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Old 11-07-2014, 11:25 AM   #5776
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Default Joren Neumann

Dear Xray, there is a free agent hotshoe you should pick up to replace Renaud! Sign Joren Neumann (ex-Durango) now!
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Old 11-07-2014, 03:23 PM   #5777
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So I've narrowed my issue down to the front end being too soft and/or too much weight transfer to the front of the car. To recap, we run on a super high bite wet clay track with slicks. My car has soo much front grip, that the rear can't stay planted. The car is incredibly darty and can turn inside a dime. On hard braking even with 40% brake, the car almost endos as the front end collapses. The front of the car drives soo hard, it just slings the rear around behind it.

I've been running the 3 dot spring and sway bar up front and the 2 dot spring and sway bar in the back with 19mm ride height front and rear. So last night in a desperate attempt to take grip away from the front and since I didn't have the newest 4 dot front spring, I just kept cranking down the collar and raising the front ride height . . . bingo! the car still had good steering, but the weight stayed on the rear and took that dartiness away. The braking was greatly improved too as the car didn't lurch forward and get squirelly. It tracked straight and controllable when hard on the brakes. I kept cranking down the collar until the car actually began to get worse and then backed it off and measured. My issue is that I'm running 24mm front ride height and 19mm rear ride height. This can't be good right?

What else can I do to keep the weight rear-ward most of the time and be able to lower the front ride height a bit? I assume the heavier spring will help a little, but what else?

More front droop and less rear droop?
Less front kick-up?
Heavier front oil and/or smaller hole pistons?
Less Anti Squat?
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Old 11-07-2014, 04:19 PM   #5778
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So I've narrowed my issue down to the front end being too soft and/or too much weight transfer to the front of the car. To recap, we run on a super high bite wet clay track with slicks. My car has soo much front grip, that the rear can't stay planted. The car is incredibly darty and can turn inside a dime. On hard braking even with 40% brake, the car almost endos as the front end collapses. The front of the car drives soo hard, it just slings the rear around behind it.

I've been running the 3 dot spring and sway bar up front and the 2 dot spring and sway bar in the back with 19mm ride height front and rear. So last night in a desperate attempt to take grip away from the front and since I didn't have the newest 4 dot front spring, I just kept cranking down the collar and raising the front ride height . . . bingo! the car still had good steering, but the weight stayed on the rear and took that dartiness away. The braking was greatly improved too as the car didn't lurch forward and get squirelly. It tracked straight and controllable when hard on the brakes. I kept cranking down the collar until the car actually began to get worse and then backed it off and measured. My issue is that I'm running 24mm front ride height and 19mm rear ride height. This can't be good right?

What else can I do to keep the weight rear-ward most of the time and be able to lower the front ride height a bit? I assume the heavier spring will help a little, but what else?

More front droop and less rear droop?
Less front kick-up?
Heavier front oil and/or smaller hole pistons?
Less Anti Squat?

dont use front slicks. use a ghost pinned tire or something with some tread to take away some the steering/ dartyness

what pistons are you running? whats your oil weight? what size sway bars?
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Old 11-07-2014, 05:38 PM   #5779
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dont use front slicks. use a ghost pinned tire or something with some tread to take away some the steering/ dartyness

what pistons are you running? whats your oil weight? what size sway bars?
Front piston is the 3 hole 1.3 with 45 wt AE oil. I just bumped it up from 40wt but haven't tried it yet. Front sway bar is a 3 dot.
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Old 11-07-2014, 06:19 PM   #5780
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Wease - it'd be a lot easier to help ya out if you posted your complete set up all in one post...

...and no, 24mm front and 19mm rear ride height is not what you want. Cranking down on the spring collars does not increase the spring rate - it only changes the ride height.

For some reason, the XB4 uses a fairly stiff front end and what seems like a really soft rear end to be fast. If you only have the kit pistons, try this Tyler Vik set up:
http://www.petitrc.com/setup/xray/se...CRC2014012426/

...I bet switching to one dot rear springs (or anything that's 2.00lbs, like TLR yellow or AE green - they work too) would help right away. Your oils need to be at least 10wt-12.5wt apart as well (ie. 40wt front, 27.5wt rear).
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Last edited by HeavyD99; 11-07-2014 at 06:53 PM.
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Old 11-08-2014, 07:05 PM   #5781
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It turns out it was my slipper being too tight! I tried every combination of springs, sway bars, diff fluids, camber links, shock positions, etc., and nothing would stop the twitchiness and grabiness of the front end. I was watching the AE guys with their new B44.3 cars change the suggested 100K center diff fluid out for 60K all day at our track. So I thought, why don't I try loosening my slipper. The manual says the distance between the shoulder and the spring collar should be between 5.0 - 6.3mm and I had mine at 5.2mm. I never could hear my buggy slip so what did I have to lose. Each round I loosened the slipper and each round the buggy got easier to drive. Right before the main my slipper was at 6.39 mm and I loosened it to 6.59mm. That might have been just on the loose side, but the buggy was pretty hooked up front and rear and that was on a dusty track. The only reason I thought it might have been a little loose was because I had trouble clearing this triple right after a hard 180 with no run at the jump lip.

So it seems the problem was that with each punch of the throttle, full power was going to both the front and rear of the car with most of the power going to the front yet still diffing out the rear of the car.

As you can see, my car's ideal slipper setting was outside the range specified by the manual. Could this be the reason some guys are roaching their diff gears even though they have their slipper setting within the range specified by the manual? For me anyway, the manual suggestion was too tight for my high traction track.
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Old 11-08-2014, 09:03 PM   #5782
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The manual says 5.5-6.2 for the slipper adjustment.

This is ONLY a recommendation. Each car is different from the next. On high bite with new pads and spring I was at 6.79. Now you know why people blow out their bevel gears by not adjusting their slippers properly
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Old 11-09-2014, 04:14 PM   #5783
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The manual says 5.5-6.2 for the slipper adjustment.

This is ONLY a recommendation. Each car is different from the next. On high bite with new pads and spring I was at 6.79. Now you know why people blow out their bevel gears by not adjusting their slippers properly
Is there a way to bench test the slipper on the XB4? On a 2wd buggy you can hold both rear wheels and blip the throttle to see if the slipper slips or the front wheels rise. I don't suppose that's going to work on a 4wd without damaging the drive train.
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Old 11-09-2014, 04:46 PM   #5784
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Is there a way to bench test the slipper on the XB4? On a 2wd buggy you can hold both rear wheels and blip the throttle to see if the slipper slips or the front wheels rise. I don't suppose that's going to work on a 4wd without damaging the drive train.
Tyler Vik says he adjusts his slipper on his XB4 the same way people do it on a 2wd vehicle, hold the read wheels and blip the throttle. It's posted somewhere on here.
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Old 11-09-2014, 05:23 PM   #5785
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Anyone have any experience with the Dhawk carbon chassis? Thinking about buying one, but not sure if there is an advantage (more flex) to be gained other than less weight and $$ in my pocket...
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Old 11-09-2014, 06:28 PM   #5786
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Default xb4 2015??

just wondering when the xb4 2015 edition will be out. anyone know? Anyone, ANyOne, come on anyone out there know, ANYONE ???

just saying xray. you released a teaser weeks upon weeks ago. im not asking you to release the damm kit tomorrow, but give us the specs and atleast a release date.

anyways that's my rant. hopefully someone at xray understands that staying in contact with your customer's is key in this hobby
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Old 11-09-2014, 06:56 PM   #5787
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+10000
I'm waiting !!!!!!!!!!!!!!!!!!
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Old 11-09-2014, 07:16 PM   #5788
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I'm waiting 2..... come on xb4 2015
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Old 11-09-2014, 08:16 PM   #5789
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Anyone have any experience with the Dhawk carbon chassis? Thinking about buying one, but not sure if there is an advantage (more flex) to be gained other than less weight and $$ in my pocket...
I'm curious about them as well. I'd imagine they'd provide more flex, naturally, than the Xray aluminum chassis. I'd prefer the aluminum for indoor carpet, but for outdoor clay, it might be nice!

Let us know how you like it if you get one.
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Old 11-09-2014, 08:47 PM   #5790
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Anyone have any experience with the Dhawk carbon chassis? Thinking about buying one, but not sure if there is an advantage (more flex) to be gained other than less weight and $$ in my pocket...
There is more flex for sure(but I dont run saddle battery straps either). Its roughly 34 grams lighter.

Also waiting on the 15 gear diff.. Cant seem to dig up one that will fit.
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