set up problem
06-24-2015, 12:41 AM
#1
set up problem
hi everyone.me car is xray xb808 and i am having a problem.my car oversteer in off throttle and understeer in on throttle!my current shock set up is rear 1.3 6hole with 450cps oil front shocks 1.4 6hole with 550cps oil.diffs are 10-7-2.droop rear 115 front 105 measured shock length.rear longer upper camber link one hole down in tower front one hole up in tower.accerman forward hole.so do you think i should go to heavier shock oils???or reduce droop??
06-24-2015, 01:28 AM
#2
Try 5k in the rear diff
And use the upper hole on the rear tower.
And usually you choose to run pistons with the largest hole in the rear shocks, so I'd swap them.
Changing the ackerman could also help to calm the car down on corner entry.
And use the upper hole on the rear tower.
And usually you choose to run pistons with the largest hole in the rear shocks, so I'd swap them.
Changing the ackerman could also help to calm the car down on corner entry.
07-15-2015, 03:03 PM
#3
i swap the shock pistons and my current set up is 1.3 6 hole 500cps front and 1.4 6hole 550cps rear.rear camber link in tower all the way up.diffs oil is 10-7-3.my car oversteer in off throtle and in low speeds too wide turn radius.if i use thicker rear oil like 4000 does that will make the rear end loose???also rear end fells too soft in bench
07-16-2015, 03:53 PM
#6
my settings are diff oils 10-7-3.front 41t gear overdrive.front camber link in tower all the way up.rear camber link long and one hole down from up in tower.front toe out 1.5 rear toe in 2.front camber 2 rear camber 3 ride height front 26 rear 28.accerman forward hole.bump steer 3mm.shocks inner upper hole in tower inner hole in arms.droop front 105 rear 115.also the car accelerates too hard clutch settings 2x0.9 springs 1x 1.0 spring metal shoes.clutchbell 16t
07-17-2015, 07:08 AM
#8
I think you diff oil setup is way too aggressive in the front and could certainly cause the understeer exiting the corner. Looking at some of the last setup sheets posted on Xray's website the last setup by a team drive leaves the diff oils in thier stock config, which is 5-7-2. His shocks use the 1.3 holes front and rear with oils being 600 and 450 front to rear respectively.
If when you get on the gas coming out of the corner and your front tires turn into pizza cutters you know your sending way too much power to the front. I understand you were probably expecting the additional weight to increase your front pull through the corner but your handling traits sounds like you went too far.
What's your caster setting?? adding more caster will help pull the car's front end through a corner while on the gas, but understand that you will lose some the corner entry steering.
It's all about finding a balance. You might want to put one of the team driver's or the stock settings back on the car and start tuning over again remember to do one change at a time and be methodical about it. If the setting you change made your car worse, undo the change and try a different setting. If it made the car better examine your laps and try to figure out your next move.
It kind of sounds like you might have gotten lost on finding the proper setup and you should start over at this point. Yes it takes time but if you want it to be good then you need to take that time.
Best of luck. Keep asking the questions though we are here to help. Also the Hudy tuning guide is great to use if you decide to start over and need help finding the next move.
If when you get on the gas coming out of the corner and your front tires turn into pizza cutters you know your sending way too much power to the front. I understand you were probably expecting the additional weight to increase your front pull through the corner but your handling traits sounds like you went too far.
What's your caster setting?? adding more caster will help pull the car's front end through a corner while on the gas, but understand that you will lose some the corner entry steering.
It's all about finding a balance. You might want to put one of the team driver's or the stock settings back on the car and start tuning over again remember to do one change at a time and be methodical about it. If the setting you change made your car worse, undo the change and try a different setting. If it made the car better examine your laps and try to figure out your next move.
It kind of sounds like you might have gotten lost on finding the proper setup and you should start over at this point. Yes it takes time but if you want it to be good then you need to take that time.
Best of luck. Keep asking the questions though we are here to help. Also the Hudy tuning guide is great to use if you decide to start over and need help finding the next move.
07-17-2015, 09:18 AM
#9
I think you diff oil setup is way too aggressive in the front and could certainly cause the understeer exiting the corner. Looking at some of the last setup sheets posted on Xray's website the last setup by a team drive leaves the diff oils in thier stock config, which is 5-7-2. His shocks use the 1.3 holes front and rear with oils being 600 and 450 front to rear respectively.
If when you get on the gas coming out of the corner and your front tires turn into pizza cutters you know your sending way too much power to the front. I understand you were probably expecting the additional weight to increase your front pull through the corner but your handling traits sounds like you went too far.
What's your caster setting?? adding more caster will help pull the car's front end through a corner while on the gas, but understand that you will lose some the corner entry steering.
It's all about finding a balance. You might want to put one of the team driver's or the stock settings back on the car and start tuning over again remember to do one change at a time and be methodical about it. If the setting you change made your car worse, undo the change and try a different setting. If it made the car better examine your laps and try to figure out your next move.
It kind of sounds like you might have gotten lost on finding the proper setup and you should start over at this point. Yes it takes time but if you want it to be good then you need to take that time.
Best of luck. Keep asking the questions though we are here to help. Also the Hudy tuning guide is great to use if you decide to start over and need help finding the next move.
If when you get on the gas coming out of the corner and your front tires turn into pizza cutters you know your sending way too much power to the front. I understand you were probably expecting the additional weight to increase your front pull through the corner but your handling traits sounds like you went too far.
What's your caster setting?? adding more caster will help pull the car's front end through a corner while on the gas, but understand that you will lose some the corner entry steering.
It's all about finding a balance. You might want to put one of the team driver's or the stock settings back on the car and start tuning over again remember to do one change at a time and be methodical about it. If the setting you change made your car worse, undo the change and try a different setting. If it made the car better examine your laps and try to figure out your next move.
It kind of sounds like you might have gotten lost on finding the proper setup and you should start over at this point. Yes it takes time but if you want it to be good then you need to take that time.
Best of luck. Keep asking the questions though we are here to help. Also the Hudy tuning guide is great to use if you decide to start over and need help finding the next move.
07-17-2015, 09:25 AM
#10
this is a video of the track i run if that will help.not my car in the video https://www.youtube.com/watch?v=UDv4LUf5IKU
07-17-2015, 09:29 AM
#11
i mark in the picture the corners that i have more problem.especially in the corer after the straight the looses the rear end and spins
07-17-2015, 12:51 PM
#12
I would suggest going to 5K in the front diff. That could and should reduce the under steering in the one corner. See how that effects the car. I've never tried overdriving a gear box, like you said with the 41T in the front diff. But with the overdriven gear box and the heavy front diff oil your almost doubling the overdriving and effectively turning your car into a front wheel drive car. I would suggest going back to the stock gearing all around.
Your track seems pretty fast and flowing, To help with the first turn where you are over steering, try lengthening the wheel base or reducing the camber to 2° or both. This should give you more stability in fast sweepers.
As for shocks I personally like using the same pistons front and rear and using the oil to control the dampening. So Again I would suggest the 1.3 pistons all around, then going with the 600 in the front and 450 in the rear. Just seems right to me. From the looks of it your track looks pretty bumpy and your going to be fighting to keep the car soft enough to soak up bumps and stiff enough to handle the transitions. This will be your toughest challenge to find the right balance. If you think its weight transition is too much, Diving or squatting, then the right thing to do is bump up the oil, try the next thickest oil.
Please remember to try one thing at a time don't make all these suggested changes at once and think it will be better. I haven't seen you drive your car so your under steer problem could be your not hitting the brakes early enough and allowing it to roll through the corner, you could be going in too deep and getting into the fluffy dirt on the outside of the line and that compounds what you think is a setup problem when it really is just how your driving.
Your track seems pretty fast and flowing, To help with the first turn where you are over steering, try lengthening the wheel base or reducing the camber to 2° or both. This should give you more stability in fast sweepers.
As for shocks I personally like using the same pistons front and rear and using the oil to control the dampening. So Again I would suggest the 1.3 pistons all around, then going with the 600 in the front and 450 in the rear. Just seems right to me. From the looks of it your track looks pretty bumpy and your going to be fighting to keep the car soft enough to soak up bumps and stiff enough to handle the transitions. This will be your toughest challenge to find the right balance. If you think its weight transition is too much, Diving or squatting, then the right thing to do is bump up the oil, try the next thickest oil.
Please remember to try one thing at a time don't make all these suggested changes at once and think it will be better. I haven't seen you drive your car so your under steer problem could be your not hitting the brakes early enough and allowing it to roll through the corner, you could be going in too deep and getting into the fluffy dirt on the outside of the line and that compounds what you think is a setup problem when it really is just how your driving.
07-17-2015, 01:10 PM
#13
I would suggest going to 5K in the front diff. That could and should reduce the under steering in the one corner. See how that effects the car. I've never tried overdriving a gear box, like you said with the 41T in the front diff. But with the overdriven gear box and the heavy front diff oil your almost doubling the overdriving and effectively turning your car into a front wheel drive car. I would suggest going back to the stock gearing all around.
Your track seems pretty fast and flowing, To help with the first turn where you are over steering, try lengthening the wheel base or reducing the camber to 2° or both. This should give you more stability in fast sweepers.
As for shocks I personally like using the same pistons front and rear and using the oil to control the dampening. So Again I would suggest the 1.3 pistons all around, then going with the 600 in the front and 450 in the rear. Just seems right to me. From the looks of it your track looks pretty bumpy and your going to be fighting to keep the car soft enough to soak up bumps and stiff enough to handle the transitions. This will be your toughest challenge to find the right balance. If you think its weight transition is too much, Diving or squatting, then the right thing to do is bump up the oil, try the next thickest oil.
Please remember to try one thing at a time don't make all these suggested changes at once and think it will be better. I haven't seen you drive your car so your under steer problem could be your not hitting the brakes early enough and allowing it to roll through the corner, you could be going in too deep and getting into the fluffy dirt on the outside of the line and that compounds what you think is a setup problem when it really is just how your driving.
Your track seems pretty fast and flowing, To help with the first turn where you are over steering, try lengthening the wheel base or reducing the camber to 2° or both. This should give you more stability in fast sweepers.
As for shocks I personally like using the same pistons front and rear and using the oil to control the dampening. So Again I would suggest the 1.3 pistons all around, then going with the 600 in the front and 450 in the rear. Just seems right to me. From the looks of it your track looks pretty bumpy and your going to be fighting to keep the car soft enough to soak up bumps and stiff enough to handle the transitions. This will be your toughest challenge to find the right balance. If you think its weight transition is too much, Diving or squatting, then the right thing to do is bump up the oil, try the next thickest oil.
Please remember to try one thing at a time don't make all these suggested changes at once and think it will be better. I haven't seen you drive your car so your under steer problem could be your not hitting the brakes early enough and allowing it to roll through the corner, you could be going in too deep and getting into the fluffy dirt on the outside of the line and that compounds what you think is a setup problem when it really is just how your driving.
07-20-2015, 11:29 AM
#15
The thing to remember is raising the Oil thickness in a diff will cause that diff to have more drive.
So for example, say you start with 5-5-5 in your diffs, Front to Rear respectively. Say you raise your front to say 7, so you have 7-5-5, your going to have more drive going to your front wheels, so this could cause the car to push going into the corner and it could cause the front end to pull the front through the corner or on the con side it could cause your car to push through the later half of the turn such as a front wheel drive car with way too much power.
If you lower your front diff oil, say 3-5-5 setup your car will act more like a rear wheel drive car because more power will go to the rear of the car. Could cause the car to push cause it isn't "grabbing the ground" as well at the front but because the rear has more drive it could also cause a loose rear end feeling. (Very dependent on surface, but in most cases you will feel the car gains steering)
Say you drop the oil weight in the rear of your car, so 5-5-3. This again is making your car more front wheel drive but could also make a rear loose car more stable and tighten it up.
If you increase the rear oil, so you have a 5-5-7 setup, it could cause a tight car to have a looser rear end since it's acting more like a rear wheel drive car with posi.
As for the Center diff and it's effects, I think of it as a slipper clutch. The thicker the oil in the center the more drive your going to get from both ends. It's going to feel quicker off the line but in bumpy stuff it's going possible cause your car to be "darty" because if it catches traction it's going. When it's lighter it's going to be a little hesitant feeling coming off the line but it may be easier to drive in bumpy sections.
You tend to use a heavy oil in the center diff on a Higher traction surfaces where on loose surfaces you use a lighter center diff oil.
Hope this helps. Again it's my understanding of the theory, if someone else has something to add or to correct me please do.
So for example, say you start with 5-5-5 in your diffs, Front to Rear respectively. Say you raise your front to say 7, so you have 7-5-5, your going to have more drive going to your front wheels, so this could cause the car to push going into the corner and it could cause the front end to pull the front through the corner or on the con side it could cause your car to push through the later half of the turn such as a front wheel drive car with way too much power.
If you lower your front diff oil, say 3-5-5 setup your car will act more like a rear wheel drive car because more power will go to the rear of the car. Could cause the car to push cause it isn't "grabbing the ground" as well at the front but because the rear has more drive it could also cause a loose rear end feeling. (Very dependent on surface, but in most cases you will feel the car gains steering)
Say you drop the oil weight in the rear of your car, so 5-5-3. This again is making your car more front wheel drive but could also make a rear loose car more stable and tighten it up.
If you increase the rear oil, so you have a 5-5-7 setup, it could cause a tight car to have a looser rear end since it's acting more like a rear wheel drive car with posi.
As for the Center diff and it's effects, I think of it as a slipper clutch. The thicker the oil in the center the more drive your going to get from both ends. It's going to feel quicker off the line but in bumpy stuff it's going possible cause your car to be "darty" because if it catches traction it's going. When it's lighter it's going to be a little hesitant feeling coming off the line but it may be easier to drive in bumpy sections.
You tend to use a heavy oil in the center diff on a Higher traction surfaces where on loose surfaces you use a lighter center diff oil.
Hope this helps. Again it's my understanding of the theory, if someone else has something to add or to correct me please do.