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Xray T4'17

Old 12-31-1969, 04:00 PM
R/C Tech Forums Expert How-Tos and Guides
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Old 09-12-2017 | 04:09 AM
  #1546  
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Originally Posted by dan_vector
Was it that the car was much easier to drive so the consistency was better or was the Xray just quicker over a single lap and if so how much quicker were you? Thanks for the feedback.
4X to Xray T4 2017. I found the 4X hard to drive outdoors, the rear end was all over the place. Never tried the new parts though. The Xray is just plain simpler to drive and work on. I drive modified outdoors. It is very easy to drive, maybe too easy for some. I rely more on consistency than hot laps nowadays.
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Old 09-13-2017 | 06:42 AM
  #1547  
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Hello
Please, I need some suggestions, I can't get enough on power steering in my T4.
I'm running a standard setup, with lower front roll center (-1mm), shorter front width (-4mm) and shorter wheelbase. The model has enough rear grip but not so much but front grip is too little in my opinion. I don't understand if front roll center is too low and if I'm moving in the right way, maybe do I need higher roll center? I don't think, but the model seems to not hear any front setup modifications. I change springs, drop, roll center and I don't see appreciable differences in the front of the car on the contrary the rear becomes every time less stable. What can me suggest to get more on power saving good rear stability?
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Old 09-13-2017 | 06:54 AM
  #1548  
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Originally Posted by maRRRco
Hello
Please, I need some suggestions, I can't get enough on power steering in my T4.
I'm running a standard setup, with lower front roll center (-1mm), shorter front width (-4mm) and shorter wheelbase. The model has enough rear grip but not so much but front grip is too little in my opinion. I don't understand if front roll center is too low and if I'm moving in the right way, maybe do I need higher roll center? I don't think, but the model seems to not hear any front setup modifications. I change springs, drop, roll center and I don't see appreciable differences in the front of the car on the contrary the rear becomes every time less stable. What can me suggest to get more on power saving good rear stability?
Can you help us out with more information. You running on Carpet/Asphalt? Stock or Modified? Also your current body your running with? Body of choice can and will determine how the chassis handles a great deal. Thanks
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Old 09-13-2017 | 07:56 AM
  #1549  
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Originally Posted by maRRRco
Hello
Please, I need some suggestions, I can't get enough on power steering in my T4.
I'm running a standard setup, with lower front roll center (-1mm), shorter front width (-4mm) and shorter wheelbase. The model has enough rear grip but not so much but front grip is too little in my opinion. I don't understand if front roll center is too low and if I'm moving in the right way, maybe do I need higher roll center? I don't think, but the model seems to not hear any front setup modifications. I change springs, drop, roll center and I don't see appreciable differences in the front of the car on the contrary the rear becomes every time less stable. What can me suggest to get more on power saving good rear stability?
The T4's tendency is to understeer, this looks to be being rectified with the 2018 release which is out anytime now. There are of course things you can do like different shells etc... but I find the rear becomes very loose when trying to achieve more front end, especially on power like you say
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Old 09-13-2017 | 12:00 PM
  #1550  
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Originally Posted by NEED-MORE-SPEED
Can you help us out with more information. You running on Carpet/Asphalt? Stock or Modified? Also your current body your running with? Body of choice can and will determine how the chassis handles a great deal. Thanks
You are right, I forgot to do it.
I run in modified class, large and fast asphalt track, medium to hight grip, fast corners at almost full throttle. LTC-R body, tried also a bitty M410 but I didn't like it so much. In this conditions I will try to reduce front roll center, but I don't know if is the way to go.

Originally Posted by Bar
The T4's tendency is to understeer, this looks to be being rectified with the 2018 release which is out anytime now. There are of course things you can do like different shells etc... but I find the rear becomes very loose when trying to achieve more front end, especially on power like you say
Yes, this was my first impression, when I load the front the rear becomes loose espacially on power and with old tyres this can let to uncontrollable spin, so you have to drive carefully.
I have to do something. Like I said, my setup is standard, with some modifications already writed.

Thanks in advance
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Old 09-13-2017 | 01:00 PM
  #1551  
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I would leave your front suspension pin adjustments alone (how you have them now should be good). Run Progressive Hard Springs front/back and 450CST Oils. Increase your rear toe to 3.5mm, 1mm more droop in the front than rear. Also your inline flex adjustment is big for asphalt (I would play with your inline flex adjustment)
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Old 09-13-2017 | 07:35 PM
  #1552  
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Originally Posted by maRRRco
You are right, I forgot to do it.
I run in modified class, large and fast asphalt track, medium to hight grip, fast corners at almost full throttle. LTC-R body, tried also a bitty M410 but I didn't like it so much. In this conditions I will try to reduce front roll center, but I don't know if is the way to go.



Yes, this was my first impression, when I load the front the rear becomes loose espacially on power and with old tyres this can let to uncontrollable spin, so you have to drive carefully.
I have to do something. Like I said, my setup is standard, with some modifications already writed.

Thanks in advance
Can you fill out and post a setup sheet?
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Old 09-13-2017 | 10:37 PM
  #1553  
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Originally Posted by maRRRco
You are right, I forgot to do it.
I run in modified class, large and fast asphalt track, medium to hight grip, fast corners at almost full throttle. LTC-R body, tried also a bitty M410 but I didn't like it so much. In this conditions I will try to reduce front roll center, but I don't know if is the way to go.
You also missed adding tire info - that's 99% of your setup.
Would be interested to know what tire combination you're using and the tyre prep involved. I find when I'm using old tires my cars have that tendency to become loose on-power.
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Old 09-14-2017 | 02:25 AM
  #1554  
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I use italian tyres, Sp racing 36, with wd40 as additive. Setup sheet is coming.
https://www.dropbox.com/s/rkwmy23kw7...table.pdf?dl=0

Last edited by maRRRco; 09-14-2017 at 02:43 AM.
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Old 09-14-2017 | 03:03 AM
  #1555  
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Originally Posted by maRRRco
I use italian tyres, Sp racing 36, with wd40 as additive. Setup sheet is coming.
https://www.dropbox.com/s/rkwmy23kw7...table.pdf?dl=0
Looking at that setup.

Firstly, your droop settings.. 4.6 F and 6.0R is basically back to front. Usual is 5-5.2 on the front, 4-4.2 on the rear (dependent on tire size).

Secondly your rear spring is too soft IMO. I would try a 2.6 or 2.7 to start with. Also consider a progressive 2.5-2.8 front, as that spring combo is the general go to nowadays. On the towers, front to hole 2 (1 up from bottom), rear to hole 3 (1 down from top).

Also i actually think you front pins are too narrow, which isnt going to help. For modified, the base starting point is FF 1.0 down and out, and FR 0.5 down and out. Will make the front more stable on entry, as well as give some sweep to help mid corner.

Also strongly suggest setting the hexs the same as well. And reset the wheelbase to 1mm either side of the arms. Diff may also want to go up to 5k minimum as that will also help on power.

I think the big difference in front and rear width is whats causing a large majority of the issue, along with the droop

Try those settings and see how you go.
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Old 09-14-2017 | 05:03 AM
  #1556  
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Originally Posted by maRRRco
I use italian tyres, Sp racing 36, with wd40 as additive. Setup sheet is coming.
https://www.dropbox.com/s/rkwmy23kw7...table.pdf?dl=0
Wide and low .5 on the front blocks would probably be a better option. And you could try 2.6 all round or hard progressives on the front, springs depend on how bumpy the track is as well as traction levels. You also have big difference with the springs you are using front to rear and the shock angles, base point would be 1 up from in all the way round. As TryHard has said just start with standard wheel base. Ride height is also quite extreme front to rear, usually just run .2 different front to rear so 5mm f 5.2 rear, depending again how bumpy the track is.

Last edited by Bar; 09-14-2017 at 05:23 AM.
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Old 09-14-2017 | 06:00 AM
  #1557  
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Originally Posted by maRRRco
I use italian tyres, Sp racing 36, with wd40 as additive. Setup sheet is coming.
https://www.dropbox.com/s/rkwmy23kw7...table.pdf?dl=0
Your setup is all over the board, I think it'll be easier to start from scratch and tune from there.

Try this setup from Halifax in the UK. Big outdoor track, lots of steering needed without compromising stability:

XRAY ::: Set-up Sheet - T4'17

A few key points:
- Definitely change to 1.1 pistons. No one runs 1.2 ever.
- Get some proper tyre additive, whatever the fast guys at your track are using.
- If you still have on-power understeer on Ollys setup, you can reduce the rear toe, or try a progressive front spring. Or go to 7k diff.
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Old 09-14-2017 | 07:46 AM
  #1558  
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Sorry, just my misunderstanding, front and rear drop are exchanged. Now I'm reading all your suggestions.

p.s ok, I've read, but I don't know why you suggest a wider front width, 0.5 or 1.0 at the moment doesn't matter, why wider?
A narrower front will give more steering and more reactivity, in all corners parts, so I moved into that direction.
I'll follow other suggestions but please help me to understand why a wider front. Thank you so much.

Last edited by maRRRco; 09-14-2017 at 08:05 AM.
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Old 09-14-2017 | 11:04 AM
  #1559  
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Originally Posted by maRRRco
Sorry, just my misunderstanding, front and rear drop are exchanged. Now I'm reading all your suggestions.

p.s ok, I've read, but I don't know why you suggest a wider front width, 0.5 or 1.0 at the moment doesn't matter, why wider?
A narrower front will give more steering and more reactivity, in all corners parts, so I moved into that direction.
I'll follow other suggestions but please help me to understand why a wider front. Thank you so much.
Remember there is a difference in how the front end can be shortened. You can move the pins in by changing the inserts in the the suspension blocks, and you can also use thinner wheel hexes.
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Old 09-14-2017 | 01:28 PM
  #1560  
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Originally Posted by tbrymer
Remember there is a difference in how the front end can be shortened. You can move the pins in by changing the inserts in the the suspension blocks, and you can also use thinner wheel hexes.
Yes, of course, I did both but... is there any difference?
Ok, by changing the inserts you change also shocks inclinations, for this reason I'm using the first hole from the bottom in the front tower instead of the second hole, to compensate the new inclination.
I don't know other differences and again I don't understand why a wider front should give me more steering, maybe changing inserts would help and thinner exes shouln't?
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