secretsg

The pipe hanger is next. Install the mount first and use red thread lock. Insert the rod and measure out the length you need. Here we can see it's too long, and will need to be cut. A good source for extra rods are bike spokes. There are good quality material and will have flex. At about a buck for a piece you can't lose.

After cutting the rod to length, tighten grub screws on mount and pipe. Use red thread lock again. I added a piece of aluminum tape on the tank to hopefully help deflect some heat away.

Lastly attach the spring from header to engine. Some engines will have built in ears like the case here. It use two short springs to attach from header to engine. IMO it's a much better system. Most RTR/cheaper engines will have one long spring to go from one side of the header to the other by wrapping around the engine.

secretsg

Now comes the last few items on the chassis. Insert the nuts on the wing mount, attach the wing by using countersunk screws and button.

Measure the Rx antenna length and cut tube to size. Capture with the grub screw.

I drilled out the splash guard to attach the fuel line, fuel filter and exhaust cooler. Check if the filter is in right direction. If it's an two piece design, make sure it is tightened. I used the dynamite big daddy filter and sullivan fuel line.

The exhaust cooler helps to lower the exhaust gas temp coming into the tank. (The only way to pressurize these model car engines.) It also acts like a reservoir, and keeps the pressure more constant. The idea is you gain some runtime and a more stable tune. If you use one make sure it's a one piece design. You don't want an air leak, thus creating more problems rather than helping.

If you are racing the legal limit includes volume from your fuel line/filter.

secretsg

I rearranged the ball link on the carb, and the mounting position on the horn for a straighter fit.

The EPA for the throttle servo is set next. You want to make sure the servo travel enough just enough to fully open the carb. You also want to to close the carb fully under brake, and make sure the gap you've set is correct. If the servo travels too far under braking, you can see the engine being pushed.

Key points here, idle gap is set with the restrictor off (Usually .5 -1mm.) However the carb only have to open past the opening with the restrictor in. Also roll the car under full braking to make sure the brake actually works. You might have to heat the carb a bit to remove the restrictor safely.

Lastly set the EPA for your steering servo. Adjust the EPA so it turns to the position you want to set it at, but not travel so far that the servo is still working when you've already hit the full lock position.

infernos777

went a little overboard w/the silicone sealant on the engine, no need for that stuff everwhere BTW

nice thread and great pics, you obviously take time with your builds and do a nice job. too bad its with that tank tamiya buggy, that car is brutal. good luck

secretsg

Thanks. I dont't think it's any more brutal than a Kyosho Inferno 777 SP3 would be It's really a copy/further development of that chassis with features of the new gen buggies.

That's the weight with nimh rx pack, heavy futaba BLS servos + aluminum tape/exhaust cooler. With the LiFe Rx pack/r614ff rx it's about 40grams less. I'm anticipating around 2870g with the TI screws/new lightweight parts before Tires/body. Even with all the extra crap I put on.

And yes it's a lot more rtv than a guy normally would use/need. I really wanted to see how the Racer's Edge stuff worked on the boot. Hoping it's not just a re-badged red RTV.

secretsg

Back to building

The last thing left on the chassis is the shocks. I like leaving it last because you can leave the chassis on the desk if you are not finishing it right away. In this case I had to travel to Japan for a week in the spring, after I started the build.

First insert the large o rings into the adjusters. Then assembled the teflon parts/o-rings into the cartridge. Tighten the bottom cap afterwards. I used VG damper grease to lubricate everything. A far more common item is the good old green slime.

Put a dab of red threadlock inside the shock shaft, assemble the piston of choice with the 2mm screw and spring washer. Tighten it as far as you can with free grip on shaft here. There's a much easier way to tight the whole assembly.

Gently pull the shaft thru the cartridge, then put a bit of grease on shock end and screw in the rod end. I used Tamiya non scratch pliers here. Integy also makes a nice shock plier if you are interested.

Now we tighten the shock piston screw by holding on to the assembled rod end. Snap in the ball collar and we are done.

secretsg

Fill the shock with damper oil. It's fine to over fill a bit here, you don't want insufficient oil before installing bladder. Move around piston slowly a couple times and you can see the air bubbles come up. Leave the whole thing upright for 5-10mins for additional bleed.

I like the losi oils because they are color coded like the Tamiyas. However they come in large bottles and and more available. A good replacement part is the Losi 8B bladder, the stock bladder tend to leak over time. The Losi Springs can also be used if you can't find the Tamiya springs.

Pull the piston to the very bottom and put the bladder on. You should get overflow here, if not you don't have enough oil put in. Clean up the spill and tighten caps. You should have at least half shock rebound at this point. (Rebound means how much the shaft will come up without spring.) You can further adjust rebound by where you place the piston when you do the bladder/cap bleed.

Attach shock boots, the fronts need to be shortened 5mm. Insert spring of choice and retainer. Attach the shocks to tower and a arms. The new one piece shocks mounts are now available as an upgrade.

We have now finished the chassis.

secretsg

Now we will do the basic setups on the car. I used a TM 1/8th setup station and board.

First mount the car on the station and makes sure wheel nuts are tight. Push down on the suspension and let suspension settle. We can start measuring the toe/camber angles after this. Here we can see here the camber is out of wack. Adjust the camber links until camber angles are all at the preferred setting.

Next use the toe plate to measure the toe angle. Adjust front toe with turnbuckles. The rear does not need adjustment since it is set on by the suspension plate. You can check the rear after some usage to see if any slop is developing in the suspension block.

secretsg

The droop also needs to set. This is done normally with droop blocks and a gauge. Unfortunately I misplaced my blocks and had to use 2 gauges for this adventure.

The adjustment is done by the grub screw on the arms. It adjusts the droop by raising the arm against the chassis. Some people have switched to a button head screw plus tubing to prevent movement of the grub screw as the car gets moving.

Lift the car up and let it drop freely on the board. The flat part of the chassis should sit against the board. The droop height is measured at the threaded part of the axle, not the hub. Make sure all four corners are at preferred setting.

secretsg

Before the next setup adjustment, we need to install the tires. I used proline V2 rim + AKA tires. (The V2 rim does not rub on Tamiya hubs)

Prep the tires by wiping rim and tire with alcohol. Slid the rim into the rim and make sure the rim seats correctly around the entire tire on both sides. Apply thin or medium CA.

If your rim has air holes, seal them with silicone or CA. Instead, punch a hole or two in the tire with a leather punch. The leather punch is available at harbour freight / princess auto type discount stores for cheap. Make sure the holes are evenly distributed if you are punching more than one, and also don't punch the foam.

secretsg

Mount the tire on a tire or prop balancer. Some people also rig up an old hub. If you have a Dynamite/Hudy type balancer like I do, I suggest removing the bearing seal and clean out all the grease. Just use a little of light oil (like Trinity lube) afterward. This will make it a lot smoother.

Use a sharpie to mark the spots, and small amounts of model clay to balance. Eventually the tire will no longer stop at one spot as you add more clay. You will need to rebalance after the first few runs when the foam/tire settles. Remember to clean all the dirt off.

secretsg

Tamiya applied threadlock to the axles already, so all we need to do is tighten the wheel nut. With the wheels on, we can set the ride height.

Lift the front end up again and let car drop on the board. The ride height is adjusted by the collars on the shock. Use the gauge to measure both front and rear ride height. (Had to two gauge it again here... grr) Make sure you measure the flat part on the front, not the angled portion of the chassis.

We are now done the basic setups you need on the car. I've left out other things like anti-roll/tweak etc. Some of the other setups are already done when we built the car. While others are non adjustable on this car and/or optional adjustments to make after test runs. I suggest you learn about them, and adjust as you need to. A good resource is the Hudy setup book, downloadable online. These basic steps should at least get you a car that doesn't handle out of spec.

secretsg

The last thing to do is the air filter. Tamiya uses the standard 1/8th filter. It's the same one Mugen uses on all their cars before the MBX6, so parts are interchangeable. I suggest you check the dimensions if you go with a different filter as the space is very tight on this car.

I use K&N oil, and just spray the foam in a zip lock. You can squeeze the filter after without getting messy. Slide the foam onto the body, and attach retainer/retainer screw plus the neck.

Don't forget to ziptie between neck to filter body, and neck to carb. You absolutely need the filter for offroad cars.

secretsg

The build is now complete. The body parts does include 2 lexan splash guards you need to install on the rear arms. I highly suggest you do this as it keeps out a lot of crud.

I will do an update with the hop ups, new optional parts and attached painted body pic. Maybe if a video if I get motivated.

Meanwhile here's a list of upgrades not listed on TRF801X page on TamiyaUSA. Some discovered by me while others are listed by the Tamiya drivers.

Tamiya parts:

84038 TRF801 Aluminum Rear Hub - L / R
1012 TRF801 HD Upper Shock Mount
1018 lw drive shafts
1021 lw diff outdrive
1019 lw front center drive shaft
1020 lw rear center drive shaft
1017 lw center joint
1024 lw captured axle
1023 rear shock tower
1022 front shock tower
51132 RC 6mm Alum. Stabilizer End (you will have to drill a bigger hole if you are using the largest swaybar, as a plus, they are blue)
84089 RC Round Head Socket Screw - Titanium 2.6x8mm 4pcs (for the swaybar retainers on the bulkhead)
49345 RC TB Evo IV Titanium Screws (this will cover 80% of your 3mm screws)
54155 RC 3mm Thin Aluminum Lock Nut - 5pcs Blue
42143 RC 4mm Alum Serrated Wheel Nut - 4pcs Blue (for the motor mount)
42119 3x38mm Blue Titanium Turnbuckle

Non Tamiya Parts:

Team Losi 15mm Shock Bladders - [LOSA5430]
Team Losi Rear Spring Set (8ight/8ight-T) - LOSA5447
Team Losi Front Spring Set - LOSA5446

KYOIFW310 Kyosho Lightweight 46T Center Spur Gear (MP777, ST-R)
KYOIFW325 Kyosho Lightweight 48T Center Spur Gear (MP777, ST-R)
KYOIFW330 Kyosho Optional SP Brake Pad (MP777/WC)
KYOIFW122 Kyosho Special Brake Disk

OFN40596 OFNA Lightweight Front/Rear Differential Outdrive Cups
OFN10099 OFNA 1/8 Clutch Bells Shim Kit

LNS1460 Lunsford 4x60mm Titanium Turnbuckle (1)
LNS1550 Lunsford 5x50mm Titanium Turnbuckle (1)

tommygun32

Excellant build thread secret. Very thorough and informative. Well done. [sm=thumbs_up.gif][sm=thumbs_up.gif][sm=thumbup.gif][sm=thumbup.gif]

Now....how does she drive???

Eman77

Very thorough build thread! I especially liked the list of upgrades you posted.

Regarding droop - why is it important? I see how we set it in the manual, but not being a racer, I'm not sure I get the point. Can you elaborate?

secretsg

Thanks. It feels like a MP777 WC/SP2 with better drivetrain/acceleration and more steering (but more steering slop.) Also has better rough track/big jump handling.

I don't think it has the durability of the old sp2 though, that thing was a tank.

secretsg

Droop affects almost everything. I suggest you read the setup book I mentioned in the previous post. It's linked below.

http://www.hudy.net/xhudy/showfile.p...252739b1ad8c24

Eman77

Must have missed your link earlier, thanks for that.

Read up on droop, not really worried about it. Like I said, I'm a basher. And none of my other current vehicles even have this control, so no worries. But...if I'm unhappy with a handling characteristic during bashing, I'll know what to do. [8D]

secretsg

As long as all 4 of your droop screws have the same height, you should be fine for bashing.

lez1troubles

Wanna race???[sm=punching.gif]