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Old 12-15-2008, 01:52 AM   #3676
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Good day!

I have this problem with the rear traction of my car, coming out of turn going to the straight the rear end tends to lose traction. im racing on asphalt, medium grip, mildy technical track. can anyone please help me to overcome this problem.

My settings:
running 11.5T brushless motor.
rear toe: 2.5 deg
Swaybar: Front: soft, Rear: soft
oil: muchmore 400, F and R.
Spring: tamiya red Spring F and R
spool

Thanks in advance.
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Old 12-15-2008, 02:30 AM   #3677
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First, I'd try stiffer springs. Try out blue fronts with yellow rears or white fronts with blue rears.
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Old 12-15-2008, 02:44 AM   #3678
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Quote:
Originally Posted by danjoy25 View Post
So is the pic below correct if the set up sheet says 5mm rear droop.
Hi Danjoy,

I read Jun's droop measurement guide and whilst it would be accurate, it is a long way round to get your droop. I've found this to be the simplest way of measuring my droop and you can do it anywhere.

First set your arms to a "droop gauge" so they have equal travel. Do this without the shocks and bars attached. Then to make sure your arms travel equally with the bars attached, re-attach them and then adjust accordingly. Once you have done this, you shouldn't have to do it again at the meet, unless you cop a big hit or have the time to recheck it all. Then once happy, re-attach your shocks, replace you rims/tyres and set your ride height. From this point all you need to do to adjust is the following, so you could do the above at home, then at the track, even if you want to change droop, just do the following. With the car at rest, push down on the car evenly to settle, then measure from the board to the bottom of your chassis in the centre of either the rear or front. Then, lift the car until the wheels just lift off the board, then measure this the same way. The difference between your rest height and when the wheels lifted is your droop setting. Your wheels will always lift equal as you have pre set them via your guage earlier, all you do now is screw in or out the set screw and you can change droop on the fly.

Droop is as it say's, the droop in your suspension arms as the chassis rises. Some call it downstop.

It's not super accurate for those that need to be mm perfect, but it doesn't have to be, no human could tell if your droop was .5 of a mm out side to side, so it is commonly payed much to much attention, just make sure you have even travel and the tyres leave the board evenly. It is an important setting as it can make big changes to handling, but half a mm out is undetectable. This method allows you to quickly make changes to get sets ups and is accurate enough.

Cheers
Aaron
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Old 12-15-2008, 07:14 AM   #3679
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Originally Posted by John St.Amant View Post
not only that but then are your shocks allowing the full droop as well?
Generally the shocks will be long enough to allow for full droop. If you cant pull the shock end cup past it's mounting ball on the arm after you've set the droop then just unscrew the end cup a bit. Unless you were running a ton of droop this won't be a problem though.
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Old 12-15-2008, 08:17 AM   #3680
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hi do you know the number parts for the new tamiya springs that was used in thailand
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Old 12-15-2008, 09:53 AM   #3681
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Originally Posted by Nuno Gancho View Post
hi do you know the number parts for the new tamiya springs that was used in thailand
HPI Silver or blue
http://rcmarket.com.hk/index.php?cPa...sort=2a&page=7
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Old 12-15-2008, 11:39 AM   #3682
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Quote:
Originally Posted by zacabrandy View Post
Hi Danjoy,

I read Jun's droop measurement guide and whilst it would be accurate, it is a long way round to get your droop. I've found this to be the simplest way of measuring my droop and you can do it anywhere.

First set your arms to a "droop gauge" so they have equal travel. Do this without the shocks and bars attached. Then to make sure your arms travel equally with the bars attached, re-attach them and then adjust accordingly. Once you have done this, you shouldn't have to do it again at the meet, unless you cop a big hit or have the time to recheck it all. Then once happy, re-attach your shocks, replace you rims/tyres and set your ride height. From this point all you need to do to adjust is the following, so you could do the above at home, then at the track, even if you want to change droop, just do the following. With the car at rest, push down on the car evenly to settle, then measure from the board to the bottom of your chassis in the centre of either the rear or front. Then, lift the car until the wheels just lift off the board, then measure this the same way. The difference between your rest height and when the wheels lifted is your droop setting. Your wheels will always lift equal as you have pre set them via your guage earlier, all you do now is screw in or out the set screw and you can change droop on the fly.

Droop is as it say's, the droop in your suspension arms as the chassis rises. Some call it downstop.

It's not super accurate for those that need to be mm perfect, but it doesn't have to be, no human could tell if your droop was .5 of a mm out side to side, so it is commonly payed much to much attention, just make sure you have even travel and the tyres leave the board evenly. It is an important setting as it can make big changes to handling, but half a mm out is undetectable. This method allows you to quickly make changes to get sets ups and is accurate enough.

Cheers
Aaron
If my droop is off by a half mm in front , my car turns away from the down side under acceleration , and visa versa in the rear. If you cant feel it I would suggest that you have far too thick of oil in your shocks. I doubt you are using a far too soft spring. Maybe thats just me pushing the car but ... I feel a mal adjusted droop
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Old 12-15-2008, 11:45 AM   #3683
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I measure droop using a gauge under the A-arm, with both shocks and screws attached. Now, as I don't use blocks (I use a gauge that rests under the chassis) I can knock out the effects of the shocks/sway bars by pulling lightly down on the arms until they are resting on the droop screw. I hate with a passion using the lift technique, simply as too my mind it's too inaccurate, as you can't take into account any differences with tyre diameter caused by air gaps, and your relying on judgement (never good IMO) to tell when the car is off the ground. Having said that, if it works for you, fair enough

As Randy points out, your shocks should be long enough to allow for the full droop. This was a real probem on the first 415, where if you wound the shock end in all the way, you couldn't get the enough droop in the car. As a general rule of thumb, I tend to build my shocks between 61.5 and 62mm in overall length, this gives enough range to go down to 3mm on a gauge.

As for the sway bars... I actually use the droop gauge to set them up as well Basically, I'll set the drop links up equal length, then remove the shocks, and make sure the arms drop freely, and then set the droop eqaul on both sides. Then, with the bars mounted (as central as possible obviously ) I'll then raise one arm up using the steps on the droop gauge, until the opposite arm just starts to rise up. I'll note the figure, and then repeat on the other side... and then adjust the links until the arms raise the same amount each side.
For example if the left arm starts to rise when the right arm is on 7, but the right arm raises when the left arm is on 9, I'll either lengthen the the right hand link (to make the left amr raise on a bigger number) or shortern the left hand link (to make the right arm raise on a lower number).
I know it sounds complicated, but after a few goes it actually becomes fairly easy to figure out. It's the most easily repeatable (with reasonable accuracy) way I've found to get the bars equal side to side.

I'll try and get some pictures up, but unfortuantly my camera is bust so awaiting christmas to get a new one

HiH
Ed
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Old 12-15-2008, 11:54 AM   #3684
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Not complicated Ed. Just exactly how it should be done!
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Old 12-15-2008, 01:29 PM   #3685
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Quote:
Originally Posted by TryHard View Post
I measure droop using a gauge under the A-arm,...
Crap! I've been running too much droop then, as I've been measuring to the bottom of the actual pin itself...
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Old 12-15-2008, 01:44 PM   #3686
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Originally Posted by TRFwhitey View Post
...........
Now some may wonder, "how can I fine tune rebound with a vent hole?". You can do this by purchasing, making(cutting those crappy red foam pieces included in your shock baggies), or using left over o-rings from the build to adjust the space between the cap and bladder to give you the desired effect.
Cheers!
Your setup sheet indicated no foam or o-ring between cap and bladder.
Correct?

Which class (motor size) did you race with this setup? Mod?

...
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Old 12-15-2008, 03:12 PM   #3687
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Stein, unfortunately it was 13.5... This is fastest rubber tire class they run on carpet at any race here in north america other than the IIC. I only ever practice with mod, I rarely have the chance to race it. This setup is very close to my mod setup anyways, main difference was my dual-rate was about 10% less lol. As for the shocks you are correct, I ran no pieces between the cap and bladder. I highly recommend this setup for almost any grip level!
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Old 12-15-2008, 03:18 PM   #3688
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Just to give you an idea of 13.5 vs mod(rubber), lap time spread between the two on this track are only around .3-4 sec
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Old 12-15-2008, 03:31 PM   #3689
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Corey: Do you drill the hole on the top of the plastic portion or on the side of the alloy cap?
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Old 12-15-2008, 05:02 PM   #3690
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It would have to be in the plastic portion on top. This vents the upper air chamber to the atmosphere. A hole in the metal cap wouldn't do anything...

BTW: As far as I know, this vented shock cap was pioneered by Tamiya with the 1988 release of their aluminum "High-Cap Dampers" (short & Mini) for off-road. These alloy shocks have a hidden vent hole where the upper 6mm ball fits into the cap. I always thought this was an interesting effect. Those dampers were incredibly smooth and seem to perform rather well on my vintage buggy. They were later replaced by a Teflon sleeved aeration damper that's more similar to the modern 501X dampers...

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