Build Thread Kaladeth's Mecatech FW01

[kaladeth]

Tire Warmers

12V and 4A per pair seem sufficient. I get the tires to around 140oF.

 

[kaladeth]

Race Day #3

Installed an exhaust deflector :

Bruised from battle but ready to fight:

Qualifiers were promising. The car had the pace but in the end I ran out of tire. Was my first 25 minute main!

Q1 P2 fast lap 19.464
Q2 P3 fast lap 19.323
Main P3 fast lap 20.095

Only damage was a bumper mount post. Overall, a very good race day!

 

[kaladeth]

Upgraded the spark plug to an NGK CR7HIX. Gap is perfect straight out of the box. This needs a terminal nut.

Torque to 8 ft-lb.

 

[kaladeth]

Front brake servo went bad, so I am going to go ahead and replace the remaining Futaba servos with Savox.

I am also going to take this opportunity to replace the old power cable. Will be using the new 1Up Racing “Lockdown” adjustable bullets.

The Savox servos were reverse polarity from the Futabas - this was an easy fix on the radio.

Also had to fix subtrim on Channel 4 so that it supports the correct geometry. Once the servo arm goes to a certain point the (front) brake lever won’t pull any further. You want the servo arm to pull the brake lever thru the entire movement because we use so much front brake. Ideally the rear brake would be setup the same way, but we need movement in both directions to be as linear as possible so we compromise and put the Channel 2 servo arm perpendicular.

Would have liked to put a short piece of shrink tubing on the bullet side also; this will have to do for now.

 

[kaladeth]

Crazy race weekend. Just a quick update after a grueling three-day event :

• Q1: 18.039
• Q2: 18.082
• Q3: 17.646
• Q4: 18.116
• Mains: 17.716
• Finished third

Things that helped :

• Checking and setting droop
• Checking and setting ride height
• Fixed throttle end point
• Smoother driving
• New tires

 

[Doom!]

Not bad at all!

 

[kaladeth]

Save this spot for the complete teardown, cleaning, and rebuild!

 

[kaladeth]

Upgraded the air box with one from MCD

Old airbox removed:

Old adapter removed:

New adapter installed:

Done!

 

[Benmectec]

Receiver and Servos

Managed to fit a Radiolink R8FG in there, along with the MyLaps transponder.

View attachment 219694

From Car Left to Right	Wire Label	Function	Radio Channel
Servo A	“2”	Throttle / Rear Brake	Ch 2
Servo B	“1”	Left Steering	Ch 1
Servo C	“3”	Right Steering	Ch 3
Servo D	“4”	Front Brake	Ch 4

View attachment 219695

The servos are Futaba CB701, max 8.4V.

• 0.075 sec/60° at 7.4V
• 680.5 ozf/in at 7.4V

Radio Setup

Two servos are used for steering. Two ways to hook them up: (a) use a Y cable and only use Channel 1, or (b) put one on Channel 1 and the other on Channel 3.

I went with (b) so that it’s easier to zero the servo with the radio's subtrim function. I used steering mixing to achieve this, but do not plan to adjust steering endpoints on the fly at this time, to keep it simple.

View attachment 219707View attachment 219708

For brakes, Channel 2 is both throttle and brake (brake1/rear brakes). Channel 4 is brake2 (front brake).

View attachment 219709

To adjust brake bias while driving, I assigned DT3 to adjust the front brake endpoint, and DT4 to adjust the rear brake endpoint.

View attachment 219710

Car looks great mate and nice setup. Mines being ordered tomorrow. I've got a Y lead coming as going to run x 2 40kg AGFRC servos and got 45kg ones for throttle and brakes. If you wasn't running a Y lead how would you plug in transponder as theres only place for 4 plugs on Futaba receiver?

 

[Benmectec]

Picked mine up last week. Waiting on exhaust to arrive tomorrow. They are an awesome bit of kit

Have you got any pictures of where all the fuel lines go please mate. I've got the fuel return tank on mine but dont know where to run all the pipes

 

[kaladeth]

Car looks great mate and nice setup. Mines being ordered tomorrow. I've got a Y lead coming as going to run x 2 40kg AGFRC servos and got 45kg ones for throttle and brakes. If you wasn't running a Y lead how would you plug in transponder as theres only place for 4 plugs on Futaba receiver?

Conveniently it all fits:

Ch 1: steering (L)
Ch 2: throttle + rear brake
Ch 3: front brake
Ch 4: steering (R]
S: transponder (power only) on Y to RX battery

Picked mine up last week. Waiting on exhaust to arrive tomorrow. They are an awesome bit of kit

Have you got any pictures of where all the fuel lines go please mate. I've got the fuel return tank on mine but dont know where to run all the pipes

View attachment 250259

Wow so nice! Congrats! Where are you planning to run it? I do not see a diff yet.

Fuel lines, take a look at post 28 above:
- from main tank to carb fuel intake
- from main tank to carb fuel return
- from main tank (cover) to top of overflow tank
- from main tank to bottom of overflow tank
- from top of overflow tank to side of car

 

[Dan B.]

Holy smoke, @kaladeth ! What a completely cool build. I could see myself having one of these, but I’m a little terrified of jumping down the gas rabbit hole. So freaking cool, man.
It’s also been awesome to follow your journey as you gain track experience. It would be so cool to have a track somewhere closer than three states away.

 

[Ledzoix]

Hi kaladeth, Thanks so much for this wonderful summary. It's a great way to learn more about gas cars and racedays
Really enjoyed reading it.

 

[kaladeth]

I have been busy, but suffice to say I must be doing something right!

Race Day 6: TQ, P1, 17.067
Race Day 7: TQ, P1, 16.967
Race Day 8: TQ, P2, 17.305
FG Supply Grand Prix: TQ, P1, 17.391

These are now on my regular checklist after every race day:

• Check bearings
• Check shocks
• Check brakes
• Check for loose screws
• Check droop
• Check ride height (every run)

Some of the biggest changes leading up to the step change in lap times:

July 11: Complete cleaning and rebuild from the ground up, replaced all bearings, upgraded air filter box

July 26: Changed diff setting from A1 to A3

And some issues that might have caused the slight drop, in addition to other race conditions like track temp etc.:

August 18: Broke rear LH pillar. Replaced.

September 28: Broke rear right axle. Replaced.

October 11: Found out I’ve lost rear brakes, and my front brakes were blocked. Cleaned out rear brake cylinder and replaced brake fluid on both from DOT 4 to DOT 5.

Only two more points races before the end of the season, with a clear line of sight to winning the championship. Two things to focus on:

• Continue proper car maintenance
• Continue improving consistency (in particular turns 1, 2 and 3)

Holy smoke, @kaladeth ! What a completely cool build. I could see myself having one of these, but I’m a little terrified of jumping down the gas rabbit hole. So freaking cool, man.
It’s also been awesome to follow your journey as you gain track experience. It would be so cool to have a track somewhere closer than three states away.

@Dan B. do it do it you know I'll be right here supporting you! If I can do it, should be easy peasy for you. Still hoping you can come visit our track someday!

Hi kaladeth, Thanks so much for this wonderful summary. It's a great way to learn more about gas cars and racedays
Really enjoyed reading it.

@Ledzoix you're very welcome! Keep us posted on your Mecatech build. Looking forward to hearing more about it.

 

[Pablo1]

Any videos of this running?

Almost afraid to ask what this has cost you to date...!

 

[kaladeth]

Any videos of this running?

Almost afraid to ask what this has cost you to date...!

You can check out the RAMS RC website at https://rams-rc.com.

Or watch one of the recent A Mains:

 

[kaladeth]

Race Day 9: TQ, P1, 17.7

Q1: 17.6
Q2: 17.8

Was a tough race with very low grip and the track was full with 8 cars running. Not perfect driving either with consistency dropping all the way from Q1 to the main. Stronger pace definitely won it again this race.

Fresh front clip and bumper:

Still need to get a proper setup station but this tool will do for now:

 

[kaladeth]

Race Day 10: TQ, P1, 17.9

Q1: 18.0
Q2: 18.2

Grip was nowhere again this weekend! But I won TQ and P1. And with that, I also won the championship by just 2 points. Kind of like Lando, except I had to win this one.

Time to upgrade the motor in preparation for the new class next year.

 

[Doom!]

Congrats on the win!

 

[CertifiedMike]

Congrats!!! What an awesome car!!!