Originally Posted by GT CRUSING (Post 15869083)

Does anyone know where you can get the upper arm for the TRF103 part no 3404089?
(Or An entire 103 kit)

I've been trying to get my hands on this kit for 2-3 years now to use in TCS but no luck. It seems like the only way to get this car is to get every single part individually online at several hobby stores with an awful price tag of about $700 total (About double of a discontinued kit price). The only part I can't seem to source anywhere is the upper arms.

I would use a 102 or 104 kit, but I don't wan't an uncompetitive and unreliable car, especially those T-Bars designs. It seems everytime the 103 dominates at TCS. And with covid, its even harder to get a 102 or 104 just to get the parts to transfer to a 103 build from spare parts.

Originally Posted by robk (Post 15676273)

TCS tires aka pit 571 572 aka CRC
Glue front outer sidewall, glue inside as well if traction is up

Ride ht 4mm fr 4mm rr
width fr usually around 190 mm ,narrow up for more reaction and turn in
rear usually around 188 mm if the car doesn't rotate, narrow rear, if it needs to slide a little wider, though it will be more stable, more "slip angle" than slide.

optional aluminum knuckles, inline kingpin, second hole from back for ballstud, 1.5 mm spacer
tamiya servo saver, 2mm spacer under ball stud, full spacers for servo mount

1.5 camber, 9 caster - page 21 in manual for insert settings - sometimes I have used the BB13 insert with the notches facing out to the tires to remove camber, closer to 1 or 0.5*. Caster is probably like 10*
silver front spring (soft)

front droop approx. 1mm more if the car stalls mid corner, go to 0.5 to help flatten car
kingpin spacers will be different if you use the plastic knuckle vs. aluminum. The main thing is adding total spacers on the kingpin removes droop, remove spacers will add droop. Swapping them above or below knuckle changes ride height. Swapping them above or below the upper arm changes camber gain and roll center. Less spacers above arm = more camber gain, higher roll center. more spacer above lower roll center, less camber gain. Flatter arm is usually better for high traction, less reaction. More arm angle, more reaction. I like one spacer on top of arm in most cases, unless track is really tight or traction is mediocre.

No spacers on inner pivots of upper arms. You can add 0.5 or 1mm to rear upper pivot to reduce some traction roll, but this kills mid corner steering. Adding spacers to both inner pivots is the same as flattening the arm, lowers roll center and reduces camber gain.

toe -2 each side

tamiya hard grease on kingpin

rear
center shock 30 wt oil 3 hole
long shock extension approx. 83 mm
3mm spacer front of shock, 2mm rear
Red mini car spring, but change per track. I like to start soft, great advice given to me " stiffen the spring until the car slows down in the chicane" . The stiffer you go on the spring, the more the front tire gets heated - this can fade fronts late in race for a big push.
Links in outer holes. 0.5 spacer under link balls if you need to get the car out of the track.
Copper/pinkish side spring. Set side spring just touching. Add 1/2 to 1 turn preload to make car more stable, back spring off pod 1/2 to 1 turn to add rotation/reaction
Start with 7k in tubes.
Ball diff with tamiya pink VG grease (tamiya 42170) or other thick grease and steel axle, fairly tight. Use Tamiya 54424 diff pegs and a Tamiya spur to make a spool for super high traction. I use the steel axle unless traction is really high. This is all TCS stuff, if you are not racing TCS, just get the Exotek 1/4" axle conversion and use an Xray gear diff or any 1/4" spool.
Short wheelbase most of the time, if the car gets too hard to drive go long

90/30 gears
Tamiya 2017 body and wings or Ferrari F60 body and wings (TCS)

Battery long way on chassis. Push forward as traction comes up to kill traction roll. Switch to transverse if the track is very twisty/short

14g lead each side of car next to posts for upper deck

Originally Posted by Apex (Post 15877874)

This setup is legit. Did the TCS race in MD yesterday and car was really good once I got the glue right on the front tires. Definitely have to glue to the lip on the crc tires. Have to build the layers up.

• Ran the battery transverse and 96/36 gear ratio
• Ran the rear diff really tight, but got crunchy
• Full compound rear and 1/4 to1/2 up front
• Carbon axle

Will try the pegs at another TCS race there next month. Yeah, they got 2 TCS races this year!

Originally Posted by riddic (Post 15878470)

Robk mentioned he use TCS legal steel axle, any one know the tamiya part number for TRF103? I broke my carbon axle, want to try steel axle on low grip asphalt but found out 84173 or 54162 seem need a different diff housing(54158) and diff ped(51347).

Originally Posted by Apex (Post 15878614)

I think you need to get the F104 differential to use the steel axle cause the axle that comes on the TRF103 is a one-piece carbon axle like 1/12 uses.

Originally Posted by f1larry (Post 15878811)

you need #84381 https://www.tqrcracing.com/shop/prod....asp?p_id=8222
hard to find though

Originally Posted by MikeR (Post 15869369)

Hey Phillip, You can borrow my car this year at Cal. It's set up and ready to go (back to back TCS winner :) ). I'm going to focus on GT1/GT2 this year.