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Old 09-29-2009, 10:55 PM   #6721
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Evening all...

So after part of my conversation with Randy was over setting up a car for lower LiPo weight (1350g is rumoured for BRCA/EFRA), so here we go... no phaffing with a scales or stuff, just a MIP tweak board.

First up, I set the car up with tie-rods instead of shocks (set equal L-R, and on the ends to give the right ride height) so I can get the weight balance sorted. Technically, this is setting the FR/RL and FL/RR cross-weight... but does the trick.
First two pic's show thats it's equal side to side when using the solid links instead of shocks. This is with the cells hanging over the edge the amount in the forth pic. I did try it with the cells in the usual slots, and suprise suprise, the weight was well off to the motor side

Next two pics are with it with shocks on... as you can see, spot on. Only change I had to make was one full turn on the RL shock collar. Supports the thinking that this is the heaviest side... so any extra lead I need to put on the car to get too 1350g (and I will need too, I'm pretty sure... got to 1400g with 60g of lead and a heavy motor fan recently!) will be going behind the cells to help, probably on the outside.

Some things to note... Cells can be tapped in happily using current slot, without obscuring the negative terminal...just! It's a little wobbly in the car atm, but I'm going to make up some light weight carbon locators for the bottom of the cells to hold them in place better
Also, with the cells out so far its now possible to access the bottom motor screw without removing the cells

So there we go, thats what I'll be running...

HiH
Ed
so I just started messing with the balance of my car and I have a few questions.

Does adding weights to the outside of your battery or pushing the battery out over the edge of the car negatively effect handeling. I dont have alot of racing experience and im a pretty slow 17.5 driver so I dont really know.

Next question
As stated in a previous post I trying to balance my car using a saddle pack. I flipped my belts to give me better balance with the motor side saddle.
To flip the belts I had to mount the diff in spool in the high position (by rotating the eccentric) does mounting the spool and diff high negatively effect handeling?





I guess I just wanted to throw something out here for consideration.

When we are balancing our touring cars using tweak stations or scales we are measuring the the relative static weight (force) on each tire. However when we are driving our cars the force on the tires is being applied my moving weight. When the weight of our chassis moves (rolls) it develops momentum and inertia. This inertia is effected by both the amount of weight on each tire (what we measure) and the placement of that weight which I think we dont measure (I think this is called the polar moment of inertia but I dont really know). The further that weight is away from the center of the chassis the more resistant it is to rolling.

I guess an extreme wey to put it is ;
You could balance your lipo touring car with only one gram if you somehow mounted that gram a foot off your chassis. However this one gram balancing weight would be much worse than balancing with 50g near the center of your chassis because of how it effects the cars moment of inertia?

Just wondering if anyone has done any testing on this or if Im just way over thinking balancing my car
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Old 09-29-2009, 11:18 PM   #6722
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Just a question on the split suspension blocks

Are you running them on both the FF and FR , RF and RR or only on one of them?
Chris, I'm only using mine FR. This is where they are most needed. But you can also use them at RF.
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Old 09-29-2009, 11:37 PM   #6723
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Originally Posted by wstuart View Post
so I just started messing with the balance of my car and I have a few questions.

Does adding weights to the outside of your battery or pushing the battery out over the edge of the car negatively effect handeling. I dont have alot of racing experience and im a pretty slow 17.5 driver so I dont really know.

Next question
As stated in a previous post I trying to balance my car using a saddle pack. I flipped my belts to give me better balance with the motor side saddle.
To flip the belts I had to mount the diff in spool in the high position (by rotating the eccentric) does mounting the spool and diff high negatively effect handeling?





I guess I just wanted to throw something out here for consideration.

When we are balancing our touring cars using tweak stations or scales we are measuring the the relative static weight (force) on each tire. However when we are driving our cars the force on the tires is being applied my moving weight. When the weight of our chassis moves (rolls) it develops momentum and inertia. This inertia is effected by both the amount of weight on each tire (what we measure) and the placement of that weight which I think we dont measure (I think this is called the polar moment of inertia but I dont really know). The further that weight is away from the center of the chassis the more resistant it is to rolling.

I guess an extreme wey to put it is ;
You could balance your lipo touring car with only one gram if you somehow mounted that gram a foot off your chassis. However this one gram balancing weight would be much worse than balancing with 50g near the center of your chassis because of how it effects the cars moment of inertia?

Just wondering if anyone has done any testing on this or if Im just way over thinking balancing my car
From memory, rotational moment = force x distance. So to achieve the same moment with 50g and 100g, your 50g will need to be twice as far from the centerline. However, you are carrying 50g less which means better acceleration and braking. There is probably a better, more correct way to analyze this but this is good enough (and simple enough) for me...

A few things to watch out for when flipping you diffs:
1) The spool cups will probably rub on the bottom of the top bulkheads if you run them high.
2) Running the diff high causes more roll as the weight is higher.
3) If you run the diffs low, you will need to dremel some clearance holes for the diff pulleys.
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Old 09-30-2009, 03:14 AM   #6724
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Originally Posted by TryHard View Post
So after part of my conversation with Randy was over setting up a car for lower LiPo weight (1350g is rumoured for BRCA/EFRA), so here we go... no phaffing with a scales or stuff, just a MIP tweak board.
(...)
Ed
Thanks for the photos etc! Looks pretty good. How well are the cells held in like that?

It looks like the STCC will go to 1425g next year... I know over the Winter us at Eversley will have the limit at 1450 (same for Rug Racers I believe), and Carpet Wars I think will follow whatever happens at the BRCA AGM. Going to try to balance my car up at 1425 this week, see what I get!

Come and do Eversley I think we're now the largest temporary indoor carpet track in the UK
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Old 09-30-2009, 01:51 PM   #6725
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Thanks for the photos etc! Looks pretty good. How well are the cells held in like that?

It looks like the STCC will go to 1425g next year... I know over the Winter us at Eversley will have the limit at 1450 (same for Rug Racers I believe), and Carpet Wars I think will follow whatever happens at the BRCA AGM. Going to try to balance my car up at 1425 this week, see what I get!

Come and do Eversley I think we're now the largest temporary indoor carpet track in the UK
Hehe... I would like too, but it's just too far to travel with doing the wars too

1350g is *hopefully* what the wars will run too, I know there was a lot of discussion at the last national about going down to that weight. Grainger even ran his 6.5LiPo car at that weight in the last final to prove a point, it was a little quicker, but not hugely so. Lower powered motors shoudl see a bigger benefit...

Cells hold in ok, a little wobbly. I'm going to get some carbon locators made up at work to keep them in better, just need to stop them moving around slightly. Tape wise it's fine

Ed
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Old 10-01-2009, 10:44 PM   #6726
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has anyone tried these on there 416 yet
http://store.hkshobby.com/product_in...112a5903ec0cca
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Old 10-01-2009, 11:07 PM   #6727
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I've been waiting for some feedback on those as well. The main issue with the LCD style driveshafts is that if they aren't extremely tight on their tolerances, and have little to no slop in their universal joints, they will make the car push badly.

I'm just skeptical I guess..
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Old 10-02-2009, 10:41 AM   #6728
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has anyone tried these on there 416 yet
http://store.hkshobby.com/product_in...112a5903ec0cca
get off COD:WaW and go try em. and give us feedback.
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Old 10-02-2009, 12:02 PM   #6729
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get off COD:WaW and go try em. and give us feedback.
hey i have only played the game for 25 days
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Old 10-02-2009, 12:38 PM   #6730
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has anyone tried these on there 416 yet
http://store.hkshobby.com/product_in...112a5903ec0cca
I've run them once and they worked without issue but I haven't inspected them closely since that run for wear. I like that I can take them apart and lube them. They seemed to work smoothly. I didn't feel them bind at all. Durability is something only time will tell
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Old 10-02-2009, 01:06 PM   #6731
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hey i have only played the game for 25 days
25 days straight?

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I've run them once and they worked without issue but I haven't inspected them closely since that run for wear. I like that I can take them apart and lube them. They seemed to work smoothly. I didn't feel them bind at all. Durability is something only time will tell
did someone say durability? give em to me... im a great durability tester.
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Old 10-02-2009, 11:59 PM   #6732
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25 days straight?



did someone say durability? give em to me... im a great durability tester.
This is true. Chris blows out all the time!
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Old 10-03-2009, 01:47 AM   #6733
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Im trying to set up my sway bar I wanted to know if anyone can help me.
My question is how long should the front and rear sway links that connect to the lower arms
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Old 10-03-2009, 02:08 AM   #6734
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Im trying to set up my sway bar I wanted to know if anyone can help me.
My question is how long should the front and rear sway links that connect to the lower arms
Mine measure at about 23mm front and rear, measured centre ball-centre ball. Start somewhere around this size but then don't forget to set them properly!
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Old 10-03-2009, 08:14 AM   #6735
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Im trying to set up my sway bar I wanted to know if anyone can help me.
My question is how long should the front and rear sway links that connect to the lower arms
I leave about 4mm of the bar sticking through on the rear, and 1mm sticking through on the front. Getting them set tight with no bind but as little play as possible is very important. Once you do that set the droop on the car and then adjust the swaybar turnbuckles so that they lift the arms evenly.
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