billtc3

hi everybody! i just bought a pro 4 and i have a couple of questions.

--- i can't seem to adjust the diff so that it performs properly. i fully tightened the screw and then went back 1 turn loose but the diff is still not smooth. i ran a couple of batteries, thinking that it'll probably set in, but that didn't solve the problem. it feels like the diff rings touch the gear, as if the gear was thicker than the diff balls. i know this is not the case, cause the gear is free even when the diff is fully tightened. maybe the spring is too hard. so, if 1 turn loose is not enough should i go to 1.5 or 2 turns? this doesn't sound normal! how do you adjust your diffs? i used to unscrew my tc3 diffs 1 turn back from fully locked and they ran very smoothly, loose but not slipping. how can i achieve the same with the pro4?

-- the pro4 aluminum shocks are beautifull, but i have a problem with the shock cups. why do they have a small hole? is it for bleeding the shock? two of them i can screw on the shock body until they compress the bladder and lock the plastic ball cup you mount on the shock tower. the other two though, i can't tighten enough to lock the ball cup. first, i thought that the bladders were not thick enough and that the shock cup would screw all the way on the body, without touching the bladder. wrong, after disassemply i noticed that the bladders are similar but two of the cups had fewer grooves on the inside than the other two. the grooves hardly reach the (bleeding?) hole on the cup. are they defective? which ones are deffective, the fewer or the more grooves?

i hope the above make sense. any help would be appreciated!

Geetoo

iTrader: (1)

The Pro4 diff is different from any other diffs I tried. Tamiya diff progresses the pressure as you tighten it where as hpi has constant pressure at the plates. Tightening the diff screw, make sure the outdrives won't slip and I do it just as close to slipping. Mine worked out pretty well after building it...was perfect.

Skill

There have been a few people having shock caps without the threads cut properly, just give HPI a ring and they should sort it out for you.

The small holes are for bleeding, thats what makes the HPI shocks so good, you just fill them up right to the top and screw on the cap, then the excess oil comes out and you get a perfectly built shock.

csilve

Good luck with the shock caps, it took almost 3 months and 3 phone calls to HPI to get the 1 cap that I needed.

RCGaryK

iTrader: (3)

Don't worry about the number of turns out the diff screw is, just worry about the slippage. I hate that some manufacturers use the "Tighten the diff all the way then back it out X turns" advice. You're almost guaranteed of flatspotting a diff ball ot denting a ring when you do this. I built my Pro 4 diffs up with Black AE grease on the thrust bearing and AE Clear lube on the mdiff balls and my diff was pretty smooth. When I went to the delrin diff halves it got even smoother. I don't know how many turns out it is, I just have it set so that if I hold one tire and the spur I can bearly turn the opposite wheel. In any car you should set the diff by amount of slippage.

jonny69

I ran my two dodgy shock caps for ages before I bought some replacements, All you need to do is run a length of solder around the bottom of the cap, this way works really well, allows you to tighten the Cap up so it will not leak, only prob is that the front (in my case) shocks were slightly longer than the rears. I do not think that it really made a difference swapping to new caps, just gave me an excuse to rebuild the shocks. Jonathan

WesB

does anyone know where i can find a complete list of all the pro 4 option parts.

RCGaryK

iTrader: (3)

www.speedtechrc.com

Steve's got a great site, great shop, and great deals. Check there and look under http://64.70.208.72/speedtechrc/104.html

Aurra Sing

http://www.hpiracing.co.jp/contents/kits/pro4/opt.html pics

Bodido

I had the same problem with the shock caps. I have one bad one. My boss/ LHS owner called HPI customer service and told them about it for me. They said they'd send one right out. After a few weeks I recieved nothing. So I just bought a gray one we had in stock so I could at least drive my new car. I then called customer service again. I told them my story, and also told them I had the version 1 gears. They were very apologetic and said they would send my shock cap and 1.1 gears right out. This was several months ago. STILL NOTHING. The car is excellent, really. The customer service is lame, however. Others have had good luck with HPI's customer service. But, I believe it was just that.... luck.

So currently I have a beautiful car with that one gray shock cap staring at me, and the old 1.0 gears. I'm running diffs since I'm inside on carpet for the winter, so I'm not too worried about the gears for now. When I get back to running a one-way or spool it may be an issue. It's just the principal of it all. I must admit that they were very courteous on the phone, but without results, coutesy only gets you so far.

Oasis

iTrader: (38)

The 1.1 gears are not a fix all,You can still break them,I have had great luck with HPI's customer service.

yeuc001

hey guys,

I am running a stock pro4 on a really tight carpet track, with lots of "u" truns. I try the offical hpi "Thad"'s setup and it is pretty good. however I want to accelerate sooner when I get out of those U turns.

right now, the car seems to settle for a bit before it will accelerate again.

I see that my fellow racers can somewhat "glide" thru the U turns with lots of speed. ( is there any secret to that?)
I can't really copy their setup because they are using xray ft and tc4

any suggestion on the setup?

thanks guys

RCknight

iTrader: (5)

what kind of speed control and radio do you have? How much rear toe are you running? Hows your gearing?

Kenneth Tan

iTrader: (1)

Try increasing rear anti-squat? Does that help?

RCknight

iTrader: (5)

Do you have to remove the top gear case to remove the swaybar?