Thunder tiger ST-1
#3901
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I thought heavy in the center transfers powere more evenly to the front and rear diffs more like all wheel drive. Then the thinner in the rear will let the rear tires do more of the work and thicker in the front. Correct me if I am wrong please

#3902
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Makes sense vnmsgt. But not sure myself. The 3 diff set up is still new to me.
ericem, it was your truck in the video doing wheelies right? Was that with the stock engine or the LRP? And thats with the 7/20/3 set up?
ericem, it was your truck in the video doing wheelies right? Was that with the stock engine or the LRP? And thats with the 7/20/3 set up?
#3904
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Issue 130 (September 2006) Words: Derek Buono
For many of us, differentials in 1/8-scale vehicles are among the most abused and neglected parts on the kit. But for many they are the #1 tuning option when they hit the track. All 1/8-scale buggies and truggies have three of them: one for the front, one for the center, and one for the rear of the car. As a racer, I usually search the hot combination, but rarely use it as a tuning aid. The effects that the diffs have in the handling of the car are huge; they can drastically alter the way a car handles bumps, exits a corner, and accelerates. We decided to talk to one of the pro drivers who has been experimenting with different combinations for years. Chad Bradley recently switched to Jammin' where he's been tearing up the track with both the X1 CR and the CRT. Most of today's differentials are tuned in with silicone oil, and the most common weights used range from 1,000wt to 50,000wt. Understanding what each differential has to offer, and how to tune them properly, can give you an edge over the track conditions as well as the competition.
Chad Bradley on Diffs
Front Differential
Buggy and truggy front (Steering): Depending on how your buggy/truggy is handling, you can alter the amount of steering by altering the weights in the front diff. If you want more steering entering the corner try running lighter oil (3,000wt buggy, 7,000wt truck) This will give the vehicle more off-power steering, which is better on tight tracks. Heavier oils (7,000-10,000wt buggy, 10,000-20,000wt truck) will give your car better on-power steering and will help on higher speed tracks.
Why Have Differentials
Hopefully it's no surprise why we have differentials, but if you were just born here's a quick explanation: During a turn the inside wheel travels a shorter distance, and therefore can spin at a slower speed than the outside wheel, which has to go farther. Since both are on the same car, it would be difficult for that to happen without the invention of the differential. A diff allows one wheel to spin faster than the other, which improves handling in corners. In four-wheel-drive vehicles a third diff is used in the center, to allow the front and rear wheels to travel at different speeds as well.
Without any friction with the ground, the system would transfer power to the wheel with the least resistance, and result in a loss of speed in a corner and over bumps. We've all seen Subaru commercials explaining that having power to the wheels that grip (have the most resistance) improves handling. The way that is controlled in RC vehicles is with silicone diff fluid (and in some cars thick grease). This acts as a "limited slip" differential, and allows the wheels to spin at different speeds - but maintain power delivery to the wheels with more traction. The thicker the oil, the closer to a solid axle the diff acts, and the thinner the closer to an open differential it is.
It is by controlling the diffs with fluid viscosity that we alter the handling characteristics of a car for faster acceleration or more steering. Chad went through the ranges for his vehicles, but they hold true as starting points for any brand, and how you drive may alter what you end up with.
Quick Oil Reference: what should be in your diffs:
OIL CHANGE
Fluids wear out. Even though you really cannot judge the effectiveness of any oil by the color, it is a good indicator that it's time for a change. Chad usually changes his diff oil every three to four club races, and rebuilds his diffs before any major event, and if he's comfortable with the setup he generally doesn't change it. Regular rebuilds are a cheap way to make sure the differentials stay consistent.
Buggy and truggy front (Bumps): You also have to consider how the diff affects the handling through bumps. Lighter oils (3,000wt buggy, 7,000wt truggy) are better for bumpy conditions. If the oil is too heavy it will make the car want to change direction or oversteer in the rough or rhythm sections.
Center Differential
Buggy and truggy: Lighter center oils help the buggy or truck track straight while accelerating (3,000-5,000wt buggy; 7,000-10,000wt truck). Running lighter oils in the center has a negative effect on the acceleration. The lighter oil allows the power to be directed toward the front of the car and hamper acceleration out of corners. If you're having trouble clearing jumps that are out of a slow corner, that could be a sign that the center diff is too light, but for really bumpy sections having lighter oil in the center will allow the car to accelerate better and straighter.
Rear Differential
Buggy and truggy: I don't adjust the rear too often, and if I do it's usually only in 1000wt increments. Lighter oil in the rear diff gives the vehicle more off-power steering, but can make the car or truck feel inconsistent around the track, especially in long main events. The majority of the time I will use 2,000 and 3,000 in the rear diff in both buggy and truck.
Differential Tuning With Chad Bradley
We ask these questions all the time when we're racing, and have heard them asked at least seven times while at the track... and we're sure that as you're reading this you may be asking "What do I do when...?"
...the track is rutty:
Buggy: Try changing the center to a lighter setting first (3,000-5,000wt); if the car is changing directions out of a bumpy corner, try making the front lighter (3,000-4000wt).
Truck: Same as buggy but the diff setting to try for the front (7,000wt) and for the center 7,000-15,000wt.
...the track is loose and smooth:
Buggy and truggy: The best way I've found to increase traction with the diffs is to increase the oil weight in the rear diff slightly -3,000-5,000wt.
...if the track is loose and rutty:
Buggy: A "square" diff setup here helps -5,000wt front, 5,000wt center and 3,000-5,000wt rear.
Truck: Lighter center and front -7,000wt front, 10,000wt center.
...the track is blue groove:
Buggy: Most of the time I run between 5,000-7,000wt in the front, and 7,000-10,000wt center.
Truck: Most of the time on blue groove the cars and trucks on throttle turn-in good because of the weight transfer to front tires, but you lose some steering coming out of the turn. So to sacrifice some turn in for out of the corner steering and acceleration, a heavier front and center is better suited majority of the time -20,000wt front, 30,000-50,000wt center.
...the track is blue groove and rutty:
Buggy: I would normally just go lighter in the center, but not too light (5,000wt)
Truck: Since most trucks handle the bumps I wouldn't change the diff settings from the smooth blue groove setup.
... I want more steering entering the turn:
Buggy: Lighter front oil (3,000wt) and rear (1,000wt)
Truck: Lighter front oil (5,000-7,000wt) and rear (1,000-2,000wt)
...I want more steering exiting:
Buggy: Thicker front oil -5,000-10,000wt
Truck: Thicker front oil-10,000-20,000wt
...I want more acceleration out of a turn:
Buggy: Thicker center oil - 7,000-10,000
Truck: Thicker center oil - 20,000-50,000wt
...I want it to go better through a rough section:
Buggy: Use thinner oil for the center (3,000-4000wt) and thinner oil for the front as well (3,000wt).
Truck: Use thinner oil for the center (7,000-10,000wt) and thinner oil for the front as well (5,000-7,000wt).
...it pulls around too much through ruts:
Buggy and truck: Usually this happens because the oil in the front and center differentials is too thick; reduce weights.
Starting Point
All this is worth nothing if you don't have a starting point. Chad gave us some starting weights for a variety of conditions that will be good at most tracks. You can apply what we've gone over in the article to fine tune your vehicle:
Conclusion
Once you understand the principal of how a diff works and how different weight oils slow the action you will be a master tuner in a few short days. This doesn't mean that dropping 1,000wt in the front will make you a better driver. Learning how to drive is something that has to be done before you can fine tune to get the car to behave like you want.
For many of us, differentials in 1/8-scale vehicles are among the most abused and neglected parts on the kit. But for many they are the #1 tuning option when they hit the track. All 1/8-scale buggies and truggies have three of them: one for the front, one for the center, and one for the rear of the car. As a racer, I usually search the hot combination, but rarely use it as a tuning aid. The effects that the diffs have in the handling of the car are huge; they can drastically alter the way a car handles bumps, exits a corner, and accelerates. We decided to talk to one of the pro drivers who has been experimenting with different combinations for years. Chad Bradley recently switched to Jammin' where he's been tearing up the track with both the X1 CR and the CRT. Most of today's differentials are tuned in with silicone oil, and the most common weights used range from 1,000wt to 50,000wt. Understanding what each differential has to offer, and how to tune them properly, can give you an edge over the track conditions as well as the competition.
Chad Bradley on Diffs
Front Differential
Buggy and truggy front (Steering): Depending on how your buggy/truggy is handling, you can alter the amount of steering by altering the weights in the front diff. If you want more steering entering the corner try running lighter oil (3,000wt buggy, 7,000wt truck) This will give the vehicle more off-power steering, which is better on tight tracks. Heavier oils (7,000-10,000wt buggy, 10,000-20,000wt truck) will give your car better on-power steering and will help on higher speed tracks.
Why Have Differentials
Hopefully it's no surprise why we have differentials, but if you were just born here's a quick explanation: During a turn the inside wheel travels a shorter distance, and therefore can spin at a slower speed than the outside wheel, which has to go farther. Since both are on the same car, it would be difficult for that to happen without the invention of the differential. A diff allows one wheel to spin faster than the other, which improves handling in corners. In four-wheel-drive vehicles a third diff is used in the center, to allow the front and rear wheels to travel at different speeds as well.
Without any friction with the ground, the system would transfer power to the wheel with the least resistance, and result in a loss of speed in a corner and over bumps. We've all seen Subaru commercials explaining that having power to the wheels that grip (have the most resistance) improves handling. The way that is controlled in RC vehicles is with silicone diff fluid (and in some cars thick grease). This acts as a "limited slip" differential, and allows the wheels to spin at different speeds - but maintain power delivery to the wheels with more traction. The thicker the oil, the closer to a solid axle the diff acts, and the thinner the closer to an open differential it is.
It is by controlling the diffs with fluid viscosity that we alter the handling characteristics of a car for faster acceleration or more steering. Chad went through the ranges for his vehicles, but they hold true as starting points for any brand, and how you drive may alter what you end up with.
Quick Oil Reference: what should be in your diffs:
OIL CHANGE
Fluids wear out. Even though you really cannot judge the effectiveness of any oil by the color, it is a good indicator that it's time for a change. Chad usually changes his diff oil every three to four club races, and rebuilds his diffs before any major event, and if he's comfortable with the setup he generally doesn't change it. Regular rebuilds are a cheap way to make sure the differentials stay consistent.
Buggy and truggy front (Bumps): You also have to consider how the diff affects the handling through bumps. Lighter oils (3,000wt buggy, 7,000wt truggy) are better for bumpy conditions. If the oil is too heavy it will make the car want to change direction or oversteer in the rough or rhythm sections.
Center Differential
Buggy and truggy: Lighter center oils help the buggy or truck track straight while accelerating (3,000-5,000wt buggy; 7,000-10,000wt truck). Running lighter oils in the center has a negative effect on the acceleration. The lighter oil allows the power to be directed toward the front of the car and hamper acceleration out of corners. If you're having trouble clearing jumps that are out of a slow corner, that could be a sign that the center diff is too light, but for really bumpy sections having lighter oil in the center will allow the car to accelerate better and straighter.
Rear Differential
Buggy and truggy: I don't adjust the rear too often, and if I do it's usually only in 1000wt increments. Lighter oil in the rear diff gives the vehicle more off-power steering, but can make the car or truck feel inconsistent around the track, especially in long main events. The majority of the time I will use 2,000 and 3,000 in the rear diff in both buggy and truck.
Differential Tuning With Chad Bradley
We ask these questions all the time when we're racing, and have heard them asked at least seven times while at the track... and we're sure that as you're reading this you may be asking "What do I do when...?"
...the track is rutty:
Buggy: Try changing the center to a lighter setting first (3,000-5,000wt); if the car is changing directions out of a bumpy corner, try making the front lighter (3,000-4000wt).
Truck: Same as buggy but the diff setting to try for the front (7,000wt) and for the center 7,000-15,000wt.
...the track is loose and smooth:
Buggy and truggy: The best way I've found to increase traction with the diffs is to increase the oil weight in the rear diff slightly -3,000-5,000wt.
...if the track is loose and rutty:
Buggy: A "square" diff setup here helps -5,000wt front, 5,000wt center and 3,000-5,000wt rear.
Truck: Lighter center and front -7,000wt front, 10,000wt center.
...the track is blue groove:
Buggy: Most of the time I run between 5,000-7,000wt in the front, and 7,000-10,000wt center.
Truck: Most of the time on blue groove the cars and trucks on throttle turn-in good because of the weight transfer to front tires, but you lose some steering coming out of the turn. So to sacrifice some turn in for out of the corner steering and acceleration, a heavier front and center is better suited majority of the time -20,000wt front, 30,000-50,000wt center.
...the track is blue groove and rutty:
Buggy: I would normally just go lighter in the center, but not too light (5,000wt)
Truck: Since most trucks handle the bumps I wouldn't change the diff settings from the smooth blue groove setup.
... I want more steering entering the turn:
Buggy: Lighter front oil (3,000wt) and rear (1,000wt)
Truck: Lighter front oil (5,000-7,000wt) and rear (1,000-2,000wt)
...I want more steering exiting:
Buggy: Thicker front oil -5,000-10,000wt
Truck: Thicker front oil-10,000-20,000wt
...I want more acceleration out of a turn:
Buggy: Thicker center oil - 7,000-10,000
Truck: Thicker center oil - 20,000-50,000wt
...I want it to go better through a rough section:
Buggy: Use thinner oil for the center (3,000-4000wt) and thinner oil for the front as well (3,000wt).
Truck: Use thinner oil for the center (7,000-10,000wt) and thinner oil for the front as well (5,000-7,000wt).
...it pulls around too much through ruts:
Buggy and truck: Usually this happens because the oil in the front and center differentials is too thick; reduce weights.
Starting Point
All this is worth nothing if you don't have a starting point. Chad gave us some starting weights for a variety of conditions that will be good at most tracks. You can apply what we've gone over in the article to fine tune your vehicle:
Conclusion
Once you understand the principal of how a diff works and how different weight oils slow the action you will be a master tuner in a few short days. This doesn't mean that dropping 1,000wt in the front will make you a better driver. Learning how to drive is something that has to be done before you can fine tune to get the car to behave like you want.
#3906
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ORIGINAL: KeithjV
Makes sense vnmsgt. But not sure myself. The 3 diff set up is still new to me.
ericem, it was your truck in the video doing wheelies right? Was that with the stock engine or the LRP? And thats with the 7/20/3 set up?
Makes sense vnmsgt. But not sure myself. The 3 diff set up is still new to me.
ericem, it was your truck in the video doing wheelies right? Was that with the stock engine or the LRP? And thats with the 7/20/3 set up?

I think it was the dude here posting vids of his car with a .28 motor. forgot which one was pretty sick though.
#3911
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Woot!!!!!!!! All this came today, got the rear dif done. Also, so far all the screws that are in metal have had threadlocker on them, AND it looks like the Saxton mod may already be done (???) Ill have some better pics tomorrow night of the steering.

#3912
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ORIGINAL: jay863fl
Woot!!!!!!!! All this came today, got the rear dif done. Also, so far all the screws that are in metal have had threadlocker on them, AND it looks like the Saxton mod may already be done (???) Ill have some better pics tomorrow night of the steering.
Woot!!!!!!!! All this came today, got the rear dif done. Also, so far all the screws that are in metal have had threadlocker on them, AND it looks like the Saxton mod may already be done (???) Ill have some better pics tomorrow night of the steering.

#3913
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Its the RTR, I took that pic before I tore it down to fill the difs, swap the steering servo, etc. I didnt plan on buying the Spektrum, had I known I would be getting one so soon I would have went with the pro kits, but hindsight is 20/20. I now have about 5 AM radios laying around, luckily for me, I know a local guy thats a semi-famous rc airboat builder......so gonna put all those AM's to use for that. Should be able to get me some wood cheap enuff, and the plane engines arent expensive at all. Plus when it rains, thats one more toy to whip out after =P
#3914
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from the looks of it, the steering mod has not been done. bronx boy, naw you don't have to shim the brake calipers with the cradocks. i have them on mine. just tighten the screws a little that hold the calipers and you'll be fine.
#3916
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Good thing I bought a battery holder last week, it was 2.99 then now its 7.99. Does amains prices regularly fluctuate so much? Anyways, does anyone else use the TT batter holder for BEC? Im having trouble getting the lid to seal flush with this pack in there and sand is blowing in there. How do you fit yours in there? The only thing holding it from fitting all the way at the bottom is the screw protruding up. Thanks
#3917
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My friend had the same problem!! So he just got a rx pack lol. Make sure your not on to many wires or on the little piece at the corner on the bottom. Put it on the lowest spot of the receiver box.
#3918
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ORIGINAL: ericem
My friend had the same problem!! So he just got a rx pack lol. Make sure your not on to many wires or on the little piece at the corner on the bottom. Put it on the lowest spot of the receiver box.
My friend had the same problem!! So he just got a rx pack lol. Make sure your not on to many wires or on the little piece at the corner on the bottom. Put it on the lowest spot of the receiver box.
#3919
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No problem nothing to do but sit at home all week lol. It's not like I can go ride my bike when there is ice and snow outside and my tires are bald. It's fun sliding around, but now I live even farther away from where I usually go....
#3920
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ORIGINAL: ericem
No problem nothing to do but sit at home all week lol. It's not like I can go ride my bike when there is ice and snow outside and my tires are bald. It's fun sliding around, but now I live even farther away from where I usually go....
No problem nothing to do but sit at home all week lol. It's not like I can go ride my bike when there is ice and snow outside and my tires are bald. It's fun sliding around, but now I live even farther away from where I usually go....
#3921
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lol. Now we are in the positives today was freezing. Tomorrow though will be much better 4C. which is pretty good F lol to lazy to convert

#3922
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Got another question! I was looking at some ST-1 pictures and saw some antennas coming off the truck that were only around 4 inches high then capped off. I remember the manual saying to not cut ANY off of it, but the plastic tube did come with a cap after all, it would be nice not to have all that wire hanging out. Whats the take on this? Should I, shouldnt I?
Also, the last project I have to do is cut a hole in the window for gas, you dont even want to see my windshield hole I cut with hole saw..ripped a lot of the paint up and stickers, and had to finish cutting it and smoothing it out with a razor knife...what would be another option for cutting the hole (besides a reamer)?
Also, the last project I have to do is cut a hole in the window for gas, you dont even want to see my windshield hole I cut with hole saw..ripped a lot of the paint up and stickers, and had to finish cutting it and smoothing it out with a razor knife...what would be another option for cutting the hole (besides a reamer)?
#3923
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I pull my wire in the receiver box to the point where there is still 40cm of antenna wire on the outside or an extra 2 inches past the tube. Works fine. Once again all my friends calls are setup the same way lol. We do all have failsafes though, but they never kick in when the vehicles are far away. So you don't cut it just put some of the wire on the inside of the receiver box. Try to keep the wires tidy from the wires on servo and the battery. I usually shove it behind my recever box or on the same side coming out with the antenna of the receiver. Hopefully you have a failsafe just incase it does create a signal issue. If you run spektrum 2.4ghz radio systems you barely need any wire coming out of the receiver box, actally you don't even need a hole in your body to be honest you can jsut run it from the inside with spektrum because it's so short.
You can kind of tell in this pic how i shoved the wires on the same side the antenna wire comes out of the receiver. I have to take a clear pic later or tomorrow with my actual camera.

You can kind of tell in this pic how i shoved the wires on the same side the antenna wire comes out of the receiver. I have to take a clear pic later or tomorrow with my actual camera.

#3924
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Thanks for the picture. I bought my cousin an ST-1 that came in yesterday and his cooling head has the slots in it, why doesnt mine and whats the difference?
EDIT: Im going to make a video next time I take it out so you can tell me if it sounds like it's running/idling right, should be in HD so be prepped!...
EDIT: Im going to make a video next time I take it out so you can tell me if it sounds like it's running/idling right, should be in HD so be prepped!...