My Tamiya TRF511 build

I have been trying to decide what 4wd car to run this year, and having had a TRF501X for 4 years now, and a brief spell with a TRF511 last year, and an even briefer spell with a Durango DEX410, Ive settled on another TRF511, prefering it over the TRF502 for various reasons.
My friend is running a TRF502 this year, so it will be a good comparison.

I have ordered the TRF511 kit, and the following hopups, to run the car in the UK national series, and UK North East regional series.

Tamiya 53984 buggy racing wing
Tamiya 54133 trf511 body and fairing ver 1
Tamiya 53975 rear spring set
Tamiya 53974 front spring set
Much More 50deg Green orings
Tamiya 53979 piston rod guide set
Tamiya 54043 titanium coated rear damper shaft
Tamiya 54042 titanium coated front damper shaft
Tamiya 53977 1.3mm pistons
Tamiya 53978 1.4mm pistons
Tamiya 54063 12 degree castor block
Tamiya 53962 aluminium rear uprights
Tamiya 53971 Aluminium Steering Arm
Tamiya 53972 Aluminium Steering Bridge
Tamiya 53973 Aluminium Steering Base
Tamiya 53951 front one way
Tamiya 54006 front one way adapter
Tamiya 54023 37t one way pulley
Tamiya ABS system
Jaad Racing Titanium ball studs
Jaad Racing Ceramic thrust races
Rudebits Brass weight kit
Lunsford Titanium turnbuckles
RPM ball ends
Answer RC 3mm Grade 3 ceramic diff balls
Avid racing bearings (revelations - ceramic and stainless mix)
Tamiya 42143 Serrated Wheel nuts
Tamiya 53539 spacer set
Fibre-lyte 5mm front shock tower
Fredrik Emilson transmission housing (rear)
Screw kit - alloy / titanium and stainless steel where appropriate
Tamiya hop up upper shock mounts
RW Machined spur gear (theTamiya moulded ones are not round)
Anti roll bar kit
Alloy servo horn
Alloy servo mounts
Savox 1251 MG servo
LRP SXX ISTC
Tekin 5.5R redline brushless motor
Futaba Fasst receiver
AMB tiny lil transponder
LRP 50C Lipos
+ spares

My build will be limited as the option parts I have ordered will take time to arrive. A number of parts have been ordered from within the UK, however a lot is coming from Hong Kong and the USA, so shipping times will vary. I hope they arrive within the next week or so though, as I need to finish the car for the race meeting.

I will not document the build as per the manual, but try to highlight any additional steps I take to prepare the car.

I am not building the car following the order of the steps in the manual. The main things preventing this are my bearing kit is coming from the USA, and the Tamiya hopups are coming from Hong Kong. Also, my diff builds will have to wait until Answer RC get my ceramic balls in.

Step one for the manual is to prepare the chassis. As I am using LIPO batteries, I will not be filing the NiMh slots out. I have however, taken the edge off the front edge of the chassis, and the areas around the front alloy wishbone hangers. A smoother edge will prevent the chassis catching and delaminating on anything on the track, as the undertray may not provided enoough protection here as there is no lip on the tray in these areas. I done this by filing a rounded edge to the chassis, and sealing with super glue.
I treated the top of both shock towers in the same manner, to prevent it diggin in and snapping / delaminating when rolled.

All screws into aluminium on these cars have the tendancy to vibrate loose. To prevent this, a lot of people loctite the screws in, however this makes them difficult to get out, and stripped screws are a nightmare. I use hair gel or hair spray on the screws. Its a happy medium that means the screws dont vibrate loose, but they are not too difficult to remove.

I will not be using Tamiya grease where indicated in the manual. The driveshafts and hingepin bushes should have the grease on. This will attract dirt, dust and sand from the tracks, and cause excessive wear and failed lubrication. Instead, on the driveshafts, hingepin bushes, in the aluminium hingepin mounts, and on the diff outdrives where the driveshaft pins slide, I am coating in graphite dry lube, designed for this purpose. It adheres to the surface, and provides a lubricated low friction surface that is resistance to load baring and high temperatures.

I have decided to use Kyosho 2.5mm hex cap head screws for high stress areas, titanium 2 mm hex screws for medium stress areas, and blue alloy screws for other areas. I wanted all 2.5mm drive screws, for better driver location, however c/sunk screws are only available in 2mm drive, and I couldn't lcate 2.5mm titanium capheads.

So here is how I left the chassis last night (with Tony Evdoka's Rudebits brass weight lipo trays). I am hoping for some other bits arriving today, otherwise I am limited to driveshaft only building tonight.

Note the use of TRF501X plastic front and rear arms. The 511 flexible arms generate too much grip, and inconsistency for driving ability, so I have opted for the plastic TRF501X arms .... not as severe as going to a 501X graphite arm, but more rigid than a 511 arm.

With the arrival of my bearing set, shock parts, and front and rear hubs, I continued my build last night.

Everything is going together really well. I built the driveshafts, having coated them in dry graphite spray, and fitted them in the alloy hubs. Note the JAAD titanium ballstuds, these are much stronger than the kit items.

I used the Tamiya shim set, to prepare my camber links, bumpsteer and wheelbase to Lee Martins Robinhood Raceway setup:

http://www.petitrc.com/setup/tamiya/setupt...RHR20100509.pdf

I intend to use this as a base setup, as it is high grip astroturf. However, I dont intend to run the heavy oil in the rear, I'll be going with a 30wt oil. The setup Lee went with here at RHR, was specific to that day where the grip was crazy high. I dont think the car needs calming down as much as this setup will, on a "normal" astro track.



The belt rollers in the centre bulkhead are intended to keep the belt from skipping on the pulley. he bearings do not need to be in contact with the belt. It is easier to set these bearings correctly while the bulkhead is exposed. Adjust the cams so the bearings are only just not touching the belt. It is difficult to tell if the bearing is touching or not, as it is dark in there. The best way to check is to take up the slack of the belt (pull it tight), and try spinning the bearing.

I built up the shocks, reaming out the plastic shock bottoms as per the tr******* guide:

http://www.trfracing.co.uk/page_1265187551237.html

I used the much more 50deg orings, apparantly the best in the business for longevity (not swelling up and wear resistance), minimum leaks and minimal stiction, after reading countless forums, and talking to a lot of drivers.
I used Associated Green slime to aid the shock build, and the Tamiya Rod guide hopup to ensure precise travel of the Ti coated gold shock shafts, which will be tougher and smoother than the weaker items supplied in the kit (I've snapped a few kit items on my TRF501X, and the gold ti coated ones seemed more robust when I upgraded.)
As per the setup sheet, I went for 1.3 and 1.4 pistons. These pistons are more precise than the kit items, being machined rather than moulded, and allow a more accurate damper setting, as less oil will get around the outside of the piston.
Ill be putting on yellow springs rear, and blues front, again deviating slightly from Lees setup, for reasons mentioned earlier.

The car is still a long way from being ready, with only a week to go to the national race.
Iv'e got my fingers crossed for Diff balls and shock towers being delivered today.
Any comments, or helpful tips are welcome.

I resumed, and completed my build last night. I decided to complete the build, without having some of the upgrade components. One main component I still have not received is my 5mm front shock tower, I will phone fibrelyte today, and check on the status, and add a 5mm rear shock tower to the order.

The diff build went well, using ceramic diff balls and preassembled ceramic thrust race. Remember its black grease on the thrust race, and diff grease on the diff balls. I used Lee Martin's excellent diff build guide. Following this to the letter, including trimming the pulley of the nobbles, results in a near perfect diff.

trfracing.co.uk/page_1265187551237.html

I then tried it with the next diff. At the point where it says fully tighten the diff, and then back off.... my diff bolt snapped when fully tightening. I decided to take a different aproach, and tighten until I felt it was right (as I have done in the past), this avoids putting too much pressure on the diff components.

Here are my finished diffs, and one snapped diff screw:

Having build up all of the major components, I fitted them all to the chassis, using hardened steel / ti / aluminium screws where best suited.

I drilled and counter sunk the chassis, to fit the centre brass weight kit from Rudebits, and tried my LIpos in. they wouldnt go in. It then dawned on me that the centre bulkhead needs some cutting / filing, in order to mount Lipos in this chassis. I knew this at the start of the build, and it slipped my mind. So everything had to come out of the car again, so I could take the centre bulkheads out. What a pain in the neck... so note to others out there, do this mod first.

I reassembled the car, and went about fitting my electrics. I am notorious for having messy electrics installs. I have tried my best for a neat install here, however I do go for function over appearance. I tend not to hide wires, especially the motor wires, as I'd like enough movement on the wires to allow the motor or speedo to swing clear of the car should I need to work on them.

On final inspection, I wasnt happy with the fit of the RPM ball cups on the JAAD Ti ball studs. In the past, I have used HPI or Schumacher ballstuds, and the RPM ball cups have been brilliant, with free movement, good strength, and no popping off in collisions. However, on the JAAD Ti, and the 3 racing (poor quality) ti ball studs I had in reserve, they were not as free as I would have liked. Due to the nature of the RPM ball cups, they will not wear in. I connected the battery, and tried the steering, and the servo was buzzing a bit too much, indicating the steering was binding too much. I decided to fit Hudy ball cups I had in reserve, these are very strong, and free moving on the Ti balls, but I have no idea how resistant they will be to popping off in a collision.

I ran the diffs in, by setting the car down with the two left hand wheels on the floor, and propped it up so the right hand wheels were in the air. This is an important step for good performing, and long lasting diffs. I set the trim to 30% throttle, and let it run for 10 minutes. I readjusted the diff, per the TRF diff build guide..... done.


So here is the finished car...... camber links not adjusted properly in these pictures.

Let me know what you think. I'd especially like some comments on my wiring, and any suggestions, tips, or faults you can spot with the car in general.

Bodyshell is not yet done.



... and so I've got my 4WD car ready for the first UK national this weekend......

with 120 drivers attending (that is finals A down to L (10 cars per final),  I will be over the moon with an H final (top 80), that is my aim for my first national, and first time out with this car.