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-   -   Hpi Sprint 2 flux upgrade 90+mph (https://www.rcuniverse.com/forum/rc-electric-road-vehicles-race-cars-more-475/11526139-hpi-sprint-2-flux-upgrade-90-mph.html)

accountsmaster 05-28-2013 07:01 PM

Hpi Sprint 2 flux upgrade 90+mph
plan to get a HPI Racing sprint 2 flux car and upgraded it

I bought the following in order to get it where i want too be 70 - 90mph(goal)

-Traxxas 2933 ez plus charger plus 6 amp lipo/nimh charger
-Traxxas 3340 cooling fan velineon ESC and fan for the motor also
-Traxxas Velineon Extreme Brushless Waterproof Power System
for electric powered R/C vehicles.

FEATURES: Each component engineered to work wih each other to eliminate
restrictions and allow maximum power flow

Velineon VXL-3s ESC
Auto-detects and compatible with brushed, brushless and sensored
brushless motors
Compatible with NiCd, NiMH (4-10 cells) and 2-3 cell LiPo battery
packs-two stage low voltage detection for LiPos
Three driver profiles-Sport, Race and Training Modes
Gold-plated motor connectors
Built-in output for optional auxiliary cooling fan
Velineon 3500 Brushless Motor;
10-turn 3500kV
Optimized for extreme power and efficiency in 1/10 scale vehicles
Ultra high temp neodymium magnets, high-speed ball bearings
Precision balanced rotor
Traxxas High-Current Connector
Reverse polarity protection makes backward connections impossible
Compatible with high-current 12-gauge wire
Gold-plated wide surface terminals
Textured surface for easy gripping

INCLUDES: Velineon VXL-3s ESC, Velineon 3500 Brushless Motor and high-current connector

Input voltage: 4.8-11.1V (4-10 cells NiMH or 2S-3S LiPo)
Supported motors: Brushed/Brushless/Sensorless brushless
Motor Limit: None
Continuous current: 200A
Peak current: 320A
BEC voltage 6.0V DC
Transistor type: MOSFET
On-resisteance: 0.00075 ohms Max (0.006/8 FETs)
PWM frequency: 12,000Hz
Battery connectors: Traxxas High-Current Connector
Motor connectors: TRX 3.5mm bullet connectors
Motor/battery wiring: 12-gauge Maxx Cable
Thermal protection: 2-ge thermal shutdown
Case size (l/w/h): 2.19" x 1.54" x 1.3" (55 x 39 x 33mm)
Weight: 3.17oz (90g)

Velineon 3500 Motor
Type: Sensorless brushless
RPM/volt: 3500 (10-turn)
Magnet type: Ultra High-Temperature, sintered neodymium
Connection type: TRX 3.5mm bullet connectors
Wire Size: 12-gauge Maxx Cable w/solder tabs
Current Ratings: 65A constant; 100A peak/burst
Max RPM: 50,000
Diameter: 1.42" (36mm) (540 size)
Length: 2.165"(55mm)
Weight: 9.24oz (262g)

what other parts would i need upgrading? Eg. The traxxas 2075 high torque servo? i think i might need it bcuz not sure if the one in the flux is powerful enough for the new system

What are ur thoughts to get the max performance with that sytem??
what else should i need to add, parts wise and ensure long last durability with top performance.

ill be using 2S 70c lipo baterries,
no one has been able to help me so far, ive been on countless forums.
hope u guys expertise can help me, thnx

Foxy 05-29-2013 07:49 AM

RE: Hpi Sprint 2 flux upgrade 90+mph
Perhaps the people on other forums didn't know how to go about telling you that what you've listed there is not suitable for the stated goal.

For a start, 1/10th is not the best scale to do this with. 1/8th would be much easier. 1/10th are small and light and will be prone to take off at anything above 60 mph. Tiny rocks will have a dramatic effect on direction of travel as well as eat your belts in an instant at those kinds of speeds. It is achievable with a belted 1/10th touring car, but not without significant and expensive trial and error regarding the necessary body modifications to generate enough downforce to prevent the car taking off, but not generating so much drag that the goal cannot be achieved, as well as thoroughly cleaning the surface you will run on (yes, all of it).

Then there's your choice of electrics...the biggest issues are the motor and battery. The motor is a 3500kv, this means it will turn 3500rpm for every volt supplied. 2S batteries nominally supply 7.4v. 7.4 multiplied by 3,500 equals 25,900. Consider that your average .12 nitro engine turns 40,000rpm and will get a touring car to about 45mph on moderate gearing. Electric has a torque advantage, but I highly doubt that the gearing you will require to hit these speeds will even fit in the car...for example, to hit 70mph you are going to need an 80 tooth pinion, which doesn't exist, so int he first instance you are going to need a MUCH faster motor. Regarding the battery, you are definitely going to need to go 3S (11.1v) if you are serious about going over 60mph, but the gearing to achieve that with a velineon 3500kv even on 3S again, does not exist.

While we're talking about motors, I should also point out that you would be better off with a 4-pole. The stock motor in the Flux is a fairly quick 4 pole 5900kv, a motor which is SIGNIFICANTLY faster and more powerful than the Velineon. The Velineon is actually a huge downgrade from the stock motor. The stock motor is actually a decent choice for a 80+ speed car.

Why are you buying Traxxas stuff anyway? Did someone tell you it was good? They have very few products that could help you achieve your 70-90mph goal, and all of those products are designed for 1/8th cars.

If you said to me, I want to make my sprint 2 flux go 100mph, I'd say get the Mamba Max Pro speed control, a motor with at least 8500kv, run it on 3S and gear it to the moon.

You also realise (I hope) that this car that does 100mph will be able to go up and down once, then require time to cool? It won't be any good for anything else except speed runs, and very short ones.

If I were you, I would return everything, not buy the Sprint 2 Flux if you haven't already. Instead get a second hand OFNA DM-1 or GTP2E and a 2650kv motor, run it on 6S batteries and stick a 25t pinion on it. That should get you there or thereabouts. Bear in mind you will need a lot more money than what this traxxas stuff cost before you are even hitting 80 no matter what you choose. If your goal is a 100mph rc car as cheap as possible, again, a whole different set of recommendations would be put forward.

cenracer1 05-29-2013 01:02 PM

RE: Hpi Sprint 2 flux upgrade 90+mph
Funny.. I said the same thing as Foxy in not so many words on another post, but I guess the OP had to hear it from another source. I was nice what I said about the Traxxas setup.. Foxy was a bit more blunt...LOL... I shortened my other post because I didn't want to hijack the other post... I have alot of experience with brushless touring cars as do most of my friends.. We run them every week in a class we like to call STUPID class.. Its all RS4's and Sprint2's with the occasional Tamiya thrown in for target practice. What we found out very quickly is these cars are not drivable at anything over about 60mph.. Why you may ask.. They have a nasty habit of trying to impersonate an airplane.. and not very good at it. They are just plain too light to go much faster without taking off. Sure you can spend tons of money making a custom body, but its not a car at that point. We like to go very fast, but not at the expense of proper handling. What we settled on was this ... 5700-5900 2 or 4 pole castle motors.. even a few HK motors hang in there. nothing usable over 2S... we've tried 3S but the tires just shred or the car flips over.. neither is a good thing. With proper gearing we are running around 60mph on the straights but really don't go over 50's much.. Its plenty fast.. I know Foxy mentioned 4 poles as a good choice.. My honest opinion it really doesn't make a difference.. Your gearing and battery do.. Your gearing will always be limited in a touring car to something on the order of around 30/84.. or near that.. Good combo of speed and heat control.. You can gear higher for more top end but overheating is a strong possibility. We have tried traxxas motors on occasion..but in every touring car they were slower and a few times the magnets broke off the shaft killing the motors. Not sure why, but its happened a few times.. maybe the constant rpms of a touring car are too much for it. For real speed runs I would do exactly like Foxy said.. 1/7th car and a 2200 1/8 motor on 6S.. You will hit 100mph.. But at a cost... LOL Lastly, before any of the traxxas lovers come to crucify me.. I own many traxxas products 10 at last count. I just don't like their motors/esc.. Nothing special and no control over the parameters of the esc... All my traxxas electric vehicles have had the traxxas electronics pulled and replaced.

Car-Tune 06-01-2013 05:00 AM

RE: Hpi Sprint 2 flux upgrade 90+mph
There's people out there all they did was use a 4s and made it fit and run 100mph. Some other guy all he did was change his gearing and ran 90mph.

Why go thru all the trouble?

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