JohnP2

I posted these questions in the Losi forum, but in all candor that forum does not get a lot of activity. I'll be lucky to get one answer. Hoping one of you can provide some insight. Thanks so much!

1. I noticed it has some oversteer, so am changing the diff oil from 5k to 7k. In taking out the front clip, I noticed a spacer came out. Explicitely, where does this go? The exploded diagram is not clear. I've not put the front clip back on, but you can probably save me some time by walking me through what this is and where it goes. ;-)
2. What are the camber stand-offs for? Most of my vehicles use C-hub but I've never seen this.
3. I noticed it came out of the box with the toe non-uniform. i.e., FR toe was 2 degrees out and FL was only one degree. This has me a bit worried about all the links, so will go through and true them up. Has anyone else noticed issues with equal lengths on the rtr?
4.The buggy started to flameout during pit stops. I noticed it was caused by the HSN on the carb coming loose. This exact same thing happened on my 810 (unsure if they share the same carb or not), and wondering if this is a known issue.
5. Finally, the starter box. UGH! I noticed you have to push down on the engine (HARD) to turn the engine over. Is there a way to configure this box so all I need to press down on the wing (like I do with my OFNA box for my truggies/buggies).

johndavis

your first 3 questions would be hard to answer unless you can find someone  that races at the track you do. there is so many different setups for each track.  the diff fluid is a big part. i would change the center diff first  that will put more or less to the frount or back  diffs.  i run a 5-7-2 but thats on loose dirt . i need more frount drive. and toe adjustments is just trial and error. find what works for you. most run 2 degrees in back 1 degree in frount.    if i recall correct  why most push down on the engine is because losi's frame has flex in it . the flex has to do with the handleing of it. yoiur ofna'a frame is more stiff and you can push on the wing. i use the ofna box.  i learned this the first time i pitted for a guy with a losi 8,  i had a hard time with it till  he showed me about the flex in the frame. when i startd pushing down on the engine  it started much quicker  and less  cut fingers.

Foxy

1) Changing the rear diff oil for something thicker will INCREASE oversteer. For racing I would go with 3k in the rear. I don't know what the 'front clip' is?

1a) In general to combat oversteer, your main considerations should be these in this order...
Check the ride height, only you know what it should be, but consider that depending on other circumstances, oversteer could still happen if it was too low or too high, you need to find the balance.
Check the rear shock spring rate, too hard will cause oversteer.
Check the rear shock oils, too hard will cause oversteer.
Check the camber angle, more rear negative camber can reduce oversteer, but too much can increase it again.
Check the FRONT AND REAR anti roll bars. Thickening the front or thinning the rear will help reduce oversteer
Check droop, not enough rear droop is the most common cause of oversteer for new kit builders
Check the oil in the rear diff, thinner will improve oversteer.
Check the oil in the center diff, thinner will improve oversteer.

2) I don't know what 'camber stand-offs' are.

3) Links should always be equal length (unless that model has a weird steering setup). When tuning the steering, start with the servo horn and take the opportunity to center trim it again, with the horn exactly parallel to the steering arm. Now make sure the links are exactly the same length, they will then stay the exact same length when you adjust them, so you know if you increase the left one turn, you need to increase the right one turn, etc, etc.

4) Not being a Losi owner I can't really help there, but I would suggest an o-ring change would solve it.

5) I always start my cars by positioning the front of the car on the pegs, then pushing down on the rear of the car. Consider changing starter box if you find it requires so much pressure you can only press on the engine head. What starter box are you using? The Mugen ones are great.

JohnP2

Thanks for the replies. I probably should have been more speciic with "oversteer" in that it revolves around on-power steeringwhen exiting a corner. The buggy has a tendency to drift in the rear when doing so.

Some quick notes:

1. I was referencing increasing the weight of the front diff oil only. The thought is thicker oil would help turn less into the corner. Of course I'm getting varying advice now. ;-)
2. I think what I will do is hold off on the diff oil change, and simply consult with a TLR driver at our track for his thoughts (as was noted track needs to be taken into consideration).
3. Hopefully when i go through and true up all the links and get precise measurements it will help.
4. Regarding the box...that makes sense about the flex frame. I guess I'm looking for a way to were I don't have to push down so hard make contact with the wheel. Right now, if I push hard it triggers the motor....however, I have to push VERY hard for it to make contact. I'll look over the box but my hope is I can adjust the springs on it or something.

Thanks again for everyone's replies!

rccheech

5k front, 5k center, and 2k rear is a good starting point. The Losi 8 is a very aggressive car, it likes off power steering coming in and power out of the turns...well past the apex, come in smooth on the exit. Lightening up the oil in the rear will help with the drifting as well.

Make sure your droop in the rear is at least 105mm.

There is an adjustment on the switch for the starter box so you wont have to push so far for the motor to come on, youll have to pull the switch assembly out to adjust it, at least thats how mine is but its older, im picking up a brand new box saturday.

JohnP2

Thanks, this is good stuff. My understanding is the best way to measure the droop on this is shock end points using digital calipers. I adjusted the droop on my D8T and it really made a difference. Seems there is something to be found in this area of tuning. I'll also crack open the starter box to see where I can adjust this setting.

Foxy

Oversteer on power will not be helped by stiffening the rear diff, I promise, it will be made worse. The drifting effect is caused by both rear wheels slipping as you accelerate, if you increase the rear diff weight, they will be more locked together, if you decrease the rear diff weight, the lighter wheel will be free to spin a little, keeping the driving wheel stable and holding the line better.

Aggressive drifty drivers have stiff diffs, smooth 'line' drivers have soft middle and rear diffs and harder front diffs.

What diff oils are you currently running?

JohnP2

It's currently at 5-5-2

Foxy

Wow. OK, diff oils aren't the problem. You probably should up those numbers a little and look for your handling problem elsewhere. Take the local pro's advice on diff setup for that track and then begin looking at other factors for your drifting.

rccheech

It's a possibility that you need to get used to the cars personality on the corners, setup can only go so far. Make changes one by one if you are going to chane something.

JohnP2

Agree that it's best to make one change at a time. Actually it's my son who drives this buggy - I am just the mechanic.;-)Wefocus on the #1 item that I see and he feels when driving.The only changeI'm making is to the shock oil weight going from40/25 to 45/30. I'm alsogoing toensure all themeasurements are stock (ride height, camber, toe, droop) as I never checked it out of the box.He's put over 1/2 a gallon in it, so need to understand it's current state and then note specific changes.

I also agree it's very aggressive. I tried it once and was everywhere. However, my son likes its aggressiveness, so just have to manage it.

Foxy

You need a setup system John, don't delay it any more...they're expensive but SO worth it and you only buy them once, they last forever.

http://www.amainhobbies.com/advanced...h+setup+system

I strongly recommend you get the wallet out for the hudy set, but the Integy set will do if 150 is just too much.

Using this, you'll have your car at factory settings in minutes, and be able to make very precise changes one by one, as rccheech said.

rccheech

100% on the set up station if you want to take it to the next level. Cannot go wrong there one bit, and like said above, the Hudy is the way to go, but the integy, is fine as well, I have the integy, but I want to upgrade to the Hudy this summer if I can foot the bill.

Foxy

By the way, I nearly forgot, your assertion that changing the front diff oil for something thicker is absolutely right. Increasig the front diff weight will improve your front pull out of the corner, and by side-effect may reduce oversteer. In any case, as a smooth driver, you should be running heavy front diffs, at LEAST 7k, even 10 if you have a smooth on-road style. I run 10 in the front in all my off road cars, because I have a background in on-road racing, and they just dont feel 'right' to me with soft front diffs (for on-road of course we run one-ways usually, which gives the best of both worlds, no diff on turn in, locked on exit).

JohnP2

Just a follow upon the race setup for this buggy: we kept everything stock except shock oil. I did raise his rear ride height. Oversteering seemed to go away andmy sonwas able to be more aggressive.Losi'svehicles are always very tight andcrisp.

This buggy/engine can compete with anything at the track - and we have some pretty serious racers. Our top drivers could win with this buggy (although they'd probably ***** the whole time)...but it really is a tremendous buggy.;-) I have a lot of plans for it. My son has put in almost a gallon at the track without any big changes, so feel we kind of know what we need. Accomplishing that will be another thing! The next change will be a new clutch setup (from 2 to 4 shoes). The buggy can use somehelp lining up forbigjumps in tight spaces, so hoping this extra pop will help. Even if that is not fixed, you can never go wrong with a better clutch.

I've looked at that setup board, Foxy,and am developing my poor-man's way to measure changes. I'm simply taking ensuring everything is stock measurements (my baseline) using my digital calipers. This way, any changes will be measured and tracked in mm. To ensure I don't go over certain parameters, I'll convert the measurements to angle or degree, or what have you.

That set-up board is pretty expensive. Enough for me to tap into my creativity and see what I can do with existing resources. To me, 1/8 nitro racing is a war of attrition. Make yourride a monster!First and foremost you've got to finish. You've got to lock down your vehicle and be aware of any potential weak areas. It was great seeing some of the Kyosho's and XRay's break down in the qualifying while this little Losi held up strong! Wrenching is incredibly important with this class.

rccheech

Ya know, If you are good with coverting measument to angles, you could probably make your own set up station, I have thought of it before but just ended up buying one, due to lack of major ambition.....and alot of lazieness.

Wrenching, setup and maintenance are key factors in the racing scene. Getting very familiar with your car is crucial to finishing a qualifier and a race, not to mention a heck of alot of practice behind the wheel. Dont practice till you get it right, practice till you cannot get it wrong!!! Good luck and good racing!!