Serpent Cobra GT
#2311
Tech Master
iTrader: (42)
1. My bet is that the ackerman plate (that connects the 2 steering bell cranks together) is rubbing on the top of the mounting surface. A light dremel wheel frees this up. I had this on all the cars I've built. It isn't much but it won't free up on its own.
2. Chassis flat on the board and then measure from the bottom of the wheel hex to the board. Make sure the wheel hex flat is parallel to the board prior to measuring. RC-SHOX do some great gauges for this task.
3. Initially set the anti-roll bar connectors at the kit length accurately. You shouldn't need to adjust it more than half a turn to align the roll bar. All the kits I've built have been perfect at an accurate kit setting. Make sure the roll bar is flat (use a setup board) prior to fitting it.
2. Chassis flat on the board and then measure from the bottom of the wheel hex to the board. Make sure the wheel hex flat is parallel to the board prior to measuring. RC-SHOX do some great gauges for this task.
3. Initially set the anti-roll bar connectors at the kit length accurately. You shouldn't need to adjust it more than half a turn to align the roll bar. All the kits I've built have been perfect at an accurate kit setting. Make sure the roll bar is flat (use a setup board) prior to fitting it.
#2312
032 nova header and 2046 pipe is the fastest hands down, if you dont mind paying about 20.00 more you can order the 2046 header pipe combo from Desoto just to get the pipe. if you have a 9886 it will work very well too.
#2313
I no longer make the droop guages. i can 3d print some but I am no longer offering the machined delrin ones.
#2314
Ah that's a shame. The delrin gauges are AWESOME!! Use mine all the time.
#2317
#2318
Tech Initiate
I'm glad to see you're making progress. I run the shocks at the lowest position front and rear. 3.0mm rear arb and the 2.7mm front arb. I also run the front diff spacer as well but many don't. I run 500k rear diff and 1M front diff. I think your rear diff is way too soft. I run the car quite stiff running the new 39.5lbs hard springs. I've found that the GRP wheels rub the steering blocks at near full lock and you can't actually achieve full lock which could contribute to your understeer issues. Like I said I really don't like the GRP wheel/tyre for several reasons. Are you running the 0-degree steering blocks? These would also provide more off power steering.
i got the front diff spacer. Going to try it out tomorrow. Is the bumper spacers necessary?
Last edited by Dougie1986; 07-29-2017 at 09:05 PM.
#2319
#2320
#2321
Tech Rookie
Hello everyone,
Just joined this forum but not sure where to post this question. My 10 yr old son started racing with the Serpent 3.0 Gt about 7 mths ago after driving all types of rc cars since he was 3 yrs old. He has been competing with older guys who have been in the sport for years and holding his own. I am his mechanic/pitman and it has been a learning and rewarding experience for both of us. Came across this forum and have been reading a lot of valuable info especially by Dan Vector, Tony Luna, Paolo and others. Especially like how you guys help out newbies. I would like some help with the transmission. Using the SLX1 but not shifting into second. Re screwed shift point screws in and then backed out 3.5 turns but problem persists. Appreciate any assistance. Also some help in set up. Present set up:
Shock springs: Fr - Black Rr purple
1000 cst x 4
Diffs: Frnt - 500K Rear - 60k
Droop with flo control blocks: Fr - 24 Rr - 27
Ride Height: Fr -9 Rr - 10
Camber: Fr - 2 Rr-3
Toe: 1
Spurs 62 and 57
pinion 19 and 24
clutch: 2 carbon and 2 Al
Hard springs
Tires: GRP- Fr S5 Rr S3
or Sweeps 45E.
Appreciate any help.
Thanks,
Nafspeed
Just joined this forum but not sure where to post this question. My 10 yr old son started racing with the Serpent 3.0 Gt about 7 mths ago after driving all types of rc cars since he was 3 yrs old. He has been competing with older guys who have been in the sport for years and holding his own. I am his mechanic/pitman and it has been a learning and rewarding experience for both of us. Came across this forum and have been reading a lot of valuable info especially by Dan Vector, Tony Luna, Paolo and others. Especially like how you guys help out newbies. I would like some help with the transmission. Using the SLX1 but not shifting into second. Re screwed shift point screws in and then backed out 3.5 turns but problem persists. Appreciate any assistance. Also some help in set up. Present set up:
Shock springs: Fr - Black Rr purple
1000 cst x 4
Diffs: Frnt - 500K Rear - 60k
Droop with flo control blocks: Fr - 24 Rr - 27
Ride Height: Fr -9 Rr - 10
Camber: Fr - 2 Rr-3
Toe: 1
Spurs 62 and 57
pinion 19 and 24
clutch: 2 carbon and 2 Al
Hard springs
Tires: GRP- Fr S5 Rr S3
or Sweeps 45E.
Appreciate any help.
Thanks,
Nafspeed
#2322
Tech Master
iTrader: (45)
Hello everyone,
Just joined this forum but not sure where to post this question. My 10 yr old son started racing with the Serpent 3.0 Gt about 7 mths ago after driving all types of rc cars since he was 3 yrs old. He has been competing with older guys who have been in the sport for years and holding his own. I am his mechanic/pitman and it has been a learning and rewarding experience for both of us. Came across this forum and have been reading a lot of valuable info especially by Dan Vector, Tony Luna, Paolo and others. Especially like how you guys help out newbies. I would like some help with the transmission. Using the SLX1 but not shifting into second. Re screwed shift point screws in and then backed out 3.5 turns but problem persists. Appreciate any assistance. Also some help in set up. Present set up:
Shock springs: Fr - Black Rr purple
1000 cst x 4
Diffs: Frnt - 500K Rear - 60k
Droop with flo control blocks: Fr - 24 Rr - 27
Ride Height: Fr -9 Rr - 10
Camber: Fr - 2 Rr-3
Toe: 1
Spurs 62 and 57
pinion 19 and 24
clutch: 2 carbon and 2 Al
Hard springs
Tires: GRP- Fr S5 Rr S3
or Sweeps 45E.
Appreciate any help.
Thanks,
Nafspeed
Just joined this forum but not sure where to post this question. My 10 yr old son started racing with the Serpent 3.0 Gt about 7 mths ago after driving all types of rc cars since he was 3 yrs old. He has been competing with older guys who have been in the sport for years and holding his own. I am his mechanic/pitman and it has been a learning and rewarding experience for both of us. Came across this forum and have been reading a lot of valuable info especially by Dan Vector, Tony Luna, Paolo and others. Especially like how you guys help out newbies. I would like some help with the transmission. Using the SLX1 but not shifting into second. Re screwed shift point screws in and then backed out 3.5 turns but problem persists. Appreciate any assistance. Also some help in set up. Present set up:
Shock springs: Fr - Black Rr purple
1000 cst x 4
Diffs: Frnt - 500K Rear - 60k
Droop with flo control blocks: Fr - 24 Rr - 27
Ride Height: Fr -9 Rr - 10
Camber: Fr - 2 Rr-3
Toe: 1
Spurs 62 and 57
pinion 19 and 24
clutch: 2 carbon and 2 Al
Hard springs
Tires: GRP- Fr S5 Rr S3
or Sweeps 45E.
Appreciate any help.
Thanks,
Nafspeed
See if the car is shifting at all first. Place car on jump box and gradually accelerate the throttle, you should see and hear the car actually shift. (it may be stuck in second already or transmission is too tight that your motor can't get to high enough RPMs under load to actually make it shift) the SLX1 if very smooth so pay close attention.
Pull the 2speed and check the shoe gap. This is the gap between the actual shoes and the 2gear housing. This gap is critical to good performance. The shoes should be as close to the housing as possible but still allowing the 2nd gear housing to spin freely. The shoe gap is adjusted by the set screws on the shoes (not the set screws with springs) also note that these are the same screws that adjust the play between the shoes and the shaft. Little to no play between the shaft and shoes will provide a long lasting transmission.
Adjust the tension screws evenly at all times and make equal adjustments to each side. Trying both directions (turning right tightens the screw to provide later shift, left turn loosen to allow earlier shifting) till you get the car to shift on the box.
The manuals 3.5 turns out is a basic starting point, but shift points are different depending on the engine and clutch setup being used under load.
Modification of the 2nd gear housing can be made to make for quick on the fly adjustments to the tension screws without having to pull the whole transmission everytime. It does require a narrow shaft 2.0mm ball end driver. But will save you lots of time and effort.
Getting it to shift off load on the box will be your starting point, then you can adjust accordingly to the track or personal preference under load.
* it's extremely important to know that the adjustments should be made a 1/4 - 1/8 turns at a time*
Hope this helps
#2323
Tech Rookie
Thank you Tony for taking your time to help me out. This is Farouk from LimeRc. "Nafspeed" is my son's driving name. I opened the transmission today and checked all that you indicated. Gap is ok. Took clutch apart and checked screws, pins, shaft and springs for damage. None found. Cleaned and put back together. I had purchased this car slightly used. One thing I noticed though - the shift point springs that are on the clutch are thicker than the ones in the original Serpent pack #804371. So I replaced with the new thinner ones. As Dan Vector indicated in a previous post, I also cleaned one way bearing with nitro fuel 3 times and rolled on shaft to clean and applied one drop one way oil. Also lightly sanded shaft where bearing rests. Haven't tried the car as yet but hoping to do so tomorrow. will let you know. Also, could you or anyone else check my setup posted previously and advise of any changes to be made. Engine being used is Fx K5 DC combo with 2108 pipe and 659704 manifold. OS RP#6 plug and Maxima 25/9 fuel.
#2324
Thank you Tony for taking your time to help me out. This is Farouk from LimeRc. "Nafspeed" is my son's driving name. I opened the transmission today and checked all that you indicated. Gap is ok. Took clutch apart and checked screws, pins, shaft and springs for damage. None found. Cleaned and put back together. I had purchased this car slightly used. One thing I noticed though - the shift point springs that are on the clutch are thicker than the ones in the original Serpent pack #804371. So I replaced with the new thinner ones. As Dan Vector indicated in a previous post, I also cleaned one way bearing with nitro fuel 3 times and rolled on shaft to clean and applied one drop one way oil. Also lightly sanded shaft where bearing rests. Haven't tried the car as yet but hoping to do so tomorrow. will let you know. Also, could you or anyone else check my setup posted previously and advise of any changes to be made. Engine being used is Fx K5 DC combo with 2108 pipe and 659704 manifold. OS RP#6 plug and Maxima 25/9 fuel.
Serpent made a running change wiht the 2spd housing and they now come with the adjustment hole already predrilled for you so you dont have to modify anymore, and The new 2 spd shoes have also been update and are much better and more reliable.
#2325
Tech Rookie
I have some different techniques with transmissions but maybe this will help. Nitro fuel has castor oil in it which is a lubricant so i would not want that residue on the bearing. Clean the one way bearing with carb cleaner and then apply your one way oil or grease ( i use kyosho ball dif grease and have for years). i dont recommend sanding the shaft at all, thats what the one way bearing uses for grip so it does not slip. if that surface isnt PERFECTLY round it will slip and it will also slip if that surface is too rough.
Serpent made a running change wiht the 2spd housing and they now come with the adjustment hole already predrilled for you so you dont have to modify anymore, and The new 2 spd shoes have also been update and are much better and more reliable.
Wow, she shifts. Did what you said Marcus and shifting like a greased monkey. Also adjusted grub screw for clutch to be as close as possible to housing without binding and adjusted shift point screw in small increments out. works like a charm. Noticed the spring that was originally on the clutch was thicker than the new one #804371. Could this have contributed to the problem? Also using the new housing with the holes predrilled but had to do some reaming to work. Also painted shift pt screws 2 different colours so I wouldn't adjust the same screw twice. This clutch was built with the grub screws from the outside. Next clutch I will try the mod from the inside. Thanks also to Tony.
Serpent made a running change wiht the 2spd housing and they now come with the adjustment hole already predrilled for you so you dont have to modify anymore, and The new 2 spd shoes have also been update and are much better and more reliable.
Wow, she shifts. Did what you said Marcus and shifting like a greased monkey. Also adjusted grub screw for clutch to be as close as possible to housing without binding and adjusted shift point screw in small increments out. works like a charm. Noticed the spring that was originally on the clutch was thicker than the new one #804371. Could this have contributed to the problem? Also using the new housing with the holes predrilled but had to do some reaming to work. Also painted shift pt screws 2 different colours so I wouldn't adjust the same screw twice. This clutch was built with the grub screws from the outside. Next clutch I will try the mod from the inside. Thanks also to Tony.