rod_b

Dude, no one is trying to bust your chops. If you wanna carve away at the car go for it. All I was trying to do, unsuccessfully, was to get you to understand where the difference is between you and the faster guys. You say you finished 4th in your race...well good job. At this point you are just not doing something that the other guys are. And 100 grams isn't it.

PTP Racing

iTrader: (2)

NCC, proteus, and lilrobby all race at my local track and i think they would all agree im a pretty good driver

and i fully realize some of our local racers are out of my league (like mike dunnigan who has national championships in electric)

but ive decided im sticking with the r40 for this year and next and while practice is great i still believe the car is a little too heavy

ive got a bunch of stuff i wanna buy to lighten it but figured i could get some other ideas from you guys

how about this question last weekend my car was pushing into the corners i had to use the brakes to get a tight line anyway i was thinking about moving the inner rear camber link up a hole to change my roll center any suggestions ive already got lighter front shock oil than rear and my front sway bar is set at its softest setting and i dont like running different shore tires and i only own the kit springs i could try changing my rear toe-in but what do you guys think?

jscamry

iTrader: (5)

hey all, I was wondering, what is the best way to thread the grub screws into the 2 speed clutch shoes?

boom

iTrader: (10)

Check out what I did when my wheel clipped an apex. I wasn't even going that fast.....

What should I do guys..... Mugen balls?

BTW I cut the slot in the stud to remove it from lower arm

CraigH

I think that is just a defective pivot ball. Just install a new one.

GundamWZero

iTrader: (4)

I just gotta get my hands on a R40!!!! I own the original RS4, a RS4 sport turned to Pro (since I am in Iraq, it's in somewhat a rally version) and a Yokomo GT4! I'll gladly sell my Nexus 30 helicopter for a R40. I wanna try my Picco .15 (originally meant for the Yokomo GT4, but its a barrel carb) then bump up to a Sirro (something like that) turbo I just read in R/C Car Actions 5 fastest engines.

goldenboy

that has happened to me a couple of times, and i just replaced it with the stock ones again, but a couple of posts ago, or i should say a lot of posts ago, i think AMGracer said that hpi was comin out with titanium balls. but im not sure..... also, were you able to get the threaded part of the ball out of the a-arm with out destroying the arm?? is so, how did u do that, i just had to throw my arm away.

Solara

iTrader: (17)

If you replaced the HPI pivot balls with the MUGEN or whatever pivot ball that is so strong and is undestroyable.....the next thing will break is the steering knuckle, or the upper or lower arms...

1 thing must go (and that is a garantee).............pivot ball is a known problem of ALL pivot balls equipped RC car....and there is no real solution for it, the only way to avoid that is stay away from the board.

P.S...a bent pivot ball with a little steering is better then a broken pivot ball with a DNF.

Proteus

Now that I 've had about a month's worth or running this car, there's a couple things that I would like HPI to add or redesign.

1) Smaller gears. Right now I'm runnning the smallest available and it seems that my midrange is just a bit off. I thought about setting the the 2spd a tad tighter but I risk the change of winding out my motor too long. Right now I'm running the 20/25 60/54 combo. 1st speed is right on. But the 2nd speed is just a tad too tall. I would like to see a 24 tooth pinion. 55 and 56 tooth spur gears would be fine as well.

2) A lighter drivetrain. The hollow shafts are nice. But the diff is too big, the axles, dogbones and diff shafts are just too heavy. As far as the car being too heavy, yes it is. A 100 gram diet is rather easy. Somebody's car here (clearing throat...not mentioning any names) is super light, almost 250 grams lighter than others. I don't mind my car being a TAD on the heavy side because the heavy weight gives it the opportunity to bully the rest of the cars in it's way. What I am really concerned about reducing is the rotation mass.
Much of the weight in the diff case is from that huge bevel gear. The problem with that is the gear set is shared with the Savage so HPI had to make it big and durable. So...HPI, how about a lightened gear set with a revised rear diff case. The diff case right now is just too bulky. What would really be nice to see is the same material that Serpent uses....I believe it is "spring steel" which they use in the axles, dogbones and diff shaft (drive cups).

3) A re-designed steering plate to increase the ackerman. I think that on shorter more techincal tracks, increasing the ackerman would be advantageous.

4) Something for the newbies....and even for us old farts...a tuning section in the manual. In the parts kits, there are extra parts to adjust roll center. No mention of the use of these parts. Luckily, I was bored one day and while trying to figure out how to change the roll center on the car I came across the parts in the kit.

5) A lighter flywheel or smaller diameter flywheel with corresponding engine mounts which would allow us to lower the CG of the car. Also a revised endbell to allow the use of a bigger bearing (the flanged one) near the thrust bearing. I go through too many bearings and thrust bearings; almost one a race day. NCC had problems with his clutch the weekend before. As for installation of the clutch....I set my clutch up with zero endplay, so I don't understand why they fail. I also set my clutch to engage early as well. I've got about may half a thread showing which is more than enough punch. I also grease the thrust bearing twice a race day; after practice/before the qualifiers and before the main.

6) The other reason why I see that the car is so heavy is that because HPI uses a softer plastic unlike the carbon composite type found in the PRO 4, they had to use extra to reinforce the parts to kee them from flexing. I have the new arms coming so that should get rid of the rear flex, but I would like to the bulkheads and top pieces in the same material as well.

7) More durable belts. I hope they come out with the Kevlar type. I'm going through a rear belt a raceday...to the point where my 19t pulley is literally flattened.

Oh and for you gram techs...After swapping the hinge pins and pivot balls for the titanium I shaved about 26 grams.

Other than that....the car is great.

JB

GundamWZero

iTrader: (4)

I would like to know is who owns, maintains and races an R40? I am about three days away of purchasing one to kick some German ass! My RS4 sport turned Pro is ready to rip open some tracks in Schweinfurt, but I want to dominate when it comes to nitro! I had a exhibition run with my Yokomo GT4 when it hit a dip in the road and cartwheeled a good 30 ft. The cost to replace the normal breakable parts with aluminum ones will cost more than the R40. So, I need some real inputs. Or do I need to get a Serpent Impact 10?

boom

iTrader: (10)

I just slotted the stud with a dremel cut off wheel and backed it out with a flat blade.

Rookie, yea...... we all try to stay off the boards. Besides, my pivot ball snapped clean..... so how is that better than a ball that would have otherwise bent and allowed me to keep running.

I hope it was just a defective ball.

GundamWZero

iTrader: (4)

Trade you for a Helicopter?

jscamry

iTrader: (5)

hey all, does anyone know if there are some manufactures that make a solid diff for the R40??

thanks Jason

goldenboy

you werent able to use the suspenion arm anymore, were you??

AMGRacer

Indeed I do. Here you go:

HPI part number - 75060