HPI Sprint 2 Mods
#376
Hi for those of you who runs on asphault circuits with the sprint 2, how do you have your differential setup? Does anyone mess with it or just keeps it in stock form. Or does anyone have a writeup on running thicker weight oils or grease or whatever it is. Sorry I have the RTR version and Im trying my best to be able to keep up with the big boys. I figured this would be the best place for me to ask for setup tips.
#377
Hi for those of you who runs on asphault circuits with the sprint 2, how do you have your differential setup? Does anyone mess with it or just keeps it in stock form. Or does anyone have a writeup on running thicker weight oils or grease or whatever it is. Sorry I have the RTR version and Im trying my best to be able to keep up with the big boys. I figured this would be the best place for me to ask for setup tips.
All of my diffs (except the last purchase) have been rebuilt and shimmed per
http://www.rctech.net/forum/11400616-post149.html
I'm currently running on textured and cushioned vinyl flooring
Soon to be on carpet for the Scale Nats
Asphalt won't be until the weather breaks around the end of April most likely, unless we have another false spring like last year
Mr Whiteside from the Track @ Harbor Hobbies and I discussed diff oils briefly a few months back
I believe he mentioned that some drivers use 300,000 to 500,000 wt oil in the fronts
I don't recall what he said for the rears
My S2 =
I have a silver diff tuning spring in the front to stiffen it up a bit
The rear is stock
I tried a one way diff for one night (2 qualifiers + 5 races) =
On a small track with an uber technical course - not a lot of free running room =
I didn't care for it =
I took it out
Maybe at a larger track it might have a purpose, but for now =
Not for me at my current skill level
Here's a good read = http://radiocontrolzone.com/showthread.php?t=267694
Set up Tips For Asphalt...:
Balance the car - This is going to be a challenge because the S2 is ass heavy
The battery needs to be moved forward =
This is a mod I am currently working on (more to come soon)
My car pushes big time - lacking decent front traction...
Balance the shocks - all equal lengths
Chassis protector - or a chassis that you don't mind getting scratched to hell
The OEM chassis are CRAP out of the box =
All warped =
If you want to be competitive =
(IMAO) Go carbon fiber or aluminum for accuracy
Or just stick with the OEM POS chassis
Not sure which upgrades or fixes you have done yet - if any - now's the time to tackle the ones you like that will work for you
#378
i noticed on mine the other day after a parking lot run my rear diff spins super free when you spin the tire by hand and my front diff does'nt spin free, it feels tight when you spin the tire by hand
Diffs are stock and i am wondering which is the one with the problem? loose or stiff?
Diffs are stock and i am wondering which is the one with the problem? loose or stiff?
#379
i noticed on mine the other day after a parking lot run my rear diff spins super free when you spin the tire by hand and my front diff does'nt spin free, it feels tight when you spin the tire by hand
Diffs are stock and i am wondering which is the one with the problem? loose or stiff?
Diffs are stock and i am wondering which is the one with the problem? loose or stiff?
The grease that HPI uses is covering the gears
As you use the car the grease displaces some and the diff spins easier
HOLDING THE SPUR SO IT DOESN'T TURN
My front is stiffer because I have a tuning spring in it -
Possibly, your front had more grease than the rear (?)
Someone else with more knowledge can chime in at any time...
Last edited by Marv; 02-23-2013 at 09:02 PM.
#380
With a brand new S2 both diff will be a bit stiff =
The grease that HPI uses is covering the gears
As you use the car the grease displaces some and the diff spins easier
HOLDING THE SPUR SO IT DOESN'T TURN
My front is stiffer because I have a tuning spring in it -
Possibly, your front had more grease than the rear (?)
Someone else with more knowledge can chime in at any time...
The grease that HPI uses is covering the gears
As you use the car the grease displaces some and the diff spins easier
HOLDING THE SPUR SO IT DOESN'T TURN
My front is stiffer because I have a tuning spring in it -
Possibly, your front had more grease than the rear (?)
Someone else with more knowledge can chime in at any time...
#381
Sad day... as I watched the background graphics change =
No Sprint 2 Sport...
Sad day indeed...
http://www.hpiracing.com/news/2013021501/
Or maybe they just forgot...
No Sprint 2 Sport...
Sad day indeed...
http://www.hpiracing.com/news/2013021501/
Or maybe they just forgot...
#382
Tech Apprentice
#383
I have both types - But this one is very hard to find =
HPI72215 =
This came as a diff tuning kit for the RS4 Nitro line (same diff back them as electric)
I back the spring ends with HPI72111 SHIM(S) =
This increasesspring preload
Brit Site has a bunch in stock = http://www.hpirchobby.com/hpi-gear-d...15-p-5004.html
This one is available on the net
The spring itself is different in wire thickness an overall length
I think I have a diff with one of these in it as well
I have a number of diffs....
HPI87023
I'm not the expert -
For now, I prefer using the spring method =
Less mess...
The spring is constant = won't be affected by heat/cold as much a diff oil is (IMAO)
HPI72215 =
This came as a diff tuning kit for the RS4 Nitro line (same diff back them as electric)
I back the spring ends with HPI72111 SHIM(S) =
This increasesspring preload
Brit Site has a bunch in stock = http://www.hpirchobby.com/hpi-gear-d...15-p-5004.html
This one is available on the net
The spring itself is different in wire thickness an overall length
I think I have a diff with one of these in it as well
I have a number of diffs....
HPI87023
I'm not the expert -
For now, I prefer using the spring method =
Less mess...
The spring is constant = won't be affected by heat/cold as much a diff oil is (IMAO)
Last edited by Marv; 02-21-2013 at 06:19 PM.
#384
Just a headzup =
Swapping out a diff on the S2 is not a walk in the park
Carefull planning and keen attention to shit that flies that ain't suppose to fly and then the follow up noises = sproing ---zoooom---clack and more...
And if you don't intend on buying replacement E clips then
A)Don't lose any and
B) Give each a squeeze to snug it up some before you reinstall it...
Swapping out a diff on the S2 is not a walk in the park
Carefull planning and keen attention to shit that flies that ain't suppose to fly and then the follow up noises = sproing ---zoooom---clack and more...
And if you don't intend on buying replacement E clips then
A)Don't lose any and
B) Give each a squeeze to snug it up some before you reinstall it...
Last edited by Marv; 02-23-2013 at 09:03 PM.
#385
Just a headzup =
Swapping out a diff on the S2 is not a walk in the park
Carefull planning and keen attention to shit that flies that ain't suppose to fly and then the follow up noises = sproing ---zoooom---clack and more...
And if don't intend on buying replacement E clips then
A)Don't lose any and
B) Give each a squeeze to snug it up some before you reinstall it...
Swapping out a diff on the S2 is not a walk in the park
Carefull planning and keen attention to shit that flies that ain't suppose to fly and then the follow up noises = sproing ---zoooom---clack and more...
And if don't intend on buying replacement E clips then
A)Don't lose any and
B) Give each a squeeze to snug it up some before you reinstall it...
#386
Gotta love taking things apart.....then while you're not looking...SPROINGO!
#388
#389
Sad day... as I watched the background graphics change =
No Sprint 2 Sport...
Sad day indeed...
http://www.hpiracing.com/news/2013021501/
Or maybe they just forgot...
No Sprint 2 Sport...
Sad day indeed...
http://www.hpiracing.com/news/2013021501/
Or maybe they just forgot...