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Old 04-06-2008, 05:29 PM   #1
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Default Onroad Touring (Losi XXX-S) Tips Please

I have been racing a Losi XXX-S at the local hobby shop's club races (Superior Hobbies in Orlando, FL) for the past two months. I got this car about 7 years ago and then took a break from the hobby, so it's the racing version Losi originally released with very little wear (as opposed to the newer RTR cars). I've been racing in the Sportsman Stock (beginners and supposedly first-time racers) class in the parking lot tracks they set up.

The first time I ran it I had crappy "touring car" (non-race slick) tires, an old Trinity Green Machine 3 stock motor, 3300 Nimh batteries and a Novak Explorer II ESC. I had no traction, even with traction compound, and just no speed on the top end down the back straight. I basically just spun out a lot and had to drift my car around the course and really be easy on the throttle. I averaged around 13 laps in the 5 minutes that the races lasted for.

After that fiasco, I got a setup station, the XXX-Main Chassis setup guide, a new Excessive Force stock motor (by Putnam Propulsion, which is like a hot Epic/Green Machine), some 4000 maH batteries and some slicks. The ESC is the same. Today, I improved my times to complete 15 laps in 5 minutes (2 more laps in the same amount of time, and on a tighter course), and no mechanical or electrical issues, which I was stoked about. I found that the tires stuck much better, and using the setup station revealed some serious imbalances in my setup! I could almost stay 3/4 to full throttle on most of the track.

I still lacked the punch and top speed of some of the other racers, though. My XXX-S Manual recommends a 26 tooth pinion for a stock motor, and today I started with a 27 tooth and my motor was getting pretty hot at the end of the race. The shop guys recommended moving to a 30 tooth since they though I might be undergeared, so I gave that a shot. It helped with the top end a little bit, but I still seemed to be missing that "zip" that some of the other racers had. There wasn't a big noticeable difference when I hammered down.

My questions (after all that long backstory) are:

1) What am I missing in my setup to increase overall speed and power? I know that stock motors aren't supposed to be insane, but this motor came worked over and dyno'ed and looked to be pretty strong on paper, so I was hoping to see a difference from my last motor.

2) Will getting a better ESC make a big difference in the power and how smooth it comes on? I realize it's just an old, budget ESC but I don't know how much that factors in when only running a hot stock motor. Having more disposable income now means I could troll the for sale forums here and get a much better device.

3) Are there any gearing/drivetrain recommendations that will help me out?

4) Are any of these limitations REALLY attributed to the platform I am using, and would I notice a night and day difference by upgrading to a newer car (like and XRAY or TC5?) I don't plan on getting a new car yet, but just want to know if I am shooting myself in the foot by trying to work with such old technology. The handling is really pretty good, it's just the punch and speed I am missing. I'm assuming that the others were sticking to the rules and just running a brushed stock motor.

I'm not looking to turn this thing into a bullet with just a stock motor, but now that I've worked out the setup, handling, and mechanical kinks, I need to start squeezing out every last bit of performance I can. Thanks, you guys have already really helped in the handling arena.
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Old 04-06-2008, 05:40 PM   #2
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Were the others in your class possibly running BL systems? If so there is your lack of top end compared to them. You can make a brushed motor compete with BL, but it will have to have the comm cut after every run and may have the magnets crap out on you due to heat. Motors just get hot in TC and there is not much you can do about it other then putting fans or a snap on heat sink to draw the heat away. The XXXS is not a bad car and can be competitive if setup right and your driving gets better. As you already found out tires and battery can make a difference. Just ask a lot of questions of the locals that race there as well and tend to be the fast guys, they will help you out.
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Old 04-06-2008, 05:44 PM   #3
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The guy that lapped me was not using a brushless system, or so he said. The class rules call for brushed stock motors, but they don't check so I could be running at that disadvantage without even knowing it.

I do know that I was taking it easy and not pushing the car all out, because I wanted to concentrate on driving smoothly instead of having to alternate between full throttle and brakes all the time. However, when I did push the pedal to the floor, the power just wasn't there.
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Old 04-06-2008, 05:52 PM   #4
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What spur are you running in that car? Meaning how many teeth on it and what motor were you using? Also what speedo are you using as well. Here is a link to setups for that car, just look through them and try to find one that best suits the track conditions that you have where you race at: http://www.losiboard.com/onroad.html
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Old 04-06-2008, 06:37 PM   #5
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I race a XXX-S locally (winter carpet, summer parking lot at HobbyTown)...

The first place to look is the belt tension. The single belt design is actually very good, but most racers make the mistake of getting the belt too tight, creating drag and killing accelleration and speed. Loosen the belt until it almost slips -- in fact, a belt in good condition can actually be set loose enough to allow it to "skip" a few teeth under extreme braking... Running Stock motors (even 13.5 brushless), I find it is very hard to make the belt skip, so experiment -- running open Mod, it is easy to "eat" the belt, so be more cautious...

Don't forget the usual suspects, too: dirty/dragging bearings, tires rubbing (more on this later), etc...

One thing to watch for regarding "tires rubbing" (actually "wheels" rubbing)... some wheels have a deep hex area in the center, and the LOSI drive hexes are a bit more shallow than say an Associated. when the wheel is tightened on the axle, it is possible for these wheels to hit/rub on the outer face of the hubs...
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Old 04-06-2008, 06:44 PM   #6
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Quote:
Originally Posted by Yeti35 View Post
What spur are you running in that car? Meaning how many teeth on it and what motor were you using? Also what speedo are you using as well. Here is a link to setups for that car, just look through them and try to find one that best suits the track conditions that you have where you race at: http://www.losiboard.com/onroad.html
The spur is the stock 88 tooth (48 pitch) that came with the kit, with a 27 or 30 tooth pinion (26 recommended by guide, but that led to overheating the motor, I think). Internal drive ratio is 1.83.

Speedo is a Novak Explorer II. Not high end by any means, but lets me go and stop.

Motor is a Putnam Excessive Force, Green Machine-based version.
http://www.putnampropulsion.com/putnam_stock.htm
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Old 04-06-2008, 06:53 PM   #7
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Originally Posted by tfrahm View Post
I race a XXX-S locally (winter carpet, summer parking lot at HobbyTown)...

The first place to look is the belt tension. The single belt design is actually very good, but most racers make the mistake of getting the belt too tight, creating drag and killing accelleration and speed. Loosen the belt until it almost slips -- in fact, a belt in good condition can actually be set loose enough to allow it to "skip" a few teeth under extreme braking... Running Stock motors (even 13.5 brushless), I find it is very hard to make the belt skip, so experiment -- running open Mod, it is easy to "eat" the belt, so be more cautious...

Don't forget the usual suspects, too: dirty/dragging bearings, tires rubbing (more on this later), etc...

One thing to watch for regarding "tires rubbing" (actually "wheels" rubbing)... some wheels have a deep hex area in the center, and the LOSI drive hexes are a bit more shallow than say an Associated. when the wheel is tightened on the axle, it is possible for these wheels to hit/rub on the outer face of the hubs...
The belt has about 1/4" of vertical movement in it currently. It doesn't seem too tight, but I will play with the tensioner to see if that makes a difference and frees up some drag in the drivetrain.

The wheels aren't rubbing the hubs as far as I can tell, but I did have to trim the tops of the ball cups so that they didn't rub on the inner edge of the rim. I'll check the rest of the wheel/hub combo to make sure there isn't any unneeded friction happening there. I didn't think about the belt at all - thanks for the tip!
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Old 04-06-2008, 09:26 PM   #8
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Default XXX-S Thread

There is a multi year XXX-S thread on the board with w wealth of information.
Almost every question there is to ask has been asked at one time or another.

It would take a day or more to read the whole thing but whatever time you can devote to it will be worth it.

What I do is have a copy of Word running in another window, whenever I read something that seam helpful, I highlight it copy it and then paste it into word. I then repeat th process with the next vaulable piece of information eventually I end up with pages of key facts and info about the subject I am studying.
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Old 04-06-2008, 09:35 PM   #9
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Angry help

i own a tweaked chassis. what can i do?


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Old 04-07-2008, 11:22 AM   #10
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Start HERE. Its even a Losi!
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Old 04-07-2008, 11:41 AM   #11
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i can relate so much to your first post. I used to have a xxx-s G+ around a year or two ago and when i drove by myself out in the street i felt like my car was the fastest thing out there. but when i got out on the track these other cars were lapping me like no tommorow. I even felt stupid because the other guys had a table full of electronics with chargers and balancers and power supplys, things ive never seen before. It really bothered me because i couldnt never figure it out and just decided to sell everything. My best guess were my batteries because i was running unmatched 3600 mAh batteries i found on ebay, used motors bought on this forum, and a hobbico charger (would charge max 2.0 amps). I never had any of the cool balancers chargers or dischargers.

im also curious on this topic and ill be following to maybe get a good answer.
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Old 04-07-2008, 04:24 PM   #12
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Originally Posted by venom2034 View Post
i can relate so much to your first post. I used to have a xxx-s G+ around a year or two ago and when i drove by myself out in the street i felt like my car was the fastest thing out there. but when i got out on the track these other cars were lapping me like no tommorow. I even felt stupid because the other guys had a table full of electronics with chargers and balancers and power supplys, things ive never seen before. It really bothered me because i couldnt never figure it out and just decided to sell everything. My best guess were my batteries because i was running unmatched 3600 mAh batteries i found on ebay, used motors bought on this forum, and a hobbico charger (would charge max 2.0 amps). I never had any of the cool balancers chargers or dischargers.

im also curious on this topic and ill be following to maybe get a good answer.
While I know that batteries and chargers make a big difference, I think I am doing ok. I have a couple packs of 4000 mAh that I got custom made off of cheapbatterypacks.com (I don't think they are matched, though), and use a Team Checkpoint TC1030 charger that does a fantastic job. I could see how what you were using would definitely limit you though - only being able to charge at 2 Amps wouldn't give your batteries that "punch" that you probably needed. Too bad you got discouraged and sold everything off - it's still fun for me to be able to run on a track as opposed to up and down my street in front of my house

One thing that I asked and hasn't been addressed yet: how big of a difference does the ESC make? I'm running an old (in good shape, just outdated) sport ESC. What would happen if I upgraded to a pro ESC? Anything drastic? I have an old Tekin 411something, and the only other ESC I've ever used is a Traxxas Velineon. Would it be worth to drop the dime on a newer LRP or Novak?
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Old 04-07-2008, 06:48 PM   #13
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Default ESC do matter

When I switched from an Explorer ll to a Ko VFS 2000, I could not believe the speed difference. No other evidence beyond the fact that many fast guys do nto hold on to esc long. they sell them off and often get a new one of exactly the same type or try something new.
Want proof? Buy yourself and old Novak TC2 or for just a little more a new Ko from Rc America. I hear they are selling for cheap cheap these days.
As for the stock motor wars, don't sweat it. I have seen at least 4 guys running stock motors that simply are straight faster than most of the 19T motors at our club. The Co27 seems to be fully capable of being tuned to the edge and performing at an insane level. I have also seen at least 2 of these cause the release of the magic smoke.
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Old 04-07-2008, 07:54 PM   #14
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When I switched from an Explorer ll to a Ko VFS 2000, I could not believe the speed difference. No other evidence beyond the fact that many fast guys do nto hold on to esc long. they sell them off and often get a new one of exactly the same type or try something new.
Want proof? Buy yourself and old Novak TC2 or for just a little more a new Ko from Rc America. I hear they are selling for cheap cheap these days.
As for the stock motor wars, don't sweat it. I have seen at least 4 guys running stock motors that simply are straight faster than most of the 19T motors at our club. The Co27 seems to be fully capable of being tuned to the edge and performing at an insane level. I have also seen at least 2 of these cause the release of the magic smoke.
Thanks for the info on the ESC. I figured that a budget ESC like the Explorer II wasn't the best choice for racing, but didn't know what kind of impact it would have on my performance. Especially because you can buy remanufactured ones from Novak for $20 on their site now I'll do some searching on the for sale forums here and see what I can upgrade to reasonably. I'm sure the brakes will improve a lot, too. I also have an old Tekin 411-G2 I might give a shot with - that thing was pretty sweet back in the day.
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Old 04-07-2008, 08:08 PM   #15
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If your going to stay with brushed and want to stay with novak then you can find GTX's used here for $65-$80 all the time. Should be much better than the one your using.
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