tonyv65

please keep the tips comming, this thread is great for a newb like me.

thanks to all that contribute.

Tony V

robk

iTrader: (22)

I'm trying to stay TCS legal. Is there a minimum diameter in the rules? It doesn't matter much for the front anyway, since you will run out of ride height pretty fast.

robk

iTrader: (22)

I practiced today. Went to 30,000 oil on the dampner plates. The car stayed flat as a board around the track, especially with the dampner spring tightened down. I also went to 20 wt oil in the shock from 40wt, figuring the extra dampening on the plates was a bit much with 40wt oil. The track had some bumps and this helped. Tires were HBR med fronts, glued sidewall, and HBR soft rear.

kavadni

iTrader: (1)

robk,

How do the oil weights you are using relate to the Tamiya Greases sold for the damper plates?

Kevin

robk

iTrader: (22)

I have no idea on the Tamiya grease. 30K is very heavy. If anything, I would go with the heaviest stuff they have. Otherwise, 1/8 diff oil is a good solution since it is available everywhere in a wide range.

kavadni

iTrader: (1)

No worries Robk, I'll start with the Tamiya thickest.

Can anyone shed any light on roll centers with this car, F103RM?
I'm not sure I get it with this design. In particular does the rear even have a roll center, and where is it?

Kevin

liljohn1064

iTrader: (17)

Anyone have favorite gear ratios for the silver can on carpet for 64 pitch gears? I just ordered the teflon spacer to fit standard 64 pitch spurs. Right now to keep the same physical dimensions and gear ratio, I have a 92/25 ready to go in. What I don't know is do the silver cans like a higher or lower ratio from the box stock 63/17 (92/25) and FDR of 3.7?

robk

iTrader: (22)

Looking at Carroll Smiths' Tune to Win, solid axle cars seem to locate the roll center at axle center, or the pivot point on a Watts link, or where the vehicle center line and the Panhard rod intersect. I'd imagine it's probably the center of the pivots of the T bar, but that is my best guess.

In 1/12 moving the pivot balls up or down will move the roll center up or down.

The problem with Tamiya cars is that your going to be cutting stuff up a lot of times to move roll centers, which you may or may not care about, unless you race TCS.

kavadni

iTrader: (1)

Thanks for that Rob, I'll have to try and get hold of some of Smith's books - they sound like interesting reading.

I should get the last of the parts to build my 103 tomorrow (GT to RM conversion).

I have heard mention of some using the GT front suspension - hingepins on the upper arm and suspension balls on the king pins.

Have you or any others here, tried this?

Although I dont yet have the RM king pins or RM front arms, I am not sure if the GT suspension will work as the diameter of the suspension balls appears from illustrations to be much thicker than the RM arms, and might overcompress the springs and limit travel.

Any advice and tips would be appreciated. I am keen to use them as I have a 3 Racing upgrade that allows castor setting.

Kevin

kavadni

iTrader: (1)

liljohn,

Personally I don't think there is a favourite gear ratio for a specific motor on a specific surface. I think it's related track size, layout, and driving style.

Big track, long straights = low FDR
Small track, short straights and technical = high FDR

I race at two tracks, with a 19T brushed, same motor.
One is basketball court sized - FDR is around 8.5
240M track with 70M straight - FDR is around 6

Also the pitch of the gears makes no difference. Silver cans on a big track can be geared pretty hard. I have heard of people getting to the low 4's.

A good starting point is to gear such that you hit maximum speed before the end of the longest straight.

Then adjust for lap times.

Kevin

liljohn1064

iTrader: (17)

OK, I'm back to tweaking my setup. I have a 104/22 in it at the moment. It comes off the track respectably warm, but not fry an egg hot. I'm getting a lot of push coming into fast corners now. That might be a lack of traction compound on the fronts. Initial turn in seems a little sluggish. I'm only putting compound on the inner 1/8th of the tire. I've also switched to the harder front tire after I wore the soft kit front tires down to 55 mm. I'm guessing more compound and maybe a higher rear ride height to force more force on the nose in the corners. Right now I've got the rear axle right in the middle. I did not get to test any of my theories this week, but will be at the track tomorrow for some serious testing.

VooDooPH

iTrader: (18)

any suggestions on curing traction roll and oversteer?

kit is a cross, foam tires on asphalt.

Foxxrocket

Has anyone ever thought of running a soild axle? Is it even worth it?

cherokee

iTrader: (1)

I don't know anything about F1 RC cars, but I am intrested in them. Does anyone make a rubber tire for the cars?

Foxxrocket

TRG