Limitless Mr.Duke’s Limitless Build

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I don’t know how to really answer this without going geek mode.....

Any rotating solid shaft has what’s called a “critical speed” where the shaft will deflect at a given rpm and cause the shaft to bend away from the axial centerline in a harmful way to power transfer. The load, diameter, length, balance and stiffness of the material the shaft is made from, will ultimately determine the rpm that this critical speed takes place and we get harmful vibrations and wobble or complete shaft failure. Increasing the diameter of the shaft, stiffness or reducing its length will almost always increase the shafts rpm where this harmful deflection takes place.
By lengthening the spool, the stiffest part of the assembly, it also shortens the driveshaft at the rear which raises the rpm at which that shaft reaches critical speed.

sorry, cooking Mother’s Day breakfast and replying at the same time

*edit to add more in depth info on this topic
https://en.m.wikipedia.org/wiki/Critical_speed

https://en.m.wikipedia.org/wiki/Rotordynamics

https://en.m.wikipedia.org/wiki/Torsional_vibration

Ok.. That I can understand 😉
Short answer, Arrma designed the rear shaft far too long for any REAL speed application..!!
 
Thank you guys for pointing me in the right direction.
It barely got by with the GRP tires, but once I put the hoons on I realized that without shaving off 4mm it wasn’t going to have enough clearance. That’s what I get for being stubborn.
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Ok.. That I can understand 😉
Short answer, Arrma designed the rear shaft far too long for any REAL speed application..!!
Just FYI I've ran that stock rear center shaft up to 137mph and stock Hoons to 138mph so far. I'm now running the Scorched center shafts but still running the stock Hoons👍
 
Just FYI I've ran that stock rear center shaft up to 137mph and stock Hoons to 138mph so far. I'm now running the Scorched center shafts but still running the stock Hoons👍
When it works, it works! Maybe i should give Hoons a second chance too.
I am really impressed with BSR XX pink's, decent grip and acceptable wear, except for their price + overseas shipping.
 
Limitless is done and ready for its maiden shakedown pass at sunrise tomorrow.
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1st couple passes will be on 6s to check the wear pattern on the tires and finish dialing in the alignment before switching over to 8s and collecting some good baseline data.
 
Sometimes this is a price you have to pay for ignoring when to let out and abort a bad run, versus staying in it with a “never lift” style mentality....
which was where I found myself yesterday morning.
That solid plan I had Saturday morning to run 6s and start out nice and slow got overtaken with F-this let’s send it. Never even put the 6s pack on the charger and went out loaded with 8s and what I figured would be a low 122-124 max setup.

Got to my spot at around 7am and made one half throttle pass to make sure everything sounded good and went straight with a maiden 88mph shakedown pass.

made couple minor tweaks and went right back out with a surprisingly fast 129mph pass under full throttle
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As soon as I saw the 129mph on a non aggressive pass pop up, I knew that I had to try for that 130+ pass.

‘Twas not the case unfortunately and poor decisions were made. 😂
After a horrible start and twice as many steering corrections on the run up, I stayed in it anyway and the car drifted to the right side of the road riding the white line for way too long trying to slowly work it back to the center of the road.

Not so much, and balled it up on the big end by getting the front splitter onto the grass and sending the car into the edge of a field.
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If all my parts come in by Friday I’ll be back out for more passes with a completely rebuilt rig Sunday morning.

Gotta pay to play 😎
 
That is probably the single hardest thing to learn. You want that 8s run so badly, but if the car is not driving straight it is time to abort the run.

I did the same thing with the Typhon. My run spot is over 1 hour away so I felt more of that "I have to try" in my head. The car was not driving good on 4s, so I knew 8s would be a disaster.

Glad you can get it back on the road for a reasonable price and timeline. Usually, as long as electronics are not damaged then it is not a total disaster...
 
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My last pass I got into it late and tried to make a longer pass than normal and drove out of visual range due to a change in elevation. I should have just waited to make another clean pass instead of sending it longer on the first one. I too find myself with the meathead mentality of pushing beyond what is logical. I only blame myself for the damages done, however slight they were. More than anything, I’ve damaged my will.
 
That is probably the single hardest thing to learn. You want that 8s run so badly, but if the car is not driving straight it is time to abort the run.

I did the same thing with the Typhon. My run spot is over 1 hour away so I felt more of that "I have to try" in my head. The car was not driving good on 4s, so I knew 8s would be a disaster.

Glad you can get it back on the road for a reasonable price and timeline. Usually, as long as electronics are not damaged then it is not a total disaster...
Yeah, I was already making plans on the short 5min drive back to the farm to locate another new Limitless and be there when they opened if the damage was extensive. Fortunately that wasn’t the case this time and didn’t need to break this car down to use as spares.
I placed 3 orders yesterday for a total of 210-ish plus some odds and ends that I already have spares for (diff case, body mount, splitter l, front end pieces etc...)

All electronics minus the servo made it out unscathed
 
I recently found a really close spot to run, but it is way more punishing than the airport, and the more I think about it, the happier I am that I decided not do make any high speed runs this weekend instead of really winding it out at the much safer airport this coming weekend.
 
Yeah, I was already making plans on the short 5min drive back to the farm to locate another new Limitless and be there when they opened if the damage was extensive. Fortunately that wasn’t the case this time and didn’t need to break this car down to use as spares.
I placed 3 orders yesterday for a total of 210-ish plus some odds and ends that I already have spares for (diff case, body mount, splitter l, front end pieces etc...)

All electronics minus the servo made it out unscathed
Hey man, great job.
Remember, it's not the catch, it's the chase. (Old Klingon proverb)
 
I learned the hard way myself. I don't know if it was me or my remote. But it would only move under 100% throttle.... not willing to accept it was me I sold it 😂
 
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