60mph! with a lehner 4200

RCcarnut · 04-06-2004, 06:39 PM

Well after tuning my suspension making it lower and stiffer and making some tire changes, I finally did it.. With the setup in the picture the car was easily handling the 60mph and I could actually control it. My last couple runs I didn't even wipe out.I don't have a video camera sorry. I had it geared at 72/28, lehner 4200, schulze 18.61k, and 11 unmatched gp3300 cells,61.9mph .Here's my only proof.

_rollin_ · 04-06-2004, 08:11 PM

looks like 60 club has another member,and swami has to change his page again lol,sorry swami.
congrats on 60 though

RyguyJones · 04-06-2004, 08:33 PM

Cool. Good job. By the way, are those the stock Rusty front tires on the rear?

Aken77 · 04-06-2004, 08:50 PM

Welcome to the Club!!

regards,
Aken

wunuvakindrusty · 04-06-2004, 08:55 PM

heres what u should do next: no body (gives better aeros from what I hear), smaller & thinner fronts, and definately some decent tires in rear (2.2's). Also, what kind charger did ya use for 11 cells, and why not get a warrior 7018 w/ a <b><u>BEC<\u><\b> no Rx pack would save a lot of weight.
L8R,
KinZ

RCcarnut · 04-07-2004, 05:59 AM

Quote:

are those the stock Rusty front tires on the rear?

Yes they are, they were lighter and got me the fastest speeds.The buggy tires I used at first are on the front and I though they were loosing me control,so I used these and they worked great.They also stopped me from rolling as much because the grip isn't that great.

Quote:

no body (gives better aeros from what I hear), smaller & thinner fronts, and definately some decent tires in rear (2.2's). Also, what kind charger did ya use for 11 cells, and why not get a warrior 7018

I have tried with no body and with the bandit body on it seemed more aerodynamic.
I had thinner fronts on but that was one of the reasons I was loosing control I believe.
I charged the batteries seperately and soldered them together at first.The last couple runs I shorten my battery wires enough so that I could use a swami type connecter and still be within schulze wire length regulations.This way I didn't have to solder them together.
I didn't get a warrior 7018 because first ,they are in germany and hard to deal with, second, the schulze 18.61k can take up to 18cells and third, schulze's have a lifetime warranty if purchased from finedesign.
Yes the receiver pack probably adds some weight but I had incredible range with my AM radio. 300ft at least. I have never had that range with my Novak SS and I wonder if BEC is the reason.Cogging was minimal and honestly my Novak's glitching is worse than the lehner's cogging.

Thanks alot guys! I would love to go faster but my next run I want 70

This is really alot of work also lol and I just want to bash for a while. I think I would need a 5300 for 70 or risk my 4200 on 15cells or something. When I try again I want a video camera also.

Swami · 08-03-2004, 10:53 AM

wow, I found this on a search.. Never saw the thread before.

I added you to the "60mph Club" page.
http://www.swami-rc.com/speedrecord.htm

Anyone else that has broken 60 is certainly welcome for mentioning on the page.

Just let me know.

My .02. No need to get too picky about the weight on the RC itself. It seems largely irrelevant. Wheel weight does seem to make a big difference though.

An easy way to increase aerodynamics, is to just cut the back of the body off. That way, you still have a curved ram on the front, pushing air out the way, and then there is no "parachute" effect if you cut the back off.

Swami

CADtech · 08-03-2004, 12:56 PM

Quote:

Originally posted by Swami
...An easy way to increase aerodynamics, is to just cut the back of the body off. That way, you still have a curved ram on the front, pushing air out the way, and then there is no "parachute" effect if you cut the back off.

Swami

Not having reached 60mph, I'm no expert; but conventional aerodynamic theory would dictate that a best case wind management approach would be to put a pointed end on the back - like the tail of a water droplet.
Maybe try splicing the front half of another bandit body (pointing backwards) onto the rear of the vehicle?

After reading several people's problems with high-speed directional stability, perhaps "wing vents" running vertically would help stabalize the front end?

Swami · 08-03-2004, 03:30 PM

Well, yeah. The teardrop shape is obviously best. Cutting off the back is simply an improvement over whats there.

I'd love to have a bullet body for speed runs, but not enough to make one, lol.

Swami

RCcarnut · 08-04-2004, 07:06 PM

Thanks Swami

It was a personal accomplishment and for fun.I can't believe how much work it actually took to get it that fast. Hats off to you guys who have gone faster

azndsoldier · 08-06-2004, 10:41 AM

BTW, what was your setup on the 61.9mph run?

wunuvakindrusty · 08-06-2004, 12:23 PM

Uhhhh... Its @ the top. First post?!?!

Am I missing something?

azndsoldier · 08-06-2004, 12:50 PM

I meant the whole setup including all the parts that are non-stock.

RustlerRacer119 · 08-06-2004, 04:41 PM

How do the stock rib tires work in the rear, lol?

RCcarnut · 08-08-2004, 06:52 AM

Quote:

BTW, what was your setup on the 61.9mph run?

Except for an aluminum idler and aluminum shocks the rest is stock.Also the radio is a tower hobbies 75 mhz AM.

Quote:

How do the stock rib tires work in the rear, lol?

I have tried alot of tires for speed runs and for some reason these always got me the fastest speeds. Also because the grip isn't that great, if I made a turn at high speeds the car would spin out instead of roll over. It saved me alot of broken parts

This is getting me the itch to try again. I am getting a 5300 lehner for my next try though so it will be a month or 2 until I have the funds for that. I will try for 70 with the same setup and a 5300 instead. I also have a video camera finally so it will be a video instead of just pics

muck duck · 08-08-2004, 01:34 PM

Instead of a battery pack you could use one of these ultimate bec . They now make them in 6 volt for cars. I have one and it works good. It is much, much lighter wieght and takes up much less space. I highly recommend it.

mtrsprt · 08-09-2004, 06:41 AM

Wondering what the 4200 hit for RPM under load.

Have you tried gearing a little lower, to maybe let the motor spool up a little higher?

According to the speed calculator(which is almost dead on with my XL3600 powered E-Maxx,geared very low), if your motor was spinning @55,000rpm with 12.76V under load (1.16V per cell),with a final drive ratio of 6.994, and 3.5" tires, perfect world speed should be about 79-80mph. Do you follow?

mtrsprt · 08-13-2004, 06:11 PM

You could also try 12 or 13 cells(with 13 cells being a tad over MAX rated RPM's).

kraz · 08-13-2004, 10:34 PM

do these motors suk up batteries quick or no?

RCcarnut · 08-14-2004, 05:02 AM

The lehner gets me about 10-12 min rumtime or so. It sucks up batteries alot faster than my Novak SS.

Quote:

You could also try 12 or 13 cells(with 13 cells being a tad over MAX rated RPM's).

Yes but at the gearing I had going I was already pushing it with the ESC and motor. The 4200 is only rated for 6-8 cells according to finedesigns.

mtrsprt · 08-14-2004, 06:43 AM

Quote:

Originally posted by RCcarnut

Yes but at the gearing I had going I was already pushing it with the ESC and motor. The 4200 is only rated for 6-8 cells according to finedesigns.

Yes, but these are base guidelines. The motor rating is more based on input voltage/max RPM, then it is cell count. The motor would not even come close to 65K rpm with 8 standard 1.2V cells.

The cell count is a basic starting point for beginners. So they do not overgear the motor with a higher cell count.