temp it. Worked for me perfectly today. Brushes wear out but motor was ballistic the whole 5 minutes.
02-13-2006, 12:24 AM
Tech Master
I just recenntly changed my C-hubs to aluminum. Thanks to Geeto for the very cheap price. Anyway, first I thought it was just "bling", but then my pro4's cornering improved because the auluminum C-hubs doesn't flex on corners like the graphite plastic. Which comes to a point that the aluminum C-hubs are not just bling but plays a good role in the cornering.
02-13-2006, 04:36 AM
Tech Adept
nice tip mikerr , 13 turn motor hpi pro 4 . what pinion . i could never get this gearing thing right. help me !
help me !
02-13-2006, 08:33 PM
Tech Addict
clicking problems
you guys were right about those clicking problems! the rear gearbox had only one brass shim on eigther side. things are properly shimmed up now and there's no more clicking! thanx a heap!! 
02-14-2006, 04:27 AM
Tech Apprentice
Lord Shado,
The manual says to for a 12 turn to gear it at 7.3-7.4 ratio which with a 98 spur would be a 33 pinion. Lokking at how the ratios are changing in their chart it looks like you would be close to gearing it like a stock motor for 13 turns. I would imagine this is for rubber tires which are larger in diameter than the foams. I posted the roll out formula a page or so back so you can work your tire diameter into that equation and get a feel for where you need to be if you are running foams.
If you need some help with it, post your tire diameter and I'll work it out for you. Just let me know if you are using 48 or 64 pitch gears.
Greg
The manual says to for a 12 turn to gear it at 7.3-7.4 ratio which with a 98 spur would be a 33 pinion. Lokking at how the ratios are changing in their chart it looks like you would be close to gearing it like a stock motor for 13 turns. I would imagine this is for rubber tires which are larger in diameter than the foams. I posted the roll out formula a page or so back so you can work your tire diameter into that equation and get a feel for where you need to be if you are running foams.
If you need some help with it, post your tire diameter and I'll work it out for you. Just let me know if you are using 48 or 64 pitch gears.
Greg
02-14-2006, 02:23 PM
Tech Regular
Originally Posted by Nicadrauspro4
I just recenntly changed my C-hubs to aluminum. Thanks to Geeto for the very cheap price. Anyway, first I thought it was just "bling", but then my pro4's cornering improved because the auluminum C-hubs doesn't flex on corners like the graphite plastic. Which comes to a point that the aluminum C-hubs are not just bling but plays a good role in the cornering.
02-14-2006, 09:08 PM
Tech Master
Originally Posted by bosfan
where did you get the c-hubs?