6LikesHPI Sprint 2 Mods
12-21-2012, 04:33 PM
#197
I went to a practice session today, had a blast, but at the same time, i'm disappointed a little of the car's performance.
It was incredibly smooth, i had a lot of traction, but doing setup changes was a chore, i had to remove so many parts to get to, example the shock ball cups, and because the plastic in the arms is soft, the car was not consistent, i couldn't get 2 laps the same.
I am going to try to get the Sprint 1 steering posts online somewhere, to help with the slop in the steering. I noticed my front wheels were not true in a turn they were not bounce around, but wiggle, and i know it wasn't because of my servo, the wheels or the servo saver. Just need to find someone who still has the parts!
I will also try to find the shock towers in carbon fiber, might help with the consistence, for the suspension geometry, the top arms where the ball stud is able to move because of the plastic. Good in accidents, but not great in racing. I'll convert this car to VTA and see what's out there for Sedan 17.5 stock.
Everything else was great, the RPM cups were strong, the dog bones never popped out from all the shims (thanks Marv)
It was incredibly smooth, i had a lot of traction, but doing setup changes was a chore, i had to remove so many parts to get to, example the shock ball cups, and because the plastic in the arms is soft, the car was not consistent, i couldn't get 2 laps the same.
I am going to try to get the Sprint 1 steering posts online somewhere, to help with the slop in the steering. I noticed my front wheels were not true in a turn they were not bounce around, but wiggle, and i know it wasn't because of my servo, the wheels or the servo saver. Just need to find someone who still has the parts!
I will also try to find the shock towers in carbon fiber, might help with the consistence, for the suspension geometry, the top arms where the ball stud is able to move because of the plastic. Good in accidents, but not great in racing. I'll convert this car to VTA and see what's out there for Sedan 17.5 stock.
Everything else was great, the RPM cups were strong, the dog bones never popped out from all the shims (thanks Marv)
12-21-2012, 08:22 PM
#198
You should look at aluminum a arms. They are fairly cheap and pretty durable, but are quite heavy compared to the weak plastic stock ones.
12-21-2012, 09:10 PM
#199
It was incredibly smooth, i had a lot of traction, but doing setup changes was a chore, i had to remove so many parts to get to, example the shock ball cups, and because the plastic in the arms is soft, the car was not consistent, i couldn't get 2 laps the same.
I am going to try to get the Sprint 1 steering posts online somewhere, to help with the slop in the steering. I noticed my front wheels were not true in a turn they were not bounce around, but wiggle, and i know it wasn't because of my servo, the wheels or the servo saver. Just need to find someone who still has the parts!
I will also try to find the shock towers in carbon fiber, might help with the consistence, for the suspension geometry, the top arms where the ball stud is able to move because of the plastic. Good in accidents, but not great in racing. I'll convert this car to VTA and see what's out there for Sedan 17.5 stock.
(thanks Marv)
12-22-2012, 11:43 AM
#200
I went to a practice session today, had a blast, but at the same time, i'm disappointed a little of the car's performance.
It was incredibly smooth, i had a lot of traction, but doing setup changes was a chore, i had to remove so many parts to get to, example the shock ball cups, and because the plastic in the arms is soft, the car was not consistent, i couldn't get 2 laps the same.
I am going to try to get the Sprint 1 steering posts online somewhere, to help with the slop in the steering. I noticed my front wheels were not true in a turn they were not bounce around, but wiggle, and i know it wasn't because of my servo, the wheels or the servo saver. Just need to find someone who still has the parts!
I will also try to find the shock towers in carbon fiber, might help with the consistence, for the suspension geometry, the top arms where the ball stud is able to move because of the plastic. Good in accidents, but not great in racing. I'll convert this car to VTA and see what's out there for Sedan 17.5 stock.
Everything else was great, the RPM cups were strong, the dog bones never popped out from all the shims (thanks Marv)
It was incredibly smooth, i had a lot of traction, but doing setup changes was a chore, i had to remove so many parts to get to, example the shock ball cups, and because the plastic in the arms is soft, the car was not consistent, i couldn't get 2 laps the same.
I am going to try to get the Sprint 1 steering posts online somewhere, to help with the slop in the steering. I noticed my front wheels were not true in a turn they were not bounce around, but wiggle, and i know it wasn't because of my servo, the wheels or the servo saver. Just need to find someone who still has the parts!
I will also try to find the shock towers in carbon fiber, might help with the consistence, for the suspension geometry, the top arms where the ball stud is able to move because of the plastic. Good in accidents, but not great in racing. I'll convert this car to VTA and see what's out there for Sedan 17.5 stock.
Everything else was great, the RPM cups were strong, the dog bones never popped out from all the shims (thanks Marv)
Mine hopped/lurched before I upgraded to the Universal Dog Bones aka CVD's, aluminum C blocks and shimmed up ALL of the steering and axle parts.
I'd turn tight and the inside wheel would lurch/hop.
As you turn the OEM dog bones shift back and forth laterally and partially bind {especially in a tight turn}.
CVD's don't move back and forth laterally.
Also, what I found was that after I shimmed the flange pipes themselves AND replaced the upper 4-40 ball stud with a M3 ball stud = I have no more lurch/hop.
Your wiggle may also be linked to the hex nut to wheel fit = They don't fit tight. The hex nuts need to be shimmed {wrapped in tape} for a tight centered fit.
SHIMS =
Steering components
Suspension components
Front & rear diffs
Axles
Main shaft
Spur gear
Weight distribution - GOTTA have even cross weight / right-left.
If you slot the battery holders {as outlined in this thread} then you can adjust cross weight {side to side} by moving the battery right or left.
If your battery isn't anchored it will move around - GOTTA have the battery mounted solidly.
I use a 1/2" strip of leather and gravity for a scale to set my weight.
It may not be a dead-nutz accurate way to do it, but it's cheap and...
It works for me.
The OEM black #20 springs may well be TOO stiff for the track surface & type of course you are trying to drive.
Watch this series of YT videos this guy posted - see if you can figure out his issue:
| + YouTube Video | |
12-22-2012, 01:07 PM
#201
You tube video
Looks like too much angle on the universal joint to me. You shouldn't need that much steering to get these cars to turn.
12-22-2012, 06:59 PM
#202
Yup, as he turns tighter, the CVDs bind - just like on a 1:1 -
Also the dog bones in the ball diff drive cups are not stabilized...
Watch close them closely as he goes to full turn.
There's a good chance that his hex nuts are a slop fit in the wheel hexes - After he puts the wheels on you can see the one is running out or round in addition to the natural wheel warp itself.
Mine were hopping like that before I shimmed everything up AND upgraded to the CVDs & changed out the front camber link to C block 4-40 ball stud with an M3 ball stud.
Also the dog bones in the ball diff drive cups are not stabilized...
Watch close them closely as he goes to full turn.
There's a good chance that his hex nuts are a slop fit in the wheel hexes - After he puts the wheels on you can see the one is running out or round in addition to the natural wheel warp itself.
Mine were hopping like that before I shimmed everything up AND upgraded to the CVDs & changed out the front camber link to C block 4-40 ball stud with an M3 ball stud.
12-22-2012, 07:17 PM
#203
The Silk Purse survived another night at Westgate.
Last week Coach said it looked like the Purse was pushing, so I added some weight to the front of the body for more front traction...{easier than changing shock springs}.
It seemed to work.
The recommended hoops @ Westgate are the pre-glued Sweep OG SPEC w/SWA-S inserts.
I was reluctant to change from my USVTA hoops, but it isn't a USVTA race...
Last night I ran a set of pre-glued Solaris S-TSHGM4B, that I had.
I was as hooked up as good as anyone I suppose, but I wasn't running balls-to-the-wall like the rest were and I spent most of my time getting out of their way...
That put me in the shitz = My tires got full of dust and glitter.
Vintage hoops are like combat boots compared to the Solaris =
Changing over lightened up the race weight a good 20 grams.
Weighing in at a petite 1660-ish grams with the Solaris (1680-ish w/Vintage) -
My car is still a friggin' tank compared to the light weight CF chassis and TC bodies.
In a field with a Schuemacher, T2 XRay, two TC5s, TC4, TC6 and a Cyclone (HPI) - The Purse took several direct and really brutal hits during the course of the evening with the worst one knocking a rear hub so hard that the camber link popped off the ball stud and she spit a dog bone.
I noticed a crack in a body seam at the rear valance panel that I neglected to glass-n-goo, but nothing major.
That's been all G&G'd now.
My ESC & switch are chassis mounted - probably not a good idea...
Last week I side banged one of the barrier ends and it shut off my ESC power switch.
That evening after I got home, I made a ESC/switch guard, sort of a nerf, for my ESC & on/off switch -
Anyway, that got smacked & got knocked loose once and knocked off once...
I'll be mounting that with screws before the next race.
But it's a damned good thing I made & installed it -
Otherwise those hits coulda wiped out my ESC & switch.
Other guys weren't so lucky: two guys trashed front control arms (the T2 Xray & the Cyclone), one fried his Tamiya Black Can (TC6) and another had his servo bite the dust (Schumacher).
And these are only 5 minute races!
But they're fast & furious and on a tight course.
Last week Coach said it looked like the Purse was pushing, so I added some weight to the front of the body for more front traction...{easier than changing shock springs}.
It seemed to work.
The recommended hoops @ Westgate are the pre-glued Sweep OG SPEC w/SWA-S inserts.
I was reluctant to change from my USVTA hoops, but it isn't a USVTA race...
Last night I ran a set of pre-glued Solaris S-TSHGM4B, that I had.
I was as hooked up as good as anyone I suppose, but I wasn't running balls-to-the-wall like the rest were and I spent most of my time getting out of their way...
That put me in the shitz = My tires got full of dust and glitter.
Vintage hoops are like combat boots compared to the Solaris =
Changing over lightened up the race weight a good 20 grams.
Weighing in at a petite 1660-ish grams with the Solaris (1680-ish w/Vintage) -
My car is still a friggin' tank compared to the light weight CF chassis and TC bodies.
In a field with a Schuemacher, T2 XRay, two TC5s, TC4, TC6 and a Cyclone (HPI) - The Purse took several direct and really brutal hits during the course of the evening with the worst one knocking a rear hub so hard that the camber link popped off the ball stud and she spit a dog bone.
I noticed a crack in a body seam at the rear valance panel that I neglected to glass-n-goo, but nothing major.
That's been all G&G'd now.
My ESC & switch are chassis mounted - probably not a good idea...
Last week I side banged one of the barrier ends and it shut off my ESC power switch.
That evening after I got home, I made a ESC/switch guard, sort of a nerf, for my ESC & on/off switch -
Anyway, that got smacked & got knocked loose once and knocked off once...
I'll be mounting that with screws before the next race.
But it's a damned good thing I made & installed it -
Otherwise those hits coulda wiped out my ESC & switch.
Other guys weren't so lucky: two guys trashed front control arms (the T2 Xray & the Cyclone), one fried his Tamiya Black Can (TC6) and another had his servo bite the dust (Schumacher).
And these are only 5 minute races!
But they're fast & furious and on a tight course.
12-22-2012, 07:35 PM
#204
The Silk Purse survived another night at Westgate.
Last week Coach said it looked like the Purse was pushing, so I added some weight to the front of the body for more front traction...{easier than changing shock springs}.
It seemed to work.
The recommended hoops @ Westgate are the pre-glued Sweep OG SPEC w/SWA-S inserts.
I was reluctant to change from my USVTA hoops, but it isn't a USVTA race...
Last night I ran a set of pre-glued Solaris S-TSHGM4B, that I had.
I was as hooked up as good as anyone I suppose, but I wasn't running balls-to-the-wall like the rest were and I spent most of my time getting out of their way...
That put me in the shitz = My tires got full of dust and glitter.
Vintage hoops are like combat boots compared to the Solaris =
Changing over lightened up the race weight a good 20 grams.
Weighing in at a petite 1660-ish grams with the Solaris (1680-ish w/Vintage) -
My car is still a friggin' tank compared to the light weight CF chassis and TC bodies.
In a field with a Schuemacher, T2 XRay, two TC5s, TC4, TC6 and a Cyclone (HPI) - The Purse took several direct and really brutal hits during the course of the evening with the worst one knocking a rear hub so hard that the camber link popped off the ball stud and she spit a dog bone.
I noticed a crack in a body seam at the rear valance panel that I neglected to glass-n-goo, but nothing major.
That's been all G&G'd now.
My ESC & switch are chassis mounted - probably not a good idea...
Last week I side banged one of the barrier ends and it shut off my ESC power switch.
That evening after I got home, I made a ESC/switch guard, sort of a nerf, for my ESC & on/off switch -
Anyway, that got smacked & got knocked loose once and knocked off once...
I'll be mounting that with screws before the next race.
But it's a damned good thing I made & installed it -
Otherwise those hits coulda wiped out my ESC & switch.
Other guys weren't so lucky: two guys trashed front control arms (the T2 Xray & the Cyclone), one fried his Tamiya Black Can (TC6) and another had his servo bite the dust (Schumacher).
And these are only 5 minute races!
But they're fast & furious and on a tight course.
Last week Coach said it looked like the Purse was pushing, so I added some weight to the front of the body for more front traction...{easier than changing shock springs}.
It seemed to work.
The recommended hoops @ Westgate are the pre-glued Sweep OG SPEC w/SWA-S inserts.
I was reluctant to change from my USVTA hoops, but it isn't a USVTA race...
Last night I ran a set of pre-glued Solaris S-TSHGM4B, that I had.
I was as hooked up as good as anyone I suppose, but I wasn't running balls-to-the-wall like the rest were and I spent most of my time getting out of their way...
That put me in the shitz = My tires got full of dust and glitter.
Vintage hoops are like combat boots compared to the Solaris =
Changing over lightened up the race weight a good 20 grams.
Weighing in at a petite 1660-ish grams with the Solaris (1680-ish w/Vintage) -
My car is still a friggin' tank compared to the light weight CF chassis and TC bodies.
In a field with a Schuemacher, T2 XRay, two TC5s, TC4, TC6 and a Cyclone (HPI) - The Purse took several direct and really brutal hits during the course of the evening with the worst one knocking a rear hub so hard that the camber link popped off the ball stud and she spit a dog bone.
I noticed a crack in a body seam at the rear valance panel that I neglected to glass-n-goo, but nothing major.
That's been all G&G'd now.
My ESC & switch are chassis mounted - probably not a good idea...
Last week I side banged one of the barrier ends and it shut off my ESC power switch.
That evening after I got home, I made a ESC/switch guard, sort of a nerf, for my ESC & on/off switch -
Anyway, that got smacked & got knocked loose once and knocked off once...
I'll be mounting that with screws before the next race.
But it's a damned good thing I made & installed it -
Otherwise those hits coulda wiped out my ESC & switch.
Other guys weren't so lucky: two guys trashed front control arms (the T2 Xray & the Cyclone), one fried his Tamiya Black Can (TC6) and another had his servo bite the dust (Schumacher).
And these are only 5 minute races!
But they're fast & furious and on a tight course.
And is the Tamiya silver can faster/more powerful than the stock Firebolt 15T?
12-22-2012, 08:16 PM
#205
Marv, the vibrations you were experiencing are due to the fact that you are using CVD drives with a spool up front. You need to get DCJ's( double cardan joints) to run up front, and I think hpi or hb makes One , but I don't know if their dcj's will fit your Car... Good luck, and you can google/search for dcj's , ecs drives(aftermarket)......
12-22-2012, 08:20 PM
#206
Jesus! In SCT racing, the worst thing that ever happened was someone's lipos exploded and caught fire. The truck exploded too. Mostly, the worst thing that happens is that you het rear ended and get som cracks or dings. And my esc is far in board and is flawless. I have nerf bars from the chassis out to the body which are priceless.
And is the Tamiya silver can faster/more powerful than the stock Firebolt 15T?
And is the Tamiya silver can faster/more powerful than the stock Firebolt 15T?
Keeping in mind that these guys have been running together for some time & I'm the noob {in more ways than one}...
AND I'm running a 25.5 w/o any timing advance against 21.5s and Black Cans =
I'm doing ok by my standards.
No - The Firebolt is {suppose to be}faster =
Less turns - 15T.
TSC is about 27 turns I believe.
The Firebolt won't last long.
Consider upgrading to a brushless system.
Believe it or not - There's a TAMIYA SILVER CAN THREAD here on R/C Tech = http://www.rctech.net/forum/electric...ps-tricks.html
Last edited by Marv; 12-29-2012 at 06:53 AM.
12-22-2012, 08:23 PM
#207
Hpi DCJ drive part# 67699 $38 . It was not made for the sprint2 though. Maybe it can be retrofitted......
12-22-2012, 08:44 PM
#209
These DCJ's fit the HB cyclone tc that uses the B021 (5mm) wheel Bearings, and it seems that the Sprint2 also came with those same Bearings. All that's left is to make sure the dcj bones are long enough to reach the drivecups.So I think you're good to go...
12-23-2012, 09:35 PM
#210
Keeping in mind that these guys have been running together for some time & I'm the noob {in more ways than one}...
AND I'm running a 25.5 w/o any timing advance against 21.5s {and that lone TBC} =
I'm doing ok by my standards.
No - The Firebolt is faster = Less turns.
TSC is about 27 turns I believe.
The Firebolt won't last long.
Consider upgrading to a brushless system.
Believe it or not - There's a TAMIYA SILVER CAN THREAD here on R/C Tech = http://www.rctech.net/forum/electric...ps-tricks.html
What Brushless system should I get?
An Hpi Flux Vektor from a sprint 2 flux?
A Traxxas Velinion? (Hence my name)
A castle system (probably too expensive)
Anyways, I want a durable motor that requires little to no maintenence, smooth acceleration, under $130, and is easy to get parts for.