First test

App 17-18 deg celsius outdoor, sunny..track´s traction kind of poor(flowers dust on whloe track ,yellow stuff,dont know the name)

100/20
one unmatched 3600 pack (not so good)
7700 motor..
Jack he gripper for only 22 min rear and 20 front (in 1:12 we ran 50 min rear and 30 front, and have full grip al pack long)

The speed is ok, i think with my 4200 matched SMC it will be something else, to bad the track was full of this yellow powder so the tires gripper tracktion went out after 10-12 laps (one lap app 22-23 sec)

He car feels great, there is tons of grip(before it went out), i havnt done anything on my setup it was only a test..1.5deg camber in the front, stock spring/silver, 20w oil(will do some testing here...

Purple front and Grey in rear (JACO)

Motor temp 53 deg celsius
ESC Temp app 76 ( real bad conection with batt)
Batt temp app 52 deg celsius..

ut overall, i like te car, real nice :D

Tires usually come between 2.45" and 2.5" depending on the manufacturer. I have to disagree with you on the chassis rake issue. This is a very common and widely used adjustment on 1/10 oval cars, no matter the surface. Having the front lower than the rear will provide more forward grip, particularly from center of the turn out. Having rear rake will generally make the chassis push from the center of the turn off.

-E

Thomas-Thanks for the report. Motor and Battery temps are good. The speed control is a bit hot, 176F. Add a fan on top of the speed control if you have not done so already. If you have a fan already then gear a little lower. It's hard to get traction with pollen on the track. If you have good traction for 10-12 laps, then procedures and tires are good. You will add laps as you get more exjperience with the car. That was my case. You learn to stay within the limits of the tire on acceleration and while cornering. This keeps you hooked up longer.

My GRP 1/10 pan tires come at 2.40 inches new. I get about 12- 16 runs on that first .1 inch. On my track the rear tires work super good when brand new. They accelerate through the bumps better and deliver more top speed from the increased traction. This is not gear related but traction related.

John

Exactly - and since most people, when they drive, have spin problems when they roll on the throttle and the rears want to spin, giving more forward grip (as opposed to rear grip) is a recipe for spinning out.

Oval is completely different from road-course. Oval can heat the tires and get purples to feel like greens. . . (exageration! :D ) and once you're at speed, you're pretty much at speed. In addition, Oval uses a LOT of adjustments to fine tune a specific movement.

Road-course has to deal with more variables and really has to deal with on-throttle spins. A forward-rake may be fine for Oval, but it's murder for Road-Course. With Road-Course, we tend to fight for rear traction on exit - we can't run those massive wings that Oval runs. ;)

So - I'll qualify my advice to Road-Course applications - but it's still valid. Get forward rake on a Road-Course car and expect to spin out unless you are Deific with your throttle control. . . :cool:

This is one of the best threads at RCTECH. Thanks to all the contributors esp. John S. :nod:

Sydewinder-Thanks. I thank the other cotributors as well. A lot of experience here.


Here is a pic of the Novak 3.5R which I am making ready for the eventual return of my GTB speed control. I though you might want a peek from the backside which you may not have seen. Note the black stack (core) around which heavy gauge wire is wound. This stack increases the inductance (amount of magnetism produced by each bit of current) at the expense of some hand work installing the wire. Also note the small hall effect sensor array. I need a new harness which melted in my last bearing seisure meltdown. I'll borrow one from anther motor. Not too hard to dissasemble. Just unsolder and it all comes apart. I made some marks to be able to restore the same timing.
John

Thuderpower Battery
I have six cycles on the battery now. I had a chance to run it today, but the track was very dusty. Run times repeated at about 13 minutes. Mamba Max, Novak 4.5R, geared 6.0. The long runtimes were an indication of poor traction. The Thunder Power Lipo felt good in the car. It had good top speed and good punch. Nothing to complain about yet except that it is too long to fit most RC cars. Max motor temp 145F, Battery Temp 125F. Not enough traction to have a problem here. You could see a Rooster tail of dust on the worst corner today. I did blow the track off.

Under the slick conditions the Mamba max easily made four times the mistakes that I did. It especially did not like a slow transition from low to medium throttle which was common today even on the straight and the sweeper. It spun on the straight, completely locked up and spun on the sweeper. These were speed control issues not driver issues. Many poor starts after poor braking caused a small spin and stall and then a stuttering return to forward. It works considerably better with more traction.

John

doesn't sound good for the mamba. that battery info isn't sounding good either. maybe its nearly 3am for me and thats the problem lol.

As you have disassembled your motor, do you know what is the diameter of the Novak sintered rotor?

John,

It is a bummer that the Mamba doesn't seem to work very well yet, but I think it is a work in progress. I have been running a Schulze U-Force 75 since they came out and I haven't had any of the problems that you have had with the Mamba. This tells me that the Mamba's software just isn't up to par quite yet. This leaves hope that other companies like Tekin, GM (Graupner), Traxxas (yes they are going to make some kind of brushless), and others, with get the software to the next level. Here is a video to check out. There is one sensorless-brushless car in the field. I know it isn't pan cars, but it is still interesting.

http://kufman.com/img/rc/AJs%202005%20Divx2.avi


Matt

Mason-That battery will fit cars able to hold 7 cells like the TC4. Modest changes at the factory would make it fit 6 cell only cars. I am quite happy with it at this point.

Matt-Well maybe there is some hope for sensorless, but I know that several people tell the same good story for the Mamba. Some even attribute its bad traits to the spectrum receiver. This might be worth investigating.

The video would not decompress for me I get the sound only. I tried AOL and Quicktime

V12- Here are some Novak sintered rotor dimensions
diameter of magnet = .484 inch
length of magnet 1 inch
magnet distance to tail end of shaft .580 inch
distance between bearing journals = 1.675 inch
Overall length = 2.648 inch
Bearing ID 3/16 inch
Shaft ID under pinion 1/8 inch

This is one strong little magnet
John

John
Thanks for the measurements. I wondered why the Novak motors do have so high revs even with sintered rotor. It seems airgap is much higher than with other motors.

V12-That original bonded magnet measures .566 and has quite a bit less air gap. More air gap between the rotor and the windings gives more RPM, I believe. The magnet is stronger which gives fewer RPM. They probably struck a good balance.

Ground Effects/Lower Wing

Well I was completely rained out this weekend, so it was time for a new baby project. Groundeffects. It did not take long to add a sheet of .040 Lexan to the bottom of my rear pod. The angle is adjustable with the top link length. The height is adjustable with the normal rear axle ride height spacers. It will either scoop more air (more cooling maybe) with the leading edge and act as a secondary wing providing downforce or I will get some modest ground effects from air that flows underneath the leading edge. At certain low chassis positions all the air underneath the car will be going under the ground effects wing (like when the chassis is highly loaded just before the sweeper and on bumps) In both cases some extra downforce would be good. Note that my rear pod is unsprung and stays mostly fixed as the rear of the chassis moves up and down. There is no center pivot. It is a three link with Panhard bar suspension. Ground Effects report later in the week.

New text and pic. The third pic shows an extension I added to the ground effects. The first section tilts from about 2mm off the ground to 7-8 mm off the ground. I put a bend in this aft of the panhard bar and extended it upward.

Hopefully either my GTB will come in or the LRP Pro Comp TC edition will become available here next week. I see the LRP is in stock in Malasia, Hong Kong, and the UK now.

Mason-I took a good look at those link you provided on the Nissan P35 project of which the NPT90 was a middle part. A few little things. They got away with such a low wing on some versions of the car because they were using it more for a underbody air extractor than a wing. On some bodies the wing was below the top rear edge of the body. The final version of the car developed about 9000 lbs of downforce with maybe 1500 lbs of drag at 200mph. These numbers made the car superior in the corners and on braking. Top speed of 245 mph at an arizona track.

The last car that was developed for GTP racing in maybe 1991-1993 was the Dan Gurney Toyota Eagle MKIII (some pics and text about this car). It dominated. It seems at this point a worlwide recession shut GTP racing down.

Boca Bearings
Products on the Way. We had discussed these previously.
SR3C-2ys#5 NB2 shields
SR3cYzz #5 NB2 rubber seals.
Boca bearings for the pinion end of the Novak 3.5R. One is rubber sealed which I will try first and one is has just shields. Both are High RPM models. I'll see if this rubber seal model will last without hurting speed too much.

Some green contact sealed rear axle bearings. I will see if these last longer from lack of dirt entry.

I found an old stash of Gold 12 tooth pinions, so I may be running that 3.5 again soon.

John

for group c cars check out www.mulsannescorner.com one of my favorites.