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Old 11-25-2009, 04:29 PM   #121
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Just out of curiosity why did you go with the gpm shocks instead of the threaded losi's?
I seem to remember that quite a few of the plastic suspension parts were available in 3 variations, rtr/original kit, graphite, and ea3 materials. I tried graphite for a bit, but went with the original as it held up better to my less that stellar driving skills at the time. The ea3 material looks like a good option but I haven't tried it yet. I also found that the front arms came in two styles under the original p/n. The first was with a 'boss' around the inner hingepin and the second had a constant thickness. I would guess the second variation was rtr parts replacing the stock of kit parts as a running change . The rear upright ballstud was a trouble spot for me. I pulled it out of the upright on some pretty mild hits. I ended up using a ballstud with a longer thread than stock.
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Old 11-25-2009, 06:24 PM   #122
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I got an idea for the front spool set up which ive been running in stock (17.5) class for a while without any dramas
not sure how it will be in mod etc but mite be an idea
When building the front spool it says 2 still use the 2 bearings in the diff, instead i replaced these with 2 plastic bushings from an RTR steering rack (little black plastc ones)
saved a bit of weight there for rotational mass.
and sein the diff is virtually locked i cant see it bein a prob.
would like 2 work out a way of removing th e bevel washers an thrust bearing too and just bolt the diff together mite save more weight there for quicker corner exit acceleration etc
Did you pass on the idea of getting the IRS spool diff ??
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Old 11-25-2009, 07:44 PM   #123
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paraletic. You need the thrust bearing in case there is any slip. The screw will unscrew otherwise. You can try it by shortening the plastic bushings you put in and leave out the steel rings for stock. It might work OK plastic to plastic. My earliest ones were like this. Very light.
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Old 11-25-2009, 09:55 PM   #124
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Did you pass on the idea of getting the IRS spool diff ??
I thought about it but with what John said earlier about having some slip due too the spool pads mite be a good thing
plus I wasn't sure on the weight of them either seeing I run stock I figure the lighter the better hence why I trying the plastic bushings etc

mite see about gettin some jrxs spool pulleys to try too
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Old 11-26-2009, 07:50 AM   #125
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Scott-Thanks for the post. The only reason for GPM was that they were red, cheap and aluminum. They are not really available. I have ordered the Losi threaded shocks now. I have a graphite chassis now, but mostly RTR parts. It is a good mix. My rear outer camber link ball studs do poke out the bottom of the hole.

Paraletic-yes get the JRXS spool pulley. You need that extra surface area and flat plastic.

I will mention this. With a solid spool, when you hit a board and lock up a front wheel, all the driveline inertia, including the motors which is considerable, is suddenly stopped. You tend to break outdrives and bend dogbones. With a clutch type of spool the inertia is dissipated by slip in the diff much like in a ball diff front end. Your parts stay intact. I am surprised how well my front outdrives are holding up with a 3.5 on board. I run the JRXS spool pulley with steel discs and bearings.
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Old 11-26-2009, 08:38 PM   #126
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well everything is ready to go! but mother nature says "no go". i got a chance to put around for 5 minutes then the heavens opened. from what little time i had on the car..... i'm gona go ahead and "borrow" the threaded shocks from the pro3 and fit em on the losi. those fat clamp stlye shocks urk me.

hopefully in about 3 or 4 weeks we'll have an indoor carpet track to play on. hope they have a rubber tyre class as promised.
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Old 11-26-2009, 10:39 PM   #127
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Thanks for the post.

I have a spare Losi XXX-S for sale. It is a spare. The thread will continue.
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Old 11-28-2009, 05:30 PM   #128
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Drizzled out the Saturday session. The spare Losi found a new home.

So my Nephew goes to see the Warren Thomas knife shop and he gives him this knife! It is a compact 4 inch blade knife for those not so frequent RC cutting chores. Titanium blade, graphite handle, titanium anodized pattern AND a tungsten carbide cutting edge welded to the titanium! Wow. Thought you might want a peek.
Attached Thumbnails
LOSI XXX-S, Tips and Tricks, Open Mod, etc-warren-thomas-knives-002.jpg   LOSI XXX-S, Tips and Tricks, Open Mod, etc-knives-004.jpg  
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Old 11-29-2009, 07:21 AM   #129
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Default Kind of repeating myself but..

Kind of repeating myself but..

For me the biggest plus for the XXX-S
is the availability of used vehicles(E-bay and elsewhere) for well under $100.

1. For $60 to $80 I can get a complete roller and thus a duplicate for every part.

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I set up a complete backup car with my older ESC and 27t stock motor. During practice times,at the track on race day, I run this car. It allows me to get familiar with the track and work on my hand eye coordination without putting additional wear on my primary car or risking a crash which would disable my primary car.

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One thing which has helped my vehicles reliability is extending and reinforcing my front bumper. You can buy or make a flat piece of plastic to replace the stock bumper insert(piece that goes over the foam. I have one above and below the foam. I also use a brace that connects the two front body posts directly to the front diff cover. I also have glued two pieces of stiff foam rubber to the side of the chassis just behind the front wheels(the ide is to protect the suspension if I slam into the rail sideways.
The beefier bumpers add some weight but when running lipos you have a some weight to play with.
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If I was rich and in the upper quarter of drivers skill wise, I might be tempted to buy a new X-ray T3 or similar vehicle, since I am in the lower quarter skill wise, a newer car seems like a waste of money.
As long as used XXX-S are available for cheap spare parts, I will stick with this platform.
What makes this even a more viable option is the fact that a knowledgeable individual (Mr. Stranahan) is actively experimenting with this chassis and updating the setups and adjustments. Thanks again John for this thread and your efforts.
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Old 11-29-2009, 06:41 PM   #130
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I'm a knife guy and that's one good looking tooth. lol


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Drizzled out the Saturday session. The spare Losi found a new home.

So my Nephew goes to see the Warren Thomas knife shop and he gives him this knife! It is a compact 4 inch blade knife for those not so frequent RC cutting chores. Titanium blade, graphite handle, titanium anodized pattern AND a tungsten carbide cutting edge welded to the titanium! Wow. Thought you might want a peek.
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Old 11-30-2009, 03:37 PM   #131
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thanks guys for the posts. Thanks for the bumper tips. I don't have any grams to spare though. Mine is still stock to meet 1425 grams.

Shocks, Setting different Bump and Rebound
Little by little I am improving the car to suit my tastes. The last thing I worked on is the shocks. Here is a pic. Stormer had in stock the threaded bodies with adjustable collars. The stock clamping collars work OK once you learn your lesson and use a very light touch on the clamping screws. The thread collars are much nicer when you have the car on the tweak staion adjusting tweak. Four threaded shock bodies $34. The shocks were in good shape at this point. The oil was clean.

People try to do a lot of things with the shocks. I concentrate on one thing. I want the shocks to keep the tires on the ground over the bumps as much as possible. Things like turn in, stability, responsiveness, I tune with springs and swaybars.

One thing that improves the shocks ability to keep the rubber on the road is a different bump and rebound setting. I like the tires to go up easily from a bump so the chassis is not disturbed, rebound is a little slower to keep the overall damping at a good rate.

I had some discussions on the web with a hydraulic engineer. He said this is easy to achieve with a jet of fluid passing through an orifice. You simply bevel the entrance hole where you want fluid entry eased and leave the other side alone. For me this means put a tiny .010 inch bevel on top of the piston holes. As the piston goes up, shock damping is less. As the piston goes down the oil leaves the orifice in a narrow jet. It is unaffected by the bevel. Rebound is unnafected. Overall damping is somewhat reduced, though. I have found a 5 weight increase in oil compensates for this. I used 40 weight with the RTR black pistons. Four holes in the back. Three holes in the front.

Anyway, If you notice your car dancing accross the top of the bumps you might try this shock mod to increase forward traction. Also evaluate whether that kickup in the front or antiquat in the back is really doing you any good. These two latter setting can cause the same problem.

CARBIDE
Also nice additions Carbide diff balls LOS A6951
Carbide Thurst Balls !!! LOS 3098
You have not felt a smooth diff until you do your first in all carbide.
My diff was toast after 30 very hard runs with a 3.5. It was quite rough. It never failed though.
Attached Thumbnails
LOSI XXX-S, Tips and Tricks, Open Mod, etc-losi-xxx-s-shocks-003.jpg   LOSI XXX-S, Tips and Tricks, Open Mod, etc-losi-jrxs-shock-piston-bevel-001.jpg  
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Old 11-30-2009, 04:20 PM   #132
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Quote:
Originally Posted by John Stranahan View Post
thanks guys for the posts. Thanks for the bumper tips. I don't have any grams to spare though. Mine is still stock to meet 1425 grams.

Shocks, Setting different Bump and Rebound
Little by little I am improving the car to suit my tastes. The last thing I worked on is the shocks. Here is a pic. Stormer had in stock the threaded bodies with adjustable collars. The stock clamping collars work OK once you learn your lesson and use a very light touch on the clamping screws. The thread collars are much nicer when you have the car on the tweak staion adjusting tweak. Four threaded shock bodies $34. The shocks were in good shape at this point. The oil was clean.

People try to do a lot of things with the shocks. I concentrate on one thing. I want the shocks to keep the tires on the ground over the bumps as much as possible. Things like turn in, stability, responsiveness, I tune with springs and swaybars.

One thing that improves the shocks ability to keep the rubber on the road is a different bump and rebound setting. I like the tires to go up easily from a bump so the chassis is not disturbed, rebound is a little slower to keep the overall damping at a good rate.

I had some discussions on the web with a hydraulic engineer. He said this is easy to achieve with a jet of fluid passing through an orifice. You simply bevel the entrance hole where you want fluid entry eased and leave the other side alone. For me this means put a tiny .010 inch bevel on top of the piston holes. As the piston goes up, shock damping is less. As the piston goes down the oil leaves the orifice in a narrow jet. It is unaffected by the bevel. Rebound is unnafected. Overall damping is somewhat reduced, though. I have found a 5 weight increase in oil compensates for this. I used 40 weight with the RTR black pistons. Four holes in the back. Three holes in the front.

Anyway, If you notice your car dancing accross the top of the bumps you might try this shock mod to increase forward traction. Also evaluate whether that kickup in the front or antiquat in the back is really doing you any good. These two latter setting can cause the same problem.
John you know that effect is waht it called "Pack" created by turbulence of the oil on movement.

the Pack does makes diffrence on car handling and that's why we carry diffrent holes pistons.

I see you countersunk on #55 piston and that probably do same eefect as just changing to a #54 piston.
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Old 11-30-2009, 06:50 PM   #133
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Also nice additions Carbide diff balls LOS A6951
Carbide Thurst Balls !!! LOS 3098
You have not felt a smooth diff until you do your first in all carbide.
My diff was toast after 30 very hard runs with a 3.5. It was quite rough. It never failed though.


Not sure if you have heard of them but BFast diff products
very nice feel super smooth
mite be what u like
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Old 11-30-2009, 07:35 PM   #134
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Pack
I have to disagree. Pack is created by the resistance of the oil flowing through a small diameter hole. Not by turbulence. Pack is affected by oil viscosity and hole size. Pack on the losi shock is the same for uptravel and down travel. Now how to change that. You put the bevel on top of the holes to ease up travel and keep downtravel the same. The effect cannot be duplicated by going to bigger holes as then you will have eased uptravel and downtravel. There have been tricky shock designs to do change the uptravel to downtravel proportion. Full size racing car shocks accomplish this with two separtate valves. Often a 60/40 ratio is selected. 40 for uptravel. We can do the same with a little bevel.

Shock pack certainly affects the handling. I think that often racers will use this to their detriment. The want the car to respond quick so they increase shock oil viscosity. All the while the car is now dancing over the bumps and losing 10% of its forward traction. So do this without going to extremes. A hard smooth track can handle high viscosity oil. A rough outdoor track cannot. You end up tuning to the bumps like I said.

I will check out those diff products. A link would be nice.
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Old 11-30-2009, 09:11 PM   #135
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John

Are you able to add a touch of kick up to the front suspension arms? I'm running a Pro4 with 4 deg hubs and i noticed a bit more steering on corner exit by adding a .5mm shim to create some kick up. I figured that was easier to try at the track instead of going to 6 deg hubs.

That being said though, our track is very tight and technical so you probably won't need any more steering than what you have.
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