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View Full Version : Just How Important FrontEnd Really Is


MagicMan
2006.04.04, 05:20 PM
MR 02
Front End consists of the following: (besides tires because we talked about this in the 'just how important tires really are) Camber, Castor, Toe, (Knuckes, Castor/Camber bar, Toe bar) Spring rate, (Springs), and smooth suspension (King pins).

I'm going to try to make this as simple as possible.

If you find your tires weiring on the outside more than the inside, and you are running 0 degrees camber (stock). Try to grab yourself 1 Deg, or 2 Deg knuckles. Try to stay away from the alloy. Grab Delrin if you are worried about breaking them. Now if you find yourself steering TOO much after you add your camber, but at least your tire wear problem was corrected, grab yourself a 1 Deg or 2 Deg toe in. This will lessen your turn in, AND at the same time increase stability on turn exit, and straights. Now say 1 Deg isn't enough, and 2 Deg is too much. So slap your 2 Deg toe bar on, and for more steering, go softer on the springs in the front. The softer your springs, the more weight is going to transfer to the important front tire on the turn. More weight on tire=more grip. More grip=more steering. So go with either soft/med soft/or mediums. King pins are EXTREMELY important. Ever gotten your first Mini-Z and wonder why the suspension is so grainy when you push the front end down? It's because the stock King Pins have a bad surface for the knuckls to slide on. However, I find myself lately just taking stock King Pins and some fine sand paper and sanding them down to the shiney surface. They work GREAT. No need to buy new ones. With out silky smooth travel of your front end suspension, you might as well have no suspension at all. Remember, any drag is a slowdown. So if you dont have bearings already, what are you waiting for? Kyosho obviously makes the best set. But I hear that some of these new dry bearing sets are great. I really am not picky about bearings, but make sure they spin really good and freely on the front. Do NOT over tighten your nuts. I find myself putting on the nuts PLASTIC FIRST, because the bevel will hit the part of the bearing that is supposed to stand still. And since the plastic is deeper onto the shaft of the knuckles threads, the chances of this wheel nut flying off during a race, is next to 0.
Is lowering important? Just a tiny bit. But once you do all of the above... Do you really want to bother lowering? I'd label lowering a preference and more of a 'show' thing than a 'go' thing if you know what I mean.

arch2b
2006.04.04, 08:53 PM
what grit do you use to sand the king pins? i do this as well btw :p i have tried polishign them with a dremel but i have not found a sure fire easy way to do so.

MagicMan
2006.04.04, 08:59 PM
what grit do you use to sand the king pins? i do this as well btw :p i have tried polishign them with a dremel but i have not found a sure fire easy way to do so.


Your dremel method sounds interesting. Do you use the cotton looking bit? I believe it's called polishing bit, but I'm not sure. Either way I think sanding it first would be good to get that dark colored coating off. I don't know what I used, I went in my car shop and looked at a bunch of sand paper and picked the finest one. I'll double check for you. The finer the better, it will just take longer to sand down. But once sanded, It'll be smoother. I'm gonna look into getting smoother sand paper actually, and post on here which I used when I do.

Another thing that I neglected to mention about front end, is that when using extreme offset on the front, (anything over 1) I noticed that the Kingpin to Knuckle angle of pressure becomes too far angled and the travel of the knuckle then becomes harder. It may just be the knuckles I'm using. However I'm going to have to look into this, because if this suspension travel becomes a huge issue, (in my VDS '3 offset in front') I might as well have no spring at all. This may be the reason it has no turn in even with 8's in the front. I may have to go with the Alloy knuckles I've tucked away, they have a smooth Kingpin travel to them..... Feedback?

arch2b
2006.04.04, 09:25 PM
yes, i tried both the white fluffly thing and just the pin in the dremel and a polishing rag.

some manufacturers offer font knuckles with derlin lined shaft holes claiming they are smoother. have you tried any of these? i haven't.

do you have anything to add regarding spring choice? this too i've found can really make a difference however i do not have the racing experience to describe it well. my hfay ranking is a clear indication of my driving control experience.

MagicMan
2006.04.04, 09:28 PM
yes, i tried both the white fluffly thing and just the pin in the dremel and a polishing rag.

some manufacturers offer font knuckles with derlin lined shaft holes claiming they are smoother. have you tried any of these? i haven't.

do you have anything to add regarding spring choice? this too i've found can really make a difference however i do not have the racing experience to describe it well. my hfay ranking is a clear indication of my driving control experience.

I believe I did mention something on springs, but when I re-read it, I can see how it may be unclear. I said something about the more weight transfer to a front wheel that you allow, the more grip it will have, and the more grip, the more steering. If you use hard springs, it transfers weight to the other side faster because it's stiffer. Therefore causing understeer, but if you want more steering, use softer springs, it will cause more lean. I've never seen a use for yellow or white springs in my time, I use either red, purple, or green (soft, medsoft, or medium).

arch2b
2006.04.04, 09:33 PM
thanks for the clarification, for myself and others

hobbycar
2006.04.04, 10:22 PM
Any thoughts on front ride height limiters (4mm vs 4.5mm vs 5mm)? I know they are important to keep your tires from rubbing on the body, but anything else to say about them in reference to handling characteristics?

Also note that if you "chuck" your kingpin in a dremel drill to polish it, be careful not to break off the nub at the end of the kingpin. I actually know someone who did this...okay I admit it...it was me :(

-hobbycar

MagicMan
2006.04.04, 10:41 PM
Any thoughts on front ride height limiters (4mm vs 4.5mm vs 5mm)? I know they are important to keep your tires from rubbing on the body, but anything else to say about them in reference to handling characteristics?

Also note that if you "chuck" your kingpin in a dremel drill to polish it, be careful not to break off the nub at the end of the kingpin. I actually know someone who did this...okay I admit it...it was me :(

-hobbycar


Spring travel limiters don't matter too much. I always use 4mm. Unless of course if I push down the body (front) and the bumper scrapes the floor. But some bodies, you can't help this at all, even with a 5. And then you have no travel at all. Travel is very important. Stick to the short ones if you can. And don't forget to use the spring compressors. This keeps form the spring sag that you get when you put the car on the ground and your spring already decides to push up.

michvin
2006.04.04, 11:40 PM
what grit do you use to sand the king pins? i do this as well btw :p i have tried polishign them with a dremel but i have not found a sure fire easy way to do so.
How about this: use dremel, but instead of placing the polishing bit into it put the very top of the kingpin. Then run it on lowest speed against a piece of 1200 grit sandpaper. Works like charm, but with time my kingpins developed rust, so i went with upgrades instead of polishing them again.

EMU
2006.04.05, 02:48 AM
Another thing to check when choosing your suspension limiters is the clearance between the wheel and wheel well (mainly when turning). If the tire tends to rub a little, then move up to a longer suspension limiter.

For springs, I tend to like a harder spring than Magic does... but then again, I am not as good of a driver, so a little push is more forgiving and therefore more consistant. Although, I usually do not see much difference in the spring choice, only a small amount.

For the most part, we use GPM delrin knuckles. I also use the GPM alloy knuckles as well with the delrin inserts. I prefer the complete delrin knuckle, as the alloy ones tend to have more slop on the kingpin.

As far as bearings, I truely dislike the Duratrax bearing set. Although I like the fact that they have one wide and one narrow bearing to slightly adjust the offset on the wheels, the bearings tend to have more slop on the knuckle axles. I have yet to try the Kyosho bearings, but so far the best fit has been the MZR dry bearings from the shop here. Once you screw on the wheelnut to the point where it is almost where it would start to slow down the wheel spin, there is almost no slop at all.

michvin has a good point about oxidation on the kingpins, while sanded/polished kingpins are good, over time they will oxidize. So expect to replace them down the line with some SS or Ti kingpins.

Slipstream
2006.04.05, 04:18 AM
You can use Mag polish such as Mothers to polish the black oxide off the stock pin. Put the pin in a cordless drill on the slowest setting, put some polish on a napkin and polish between your thumb and index fingers. (Becareful as the pin can get hot if you polish too long at one time) Only problem with doing this is the kingpin will have a smaller diameter than ideal. The black coating has a thickness that is account for when sizing the pin. If you remove it the pin dia. will be smaller and you'll get more slop.
Even if you get the stainless steel or TI hopup pins I recommend this method to get a mirror finish for a smooth front suspension.

I agree with Magicman on transfering weight to the front to get the car to turn by using soft springs. Only issue is your car will be slow transitioning left to right since the front will roll more.

EMU
2006.04.05, 04:24 AM
A little slop is better than a bind ;)

builthatch
2006.05.25, 01:50 PM
A little slop is better than a bind ;)

about polishing the pins- if you take some 16 awg regular non silicone wire, cut a small piece off, say 8mm. slice it carefully on one side lengthwise, and empty the wire strands out of it. You can now use this piece of sheathing to go over the kingpin so you can secure it in the dremel chuck safely. it allows you to put very little of the kingpin in the chuck, but get a good grip by tightening well w/o damaging the end of the kinpin so you can polish all of the pertinent portions of the kingpin. It spreads the force of the chuck evenly and softly across whatever amount of pin you have in the chuck. I use mothers metal polish in a microfiber rag (it's what i have around) and spin it in there on medium speed. After i spin it in the dry portion of the towel to remove all of the polish, i wipe it down with motor spray to assure all of the petroleum residue is off of the pin left from the polish as well as any towel fibers that might have spun around the bottom base of the pin.

gnehcoel
2006.09.06, 02:50 AM
Hi Magic:

How about frontend setup for AWD?

knuckle, tie rod, diff, springs, spring spacer, washer for the knuckle to lower the car, wheel offset etc ... ?

just wonder what your opinion is.

Thanks,
Leo

Fildev99
2006.12.14, 05:48 PM
I was also wondering about the FrontEnd importance with the AWD. Any suggestions there?

builthatch
2006.12.14, 05:56 PM
Hi Magic:

How about frontend setup for AWD?

knuckle, tie rod, diff, springs, spring spacer, washer for the knuckle to lower the car, wheel offset etc ... ?

just wonder what your opinion is.

Thanks,
Leo

well, magic got out of mini-z's (and rc in general) a while back. Cristian Tabush seems to have a good working knowledge of the AWD so maybe he'll show up in here...

MINIz guy11
2006.12.14, 10:44 PM
Wait, Magic sold all his Zs to propose right?

builthatch
2006.12.15, 12:04 AM
Wait, Magic sold all his Zs to propose right?

long story...but hehe, no.

i saw magic race only one night and i am confident he is the best rc driver i've ever seen, in any scale.

he's simply over rc, but, like i said, it's a long story.

someone else should take this thread over, i vote for cristian to handle the awd stuff and i am not sure about the rest because joe chen is gone too. experts needed!