Nitro TC3, project thumper

[Sharkey]

i did get most of my issues sorted out with the modded traxxas pipe. the motor now has enough exhaust flow to get it to hit peak rpm while having enough pulse to provide some tank pressure and keep fuel at the carb. i have been able to do some more tuning, the motor is running how i expect. the biggest issue right now is still the exhaust. being a composite pipe and epoxied together, it lasts about 1/2 a tank before it falls apart. both the epoxy and the composite are melting, and the silicone couplers don't stand up to 4 stroke exhaust temps. ill have to either track down a 4 stroke muffler or build something. the other option is the fuel pump, i might be able to make some room on the car for it, might just order one and see what i can do.

i did promise a video today and i do have one. unfortunetly we didnt get the 1/5 scale track set up today, but i still did get some on car camera footage. ill warn already that the video is blurry, i didnt realise the body hits the aircleaner and the vibrations from them motor travel straight into the body.

 

[Sharkey]

been a long time since ive updated this, lots has changed. i picked up an os fuel pump (its the smallest one out there) and went through a whole mess trying to get it to work correctly. the end result was the fuel pump has too much pressure for the carb, resulting in a lack of adjustability in the needles. the end result is im using the fuel pump to pump to pressurize the fuel tank, along with an old needle valve to adjust how much pressure to bleed off. all this work allowed me to run an open header. between the muffler and open header there is a pile more power. this motor easily has as much power as the .21 it replaced, it just doesn't have the rpm to keep going.

ive now replaced the os 15cvr carb with an hpi k4.6 carb. the 15cvr carb is only 5.5mm, the fs40s-c came stock with a 6.5, with the manifold ive built it essentially restricts the k4.6 carb to the same size as the port at 7.5mm. im hoping this will wake the motor up some more, as well as ease tuning a bit. once ive got all this sorted out im planning to bump the compression up a bit. forced induction would be fun but the rb superchargers are nothing more than a glorified fan, so there just arent any options out there.

here is a pic with the new carb

 

[Sharkey]

new intake manifold didnt work out so well. car was running great, was getting it dialed in and all the sudden it started bogging and idling high on the 3rd tank of fuel. turns out my manifold didnt stand up to the weight of the car and the huge amount of vibration caused by a single cylinder 4 stroke. i think what i need is a lathe, id be able to make it out of a single chunk then.

 

[antny]

Cool thread man. I check it out every week or so. My dream on road would be a 1/5 gas powered tc3 -GTC3. I've been thinking about making my own large scale gas tc3. That would be a task and a half, and a good amount of money too. I wish Associated would make one.

 

[Sharkey]

cars don't exactly scale up that well, and the tc3 just wouldnt work. think about a big gas motor sitting on one side of the chassis.

 

[antny]

I know. I don't want it exactly the same, obviously some things would have to be different. Just want something similar based off that design. I have a few ideas just don't have the time or resources.

 

[Sharkey]

really shaft drive doesn't work the greatest with touring cars for 1/5 scale. the only thing sort of like the tc3 is the losi 5ive. now shrink that thing a bit so its 535mm wheelbase and its a start, but im sure the weight balance is going to be way off. the best bet would be if the motor could be angled towards the center of the chassis (much like i did with my nitro tc3) it would help out, but then your going to run into issues with the pipe and driveshaft clearance.

honestly i think for 4wd, fg has it figured out. i know people don't like belt drive, however the gear setup used on some of the 4wd 1/5 scales makes me cringe.

 

[antny]

Yea, I'm one those who doesn't like belt drive. And part of the reason I don't have the time or resources is because I keep putting both of them in my 5ive. I think the 5ive setup would work fairly well, but I don't want go getting your thread off topic.