34LikesSchumacher Mi5
10-10-2014, 02:50 AM
#2402
10-10-2014, 04:09 AM
#2403
Thank you very much.
I will test it at the LRP-Challenge (18./19. 10.2014). I will also test an active rear suspension there. I inform you about the results
Here is a picture of the active suspension:
Attachment 1237588
And one about of my Mi5 Evo, which I repurpled
Attachment 1237592
And the matching bodywork
Attachment 1237593
I will test it at the LRP-Challenge (18./19. 10.2014). I will also test an active rear suspension there. I inform you about the results
Here is a picture of the active suspension:
Attachment 1237588
And one about of my Mi5 Evo, which I repurpled
Attachment 1237592
And the matching bodywork
Attachment 1237593
1) Rear lowershock position - It's a lot further in when using the front arms on the rear, which will dramatically alter the level of grip.
2) Rear roll bar - obviously using the front bar on the rear is needed to work with the front arms, but a shorter bar will behave stiffer than the standard longer one.
Not saying that the reactive rear won't be an interesting experiment, but you'll need to bare the above in mind when running it.
Ed
10-11-2014, 05:18 AM
#2404
I'd had a look at out fitting my evo with a reactive rear, but a couple of things to bare in mind with the setup you've gone with.
1) Rear lowershock position - It's a lot further in when using the front arms on the rear, which will dramatically alter the level of grip.
2) Rear roll bar - obviously using the front bar on the rear is needed to work with the front arms, but a shorter bar will behave stiffer than the standard longer one.
Not saying that the reactive rear won't be an interesting experiment, but you'll need to bare the above in mind when running it.
Ed
1) Rear lowershock position - It's a lot further in when using the front arms on the rear, which will dramatically alter the level of grip.
2) Rear roll bar - obviously using the front bar on the rear is needed to work with the front arms, but a shorter bar will behave stiffer than the standard longer one.
Not saying that the reactive rear won't be an interesting experiment, but you'll need to bare the above in mind when running it.
Ed
But there are easy ways to solve some of them.
1) Rear lowershock position - To adjust the ride height in the same range, you have to use other/lower spring plate. So I used them from my old HB TCX (#73510). They suit perfekt and you can easy set for example 4mm ride height.
1.2) Shock position - The biggest problem is, that the lower shock attachment ist much more inside the car and the shock has another angle, so that you have a complete different spring and shock transmission. I calculate a little bit and get a correction factor of 1.17. So your old spring hardness multiplied with 1.17 result in the spring hardness, which you have to use with an active suspension. Also you have to use harder oil. Concrete it means, if you use for example the Spec-R 2.5 Spring now you have to use the 2.9 Spring and instead of 350cSt oil you have to use 400cSt to have comparable values.
2) Rear roll bar - Here the same. To get nearly the same values, you have to use a correction factor of 1.26. So your old diameter divided by 1.26 result in your new diameter of the roll bar. So instead of the 3 point rear roll bar you have to use the 1 point front roll bar.
The biggest problem ist, that the roll center values also changed and
I have no desire to calculate that one too
and i´m not 100% sure if my calculates are general right.But we will see it next week and i will give you an detailed report
10-11-2014, 01:03 PM
#2405
Tech Adept
I find it great, that other persons build it and find the same "problems".
But there are easy ways to solve some of them.
1) Rear lowershock position - To adjust the ride height in the same range, you have to use other/lower spring plate. So I used them from my old HB TCX (#73510). They suit perfekt and you can easy set for example 4mm ride height.
1.2) Shock position - The biggest problem is, that the lower shock attachment ist much more inside the car and the shock has another angle, so that you have a complete different spring and shock transmission. I calculate a little bit and get a correction factor of 1.17. So your old spring hardness multiplied with 1.17 result in the spring hardness, which you have to use with an active suspension. Also you have to use harder oil. Concrete it means, if you use for example the Spec-R 2.5 Spring now you have to use the 2.9 Spring and instead of 350cSt oil you have to use 400cSt to have comparable values.
2) Rear roll bar - Here the same. To get nearly the same values, you have to use a correction factor of 1.26. So your old diameter divided by 1.26 result in your new diameter of the roll bar. So instead of the 3 point rear roll bar you have to use the 1 point front roll bar.
The biggest problem ist, that the roll center values also changed and
I have no desire to calculate that one too and i´m not 100% sure if my calculates are general right.
But we will see it next week and i will give you an detailed report
But there are easy ways to solve some of them.
1) Rear lowershock position - To adjust the ride height in the same range, you have to use other/lower spring plate. So I used them from my old HB TCX (#73510). They suit perfekt and you can easy set for example 4mm ride height.
1.2) Shock position - The biggest problem is, that the lower shock attachment ist much more inside the car and the shock has another angle, so that you have a complete different spring and shock transmission. I calculate a little bit and get a correction factor of 1.17. So your old spring hardness multiplied with 1.17 result in the spring hardness, which you have to use with an active suspension. Also you have to use harder oil. Concrete it means, if you use for example the Spec-R 2.5 Spring now you have to use the 2.9 Spring and instead of 350cSt oil you have to use 400cSt to have comparable values.
2) Rear roll bar - Here the same. To get nearly the same values, you have to use a correction factor of 1.26. So your old diameter divided by 1.26 result in your new diameter of the roll bar. So instead of the 3 point rear roll bar you have to use the 1 point front roll bar.
The biggest problem ist, that the roll center values also changed and
I have no desire to calculate that one too
and i´m not 100% sure if my calculates are general right.But we will see it next week and i will give you an detailed report
10-11-2014, 01:09 PM
#2406
Try using RC Crew Chief - http://rccrewchief.wrightdesign.ca/ The Mi5-Evo has been modeled so you can swap out the various dimensions for front on to rear and have the program calculate the new values.
10-13-2014, 07:30 AM
#2407
Tech Rookie
Mi5evo alloy chassis
anyone have any thoughts on alloy chassis on carpet?
10-13-2014, 10:04 AM
#2408
10-13-2014, 03:48 PM
#2410
Tech Rookie
[QUOTE=Gino S;13591703]anyone have any thoughts on alloy chassis on carpet?[/QUOTE:
We did test it to the 1st round of the Danish championship on a high grip Carpet track with Sorex 28. And this is one off the best things we have done to make the car even better on High grip tracks!
We did test it to the 1st round of the Danish championship on a high grip Carpet track with Sorex 28. And this is one off the best things we have done to make the car even better on High grip tracks!
10-14-2014, 12:38 AM
#2412
Tech Rookie
[QUOTE=KILDK;13592732]
I seem to be finding that the alloy chassis develops under-steer on high grip, and rather surprisingly seems to work quite well on low grip as well. Have moved to 2.5 rear toe. Still under-steers.
anyone have any thoughts on alloy chassis on carpet?[/QUOTE:
We did test it to the 1st round of the Danish championship on a high grip Carpet track with Sorex 28. And this is one off the best things we have done to make the car even better on High grip tracks!
Attachment 1239503Attachment 1239504Attachment 1239505
We did test it to the 1st round of the Danish championship on a high grip Carpet track with Sorex 28. And this is one off the best things we have done to make the car even better on High grip tracks!
Attachment 1239503Attachment 1239504Attachment 1239505
10-14-2014, 02:12 AM
#2413
Tech Rookie
[QUOTE=Gino S;13593687]
We did have so much steering that we did use a geardiff with Ride45 in the front to make the car less agressiv in the steering, so maybe you have to make some set-up adjustments :-)
And we did also test the same set-up at our local very low-grip track and had the same very god experience as you
And we did also test the same set-up at our local very low-grip track and had the same very god experience as you
10-14-2014, 02:32 AM
#2414
Tech Apprentice
@JWick: Car looks nice!
After reading your post it seems you are using the front Wishbones in the rear, which means that your ratio between wheel bump travel and damper travel is changed quite a lot. (damper and springs are moving less at same bump travel)
So if the ratio difference is at 1.26 (so 26% less movement), as you mentioned, you use 26% stiffer springs!
But the dampers not only move less, so damperforce is reduced by the changed ratio, also the SPEED!!! is changed. And as the speed nearly linearily effects the damping force the damper effect is reduced by the changed ratio in both ways.
Therefore you need to increase the damping effect by 1,26 * 1,26 = 1,59 (so you need 59 % more damping.) So i would recommend using about 550 cst oil. To get a) the same roll and heave stiffness and also the same roll and heave dampening.
I hope you can read my english ^^, coming from germany too.
After reading your post it seems you are using the front Wishbones in the rear, which means that your ratio between wheel bump travel and damper travel is changed quite a lot. (damper and springs are moving less at same bump travel)
So if the ratio difference is at 1.26 (so 26% less movement), as you mentioned, you use 26% stiffer springs!
But the dampers not only move less, so damperforce is reduced by the changed ratio, also the SPEED!!! is changed. And as the speed nearly linearily effects the damping force the damper effect is reduced by the changed ratio in both ways.
Therefore you need to increase the damping effect by 1,26 * 1,26 = 1,59 (so you need 59 % more damping.) So i would recommend using about 550 cst oil. To get a) the same roll and heave stiffness and also the same roll and heave dampening.
I hope you can read my english ^^, coming from germany too.
10-14-2014, 02:56 AM
#2415
Tech Rookie
[QUOTE=KILDK;13593721]
Thanks.
Did you also run the chassis braces? My car is so stiff with chassis braces and 2.5mm top decks - i'm wondering if this is over-kill?!
We did have so much steering that we did use a geardiff with Ride45 in the front to make the car less agressiv in the steering, so maybe you have to make some set-up adjustments :-)
And we did also test the same set-up at our local very low-grip track and had the same very god experience as you
And we did also test the same set-up at our local very low-grip track and had the same very god experience as you
Did you also run the chassis braces? My car is so stiff with chassis braces and 2.5mm top decks - i'm wondering if this is over-kill?!