6LikesHPI Sprint 2 Mods
03-21-2013, 07:16 PM
#451
From what I have see =
The cars come with BLACK 20.9 pound springs front and rear
If you're driving on a street/ parking lot and not a track =
Yes, rear end is going to bounce
More info would help =
Radio, receiver, ESC... etc
Could be dragging = binding somewhere
Drag brake set too high
There's many tight places on the S2 where debris and small stones can lodge and not be easily seen
Belts too tight
Crap in motor
You might consider resetting/reprogramming the ESC
OTHER
Are there any of you S2 owners (other than me) that are actually racing your S2 in track competitions?
Please post up the track you race at, the class you're racing your S2 in, the field you're racing against / other types of cars = names and models, and the results...
Thanks
03-24-2013, 10:40 AM
#452
I thought i would post a pic of my sprint 2 with new wheels and super radials for the parking lot and my 65 coupe in the driveway with mickey thompson sportsmans.
I took the rc car to the parking lot one night in the real car
I took the rc car to the parking lot one night in the real car
03-24-2013, 01:23 PM
#453
I tested the Super Radials in the culdesac and for folks wanting some grip in a "parking lot race" these things are great! HPI numbers 5130 and 4511 (26mm and 31mm)
They fit the vintage wheels but leave a larger area of chrome on the side of the rim (that the vintage tire hides) and i had to trim the foam inserts in half "long ways" with a razor blade so they were thinner inside the tire so the tire didnt "balloon" on the rim, these tires are real soft so the foam pushed the tread outward (up).
They fit the vintage wheels but leave a larger area of chrome on the side of the rim (that the vintage tire hides) and i had to trim the foam inserts in half "long ways" with a razor blade so they were thinner inside the tire so the tire didnt "balloon" on the rim, these tires are real soft so the foam pushed the tread outward (up).
03-28-2013, 05:57 AM
#455
Tech Regular
iTrader: (4)
So, I bought another Sprint 2 chassis used and got another Exotek setup for it. The 3 parts of the Exotek chassis weigh 79.8 grams total. I'll be building it to run a 17.5 Nastruck setup. I will try to get some better pictures of the mods I do to it as I build it. It should be a nice truck when I'm done.
03-30-2013, 01:46 PM
#456
So, I bought another Sprint 2 chassis used and got another Exotek setup for it. The 3 parts of the Exotek chassis weigh 79.8 grams total. I'll be building it to run a 17.5 Nastruck setup. I will try to get some better pictures of the mods I do to it as I build it. It should be a nice truck when I'm done.
Great info on the tires Max - Thanks!!!
Thanks nubi-wan for the weights on the Exotek parts -
I noticed that the Brit company that was making the aluminum chassis/upper deck upgrades is out of product again -
Hopefully they'll start up production again =
I wanted to get one, but waited too long...
With nice weather here = I have a (rough surface) tennis court across the street from me - LITERALLY across the street...
Like 50 yards maybe that I can run in but I don't want to sacrifice my one of chassis to the pavement gods...
Either I'll slap on the OEM or maybe get the HPI carbon fiber to toss on the alter -
My 1:1 is out of commission =
I'll have even more time on my hands ---
One poster suggested that I make a list of where all the various posts on mods and upgrades can be found within this thread - - -
I know it's a bite to go through this thread looking for something specific -
So I might be working on that for a spell -
Then there's the battery move mod yet to do up the pics & post on...
Last edited by Marv; 04-24-2013 at 04:23 PM.
04-02-2013, 02:03 PM
#457
AN UPGRADE/FIX FOR AN UPGRADE/FIX - STEERING BUZZ VOODOO
Everyone has their own voodoo.
This is my voodoo.
This is what works for me...
Until I find better voodoo.
*New voodoo is added as it becomes available.
THIS is better voodoo.
AN UPGRADE/FIX FOR AN UPGRADE/FIX - STEERING BUZZ VOODOO
My Savox still hard a slight buzz every once in a while =
An ever so slight "bind" somewhere in the steering =
Found it =
I replaced the RPM ball cups and OEM ball studs on the servo arm / servo saver link with TRAXXAS rod ends and used two ˝” X 4-40 Allen heads screws to mount that I had lying about from fixing a kid’s Stampede a while back (the OEM ball studs are 4-40 thread ) =
No more buzz...
PARTS NEEDED:
*TRAXXAS 1942 ($7.00 retail)
Technical info plagiarized from a web site:
This set of rod ends, balls, and screws is used on all but four of Traxxas' kits.
Includes: 4 short rod ends (17mm), 16 long rod ends (19mm), 2 ball screws, 18 hollow ball connectors
*2 Button Head Allen Screws 4-40 X 1/2”
NOTE:
I used two of the shorter ends & a small vise to pop the balls in.
This is my voodoo.
This is what works for me...
Until I find better voodoo.
*New voodoo is added as it becomes available.
THIS is better voodoo.
AN UPGRADE/FIX FOR AN UPGRADE/FIX - STEERING BUZZ VOODOO
My Savox still hard a slight buzz every once in a while =
An ever so slight "bind" somewhere in the steering =
Found it =
I replaced the RPM ball cups and OEM ball studs on the servo arm / servo saver link with TRAXXAS rod ends and used two ˝” X 4-40 Allen heads screws to mount that I had lying about from fixing a kid’s Stampede a while back (the OEM ball studs are 4-40 thread ) =
No more buzz...
PARTS NEEDED:
*TRAXXAS 1942 ($7.00 retail)
Technical info plagiarized from a web site:
This set of rod ends, balls, and screws is used on all but four of Traxxas' kits.
Includes: 4 short rod ends (17mm), 16 long rod ends (19mm), 2 ball screws, 18 hollow ball connectors
*2 Button Head Allen Screws 4-40 X 1/2”
NOTE:
I used two of the shorter ends & a small vise to pop the balls in.
04-03-2013, 03:20 PM
#458
Tech Regular
iTrader: (29)
Join Date: Aug 2011
Location: Katy, Tx..But from Riverside Cali
Posts: 401
Trader Rating: 29 (100%+)
alright guys, ive mastered my stock setup when it comes to drifting. Now, don't make fun of me. But do I lock the rear diff? front diff? or both? I was going to throw some 100,000 wt fluid.
04-03-2013, 03:34 PM
#459
Tech Regular
iTrader: (29)
Join Date: Aug 2011
Location: Katy, Tx..But from Riverside Cali
Posts: 401
Trader Rating: 29 (100%+)
besides some awesome skill and tons of practice, what do you all think this guy is running?? http://www.youtube.com/watch?v=l9PgUx81FNk
04-09-2013, 08:05 PM
#461
SNAGGED OFF THE HPI SITE:
SPRINGS -
"What they do: Springs are a part of the shock assembly. They are the coiled metal wire (usually painted) that wraps around the main body of the shock. Based upon the length of the spring, number of coils, thickness of the wire, and how they are coiled, springs will resist more or less weight. The amount of weight that it takes to compress a spring a given distance is the spring’s “rate”. For example, the HPI # 3846 Green Pro Linear Spring has a spring rate of 247 gF/mm. This means that it takes 247 grams of force to compress the spring 1mm. The greater this spring rate, the “heavier” the spring is because it will hold more weight. There are two different types of springs as well, linear and progressive. Linear springs have the same spring rate no matter how far they are compressed. For the above linear spring, 247 gF would compress the spring 1mm. To compress the spring another mm, the total force applied to the spring would have to be doubled to a total of 494 gF. Twice the distance, twice the weight. However, Progressive springs will require more weight to compress them the more they are compressed. For instance, HPI part number 6833 White Progressive Spring has a spring rate of 298 gF/mm. The first mm of travel would take 298 gF. However, the second mm of travel will require more than 298 gF to compress it. To make things easy we’ll say it increases to 305 gF. This means that to compress that spring 2mm it would take a total of 603 gF not 596 gF. Springs control weight shift during acceleration and braking. The softer the spring rate, the more weight will be transferred to that tire. Springs are usually color coded by each manufacturer so racers can easily identify the rate of each spring relative to the other springs that manufacturer sells.
How to Change them: With springs there are only two adjustments. You can change the spring’s rate or type, either linear or progressive.
When to Change them: Because springs are one of those items that determine how much weight is shifted from one end of the car to the other, namely the front to the back, you will change them in pairs. (The only exception to this is oval cars that can also change them left to right since oval cars only turn one-way). Also, since springs only work for controlling weight transfer front to rear the way to tell if you need a spring change can be determined by what the car is doing. For instance, if the car spins out when going into a turn as it is slowing down, but is good coming out when you apply throttle, this means that you should probably try going to a harder spring in front. This will let less weight transfer to the front tires keeping more weight on the rear tires thus providing more rear traction. If a car pushes as it accelerates out of the corner, then go to a harder spring in the back. Track type is also a determining factor. A track that has a lot of traction means that you will not want the weight of the car moving around too much so you can go with harder springs. Having the weight shift too much on a high traction track (or having a tire that is much too soft) will cause a traction roll. If you car traction rolls, look to using heavier springs first. A track with little traction will require the tires to do more work. By going to a softer spring you will be allowing the weight to shift around more thus putting more weight on the tires to gain more traction. The only exception to this last rule is on bumpy tracks. If the track is very bumpy, regardless of traction, a slightly softer spring than normal will have to be used so that the car can absorb the bumps on the surface. If the car seems to “hop” a lot on a bumpy track, this is a sign that the suspension or tire insert is too firm.
Tips: It is a good idea to stay within about 2 spring rates front to back. In other words, the springs on the front of the car should be no more than 2 spring rates softer or harder than the springs at the rear of the car. "
SPRINGS -
"What they do: Springs are a part of the shock assembly. They are the coiled metal wire (usually painted) that wraps around the main body of the shock. Based upon the length of the spring, number of coils, thickness of the wire, and how they are coiled, springs will resist more or less weight. The amount of weight that it takes to compress a spring a given distance is the spring’s “rate”. For example, the HPI # 3846 Green Pro Linear Spring has a spring rate of 247 gF/mm. This means that it takes 247 grams of force to compress the spring 1mm. The greater this spring rate, the “heavier” the spring is because it will hold more weight. There are two different types of springs as well, linear and progressive. Linear springs have the same spring rate no matter how far they are compressed. For the above linear spring, 247 gF would compress the spring 1mm. To compress the spring another mm, the total force applied to the spring would have to be doubled to a total of 494 gF. Twice the distance, twice the weight. However, Progressive springs will require more weight to compress them the more they are compressed. For instance, HPI part number 6833 White Progressive Spring has a spring rate of 298 gF/mm. The first mm of travel would take 298 gF. However, the second mm of travel will require more than 298 gF to compress it. To make things easy we’ll say it increases to 305 gF. This means that to compress that spring 2mm it would take a total of 603 gF not 596 gF. Springs control weight shift during acceleration and braking. The softer the spring rate, the more weight will be transferred to that tire. Springs are usually color coded by each manufacturer so racers can easily identify the rate of each spring relative to the other springs that manufacturer sells.
How to Change them: With springs there are only two adjustments. You can change the spring’s rate or type, either linear or progressive.
When to Change them: Because springs are one of those items that determine how much weight is shifted from one end of the car to the other, namely the front to the back, you will change them in pairs. (The only exception to this is oval cars that can also change them left to right since oval cars only turn one-way). Also, since springs only work for controlling weight transfer front to rear the way to tell if you need a spring change can be determined by what the car is doing. For instance, if the car spins out when going into a turn as it is slowing down, but is good coming out when you apply throttle, this means that you should probably try going to a harder spring in front. This will let less weight transfer to the front tires keeping more weight on the rear tires thus providing more rear traction. If a car pushes as it accelerates out of the corner, then go to a harder spring in the back. Track type is also a determining factor. A track that has a lot of traction means that you will not want the weight of the car moving around too much so you can go with harder springs. Having the weight shift too much on a high traction track (or having a tire that is much too soft) will cause a traction roll. If you car traction rolls, look to using heavier springs first. A track with little traction will require the tires to do more work. By going to a softer spring you will be allowing the weight to shift around more thus putting more weight on the tires to gain more traction. The only exception to this last rule is on bumpy tracks. If the track is very bumpy, regardless of traction, a slightly softer spring than normal will have to be used so that the car can absorb the bumps on the surface. If the car seems to “hop” a lot on a bumpy track, this is a sign that the suspension or tire insert is too firm.
Tips: It is a good idea to stay within about 2 spring rates front to back. In other words, the springs on the front of the car should be no more than 2 spring rates softer or harder than the springs at the rear of the car. "
04-10-2013, 04:53 AM
#462
Hey Marv,
What lipo batteries are you using? i bought a turnigy but with the hard case it wont fit the car so i took off the plastic case and it fit fine but when i go to plug it in i get a big spark so i never used it.
What lipo batteries are you using? i bought a turnigy but with the hard case it wont fit the car so i took off the plastic case and it fit fine but when i go to plug it in i get a big spark so i never used it.
04-10-2013, 07:03 AM
#463
Tech Regular
iTrader: (4)
The cells need to be insulated as the connections are now exposed unless you taped over them. Also, make sure you have marked the + and - connections properly as it sounds like you plugged it in backwards possibly. I would look back through this thread at the battery area mods that either I did or Marv did to remedy that fitment issue. Running a LiPo pack without the case is a bad idea and can burn your car up and your house down. You may have melted the connection between the cells when it sparked too. That can be fixed if neither of the cells puffed in the process. Please inspect that pack carefully and enlist some assistance if not sure. It really should be re-assembled if viable.
You need to mod the battery area to get the case to fit or find a smaller battery. Most of the hard case 2S LiPos are too big for them to fit without modding the car. I used a Dremel and files to remove about a 16th of an inch of material from the underside of the swing arms. The channel I milled is now level with the underside of the claws that hold the battery pack in. I filed the screws shorter too so they don't mess with the battery case. I know my picture is fuzzy and I will be posting some better ones soon. My largest packs, some Gens-Ace 40c packs, now fit easily with little slop. Just enough to allow some flex in the chassis. My Venom packs are a bit looser.
04-10-2013, 07:38 AM
#464
Mod links are under nubie-wan's post quote
Not to hijack the thread Marv, but I have some advice.
The cells need to be insulated as the connections are now exposed unless you taped over them. Also, make sure you have marked the + and - connections properly as it sounds like you plugged it in backwards possibly. I would look back through this thread at the battery area mods that either I did or Marv did to remedy that fitment issue. Running a LiPo pack without the case is a bad idea and can burn your car up and your house down. You may have melted the connection between the cells when it sparked too. That can be fixed if neither of the cells puffed in the process. Please inspect that pack carefully and enlist some assistance if not sure. It really should be re-assembled if viable.
You need to mod the battery area to get the case to fit or find a smaller battery. Most of the hard case 2S LiPos are too big for them to fit without modding the car. I used a Dremel and files to remove about a 16th of an inch of material from the underside of the swing arms. The channel I milled is now level with the underside of the claws that hold the battery pack in. I filed the screws shorter too so they don't mess with the battery case. I know my picture is fuzzy and I will be posting some better ones soon. My largest packs, some Gens-Ace 40c packs, now fit easily with little slop. Just enough to allow some flex in the chassis. My Venom packs are a bit looser.
The cells need to be insulated as the connections are now exposed unless you taped over them. Also, make sure you have marked the + and - connections properly as it sounds like you plugged it in backwards possibly. I would look back through this thread at the battery area mods that either I did or Marv did to remedy that fitment issue. Running a LiPo pack without the case is a bad idea and can burn your car up and your house down. You may have melted the connection between the cells when it sparked too. That can be fixed if neither of the cells puffed in the process. Please inspect that pack carefully and enlist some assistance if not sure. It really should be re-assembled if viable.
You need to mod the battery area to get the case to fit or find a smaller battery. Most of the hard case 2S LiPos are too big for them to fit without modding the car. I used a Dremel and files to remove about a 16th of an inch of material from the underside of the swing arms. The channel I milled is now level with the underside of the claws that hold the battery pack in. I filed the screws shorter too so they don't mess with the battery case. I know my picture is fuzzy and I will be posting some better ones soon. My largest packs, some Gens-Ace 40c packs, now fit easily with little slop. Just enough to allow some flex in the chassis. My Venom packs are a bit looser.
nubie-wan - you jump in anytime!!!
My voodoo isn't the only voodoo out there
Nor is it the only voodoo that works...
Amen...
+1 on what nubie-wan said - Max
SPARKS = BAD JUJU = Sounds like you crossed the polarity = Worse case scenario = You may have fried the ESC too...
To get thicker batteries in =
You'll need to do a belt lit mod / Mine is here = http://www.rctech.net/forum/10764140-post2.html
AND
A battery holder mod / Mine is here = http://www.rctech.net/forum/11005603-post62.html
And here's the USVTA/ROAR APPROVED 2S HARD CASE 5000mAh battery list = http://www.rctech.net/forum/11031684-post65.html
>>>
I have since moved my battery forward for more weight distribution, but haven't written it up yet - nor have I taken the pictures -
Still need to find seller(s) for the raw material(s) -
04-10-2013, 09:57 PM
#465
Tech Apprentice
KEVLAR BELTS =
REAR BELT = http://www.toughracing.com/zc126d/in...oducts_id=2036
FRONT BELT = http://www.toughracing.com/zc126d/in...oducts_id=2037
REAR BELT = http://www.toughracing.com/zc126d/in...oducts_id=2036
FRONT BELT = http://www.toughracing.com/zc126d/in...oducts_id=2037
Lock the rear and if you want get a 1 way for the front. I am running mine stock up front and locked in rear, makes the car much more stable when drifting.