Wolf Hobbies

We have received many emails about the G4RS and G4+ handling issues in regards to too much steering / loose rear grip. This is especially prominent when the Kfactory tires are used. This is a sample of the emails we receive:

Damn...those tires a lot of traction. The only problem I have is the 38 front is too much steering for me. I had to used jaco for front 40 and that settle my rear end. I came 2nd on sportsman due to couple mistake. All I can say about the g4rs "fast and easy to drive" I was able to drive tighter lines. And one of the expert driver going to get one (g4rs). He could not believe how good the car is

The reason why this happens is that the suspension on the G4RS and G4+ is a true advancement in R/C technology. The longer arms allow the suspension to remain consistent over their range of travel. This allows the front tires to grip much better than any previous (or current competitor’s) chassis design. As a result the slip angle is greatly reduced. For those of you who know what slip angle means, skip the next few sentences. Slip angle is the difference between the direction that the front tire is pointed in a turn and the actual relative chassis motion. As an example your tires may be turned 30 degrees but your car is only turning at 15 degrees. This would be a 50% slip angle. With the new flying wing suspension the slip angle is GREATLY reduced. I don’t have the equipment to actually measure the exact number, but on my transmitter I reduced my steering travel from 92% to 64%. So you may be asking, “If the suspension is so great why does the rear end snap around Unless I change to harder tires in the front”? The answer would be obvious if you were driving a real car and had this situation. The rear grip problem is a result of “relative servo speed”. I’ll exaggerate a little in this explanation. If you cut the steering servo travel in half and don’t change anything else to achieve the same result, you effectively double the servo speed. When you dialed out the steering travel in your transmitter you reduced the total travel so it takes the servo less time to get to the end point. If you still turn the wheel on the transmitter like you were when the servo was going farther, then the front wheels change direction so fast that they are “shocking” the suspension loose on turn-in. What make this so drastic is that the reason for the reduced servo travel is that you have so much more grip from the tires because they are not sliding as much. The cure for this is really simple. When you dial out steering you also need to slow down the steering servo speed setting on your tranmitter or slow down the rotation of the wheel on the transmitter. The latter is the overall better solution since driving smoother is the way to go. In testing, every time we slowed down the servo speed we were able to use the softer fronts without losing the rear grip.

One other question we get a lot is: “What are the ratings on the different springs in the 502143 spring kit”? And "What is the rating of the stock springs"?

1.2mm 10lb
1.3mm 13lb
1.4mm 17lb
1.5mm 20lb
1.6mm 26lb (stock and aqua springs)
1.7mm 31lb
1.8mm 41lb
1.9mm 51lb

Sp Racer

iTrader: (12)

Down here in Australia we had the same problem, massive steering but couldn't make the rear end go with it....we couldn't find that "nice" balance...

What we did was to use the lower roll center pin position in the front end - totally transforms the car.

Just a small note re. the springs , the aqua springs and the sock springs have the same wire thickness, but the stock springs have 1 extra coil ( which makes them more progressive ) - as a starting point, try aqua fronts and stock rears

jscamry

iTrader: (5)

What is the condition that you run on and what is the setup that you have?

Thanks Jason.

Pattojnr

iTrader: (19)

i think most people here are forgetting what is creating the power we use. each motor spools up different and has different torque values at lower RPM. a motor requires different gearing, perhaps to tame it low down, or to make it spool up harder and faster, dependant of the grip levels of the track.
while SP racer informed us of the front roll center, his is a great track indeed, and grip levels are quite high. one thing for certain, clutch setup is also critical. high spring tension creates a later engaging clutch, more into the power band of a motors low end power, set this too high, and it will make the car very hard to get rear traction. i used a black spring, red clutch shoe, and no weights in the throw out shoes, 0.4 spring tension, 0.5 clutch gap. this was a good clutch setup for a lower traction track, made the use of throttle control very controllable. very consistent power delivery, provided your not just grabbing that throttle, then no clutch setup will be of assistance there.
the clutch is a wonderfull thing, use it to your advantage
a basic setup for the car, would be

Front....
70K front diff oil
inner hole for outer steering link on hubs
Aqua front spring, 50W oil std holes, or you can open them up to 1.2 or more with 60W oil
outer bottom arm shock position, 2nd inner hole on tower
inner middle , or bottom lower speed shot roll center
dependant of amount of steering, 197 track width 1mm toe out -2 camber

rear...
same shock setup as front. std rear spring(silver) or mugen or serpent 1.6 spring (more progressive)
outer lower shock mount, 1st inner hole shock mount
middle inner top camber link, 2mm spacer on hub
2mm shorter wheel base, 200mm track width -2.5 deg camber
2mm toe in each wheel. soft rear swaybar
10 - 15k diff oil
the car loves 40-42 shore front tires 40 rears or 38 dependant of grip.
this is a general setup, and may require some different adjustments dependant of track conditions. but a good starting point.

TM Sean

.

prg

iTrader: (1)

Wondering if anyone can assist me, I have a g4rs with futaba 9451 servos and a spectrum reciever. It appears that the vibration of the car vibrates the sectrum reciever and causes the spectrum to go into fail safe. I have replaced the battery (in case) and the spectrum reciever but i haven t been able to stop it. I have temporarly mounted the reciever on the top deck and got the same problem (The light on the reciever goes off and i loose remote). If the motor is not ruunning or i have the reciever loose above the top deck the problem goes away.. I am not using a switch as i also eliminated that. I have also dissconected both servos from the reciever and with the reciever mounted i still loose remote.

Thanks

peter

Pattojnr

iTrader: (19)

if every thing is disconnected and engine not running and looses signal, then id say it is a comunication problem with the radio. try a fresh model number (one not setup for a car) rebind reciever, then recharge the battery. if your using a new TM pack, it may need a couple of charge discharge cycles. but it would be best to make your own pack, or switch to lipo. see if you can hook up a voltmeter to the battery while its turned on, se whats happening wiht the voltages. if nothing is plugged in, then the current draw should be minimal, and the voltage should be stable. once the servos are plugged in, stall them one at a time for a short burst, see what the voltage is dropping to. 2 digital servos will be quite a draw on the battery. some have used a capacitor from Spektrum, plugged into the Aux channel. stores some voltage in reserve when it needs it. also make sure there is no part of the wire for RX touching the carbon. if need be drill a bigger hole, and put some fuel tubing inplace and glue it. then feed the aerial through the tubing to the aerial tube.
if all else fails, try a friends transmitter and see if you have the same problem.

prg

iTrader: (1)

thanks for your response, I started out with a lippo mounted where the reciever would normally go and had a miniture spectrum reciever (of an electric car that was working fine) when the problem occured. The loss of binding occurs only when the motor is running and i believe the vibrations may be causing the problem.
I replaced the lippo with a standard Tm battery pack and the reciever with a normal size one.
I use my radio on a race day with other classes with no probs.

i will try and re bind with a new model number and also check the arial wire as suggested

thanks

peter

razzor

Just to add the G4S/+/RS chassis seem to just be better suited for use of higher/harder shore tyres.
At all the national events i ran last year i found i always got my G4S working better and more consistent running using 40f/40r or 42f/40r and in some cases 38f/40r.
On occasions that i tried softer rears i always found the rear to slide a lot more.
Im sure setup contributes to this and other factors.
I always have to dial out steering on my dual rate as teh car generates so much steering.

Pattojnr

iTrader: (19)

Hey Razzor, did you get that setup ? i still think you could get the same results from the G4S with speedshot and the new rear shock tower mount. as most people started running the speedshot and ED , a cost of $20 or so could see you with the new bracket and top arm mounts. then the setup can be used. can you Pm me your email, ill send a proper sheet through.

razzor

I got it bud, thanks.
Ran teh car this weekend after a complete rebuild.
Needs a bit of tweekingto settle it in but again as mentioned in my post above, soft tyre shores and i was all over the place and as soon as i went harder car got more planted.

Next national is at the ned of march so have some time to get it in the park.
Must say i use darren Johnsons spool setup as a base and its always close to where i need to be.

Pattojnr

iTrader: (19)

when i first went out with this setup, i thaught my god, so much steering. i came into the pits, let the car sit while i turned the steering rate down to about 65%, went back out, never looked back. it was just a pleasure to drive, every corner, for 50 laps. put a big smile on my face, even though i broke the car in a big way, i was still smiling.

razzor

Know that feeling when everything just feels right