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Bodom
2010.09.22, 08:28 AM
I am new to MR-03 and I think the front suspension of mine is way too hard. That's why I bought these:
http://i447.photobucket.com/albums/qq194/Bodom_photos/MR-03/P1070486.jpg
But even with the softest (red) springs in the set it still feels very hard :mad:
Is this normal for the MR-03 and what can I do? Buy different brand springs?
http://i447.photobucket.com/albums/qq194/Bodom_photos/MR-03/P1070495.jpg

doug01n
2010.09.22, 09:10 AM
I ask you a question.... how does your car handles? Is it oversteering? Understeering? What tires are you using, T-plate.... the whole setup?

The front suspension beeing hard or soft have his part on the setup, and have to be balanced with other factors to make your car stable.

Guinness
2010.09.22, 10:00 AM
i just recently made my front suspension stiffer. it was bouncing too much on turns

Bodom
2010.09.22, 01:16 PM
The suspension is stock. I only added oil shock and red springs. The tires are Atomic 10d radials front and Kyosho MT radials 10d semi-wide rear. I drive on low-grip granite blocks floor. The car understeers a little when pushed hard.
I drive my awd with much softer suspension compared to this.
I just can't beleive that the softest springs from this set feels so hard.

doug01n
2010.09.22, 02:05 PM
Is anything binding? Knucle arms on the king pins, upper arm?

Try to remove the springs and see if is all smooth.... The AWD springs and suspension usually works softer than the 2wd setup.

Bodom
2010.09.22, 05:23 PM
There is suspension binding. One of the arms doesn't move freely itself (no kingpin, no spring, just the arm).
There is a little bit of binding in the kingpin also. But even though the first 1mm of suspension travel is smooth (but stiff). Further that it stucks and moves hard.

vash
2010.09.22, 07:45 PM
My Mr03 used to bind up. You can polish the stock kingpin and use kingpin oil and that should free it up. If you Google "Mr03 binding" there is a tut from FPR. I would try cleaning the kingpin and oil first

Quick note: if you decide to polish be careful. You are removing material and could end up with slop. Don't know if I would mess with the pins other than cleaning. Kind of last resort.

benmlee
2010.09.23, 12:29 AM
That is what these pins are designed specifically to do to solve the binding issue.

http://www.rckenon.com/public_html/shop2/catalog/images/MR3055.jpg

http://www.rckenon.com/public_html/shop2/catalog/product_info.php?products_id=5095

The front suspension on the MR03 has poor geometry even worst than the MR02 as far as binding goes. For these pins, the top part is fixed with the e-clip, and the bottom slides. That spread the load on the knuckle so they travel smoother. They are definitely smoother than the stock even with polished stock pins.

color01
2010.09.23, 03:20 AM
The reverse kingpin setup works very well to fix binding, that's definitely an option. Softer springs can be found courtesy of PN Racing releasing the Orange and Blue super-soft spring options.

The other is to go to the Reflex kingpin setup OR the MR02 kingpin-through-ball setup, both use coilover springs so at the very least the binding friction from the arm pivot is reduced. You would be able to find a softer spring from old MR02 springs.

Bodom
2010.09.23, 07:08 AM
Thanks all. I'll try to resolve the binding with this suspension setup, and if I fail - will consider changing the suspension to coil-over type or reverse kingpin type.
The springs I need for the coil-over setup are MR-02 springs, right? Can I use AWD springs for coil-over setup (because I have a lot of them)?

benmlee
2010.09.23, 11:34 PM
The main problem with the MR03 suspension is the knuckle. It is short relative to the wheel off-set. It forms a short coupling, and inherently like to stick.
This is similar to the wacky toy climbing down a pole. Imagine your knuckle being the cylinder sliding down the pole. The bird is where your wheel is at.

http://mini-zracer.com/forums/attachment.php?attachmentid=30558&stc=1&d=1285298079

That toy is showing the principle at the extreme, but the concept is similar. MR02 has somewhat the same issue, but slightly better than MR03. This is where the majority of binding comes from. This is why people polish the kingpin both on MR02 and 03.

The purpose of the PN upside down pin is to resolve the binding issue by eliminating the need for the knuckle to slide on the king pin. No sliding means no binding. The pin moves with the knuckle, and slides on the lower ball.

The lower ball does not bind the pin because being a sphere, it is free to rotate. Therefore you get smooth suspension travel.

I could tell the handling improvement driving the car with the upside down pin.

Atomic-USA
2010.10.08, 08:13 AM
Try these "Ultra soft" springs from Atomic:

ULTRA SOFT SPRINGS for MR03 (http://www.egrracing.com/shop/mr03-front-suspension-spring-set-ultra-soft-p-3815.html)

http://www.egrracing.com/shop/images/addition_atomic/MR3-015-RS_inst.jpg

EMU
2010.10.08, 03:39 PM
Reverse kingpin is a good solution to reduce hop and binding. I recently started using reverse kingpin with the stock kingpin and ball flipped (shortened kingpin just under the notch for c-clip). The suspension travel is very smooth, as Ben said earlier.

Reflex Racing will soon be releasing a reverse kingpin kit (http://reflexracing.blogspot.com/2010/09/low-profile-front-suspension-set-up.html). What sets this apart from the PN and standard kingpin flipped... Like 1/12 scale cars, the spring is below the lower arm over the kingpin. You can still use the standard springs and upper arms if you want, this gives another alternative if you choose to use it. This will be very useful when using 4d caster and bodies that dont have much clearance in the front for the long kingpin setup.
http://3.bp.blogspot.com/_Xz71n0H7MDw/TKAf_9ItI3I/AAAAAAAAAII/adW8pIcX5dY/s400/RX1167_1.jpg

Cherub1m
2010.10.09, 04:58 PM
Reverse kingpin is a good solution to reduce hop and binding. I recently started using reverse kingpin with the stock kingpin and ball flipped (shortened kingpin just under the notch for c-clip). The suspension travel is very smooth, as Ben said earlier.


http://3.bp.blogspot.com/_Xz71n0H7MDw/TKAf_9ItI3I/AAAAAAAAAII/adW8pIcX5dY/s400/RX1167_1.jpg

Hey Eugene

Could you post some pictures of your reverse kingpin using stock kyosho parts? I a guessing your using the stock spring placement and not the underneath the lower arm?

Thanks

moz
2010.10.10, 12:23 AM
Reverse kingpin is a good solution to reduce hop and binding. I recently started using reverse kingpin with the stock kingpin and ball flipped (shortened kingpin just under the notch for c-clip). The suspension travel is very smooth, as Ben said earlier.

Reflex Racing will soon be releasing a reverse kingpin kit (http://reflexracing.blogspot.com/2010/09/low-profile-front-suspension-set-up.html). What sets this apart from the PN and standard kingpin flipped... Like 1/12 scale cars, the spring is below the lower arm over the kingpin. You can still use the standard springs and upper arms if you want, this gives another alternative if you choose to use it. This will be very useful when using 4d caster and bodies that dont have much clearance in the front for the long kingpin setup.
http://3.bp.blogspot.com/_Xz71n0H7MDw/TKAf_9ItI3I/AAAAAAAAAII/adW8pIcX5dY/s400/RX1167_1.jpg

hello EMU...
saw that u guys doing no spring setup at all?
thx....

EMU
2010.10.10, 12:42 AM
There is a spring that surrounds the kingpin under the lower tower, and held by the clip... allowing a low clearance design that can use 4d caster which is not capable with the standard MR03 spring position (long fulcrum upper arms with inboard springs).

Philip, I will try to get a pic up soon ;)

moz
2010.10.10, 01:46 AM
There is a spring that surrounds the kingpin under the lower tower, and held by the clip... allowing a low clearance design that can use 4d caster which is not capable with the standard MR03 spring position (long fulcrum upper arms with inboard springs).

Philip, I will try to get a pic up soon ;)

the PnRacing kingpin+low down spring is that the setup...
the picture will be very helpfull..thx

EMU
2010.10.10, 04:19 AM
This is the reverse kingpin with stock kingpins. Excuse the poor phone pic. I have stock front springs in, which are black so you cannot see them in the picture.
http://mini-zracer.com/forums/attachment.php?attachmentid=30684&stc=1&d=1286698331

The Reflex Reverse Kingpin has a ball that is recessed to use a spring on the bottom of the lower tower. You can see the spring just above the clip around the kingpin in this picture.
http://3.bp.blogspot.com/_Xz71n0H7MDw/TKAf_9ItI3I/AAAAAAAAAII/adW8pIcX5dY/s400/RX1167_1.jpg

moz
2010.10.10, 05:36 AM
thank u EMU...

color01
2010.10.11, 02:50 AM
I just figured out an alternative "better-than-stock" reverse-kingpin setup, thought you might be interested.

http://img40.imageshack.us/img40/7832/img0502hu.jpg

I removed the stock spring holder, and put two M2x6mm screws through the front clip in the same holes that it used to occupy. Then bolted the screws to the front clip using two M2x4mm hex nuts. I attached this front clip assembly to the chassis.

Afterwards, you can just sit two MR02 spring perches onto the ends of the M2x6mm screws, and they will just rest there on top of the plastic while being held in place by the screw! You can slip on the MR02 springs at this point and adjust preload using spacers like we've always done.

The disadvantages are the same as the normal PN reverse-kingpin setup, that is slightly increased unsprung weight; the advantages now being the use of MR02 springs, being able to lower the car as much as you need to, and of course the smoothness. Keep in mind that because of the rocker arm suspension's lever arm, you need to use softer springs than you would on the coil-over setup. But since MR02's have a much wider spring range (and you could even play with AWD springs now!) it's better than being stuck with just the MR03 spring sets. :)

SAGISI
2010.10.11, 04:33 PM
Hey Brian,
Nice post! I like how you were able to use MR02 springs in your reverse kingpin setup. Can you post more pics of how you modified the front end to incorporate those springs? I just recently installed the reverse king pin setup on my car and love how smooth it is. Zero binding!

color01
2010.10.11, 08:03 PM
Here you go Ryan:

http://img834.imageshack.us/img834/2792/img0506j.jpg

Basically you just need to bolt two long-ish screws through the front clip and then add as many preload spacers as necessary. The nice thing about this setup is that the MR02 spring perches don't fall through the chassis holes when you remove the front clip, it makes changing spring preload a lot less of a hassle. To remove the spring perches and springs, I loosen the lower arm enough such that the upper arms tilt up and free the springs.

EMU
2010.10.11, 08:29 PM
I use the Kyosho front damper in some of my cars, I dont see why you cant use an MR02 spring with it. It is also easy to adjust preload with standard MR02 preload spacers ;)