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Saito2

SRB front suspension shock upgrade

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I've been looking at vintage SRB racers of late and how coil over shocks were often added to the front end. My question is, would this arrangement place added separation stress on the lower ball joint (which would commonly wear and pull apart on the old ones)? I believe the original Super Champ manual even instructed you to place a tie wrap around the front arms to help keep them together IIRC. 

The stock arrangement uses a wound spring that works on the inner pivot of the upper arm. As such, the lower arm is really just along for the ride, its only resistance to upward motion being that of the small front dampers attached to it. I'd like to try front coil overs but not at the expense of wearing out the lower ball joints prematurely. I will probably use re-re parts here with the somewhat improved ball plate assembly.

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Hi Saito,

you are totally right and gave already all the answers. I noticed that fact as a kid on my fathers original MK2 , where I used coil overs for some month. On my 2010 Rere it was clear, that I stay with the kit springs and the separated damper. (although I use TRF Mini dampers).

On the Rere with the improved ball joint assembly, the separation would likely not happen as on the original, until the ball cup is not very heavily worn out. But wear will increase very much in my eyes. Also the knuckle play in the ball cups will not be pressed out a little bit on the upper arm. This is something happening on a real beetle front beam in the same way. There has to be a certain preload on the torsion springs inside, and always more from the upper spring assembly. Otherwise driving will be weird. In the SRB model, this is done by the spring on the upper arm. This is the reason, Tamiya made this quite unique spring design, which may seem odd to people not knowing the background. Obviously, a coil over spring on the damper would have been much easier designwise.

With the Rere and the much better spare parts availability, many people do the conversion nevertheless, and change the ball cups regularly. On the original, the missing ball cups in the 90´s here in Germany stopped me from driving my fathers Mk2. On every little bump, the axle was separating. Years of use payed their price...:wacko:

But nowadays everything is bettter. And thanks to Tamiya for the improvements on the 2010 Sand Scorcher. Well done!

Have fun Saito,

Kind regards,

Matthias

 

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Thanks! Bringing up 1:1 Beetles gave me flashbacks of installing torsion leaves and welding in Select-a-Drops or Avis adjusters to lower the front end, lol. Thanks for confirming what I had in my head. I think I will just go for a better damper up front and leave the stock top springs in place. They feel a bit better than the originals too.

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@ruebiracer or anyone else in the know, how common were bent front suspension pins? Where did they bend at? I imagine it must have been some issue as Tamiya themselves offered hardened pins in the Super Champ. If I can track down 8mm OD/6mm ID tubing, I hope to widen the front end. I've contemplated incorporating bearings for the pivots somehow, but might not go that far.

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Hi Saito,

cool that you came also in contact with real beetles and adjustable front axles! Same for me. There´s a nice book from a German author called "Bodengruppentherapie". This is the only book I know, where this preloading of the upper trailing arm is described, especially for converting the axle to height adjustment...

Regarding the suspension pins: I bent the ones from my fathers original Sand Scorcher, when hitting harder obstacles. Didn´t know, that already on the super champ Tamiya used hardened pins! Thanks for the info! I guess, Tamiya uses them on the Rere, too. At least I hope so!;)

Do you still own a beetle?;)

Kind regards,

Matthias  

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3 hours ago, ruebiracer said:

Do you still own a beetle?

Alas no, I had several about 15 years ago and even daily drove one of them for some time. I wanted to "graduate" to a 911, but the timing was never right, and judging on their skyrocketing values, its never going to happen. Before my father passed we had planned to sell our MGB to help fund a 356 project, but time ran out. I still miss VWs though and was fortunate enough to have a hand in restoring a '49 Beetle at my job once.

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On 3/1/2022 at 12:56 PM, Saito2 said:

I've been looking at vintage SRB racers of late and how coil over shocks were often added to the front end. My question is, would this arrangement place added separation stress on the lower ball joint (which would commonly wear and pull apart on the old ones)? I believe the original Super Champ manual even instructed you to place a tie wrap around the front arms to help keep them together IIRC. 

The stock arrangement uses a wound spring that works on the inner pivot of the upper arm. As such, the lower arm is really just along for the ride, its only resistance to upward motion being that of the small front dampers attached to it. I'd like to try front coil overs but not at the expense of wearing out the lower ball joints prematurely. I will probably use re-re parts here with the somewhat improved ball plate assembly.

Back in the days we all used coil over shocks. Here are some of the aftermarket parts that I put on my Sand Scorcher front suspension.

YtBGz3i.jpg

QVMoGKw.jpg

 

There are two kinds of ball cups and two kinds of lowering blocks for the front end available.

The ball joints do not comes apart with these ball cups.

.5Gp5xne.jpg

qZFYt6b.jpg

W1NPZ6H.jpg

NLsDI8E.jpg

 

 

Two kinds of lowering blocks which can also change the angle of the front end.

RvGkZ34.jpg

 

Heavy duty harden steel axle pins for my wide chassis. These ones will never bend.

zYV4VMx.jpg

zV5iBv3.jpg

 

 

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Very nice parts @yellowcat. Thanks for the pictures.  I wish some of those nice parts were around today. How much wider was the wide front end kit?

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14 minutes ago, Saito2 said:

Very nice parts @yellowcat. Thanks for the pictures.  I wish some of those nice parts were around today. How much wider was the wide front end kit?

Here is the comparison between the stock, long and wide and butterfly chassis plate.

8AsGraB.jpg

o1hTdui.jpg

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I've never seen the long SRB chassis before. I wonder if that's the same Race Prep founded by the Dunn brothers of Race Prep/AYK Pro Radiant fame? Considering how wide SRB turns (without a diff anyway) I wonder how the long variant performed, albeit with better straight line stability I imagine..

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I’m putting together a MK2 SS to run around the garden.

By no means a shelf queen or 100% vintage.

Does anyone have a recommendation for socks front and back they can share please? 
 

 

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I am putting on some Team Associated SC10 shocks on my custom build Ford F150 Ranger XLT.

OgNwvrk.jpg

09dnLMA.jpg

wVYAq9N.jpg

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7 hours ago, yellowcat said:

I am putting on some Team Associated SC10 shocks on my custom build Ford F150 Ranger XLT.

OgNwvrk.jpg

09dnLMA.jpg

wVYAq9N.jpg

Very, very nice!

What brand is the strut brace? 

I’m guessing the strut extensions are CRP? 

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24 minutes ago, Grumpy pants said:

Very, very nice!

What brand is the strut support? 

The top gold anodized one is from CRP. The bottom silver one I make it myself.

UPtIdrD.jpg

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Lovely collection of vintage hop ups there @yellowcat 👍

Agree with all the above

@Saito2 tie wraps on SuperChamp arms did indeed help reduce ball joint play / pop out but - as ever with early Tamiya - removed it acting as a ‘safety margin’ protecting the set up when the front end came down hard over higher jumps

Tie wrap anchor points also drifted toward the centre / weakest point of the arm no matter how hard you tried otherwise - which often resulted in snapping the arms vs a much easier / quicker repair fixing a ball joint 

New arms then had to be ordered in by your hobby shop in the early 80s … offering a lengthy pause to ponder the wisdom of your actions 😂

The ball joints @yellowcat has were a much better compromise 👍

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So, lacking those very nice old aftermarket ballplates/joints yellowcat's SRB has, I guess leaving the stock wound springs in place (but leaving off the tie wraps for a safety margin) and maybe just adding improved dampers will be the way to go. Perhaps. Maybe.

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10 hours ago, Grumpy pants said:

Very, very nice!

What brand is the strut brace? 

I’m guessing the strut extensions are CRP? 

Yes from CRP. There are two kinds of shock tower extension available back in the early '80s. They are either from CRP, Race Prep or RCH.

Here are some instructions I still have.

jHluJXN.jpg

 

Shock tower extension on my Rough Rider

ibxRawm.jpg

QSvqvu3.jpg

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13 hours ago, yellowcat said:

Yes from CRP. There are two kinds of shock tower extension available back in the early '80s. They are either from CRP, Race Prep or RCH.

Here are some instructions I still have.

jHluJXN.jpg

 

Shock tower extension on my Rough Rider

ibxRawm.jpg

QSvqvu3.jpg

Toto, I don't think we're in Kansas anymore.

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I’ve decided to try the TRF O rings solution with Green slime on my vintage shocks, plus I’ve bought a cheap set of 4 shocks with springs from JK as the back up plan 😂

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2 hours ago, Grumpy pants said:

I’ve decided to try the TRF O rings solution with Green slime on my vintage shocks, plus I’ve bought a cheap set of 4 shocks with springs from JK as the back up plan 😂

Try some Race Prep o rings. That's the one will never leaks. Notice how "fat" they are in comparison with the stock o ring.

6DYe0Y5.jpg

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