how bout another story? - the update log

[killerkrank]

so, first i want to start with stating that i know not all of you will read the whole way through this but i want to post it not only to tell you guys but it can also be a helpful log for myself. should you read the whole way through, post something up to tell me what you think and should you have any questions please don't hold back. anyway....

so, i had been debating for some time and after finally getting my yeti i instantly fell in love. the yeti is a very originally handling machine. the positive attribute to it are instantly very obvious. now as i was pleased with the way it handled and ran, there is always room for improvement. after running for a little while and playing i made my first plans for upgrade. i had very quickly made my mind for a choice of speed. now i'm not sure if i did this at a different angle from everyone else or not but i figured if the big trucks worked well, why couldn't my yeti be a good candidate for the same approach, so first i made my transmission a two speed. upgraded the radio to a dx4c and the 4210 receiver. my first run with the two speed proved a failure. ran it straight into the railing along side our porch and broke the turnbuckle for the steering. nice going. went to a hobby shop and picked up parts to fix.


now since i got that going i figured the next step was to change out my gearing some. small step to start. 18 tooth spur gear. now i know that that's not a big change but being that the untold part of this story is that it was a preowned yeti i guess yeah, the next failure would have been the diff wouldn't it? so now the diff has gone i upgraded it to the axial hd bevel. still the 38/13. now. since ive started upgrading ive been having a problem with my receiver shutting down. after consulting with you friendly folks and you confirming what i feared i came to the conclusion that the digital servos i put in had burned out the bec in my stock vangaurd esc. now this all set off a motion. now this is where it kinda gets complicated. when i upgraded to the two speed i upgraded to the dx4c/4210 transmitter receiver combo. but that receiver can only be run with digital servos. or else it has a habit of burning servos, at least that i have found. lost a handful of servos to it.) now for some reason the servos killed the bec and it was shutting down the receiver. for some reason the bec going killed the esc completely. anyone seeing how unfortunate this is?

so, in one foul, i got bold. added in a cc bec 2.0, motor cooling fan, esc cooling fan, changed out for a sidewinder v3 and changed from a 18t pinion to a 22 tooth pinion. now anyone who has done this has found that this thing becomes a little monster. add in the hyrax 2.2's and you'll know that this thing is seriously getting fast. the handling is a bit sub par at this point. no weight in the back and front suspension is bottoming out to fast. so i got a big gens ace 7000 mah battery. it just....JUST barely fits in the battery bay. now the rear springs are too light. upgraded the rear springs. doubled the stiffness and the rear was taken care of. the front i got a little midieval on. the girlfriends uncle had bought shocks for the rear of his yeti but were two short. i saw possibility. i bought them. now they were 10mm longer then the front shocks. they wouldn't work well with the chassis the way it was, so i made a modification. the control arms are only held back from continuing to rotate down by the chassis itself. so i cut the chassis back a little bit and put the shocks in and voila. long. travel. suspension. which does exactly as its name suggests. the car now has a full 4 inches of suspension travel. it cam come through my yard at full speed and never leave the ground and my yard isn't exactly.....smooth.

now. at the end of this tail i will give you only one more detail. the stock tranny gearing is 26/28. if you don't already know, the 2 spd kit gives you options. my high gear in the transmission is a 28/26. now i'm now good at math but there are sites for this stuff so i fed my info in and it gave me answers out. i should be hitting a top speed of 44.8 mph. i believe in actuality i'm closer to 38 or 36. theorize and all. i imagine i'm pretty close to this but can tell you for sure so instead ill give you leave to tell me your thoughts.

[thewildblue77]

My first thoughts are.. paragraphs please...that was painful.

[killerkrank]

sorry. late night post. i was tired.

[DavidH]

Originally Posted by killerkrank

...
when i upgraded to the two speed i upgraded to the dx4c/4210 transmitter receiver combo. but that receiver can only be run with digital servos. or else it has a habit of burning servos, at least that i have found. lost a handful of servos to it.) now for some reason the servos killed the bec and it was shutting down the receiver. for some reason the bec going killed the esc completely. anyone seeing how unfortunate this is?

I use the same radio. The Spektrum manual does warn about analog servos.

so, in one foul, i got bold. added in a cc bec 2.0, motor cooling fan, esc cooling fan, changed out for a sidewinder v3 and changed from a 18t pinion to a 22 tooth pinion. now anyone who has done this has found that this thing becomes a little monster. add in the hyrax 2.2's and you'll know that this thing is seriously getting fast. the handling is a bit sub par at this point. no weight in the back and front suspension is bottoming out to fast. so i got a big gens ace 7000 mah battery. it just....JUST barely fits in the battery bay. now the rear springs are too light. upgraded the rear springs. doubled the stiffness and the rear was taken care of. the front i got a little midieval on. the girlfriends uncle had bought shocks for the rear of his yeti but were two short. i saw possibility. i bought them. now they were 10mm longer then the front shocks.

I use the axial blue dot "super-firm" springs.

they wouldn't work well with the chassis the way it was, so i made a modification. the control arms are only held back from continuing to rotate down by the chassis itself. so i cut the chassis back a little bit and put the shocks in and voila. long. travel. suspension. which does exactly as its name suggests. the car now has a full 4 inches of suspension travel. it cam come through my yard at full speed and never leave the ground and my yard isn't exactly.....smooth.

I have found that the downward travel is limited more by the universals and the steering knuckles at full lock than the chassis clearance.

now. at the end of this tail i will give you only one more detail. the stock tranny gearing is 26/28. if you don't already know, the 2 spd kit gives you options. my high gear in the transmission is a 28/26. now i'm now good at math but there are sites for this stuff so i fed my info in and it gave me answers out. i should be hitting a top speed of 44.8 mph. i believe in actuality i'm closer to 38 or 36. theorize and all. i imagine i'm pretty close to this but can tell you for sure so instead ill give you leave to tell me your thoughts.

I believe the 'overdrive' option is like going about 2 teeth up from the stock pinion. This is what I have done, with the two-speed, and keeping the stock 16t pinion.

I use my yeti mostly on the rocks and trails, but on 5" tall tires it will do a somewhat controlled 32 mph on dirt/gravel, but with locked diffs it needs a gentle trigger finger to keep it pointing straight while getting there. Speed checked with a GPS app on my phone.

The yeti is about versatility. If I were building a rig for speed, I would not want the solid rear axle. Start with a rig with open diffs and a low centre of gravity like a traxxas slash or losi SCBE. YMMV.

[killerkrank]

i can run my yeti now with alomost 4 inches of ground clearance front to back and the drive shafts are just fine. unbolt your shocks and the chassis holds the control arms from rotating. ive eliminated that problem and made it a long travel suspension. it being long travel also helps with the nose heavy jumping problem.
mine is probably running at around fourty miles per hour which, no is not blazing fast but for the yeti, is about the end of the usable range of speed. with what ive done to the truck its just at the edge of the handling for this truck. i can keep it under control but its running a fine line. ive went through a lot of test running to get it just right. i know that a stock yeti can not out handle mine.