Low_E

Same for me, two days ago.
We went to drive on the track of Viol in Germany.
Very high Grip track and I used your setup Sohlman. Except for the ackerman: I only used 3mm and shock-oil: F:50 R:50 and 4mm wheel hexes.
The car had oversteer and the end of a corner.
But I have to admit I tried first without the stabilisers, just to learn what these do, to experience the difference. The car defenitely drove better with the stabs, which softened the car.

Then since I had so much steer, I thought I might as well have tried the Spool ... and this made the car even easier to drive. My times did not actually improve much, ... but at the end of this last run, I discovered that the ball-end-screw on the F bulckhead for the camberlink, sticked out on the bottem and totally ruined the Left outdrive.
So I had been driving quite Ok, keeping up the pace of my friend, experienceing some strange car-reactions .. but hey, I'm learning ... to find out in the end, I had been driving a 3WD-car instead of a 4WD. Not bad I'd say.

I must say, my friend used the Jilles Groskamp-setup. I tried his car and it falt better then mine. Now mine has an excuse (being 3WD) but next time I will try his set-up as well.
And big chance my 416 will keep the Spool in stead of the One-way ... if I get the outdrive fixed

Just to keep learning.

Another question Sohlman:
You mention 50% rebound on your shocks. How do you build/get this?

sohlman

iTrader: (92)

Place the bladder on the shock with oil filled to the rim. Push the bladder in place, oil will seep out. Lightly hold bladder in place and push up on the shaft a bit, more oil seeps out. Then screw on the cap. Test the rebound by pushing the shaft all the way in and measure, by eye, how far the shaft returns. If it returns half way, you're at 50% rebound. If less, add more oil. If more, let some more oil seep out. It takes a bit of practice.

Low_E

ok, got that

and why do you use 50% rebound?
(I always build them to have 100% rebound).
What's the difference on the track?
can't wait to test this and feel the difference.

John St.Amant

iTrader: (1)

rebound affects the "pack" in the shock under compression. there are a few theories about that . since the dawn of bladder shocks has removed the air bubble fron inside the shock body itself, the piston pushes up on the fluid over the piston and compresses the bladder in the shock cap. personally i perfer less rebound as I perfer the spring to return the piston to the static position. Truth is, it is very rare that your shock bottoms out , unless you hit something. Concider pack or rebound like the valving in an automotive strut. basically no rebound means the shock will have damping on the return stroke. 50% return is like having a 75/25 stroke and return. I use much less than that , more like 25% rebound. just a preference i guess. for that matter too much rebound is a recipie for leaky shocks and blown out o-rings .. just try to make them equal.

RC MARKET

iTrader: (12)

TRF416WC ready in Thailand RCS
http://www.rctech.net/forum/rc-marke...ml#post4987902
& Marc R.

94eg!

iTrader: (17)

That explains some things...

I'm new to shock tuning. I've always built shocks with the piston-rod at full extension (as this is how manuals instruct). I always thought that the rod would pop all the way back out after assembly was a good sign of a properly built shock . Of course that only lasted so long, even when simply sitting on the shlef. Looks like this is due to oil being pushed past the seals by internal pressure at ride height...

I suppose your desired rebound setting would really depend on whatever ride height you would be running. My question is would it be desireable to build a shock to have zero oil pressure at "static" ride height? If this was the case, all your compresson damping would have positive oil pressure and all your droop damping would negative oil pressure. How do you think this setting would effect handling?

John St.Amant

iTrader: (1)

The rebound you are all so confused about is almost irrelivant. First of all you never just put the shock shaft all tha way down and cap it. Once the cap is in position and not tightened, slowly push the piston up as u tighten it. Oil will bleed out. Pack or rebound is ONLY going to affect the sudden movement of the piston from full extension to full compression. Your car is only going to experience those extreemes in a collision. And if you have too much rebound (incorrectly built shocks) you will leak oil from either end. If you drive a decent car .... have it set up correctly, the piston isn't all the way down in the body. Or have you forgotten about droop. Everything working correctly the piston should be near the center of its travel. Therefor the 50% rebound is only a vernier to get your shocks equal. Like I said ... I Use less rebound , about 25% . My shocks never leak! Knock on wood.
Ride height is set with spring preload not rebound. Droop limits the "up" travel of the chassis. Or the "down" travel of the arm, however you want to look at it. Rebound wont help "Tune" for any circumstance. Only help make your shocks equal. Ah'ite?!

94eg!

iTrader: (17)

So then I'm correct in thinking you want rebound to be set so there is zero internal pressure at static ride height?

ie: set pistons to the length they will be at ride height before tightening the shock caps...

John St.Amant

iTrader: (1)

If you can.. but that would be 50% rebound. A bit more than I like. So yeah.... ok lol

CraigM

iTrader: (34)

from what I've found, 2mm feels pretty good in most scenarios

Adam?

I might be sold on the notion of a spool being the way to go in this car with a 13.5.

Low_E

Well, i used to drive a One-way in my 416 but wanted to try out the spool.

I had leant my spool to a mate (since running One-way) and he gave me new one in return later when his ordered parts arrived.
I opened the bag, assembled the spool and mounted it into my 416 ... and did a final test-run before hitting home again.
When I took the car off the track we noticed some damage into the cars front suspension, but we had to leave.
Once at home, It was clear that the left-outdrive (plastic) was completely destroyed.
It seemed that Front the Upper Bulckheads touched these outdrives.
+ the ball connector for the camber-link was a tiny bit to lang, sticking out on the bottom, and making some nasty scratches on the metal rings on the outdrives.

On this picture you can notice the scratched metal rings that go over the outdrives + the veeery tight fit.



I disasembled the spool, assembled a new outdrive ... but it's clearly a VERY tight fit.
I allready turned the K-part one notch, to lower the spool a tiny bit, ... but I don't think that this is the solution.
so ... where did I go wrong?

Or did my mate bought the wrong spool? I thought about this, but can't check. I threw away the package at the track. Besides, it's Grooveman, a guy with a GREAT Tamiya-knowledge and -wisdom so it would surprise me if he made a mistake.

Rogier

iTrader: (1)

Ludo,

Mostly this problem is caused by the balhead screw on top of the bulkhead. The kit screw is 8mm but with the spool you need to use the 5mm screw or you need more spacers between the bulkhead and the screw. But this depends on your setup....

Gerd

iTrader: (1)

You made the same mistake as I did
Just flip the K-part and you have enough clearance between the outdrives and the ball connector

Low_E

sorry, but what do you mean by "flip the K-part"?
Do I have to turn them, facing the other way, with the notch on the inside? ?
Or do you mean, turning them 180 ° (upside down?)