Showing posts with label Technical. Show all posts
Showing posts with label Technical. Show all posts

12.3.15

PN Racing Double A-Arm wide front conversion is finally here!

For me personally this has been one of the most anticipated parts for my Mini-Z.

PN Racings double a-arm has for many years set the standard for the Mini-Z front end.
The MR-03 version has been fantastic since its release. When adjusted properly it has next to zero bump steer, lots of steering and stability.
However, for modified racing on high grip, one thing you need is quite large offset rims to get the car wide enough to keep it on its wheels. 2 - 3 offset is the norm.

Regular version. Offset 2,8mm

Wide conversion. Same total with.



Wider offset wheels gives for many people an advantage in that it gives more scrub. With more scrub, the car will brake for you, and the tires heat up more and faster. Many drivers uses this to their advantage,
For other people it is a disadvantage, as they dont like the scrub effect, and like to control their braking and corner speed in other ways.
Driving style differs from driver to driver, so no answer is more correct than the other.

The MR-03 is a great car with fast steering response. But one thing is not that great, and that is the servo strength and also a weak servo saver.
If you look closely at the fast cars at your track, or check out some videos on youtube etc, you can see a usual problem on many cars. In long sweepers and fast corners you can see lots of cars with double steer, The car starts the corner good, holds the line, and suddenly it understeers for a moment before it grips again. This is either caused by a tire that looses grip in the corner, or in many cases that the servo just gives up.¨
See video for example.


The load on the servo increases a lot with bigger offset wheels wich are necessary on the mod cars, and the problem increases with the grip level.

The wide version of the Double A-arm will help a lot in these cases. We have found the cars to hold the lines much better, and this again yelds faster lap times.

Reduced scrub is for me personally a good thing, and I really like the way the car handles.
You have a good selection of tie rods in the kit so you can adjust toe angles to your liking. Good fitment, great quality and a good price for what you get.


Give it a try! Buy it here





1.1.13

MR-03 Mod-GT 2013 setup.

Just a small piece about my latest Kyosho Mini-Z modified GT setup.

This setup are very driveable and consistent from track to track.
For me, this works on both high, med and low grip tracks with very small adjustments. Mainly tires and offsets. Tires are very track dependent, so I will keep these out.
This setup is basically the same I used to win the latest PNWC Mod GT Race in Sweden.

Mini-Z MR-03

Front end.


  • Low profile reverse king pin setup.
  • Reflex Racing raised lower tower bar
  • Reflex Racing standard silver spring
  • Reflex Racing knuckles (Mini-Z Norway "no slop" inserts with lower 0,4mm sleeve as shim. More on this later)
  • Reflex Racing King pin
  • Reflex Racing extra long upper arm
  • Reflex Racing Adjustable upper tower
  • 0,3mm raised roll centre
  • 0,3mm between cam and adjustable arm (Roughly 1 degree camber)
  • 2 degrees caster
  • 2mm shim on top for adjusting droop/ preload
  • 0,2mm droop
Chassis

  • Regular black chassis
  • Grey SS front chassis plate for added front end stiffness
  • Reflex Racing aluminium top deck
  • Reflex Racing T-bar mount without pivot screw
  • 98mm wheelbase
  • Reflex Racing bearings
Rear end

  • QteQ soft X-fibre FRP T-bar
  • Reflex Racing 945 motor mount
  • Reflex Racing Diffuser
  • Reflex Racing Side dampers
  • Reflex Racing Silver springs with some preload
  • Reflex Racing top shock standoff. Shortened.
  • Kyosho oil shock
  • Reflex Racing oil shock spring. Silver or gold depending on grip levels. Preload until chassis is level
  • RSD Top damper mount. 
Differential

  • Reflex Racing diff halves and left hub
  • PN Racing aluminium diff shaft
  • Reflex Racing V3 spur
  • Reflex Racing 2mm spur bearing
  • Kyosho pressure plates
  • Reflex Racing ceramic diff balls
  • Reflex Racing abec 5 outer diff bearing
  • Reflex Racing O-ring
Fluids
  • Kyosho 15000WT grease in side dampers
  • Kyosho 500 WT oil in oil shock
  • Kyosho ball diff grease in the differential. Important. Nothing else gives me the correct feel. This grease contains fibre glass particles that lets you run the diff much looser and still grip. Results are a smoother diff action, that are more consistent, and since you can run it very loose you will have lots of turn in without sacrificing accelleration.

Grip dependent stuff

High grip
  • Body. Audi R8. Super light, and quite agressive
  • Offset front 2 offset wheels, with 0,5mm shim, plus the 0,4mm wider lower tower. In total this gives 2,9mm offset. 
  • Rear 3,4mm offset
  • Slightly harder differential
  • Added weight underneath chassis.
  • Silver oil shock spring
Low grip
  • Body. Lexus SC430. Light weight, and very easy to drive
  • Offset rear. 1 - 2mm. Depends on grip level. Less offset when grip are low. Increase offset when grip increases
  • Offset front. 0 - 1mm. Depends on grip level. Less offset when grip are low. Increase offset when grip increases
  • Slightly looser differential
  • Gold oil shock spring

Mini-Z Norway "no slop" inserts.
These are made to remove some of the unwanted slop in the knuckles. Slop in the front end are not always bad, as it often gives you an easier car to drive, but for added precision this is the way to go.

They are drilled to 1,97mm internal diameter, so they remove all play between knuckle and king-pin. They also increase the length of the knuckle with 0,4mm. This is done for two reasons. I always lower the car with 0,4mm, and they support better against the king pin.




8.9.11

Thermal image of MR-03

Here you can see a Mini-Z MR-03 a few minutes after running. This is with Reflex Racing alu chassis plate installed.

Peak temperatures just after running are as hot as 58 °C


Imagine having bad bearings, bad gear mesh or other drivetrain problems on your Kyosho Mini-Z Racer. Do you think the temperatures would be this low then? ;)


26.10.10

PN sidedampers with Reflex Racing damper plate.

The Reflex damper plate fits perfectly with the PN sidedampers for the LCG 98mm mount.
The angles are matching up better than ever.

Will try to come up with a way to make the RR dampers work. The PN lower mount are way to wide for them to work, and I dont want to modify the motormount. I really need to shed some rear weight on this setup.

17.10.10

Aerodynamics


A lot of talk has been going on regarding aerodynamics on these small cars.
The opinions are many, and a lot of people has been secretly experimenting with these things. 

Does adding a wing a wing really help?
Can you add downforce by changing the underside of the cars?
  • At our track we have been using lexan wings for some time now. Made fron the Autoscale boxes. Cut and bent to shape using different tools. We think it works!
  • Lately Reflex Racing has made a lexan wing that the rumors  say are much more efficient than the home made big wings. Racers all over the world says they work!
  • Brian Ma (Color01 on mini-zracer.com), and the creator of the MRCG pan car, has been making some interesting discoveries regarding front diffusers. The results so far shows that it seems to work! He are also investigating on rear diffusers.
I could not resist trying out a few things myself, so I made a flat floor and a rear "semi diffuser".
It went trough various revisions before I could barely make a conclusion. 

The first test was done with a flat floor, and a very simple rear flap to see if I could notice any effect.
It actually seemed to have an effect. A almost completely neutral car actually got a bit understeery in high speed corners.
This sparked me into making a few different diffusers, and the last one is the one you can see pics at the bottom.

The ideal solution would be to include the body in the floor, but I have not found a way to make this practical.
The diffuser itself are form fitted to the rear of the Supra. All the air that channels trough under the car will now be let out at the rear without making turbulence inside the body.

The effect I feel it gives are not a "night and day" difference, but it does something!

Notice all the grit that attaches to the roof of the diffuser. That I think shows that the air seems to attach all the  way to the end of the diffuser. 
In my mind this shows that it actually works. 


I am not sure that it actually gives any faster laps (at least so far). The grip these cars have these days are really good, but maybe in low grip situations it could help?  

Take a look at the pictures, and feel free to comment.

27.5.10

The ultimate differential. Updated. Now 5.0 grams!

This is a little article on what I feel is the ultimate differential today.

I have buildt this from the following parts:
PN Ultra light weight differential shaft. MR2045UL.
QteQ Ultrra light weight differential housing set. QT-081101
QteQ Light weight differential left hub. QT-080801
Reflex Racing 64 pitch Machined spur. RX1154
Reflex Racing High grade ceramic thrust bearing. RX1137
Reflex Racing Light weight 8mm diff rings. RX1134S
Reflex Racing ceramic differential balls. RX1119

Assembled, this differential weighs in at 5.0 grams. This is complete with left hub.



The diff is a large rotating mass, and this has a large impact on the overall handling of the car.
The lighter your diff is, the faster your car will accellerate, and the faster it will decellerate. This is one of the strongpoints for myself, as I love a car that has lots of motor brake.
The drivetrain gets much more efficient because of less friction between the spur and pinion. The spur is much narrower than other spurs, and is almost everlasting. The only downside is that you wear out the pinions at a higher rate, but everyone wants to go faster right;-)

The spur has 6 balls. This makes it quite grippy, and you can adjust it quite loose and still have sufficient engagement.

My favourite diff grease is at the moment the R246 ball diff grease.



Click here for a maintenance tutorial.


Here are the reviews of the main parts:
Review PN Racing Ultra Light alu diff shaft
Review Reflex Racing Spur gear V2
Review QteQ differential parts




Here are some product links:
R246 Ball diff grease
PN Racing Ultra light weight shaft
Reflex Racing Spur gear
QteQ Left hub
QteQ Diff housing
Reflex Racing High grade thrust bearing
Reflex Racing Light weight diff rings
Reflex Racing Ceramic diff balls















13.5.10

MR-03 96 mm setup

For the last couple of years I have been using 98mm cars exclusively. This is mainly because of the Reflex Racing side damper setup.

Now that more side dampers are available, I built myself a new car in 96mm configuration.

This car differs in a couple of things from my 98mm car.
The front end is almost stock. Only Reflex Racing kingpins delrin balls, plus some shims are used.
The top shock is Atomic's newes oil filled shock. This was a bit tricky to install with this setup, but it works absolutely fantastic. The only downside compared to the Kyosho shock is that it is exactely double the weight. See own review of the Atomic shock.

As soon as more of the RR spring cups are available again, I will order up some for this car. I am also waiting on the new Reflex Racing front end. This will be highly adjustable, and I have a feeling that this will rock the Z world.

Front end parts:
Reflex Racing king pins
PN front spring cups
PN Racing Lowdown springs
Kyosho stock arms. (modified)
Mantisworx wheels
GPM 891 30 shore tires


Rear end parts:

PN Racing 94 - 98 LCG motormount V3
PN Racing side dampers
PN Racing central shock springs for the side dampers
Atomic oil filled shock.
Reflex Racing G10 96mm T-bar.
Reflex Racing T bar mount
Mantisworx wheels
GPM 891 25 shore tires





Differential (5,1 grams total weight):
QteQ left hub
QteQ diff housing
QteQ left nut
PN Racing ultra light weight diff axle
Reflex Racing carbon ceramic balls
Reflex Racing abec 7 thrust bearing
Reflex Racing light weight diff rings
Reflex Racing spur
Reflex Racing O ring

Other:
Reflex Racing high grade bearings
Reflex Racing 36 turn Ultra performance handwound motor
QteQ wheel nuts
PN Racing hex screws

Reflex Racing body mount
Atomic TS-043 washer kits (used for spacers between front wheel bearings and various shimming)

R246 ball diff grease
PN Tire tape
AKA tire glue
Ko Propo EX1UR radio
PN front body mount
Ferrari 430GT body
Team Orion 900HV batteries





Settings Front:
1 degree static camber via shimming
0 degree caster
+0,5 offset front wheels
1mm shim under knuckle
0,2mm shim between knuckle and upper arm
0,1mm preload on front springs
PN purple Lowdown springs
Taped and glued tires





Settings rear:
Diff axle position to give next highest ride height
Kyosho 500WT oil in top shock
Kyosho 15000WT Grease in side dampers

Zero preload on top spring
PN Orange central shock springs on side dampers
0,5mm preload on side shocks
Reflex Racing 96mm hard G10 T plate
Rear pivot point is on the inner postion on the T plate mount.
Taped tires
+ 1,5 offset rear
96mm wheelbase


Total weight is 184 grams


This setup is very nimble, and quick trough the tighter section on our tracks. It is also surprisingly stable on high speed corners.
Tire wear affects the setup very little. New tires works as good as completely worned down tires.

Comparison pics of my two MR-03's.






29.4.10

My latest MR-03 setup



Front end parts:
Reflex Racing king pins
Reflex Racing Front spring cups
PN Racing Lowdown springs
PN Racing caster arms
Atomic upper suspension mount
Mantisworx wheels
GPM 891 30 shore tires

Rear end parts:
PN Racing 98 - 102 motormount V3
PN Racing side dampers
PN Racing central shock springs for the side dampers
Kyosho oil shock/ K Red spring
Reflex Racing G10 T bar.
Reflex Racing T bar mount
Mantisworx wheels
GPM 891 25 shore tires

Differential:
QteQ left hub
QteQ diff housing
QteQ left nut
PN Racing ultra light weight diff axle
Reflex Racing carbon ceramic balls
Reflex Racing abec 7 thrust bearing
Reflex Racing light weight diff rings
Reflex Racing spur
Kyosho O ring

Other:
Reflex Racing high grade bearings
Reflex Racing 36 turn Ultra performance handwound motor
TQ motor wire
QteQ wheel nuts
PN Racing hex screws

Reflex Racing body mount
Atomic TS-043 washer kits (used for spacers between front wheel bearings and various shimming)

R246 ball diff grease
PN Tire tape
AKA tire glue
Ko Propo EX1UR radio
PN front body mount
Nissan GT-R 2008 body
Team Orion 900HV batteries


Settings Front:
1 degree static camber via upper arm
0,9 degree caster
+0,5 offset front wheels
1mm shim under knuckle
0,1mm shim between knuckle and upper arm
0,3mm preload on front springs
PN White Lowdown springs
Taped and glued tires

Settings rear:
Diff axle position to give next highest ride height
Kyosho 500WT oil in top shock
Kyosho 15000WT Grease in side dampers

Reduced top shock travel by 2mm
Zero preload on top spring
PN Blue central shock springs on side dampers
1,5mm preload on side shocks
Reflex Racing hard G10 T plate
Rear pivot point is on the inner postion on the T plate mount.
Taped tires
+ 2,5 offset rear
98mm wheelbase



Total weight is 184 grams


This setup is very stable in high speed corners, and a bit on the loose side in low speed corners.
Tire wear affects the setup very little. New tires works as good as completely worned down tires.




5.4.10

Inconsistent car

This is a little write up of some troubleshooting i have been doing today.
I have been battling an unconsistent car for a couple of days now.

It worked flawlessly a long time, until it suddenly started to snap into terrible oversteer on corner entry, and even some terrible traction rolling from time to time. Not on every lap, but more and more often. So I had to change my setup towards understeer.

The reason i suspected was the track temperature had fallen quite a few degrees lately.
Today i had plans to find out if this was correct, or if something had changed on my car.

I tested for about 100 laps before I started to look at it. It was snappy as ever.

I checked every part of the car for wear, tweak and even measured the front spring rates to see if they had changed dramatically.
No faults were found.

I stared at the car for a few minutes and could not understand what the problem was.

I readjusted everything. Made the setup exactly as it was before the problem started, and tested it on track. Horrible!

I then disassembled the front end to control everything once more. Then i noticed that the king pins were a bit sloppy regarding up/ down movement in the ball cup in the lower mounting plate.
I had installed the ATM lower arm set for a few weeks ago, but this was not a problem then.
I replaced it with the stock lower cover, and BAM! The car was dialed again.

It seems that the ATM lower cover does wear out quite fast. In my case only after about 15 - 20 hours of use before it started to give me problems!
The stock cover has at least 100 hours of runtime on it without any noticeable wear.

It could be that my set was a bit loose to begin with, but I dont know. I love the ATM lower cover, but I actually think I will use the stock for a while now:-)

My favorite setup 

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