John Stranahan

iTrader: (27)

I'll start by telling you I don't like spool pads on a powerful TC5. They are probably OK for stock classes.


With spool pads it is likely that a longer screw is really needed. These are some things to reduce the length of the screw required. Delete the little washer between the nut holder and the spring. Make sure to fully compress the spring several times with pliers before assembly. Use a tool to push that nut holder inward (compress the spring) as you tighten the first few turns of the screw. If this fails grind some off the spring with the Dremel. It won't hurt a thing. There are no steel locknuts of this size available through RC channels. I agree it is too small for a locked diff using spool pads. It works OK for the ball dif.

or get the TIR spool and Nylon outdrives that I like.

svines1972

iTrader: (26)

I wound up using one from the TC4, part # 84695-06575, T nut & Diff Bolt, $3.00. Worked perfect with no hassle.

4wheeldrift

iTrader: (9)

Looking for a TC5 R for Sale.

svines1972

iTrader: (26)

When using the slipper spool (31174). The instructions say to tighten it all the way. If this is done, will it still be able to slip in case of an accident. Or do you loosen it to a certain point.

John Stranahan

iTrader: (27)

You don't want the spool slipping while driving. It only slips is a crash. Thats the ideal situation. You cannot get it too tight. Do not loosen it. Even then, check the tension once in a while and before every meet, as the pulley will compress. So how tight. Tight but do not strip that little nut.

svines1972

iTrader: (26)

Thanks for the info. One more question. I noticed that the belts were a little too tight. The kit settings show 4/Front and 11/Rear. With a 4 setting on the front belt, their is no resistance at all when I push it down to the top deck. Would this be correct?

John Stranahan

iTrader: (27)

Pay no attention to the kit setting of the belts. The front belt, especially, must have some resistance with a locked front diff. You should be able to push it to the top deck but just so with a powerful motor. It will have 1/8 to 1/4 inch of easy play. With stock motors, the belts can be quite loose. Any slippage growl must be dealt with immediately or the center pulley's teeth will be rounded off.

svines1972

iTrader: (26)

Ok, using the "A" Cam Holders, what number setting would you recommend for 13.5 Front/Rear?

John Stranahan

iTrader: (27)

a 13.5 is a super stock motor. Not a lot of power. You want to run the belt a little looser than for powerful mods. I can't give you a number. It is just a trial an error thing like fan belts on full size cars used to be. Get someone at the track that runs your class to check it for you. The belt should not sag much by gravity alone. 1/4 inch of easy play with your finger.

John Stranahan

iTrader: (27)

Weight Balance

The asphalting of the track nears. I decided to prep the TC5 for ROAR rules which we may adopt in whole. This means a weight of 53 oz ounces. I was 4 ounces shy of this with a 5400 mA-H Thunder Power Gold hard case pack. We plan to run open mod 2s LiPo. In truth there is no reason to add all this weight to a 4 wheel drive if you are in an all LiPo class. A 49 oz weight would be more reasonable. It does the car not one bit of good. It stresses the motor, speed control and axles more. Regardless, I will start at 53 ounces and see how things develop.

I thought I would show a picture of how the weight ended up in the car as the side to side weight, front to back preload, and then the corner weights ended up perfect. Photos of details of this setup are found earlier in the thread. The difference here is I have a lot of ballast added.

Side to Side Balance
With both left tires on a beam on one scale and both right tires on a beam on one scale, the weight was exactly even

Front to Back Preload
With the fronts on a beam on a scale and the rears on a beam on a scale the rear weighed 2 ounces more than the front. This is the way I like the car.

Corner weights
With the fronts on two separate scales and the rears on a beam, I adjusted the spring collars to get even weight on the front. Then I swapped the car around and put the rears on the scales. I still had even weights. This means my corner weights are perfect for road course. I will be able to corner left the same as to the right. The car should accelerate perfectly straight. This is really nice with a 3.5 on board. I'll give it a test Wednesday.

Dyno Results LRP X12 3.5
I dynoed the LRP X12 3.5 on the Homemade Dyno thread. It produced an outstanding 675 Watts. This is 150 W higher than the old 3.5 X11 motor even with the newer Nickel plated rotor.

As a result I have ordered a 6000 mA-h SMC battery in a hard case in case I need a little more capacity with the new motor. The motor is more efficient than the old so it may not be necessary.

alf.skaar

First thanks for all the great! info
It was a long read to get through it but to all I will say just do it.
You will note be disappointing and I don't drive a TC5 I run a TRF416, and my own 12 scale car.

Is this correct
53 ounces 1590 gram
49 ounces 1470 gram

In Norway they made this rules and about every body hate them
firs race had only 4 entries, this say something how will thought true this rule is


TC mod no motor limits
5 cell 1400 gram from 2008 rule and for 2009 together with
New rule 2009
6 cell 1500 gram
lipo 2 cell 1500 gram

what do you think

Alf

John Stranahan

iTrader: (27)

alf.skaar
Thanks.
Use these definitions for conversion 2.2 lb = 1 kg and 16 ounce = 1 lb

53 ounces = 1506g

49 ounces = 1392 g

If you plan to race 6 cell NiMH along with 2sLiPo then I think it is fair to ballast the cars to the same 53 ounce weight. The LiPo guys should then use the biggest capacity 2sLiPo that is legal for racing.

We plan to race open mod soon. I think most guys will show with 2sLiPo. If even one wants to run his old 6 cell pack, then we should keep the 53 ounce limit. I have asked that NiMH not be replaced with new packs of the same type. If we ever get every one on the 2s LiPo then it would be wise as a club to adopt a 49 ounce limit. Much less heat, wear and tear, only a little faster.

John Stranahan

iTrader: (27)

Periodically I do some LiPo testing and reporting. Always at 20A. This time Matt and I have home built a dyno using the Novak Sentry that can do testing at reallistic amps accelerating on a short straight. We can measure 225 amps on a Novak 3.5 motor. I kid you not. Now these are not continuous amps but representative of what these hot winds will pull at full throttle. Needless to say you don't use a lot of full throttle on most layout or things would melt.

Trackpower 5400 mA-h gold brick pack vs SMC 6000 mA-h black Max Sport brick pack

I tested these two packs to see if they are suitable for ROAR racing in open mod TC. I have retested the Trackpower pack to determine if I had an unusual result. Here is the result Track Power, 524 W,528 W. The SMC pack 681 Watts

The graph shows dyno output from the two test. A novak 3.5 motor is run up on full throttle while spinning an Aluminum flywheel. Power is calculated from RPM data and results in the two upper curves. Amp draw is measured and results in the two lower lines. Note the increased amperage the SMC battery is able to deliver near max power (the blue line is higher than the green line near 35000 RPM). Also note the huge increase in resulting power developed (the highest starred dark red line (SMC) is higher than the boxed red line.) I am simply astounded by the difference.

I took 1.5 ounces off my ballast and ordered a second SMC pack. It is best to charge packs at 1 C for best lifetime. It will take two packs and two chargers to race four club heats at this rate.

alf.skaar

Thanks
Nice test

225 amps it this a limit on the amp sensor, looks like the battery don't want
to give the motor any more amps.

Have you try the same test whit 5 cell and 6 cell Sub-C battery
to compeer ?

I have a Novak Sentry to, and i think i will be abel to make my self a
flywheel.

Thanks
Alf

John Stranahan

iTrader: (27)

Alf-only one point on those graphs is at the 225 amp limit. Right at the peak. From there the amperage reduces slowly. Note we replaced the 100 amp sensor with a 200 amp sensor. The details are in the hombuilt dyno thread. Aluminum flywheels are available from Fantom. I used one of theirs.