mcion

iTrader: (32)

I can tell you for me personally so far, The car has been awesome. Same track gained about 1 sec on laptime, the reason I know is because my old car I could not dip in to 29sec range, like 30.3, 30.1 and that was sometimes never a 29 sec lap though. Now I'm running 29's like nothing with a fast time of 29.1. Averaging probably mid 30 sec laps though. The main reason why, is the buggy is allowing me to push harder and in turns that i had to steer at angles and balance power, i have been able to power thru them without letting off the throttle. We shall see this weekend though, first race with it.

HH

iTrader: (3)

Its actually not two separate approaches as it is required to do both.. mount the engine at a slight angle as dictated by the motor mount slots machined into the chassis as well as removing some material from (chamfer) the inside rear corner of the engines crankcase to ensure there is no contact with the driveshaft.


I'm really happy with my current shock setup which is a fairly typical one here in the US for most buggies although not so much for most of the XRAY setup sheets I've looked at...

front: 35wt Losi, 1.3-8 hole pistons, 50% rebound, stock XB9 springs, 103mm c-c, hole #3 on tower, #2 on arm, 28mm ride height.

rear: 27.5wt Losi, 1.2-8 hole pistons, 50% rebound, stock XB9 springs, 113mm c-c, hole #3 on tower, #1 on arm, 29mm ride height.

I've been testing/dialing in my XB9 at Thunder Alley Raceway here in So Cal preparing for round #1 of the 2012 JBRL Nitro Series. This track has a grip of elevation changes with a lot of big air jumps and a couple of lengthy washboard sections (fun, fun, fun) . The above setup has been working awesome with 5-7-2 in the diffs on what I would call a very "US style" track.

mcion

iTrader: (32)

Unless you know magic that setup especially with the super soft springs will bottom out or chassis slap. I personally could never get away with running that low oil weight with those pistons and springs on the tracks I run at.

Brandon A

iTrader: (1)

Just out of curiosity, does anyone know off hand what tank plug (if any) you need to run to make the XB9 ROAR legal? I believe Xray increased the tank volume from what they had on the 808 series. Thanks.

HH

iTrader: (3)

Hmm.. Hasn't been a problem so far.

I was given my current setup by Travis Amezcua with the only change being that I went with 27.5wt in the rear rather than the recommended 25wt.

Most of the XB9 setup sheets that I've looked at called for either the same size pistons or larger holes in the rear. So its possible the reason that it works is due to the fact I'm running the 1.2 pistons in the rear which create more pack when landing jumps or hitting the washboards at speed etc.

Here is a link to a short video of JQ on Thunder Alley Raceways current layout.

mcion

iTrader: (32)

I have looked at other setups and they run opposite with 1.2x8 front 1.3x8 rear. And the oil are like 52.5 and 45 versus what you are proposing plus stiffer springs. Hey if it works it works but I tried a 6 hole piston with oil slightly higher and bottomed out especially with those springs.

rc-goods

Zero Force Xray XB 9 Bearing kit set (18pcs) (ZF-B11004)



www.rcgoods.com

smyka

i have been running

1.2 front pistons with 35 wt oil and blue grey springs inside hole on arm third out on tower

1.3 front pistons 37.5 blue grey inside on arm third out on tower .

this is with 8 hole pistons all around car soaks up any bump and will correct its self in air really easy
ride height is 27 front 29 rear

HH

iTrader: (3)

Brandon.. The reason XRAY includes two different size plugs is to allow for the fluctuation in total tank volume due to different fuel tubing setups. i.e short tubing w/ no inline filter, longer tubing w/ inline filter, etc.. So unfortunately the only way to be sure is to measure the maximum fuel capacity (tank, tubing, and filters, etc) of your particular setup and then install the plugs as/if required to ensure it is at or below 125cc.

Here is the section from the ROAR Rule Book..

9.2.8 Fuel Tank Specifications:
9.2.8.1 Fuel tanks must be securely mounted.
9.2.8.2 Maximum fuel system capacities are 75cc for .12 engines, 80cc for .15 engines, and 125cc for .21 engines.
9.2.8.3 There are two approved ways to determine the fuel capacity of a vehicle. The first way is by pouring the correct amount into the vehicle's system, and the second way pumps the fuel out of the vehicle's system into a measurement container. The Race Director must ensure that all waste fuel is disposed of properly.
9.2.8.4 To check a tank capacity the first way, drain all fuel from the system including fuel and pressure lines. Pinch off the pressure line at the tank, and disconnect the fuel line from the carburetor. Using a graduated cylinder, measure the proper amount of the driver’s fuel. The graduated cylinder is read at the bottom of the fuel’s meniscus when viewed from the side of the cylinder at eye level. Pour the fuel into the tank, allowing fuel line and filter (if fitted) to fill. The fuel should fill the tank to the top of the filler neck, or to a point where fuel overflows or is forced out when the lid is closed. If it does not, the tank is oversize and a fixed insert must be used to reduce the tank capacity.
9.2.8.5 To check the tank capacity the second way, fill the tank to the top of the filler neck. Make sure all fuel lines are full. Attach a fuel pump or large capacity syringe to the end of the tank-to-engine fuel line. Transfer the fuel completely out of the vehicle's system into a graduated cylinder or another accurate liquid measuring device. (Reading a graduated cylinder is described above, in this rule.) If there is more fuel retrieved than allowed, the tank is oversize and a fixed insert must be used to reduce the tank capacity.
9.2.8.6 A 10 minute cool down period may be allowed for tanks close to the limit (less than 3cc). This decision can only be made by the DRO or Race Director.

mcion

iTrader: (32)

Yea the blue springs are stiffer as the silvers are too soft.

HH

iTrader: (3)

Note: In general..

Thinner viscosity oils require a softer spring to ensure the rebound is not too rapid (like a pogo stick).

-likewise-

Thicker viscosity oils require a stiffer spring to ensure the rebound is not too sluggish.

Given this general rule..

27.5wt with a 1.2-8 hole piston will (does) work well with the silver spring.

-likewise-

37.5wt with a 1.3-8 hole piston is likely to work well with the blue-grey spring.

There is a lot of information that can be found here on RC Tech. Personally I just take what I can use and leave the rest. But you certainly won't ever find me discounting information that others have shared here, especially, unless or until I have first hand experience to the contrary. Nor will I ever be posting any information stating that something works well unless or until I have first hand knowledge through personal experience that it does work well.
I'm just sayin'...

mcion

iTrader: (32)

Lol not discounting at all. I tried it which is why I said personally for me earlier also a friend has tried it at a local track with his xb9 and no dice took off the silvers right away.

HH

iTrader: (3)

Brandon... your question reminded me that at this weekends season opener for the JBRL they require all vehicles to go through and pass a tech inspection prior to every race, qualifiers and mains. With the top 3 finishers from every race being required to go directly to a post race tech inspection where they test the fuel capacity for each vehicle per ROAR Rules.

So to ensure my buggy would pass I went ahead and checked my XB9 which has no tank plugs and no inline filter installed, with the fuel tubing routed exactly as shown on page 38 of the XB9 manual then filled to maximum capacity. The pic below shows the results.

Brandon A

iTrader: (1)

Right on the money! Thanks for the info, running the same fuel system setup as you so I don't even have to check mine now.

oggietiu

iTrader: (7)

Hey marcus, Are you still using the fioroni's? Why is it that it feels softer than it was when I was using it with my AE shocks? Are the shock body of the XB9 Bigger or my piston is done already? I will try the CSI instead. I think those will it also.