HPI RS4 Pro 4 Forum V1.0

[StevePond]

http://www.rccaraction.com/pics/pro4/pro4logo.jpg


http://www.rccaraction.com/pics/pro4/pro4.jpg


The RS4 Pro 4 will be a radical departure from the RS4 Pro 3, offering a change of concept for HPI both for suspension geometry & transmission. Extensive track testing of all existing electric 1/10th scale touring cars & HPI prototypes has already been done, the all-new RS4 Pro 4 is the result of that testing.


http://www.rccaraction.com/pics/pro4/pro4side.jpg


The Pro 4 features big changes over the Pro 3... new drivetrain, new suspension, and new steering geometry. Consistency, tuning options & drivability have all been dramatically improved. The most significant change is that the Pro 4, at the requests of our drivers & customers, uses a shaft drive transmission. Track testing revealed the benefits of low maintenance & fast acceleration that a shaft drive transmission offers. Again at the requests of our customers, the RS4 Pro 4 will be supplied in self-assembly kit form with key items like the radio, ESC, body and tires left to the choice of the driver. The Pro 4 will use the highest quality materials & will have a high standard specification to make it a force at the highest level of competition.



http://www.rccaraction.com/pics/pro4/pro4top.jpg



Our team drivers will be racing the Pro 4 at all major electric touring car races around the world by the end of the year, ensuring factory support and continued development of the platform to keep up with the latest racing technology.

Main Features:
• Woven Graphite Main Chassis
• Woven Graphite Upper Deck
• Woven Graphite Shock Towers
• Woven Graphite Steering Plate
• Purple Titanium Turnbuckles
• MIP CVD's, Purple aluminum of course!
• Carbon Plastic: Arms, Uprights, Hub Carriers, Steering Blocks, and Gearboxes
• Carbide Ball Differential
• Front One-way
• Aluminum Threaded Shocks with Bladders
• Aluminum Main Drive Shaft
• Aluminum Motor Mount
• Aluminum Spur Gear Adapter
• Aluminum Hex Clamp Hubs w/ adjustable Track (Width)
• Efficient 64 Pitch Spur and Pinion Gears
• Socket (Hex) Screws and Fasteners used throughout chassis
• Pre-cut Urethane Foam Bumper
• Drive Ratio: 2.4375
• High Quality Ball Bearings used throughout (24)



http://www.rccaraction.com/pics/pro4/pro4bottom.jpg



Front Suspension Features:

• Adjustable Camber - via turnbuckles
• Adjustable Caster - with included 0, 2, 4, and 6 degree uprights.
• Adjustable Toe - via turnbuckles
• Variable Ackerman - via the steering plate and geometry design with adjustment holes
• Bump Steer - adjustable via shims (washers)
• Adjustable Roll Center - via shims under the pivot blocks
• Vertical Inner Camber Link Adjustment - via mounting location and height with shims/ washers. 2 inboard locations
• Adjustable Down Stops (Droop) - via round point set screws
• Shock Mounting Positions - optimized for progressive wheel rates with 3 holes on the tower and two holes on the arm.
• Anti-Dive/ Kick-up - adjusted with washers
• Anti-Roll Bar


Rear Suspension Features:

• Adjustable Camber - via Turnbuckles
• Adjustable Toe - via Pivot Blocks (2.5, 3.0, and 3.5)
• Adjustable Roll Center - via shims under the pivot blocks
• Vertical Inner Camber Link Adjustment - via mounting location and height with shims/ washers. 2 inboard locations and 2 hub locations
• Adjustable Down Stops (Droop) - via round point set screws
• Shock Mounting Positions - optimized for progressive wheel rates with 4 holes on the tower and 3 holes on the arm.
• Anti-Squat - adjusted with washers
• Wheelbase Adjustment - via washers
• Anti-Roll Bar



http://www.rccaraction.com/pics/pro4/pro4rear.jpg



General Features:
• Top to bottom mounting of gearbox for precise alignment and mesh of gears
• Carbon Plastics used to increase rigidity and reduce component weight for better chassis response and tuning
• Adjustable, variable Ackerman steering geometry to increase steering feel and increase corner speed
• Completely ball raced steering assembly for smooth steering with reduced play
• Crank integrated servo saver with adjustable tension
• Included ride height and droop gauge for accurate suspension adjustment.
• Pivot Ball Block adjustments to maintain suspension precision and to reduce mis-alignment of the suspension pins.
• 3mm inboard suspension shafts for strength and 2.5mm outboard shafts for reduced weight and improved wheel clearance
• Set screws used to retain outboard suspension shafts for easier maintenance
• Overall lightweight chassis for best performance and adjustable ballast positioning with optional ballast weights.
• Low center of gravity and centralized weight for improved cornering power and overall responsiveness.
• Reduced unsprung weight for increased response and improved control

[hpijoepro2]

i told you i saw it :rolleyes:

[nomac]

when. i want......

[wanchaiwarrior]

well, Ive been trying to decide on the next car after my TA04SS, and this looks like it !!!

Gotta get it when it comes to Hong Kong !!!

Only question is, will I be able to run it with a stick pack ??? Dont have the money, skill or tools to make battery packs.

[wanchaiwarrior]

either that or the R40.......hehehe

[TRF Drive Hard]

Sorry to say but thats a tb yoko evolution tc3 freak... its the same basic shaft concept... i really dont see anything "new" about it... although it is a HUGE jump from a belt design...

[Nightz]

How come even the next generation "Pro" kit still has locked rear toe settings? I thought this was a pro level kit? Shouldn't they have used turnbuckles back there also?

[sosidge]

Nope, turnbuckles for toe-in are a pain, very hard to set evenly without a setup station, and the toe changes when you adjust the camber angles. Blocks are much easier and no less effective.

[Maxxcrazy]

chassis looks soemwhat like a durango (german 4wd buggy for those who don't know)

[Godspeed]

The Pro4 looks very much like the MRC Academy electric touring car.

[puribong]

yeah this car looks kinda like combination of MRC Academy STR-4 Pro and Tamiya EvoIII.

[FSU427P]

Even though the chassis looks very much like the TB Evo III, the MRC car, the TC3 (shaft, motor, and battery placement), and the new Yokomo car, it doesn't matter. What matters is the fact that HPI is making a real effort to produce a car that can be deemed "worthy". It's about time they listened to what we want in a car, and now that they have finally delivered (picture-wise for now), it'll be interesting to see what the car can actually do. The car may not set the standard, but for HPI people, this finally gives them something to brag about.

[Saboteur]

He's right. Still HPI has done some good work. The R40 and the Pro4 are sure to be hitting the tracks soon once they are in the LHS's.

[wess]

with a shaft driven car, there's only so many ways to place electronics and batteries. all shaft drive cars will have a motor on one side and batteries on the other, it's the only practical way to balance the chassis. so just because they have the same chassis layout as other cars out there, it has nothing to do with copying designs.

i'm glad hpi moved towards the shaft driven tranny.... hopefully xray will follow suit :D

[^j!nx^]

any idea on a price yet?

[Downforce]

Would have liked to see the motor and batteries switched, like the prototype at Cleveland.

[S15Racer]

I second ^j!nx^, what the price gonna be? lol And when might we expect to buy this kit?

[mugenseike]

http://www.team-orion.ch/live/results-cars.asp?id=138#hpiproto -mugen

[BigBadTahoe]

So this pro 4 should be able to blow off TC3's and xxx-s's right? It looks fast!:eek:

[mugenseike]

....well i don't know about it beating the xxx-s
but it might easily be able to overtake the tc3, I think the xxx-s has much more potential...more than we can handle and it might be the strongest,fastest electric car we'll have for a few more year's, the pro4 is a great improvement from the previous version...much more power and lower cg,great combo, I still don't think it will be able to top the xxx-s, heck my xxx-s goes to 60+ speed's, I doubt the pro4 will be able to do that,oh also I hope no one get's mad, I'm in no way trying to be offensive, the tc3 is a great car...that it is, anyway's I will just say that it's my opinion and i'm not declaring that the tc3 is slower than the xxx-s but you decide.
-mugen
http://www.radiocontrolzone.com/forums/showthread.php?s=&postid=1022203#post1022203-post on the belt and shaft car's being able to handle a brushless on different circumstances.

[TEM]

mugenseike, how does top speed have to do with anything realistically? What track do you race on to hit 60+ with your XXXs? I don't feel offended nor should you. Give a reason why you think the Pro4 can't hit those speeds with the same motor, gearing, wheels, body. In fact, I believe a shaft is better at very high speeds. After all this time; I don't even think belt vs. shaft is worth talking about. Wait a minute; wasn't the world record for TC's done with a shaft car(TC3)? I must say however, the XXXs is definately a good car, I mean I've driven one and it probably has the smoothest drive train for "following the instructions assembly" I've seen. Still there is much work to be done to catch up to the guy that takes the A main every week with a TC3 or something.

Although I probably won't buy one(unless HPI is willing to give me a decent trade in offer for my new condition pro 3 that has like 4 packs through it on carpet!), I'm just glad HPI is finally back to thinking again before they come out with a product. The Pro3 is a piece of crap, the american version anyways. Hara's is definately NOT a pro3! I hate tamiya's too; but I can beat the crap out of my Pro3 with my TA04R(ofcourse the TA04R is still not up to my FT TC3). Now if I was stupid, why can't and don't I make my Pro3 fast and ditch my other cars? Well it'll go as fast on a straight but will sure as hell NOT handle as well!

Anyways enough of that, the Pro4 looks like a competitive car with a blend of the popular top end chassis all in 1. You know what they say; if you can't beat them, join them! But from those pictures I can already see one thing I'd personally like changed; those shock towers look a little flimsy and easy to tweak. If only the bulks were widened just a little would be nice or leave on more carbon fiber on the tower itself. I think I've already mentioned in another thread somewhere; changing spurs and working the diffs, replacing outdrives, etc will be a pain in the butt. It's still a good performing design.

Mama says, "Slop is the Devil!" If there was no slop on this car(the Pro3 is very sloppy), then HPI should have themselves a winner here! I certainly look forward to seeing one or more of these things at the track.

[mugenseike]

hey i know the tc3 is a great car, I know I have one, tc3 team factory version which is heavily modded and it has had it's fair share of record braking moment's, it once hit 73 mph(radar tested) but that was top end drag racing, now on a smooth grooved race course(circuit) in which I race regularly it cannot compare with the xxx-s, my xxx-s is not as heavily modded as the tc3, the only key ingredient's are the tall gear's, 7 turn reedy ti motor, expensive lrp esc, ko propo racing servos, and the "frozen" batteries,hehe.All i'm saying is that even though I've done everything to the tc3 it still has not given the result's that the xxx-s on the track can get easily, i've gotten every hop up there is made, i've even done custom work on it, but still not close to the xxx-s performance, that's all, hopefully I have correctly justified my reasons.
cheers.
-mugen
oh and for the pro4 i don't doubt at all that you can get the same result's as with the xxx-s, you'll just need to modify twice as much to get the result's of the xxx-s.:D

[TEM]

The FT TC3 needs no mods! I know it needs custom work, like any other car to make it better; but no mods necessary! The car that took cleveland stock last year(I know the guy personally) is ALL STOCK! Mind you springs, swaybars, oil, tires don't count. Really, how much can you mod a FT TC3? Eye candy and performance parts are different! Have you seen Barry Baker's car? He's got the stock graphite tub; it's got custom work on it but it's not like he's gone CF double decker, nor does he or anyone needs it for performance reasons.

How would you know you'll need twice the mods on a pro4 or TC3 to get it as fast as a XXXs? Different cars work for different people. For the same design, it can be made good or made crappy. Slop or no slop, stiff or weak... I think the stock original XXXs is gone; now they only make the graphite version?...

[mugenseike]

Originally posted by TEM
The FT TC3 needs no mods!


this is very true but i don't see a 11 turn ft coming from a factory anytime soon, that's why i added a higher performance motor myself, i daresay it has a lot of spunk!

Originally posted by TEM
How would you know you'll need twice the mods on a pro4 or TC3 to get it as fast as a XXXs? Different cars work for different people. For the same design, it can be made good or made crappy.

well i have seen the design in the pro4 and it does not look like it's something that will be a hit, but then i'm not sure, look's can be deceiving ya know.

Originally posted by TEM
Slop or no slop, stiff or weak... I think the stock original XXXs is gone; now they only make the graphite version?...

yes i'm quite sure they have discontinued the original-standard version xxx-s, that's why I had opted for the graphite version instead.
-mugen

[mugenseike]

let me correct myself, they have discontinued the original xxx-s in some hobby stores, but there is still plenty on-line.
-mugen

[TEM]

"this is very true but i don't see a 11 turn ft coming from a factory anytime soon, that's why i added a higher performance motor myself, i daresay it has a lot of spunk! "

What are you talking about? Whats a 11 turn ft? I didn't think any high performance car come with a motor! You don't put in a higher performance motor; you just put in a motor of your choice.
Motor, esc, battery, radio, servo are not mods, neither are springs, oil and swaybars(most cases)! The phrase is "I had a 11t and put in a 7t" and NOT "I modded my car with a 7t from a 11t".

Are you a Basher or Racer? If you are so much towards the design of the Losi, pay extra attention to the new Corally they are working on!, That car will be a killer!

As for the design(once again, assuming there is no slop.. Did I mention I hate slop?) is not bad at all. I mean it looks like an Tamiya EVO3(awesome no doubt, despite I hate tamiyas), or a twin decker TC3 or an Academy STR4(I think thats the model name, but someone can correct me if I'm wrong). Most people don't know much about the STR4 on this side of the hemisphere; but that is a very fast car, it has flaws parts wise, but the design is decent. Actually the Pro4 looks more like the pro version of that car than anything! How about we just wait until it comes out OK.... I think everyone whos reading this thread's had enough from the both of us!

[mugenseike]

sorry,mix-up I mean't that I have not seen a 11 turn equipped factory team tc3 from the factory, that I had to modify it myself to get the performance.

I would say that I'm a basher but also a weekend racer, might I add very experienced, getting close to five year's, been practicing a lot since then.

Corally makes very nice car's and believe me I've seen their product's first-hand.
-mugen

[mugenseike]

you hate tamiya's eh, well have you ever been in a tamiya circuit trial event in Japan, I have, once, those car's are not you're average bashing car's but true performance car's, lol, go to japan some time and go to the tokyo auto salon also, very exciting, motorsport's over there is awesome.

[S15Racer]

I've heard of the STR4 Pro, I was thinking of getting one but it just didn't happen. That was a really nice car though, I read the test story of it in RCCA and they said it was the only touring car they had ever tested that could light up all 4 tires and make them squeal! I would've bought it for that reason alone! Oh, and that was with a 13t mod BTW, not a torquey little stock number:D

If the pro 4's anything like that, ooo boy its mine! I'll be trading in my pro 3 for one as soon as it comes out!