The Sleeper

That's a neat site but for some reason it accepts only front diff gear of between 20 and 30 tooth

The R40 has a 36 tooth front diff so the computer won't calculate a damn thing

But you are right, if you run the 22 tooth side pulley and want to keep the overdrive ratio at 1, the front tires needs to be 3 mm smaller than the rears.

InitialD

A ratio is a ratio. Same problem if you were to calculate MTX-3 or V1RR EVO gearing. Since the R40 has a 36T:18T in the front which is a 2:1 ratio, just put any numbers that would give a resultant ratio of 2 like 30T for the front axle pulley and 15T for the mid axle front pulley.

The Sleeper

HEY!!!!

THAT WORKS!

Nrctc3

iTrader: (2)

Well guys, I ordered my R40, it'll be here Thursday. Along with my MR-12 engine and a Trinity 1 piece pipe! I cant wait.

fastharry™

iTrader: (4)

there are alot of different tuning options on the r40..the different lower blocks for the back....the fact you can turn the front bulkhead supports upsidedown,the rubber bushings for the upper front a arms.....

and this is where HPI has dropped the ball...there is NO explanation of ANY of these tuning options,or even what they do,or how they affect the car's handling.....Not in the instructions,not on the web site.....

NO ONE will take this car seriously unless they start TREATING it like a race car.....They shouldn't be resting on Hara's win to promote a car..

I just saw a kit being put totegther in my LHS...the slop is still in the steering,the ball cups are still soft,the silver pivot ball hexe's are still loose in the knuckles..thats a bad job IMO.....

KMac

Don't be so damn naive, harry. The car just came out in August. The problems you speak of have only been learned in the last couple of months and you think HPI should have already selected new materials, run test pieces, implemented changes, gotten them into production runs, and gotten them on the shelves already???

He11, the kit you're talking about being built is probably from the early production run anyways. These aren't loaves of bread, you know, the turnover rate is not going to be high enough to implement changes that fast.

There's not a company out there that would have substantial changes implemented that quickly. And spare me the NTC3/AE & Serpent mantra, 'cause they can't do it either, and wouldn't!

fastharry™

iTrader: (4)

yeah,maybe you're right......about the upgrade parts anyway....

But they still ought to have the tuning guide..(which Associated AND serpent DID have when the car was intro'd)

and not for nothing,my tc3's and impulse had way tighter tolerances new..(and they were first edition kits)..

in fact,my tc3 is tighter after 5 gallons of gas than my r40 after 1..

The Sleeper

I have to admit I was disappointed when HPI didn't include a tuning guide with the R40. But then I figured I already know the basic stuff (camber, caster, roll center, ride height) so I really didn't need HPI to tell me again.

However, being able to turn the lower suspension mounts upside down and changing the rubber bushings has me alittle confused. What they do to the handling? Obviously they change the angle of the hinge pins. I'm guessing by changing the angle of the hinge pins, you affect how the suspension reacts to bumps and rolls.

I see where the new Serpent 710 has something called "active toe" (I'm relying on memory, correct me if I'm wrong). I think the toe angle changes as the suspension moves up and down. I wonder if the R40 has the same thing? Would changing the hinge pin angle have the same effect on toe as what the 710 is advertising to have?

treky11

true harry, but the impulse guide was weak at best. no guide ever for the veteq.

and the impulse/veteq didn't have slop, but tons of parts didn't fit at all. two speed shafts with pins that couldn't go through, same for the pulleys, arms that needed tons of reaming and sanding, etc. etc. i remember you screaming when you were building both of those. the snakes were not without their problems.

associated is tighter and does have a good guide, both out of the gate. associated, however, still hasn't come up with their own solution to The Fix, and they could fix the rear toe links too. so while associated did some things right they still haven't fixed everything and its been over a year.

sleeper, i don't think so on the active toe. if you look at the pics of the 710 it seems like there is lot more going on there than just moving a hinge pin.

fastharry™

iTrader: (4)

your right treky(my pal)...

in fact,the tc3's been out 2 years..

but you have to admit..both have better plastic than the HPI..

InitialD

Ummm, I'm not too familiar with the car but I'm guessing that the changing of the hinge pin angle has something got to do with anti squat / roll center changing.

The Sleeper

Yeah, I just look at those pics again and I think you're right. The 710 has something called a single arm wishbone on the rear. Looks like the whole rear A-arm assembly are actually 3 different pieces. I'm thinking one of those pieces doesn't swing up and down like normal but slides in and out. Something like a dogbone.

Anyhow,,,, this is the R40 forum.

Darkseid

iTrader: (9)

O'well, so much for the brief jump into the realm of, oh I don't know, R40!!!


Tell ya what, why don't you guys just let us all know when your done discussing Serpent, Mugen, and AE........on the R40 thread.

The only posts about the car that we really see lately is someone complaining about it.....and thats even coming from some people who say their happy with the car!

I know one thing, I'm still waiting for that perfect RC car that pleases everyone, the R40 aint it, but neither are any of the others, so can we please get back to the R40

The Sleeper

You're absolutly right Darkseid...

A question was brought up earlier about flipping the lower suspension mounts upside down and being able to change the position of the front upper hinge pins by using the optional rubber bushings included in the R40 kit.

The question is, what affects does these have on handling?

InitialD

Perhaps anti squat or roll center changes. I thought I mentioned this earlier.