Argh! How do I set up shocks on Procat?
 

OK I give up... I really need help setting up the shocks in my Procat. It's been running well (transmission's holding up and even raced it a bit at Stotfold) but I can't seem to get it to handle or land right. I'm probably fighting a losing battle (I'll probably get a modern car next summer) but I'm sure I can get it to handle better.

I'm using the Tamiya aeration buggy dampers, which are the same as on the 501x and DB01-R. I'm using the bleed caps. The problem with the front of the Procat is the shocks are very layed down and there's virtually no adjustability. I've removed the anti-roll bar so I could move the lower shock mount out. I've had to use No.2 piston and 60wt oil just to firm it up and stop it bottoming out... but it feels odd. Using black Losi springs at the moment.

At the rear I was using No.4 piston and 40wt oil. Losi yellow or pink springs. The rear is bottoming out after jumps and bending the rear wishbone carrier bolt. I've just changed the piston to No.3 with 30wt oil.

Has anyone else experienced this frustration? Anybody remember how they set up their Cat or Procat? Any help appreciated. Cheers :thumbsup:

http://i103.photobucket.com/albums/m...l/IMG_9508.jpg

http://i103.photobucket.com/albums/m...l/IMG_9720.jpg

if you cut the schumacher ball cup down and use a raised spring cup and spring the fit the shocks for example tamiya or ae spring you should be ok also the what tamiya piston do you have are they the ones that come on the molded spru or the proper teflon ones that come with the worlds edition 501 the spru ones dont fit the bores very good.

Thanks for your reply. I've got the cnc pistons from the TRF hop-up kit... yes, they smoother than the ones on the sprue. I have to use Losi springs and cups because I'm using I&Q dirt shields. I doubt the make of spring is the issue (I've compared them on the Excel chart... unless I'm missing something) it's more the choice of piston, oil and spring stiffness.

they are too long so you end up putting too much pre load.:thumbsup:

i know the xls wouldnt handle very well without anti roll bars so try and get it back on there, if i remember correctly the front end is very similar. if its bottoming out landing try smaller holes in your pistons

Also, fit some stiffer springs if you want it to stop bottoming out. There are only 5-5.5 turns on the Schumacher springs, so the ones you have on in the pics are far too soft. BTW, those Schumacher springs were designed to be used with anti-roll bars, so I'm not surprised you car doesn't work too well...

HTH

Thanks for the feedback.

So I need shorter shocks at the front (so I can get the roll bar back on) and shorter, stiffer springs too.

Which make could I use?

Associated springs should fit the Tamiya shocks, the fronts should be suitably short.

Thanks for the detailed advice!

OK, got the blue AE front springs, shorten ball cups and also put the front roll bar back. Only thing to sort out now is the pistons in the front. If I remember rightly, didn't the old Cat pistons just have one hole at the edge? I saw this article by Phil Davies and it says he used 1mm pistons. Is that two holes of 1mm diameter each? I have some TRF blank pistons I could drill out.

Cheers

http://i103.photobucket.com/albums/m...catpistons.jpg

Those arms on the front and rear that you have on youre car are they bosscats ?????

mvh Isobarik

I'ved used Bosscat wishbones and 1/8 inch hingepins on the rear. These are much the same as the Procat ones, just stronger. For the front I'm still using the Procat wishbones but had to use a narrower top spacer with the Bosscat hub carrier.

Definitely need to sort the shocks out. What do the holes look like on the old Schumacher 1mm pistons?

i know my bosscat was on later shumacher shocks, used grey springs on front, yellows on rear, 50wt front 30wt rear, single hole pistons, dont know hole size though but could well have been 1mm, they were drilled out. if i remember correctly there were 2mm of spacers inside all shocks to limit travel, and i had 2 o rings on front shafts a bump stops too. cant remember what xls had on a such, front springs were standard kit, rears i think were from a pb maxima,

I can get the work hubs for the rear does they need any special rear arms ???? and if they do are they hard to get ????

Kazal do you have any red belts left for the cat ???

mvh Isobarik

I found the bit in the old manual that has the shock assembly. Seems a small piston hole area compared to today's dampers. I'll drill out a Tamiya piston with a single 1mm hole and try that with 30wt.

http://i103.photobucket.com/albums/m...untitled-1.jpg

I also think the kit pistons fit like a dick in a bucket (not very tight) and have a notch in the side of them? So most oil probably goes round them?

I built a Procat for the York vintage series we used to do and I think I just put in the thickest oil I could find!

G

from what I can remember of running the cats you will never stop them bottoming out have a look on youtube at the 87 worlds you will see cats of the day and how they performed it will look very similar to yours they always bottomed out heres a pic of mine
http://i908.photobucket.com/albums/a...1998/014-2.jpg

Thanks for your posts. I sorted out the ride height at the front with shorter AE springs and shorter Schumacher ball cups. The front roll bar is back on too.

Front: AE blue springs 4.2 rate, piston 2 holes 1mm dia, 30wt oil

Rear: Losi yellow springs 2 rate, piston 2 holes 1.3mm dia, 35wt oil

If dropped onto a tabletop from about 9" it lands comfortably without bottoming out.

I've got a spare TRF511 you can buy, you won't have any problems sorting that out :thumbsup:

True true. Thanks for the offer. I'll probably look at something new this summer.

By the way, you'll have a pleasant surprise at the track... the hearse shell is gone :thumbsup:

At last ....mvh isobarik

but the paint was awsome.

rates of original Procat springs?
 

Cheers but that was Jon's work at RCS Graphic Worx. He also did my new TBG Procat shell but a different design.

Those old Schumacher front springs had few coils didn't they, almost like a touring car spring. Does anyone know the spring rate on the old CAT or Procat springs?

spring dimensions?
 

Got this out the Procat manual. What do these springs measurements mean?

http://i103.photobucket.com/albums/m...catsprings.jpg

Could it be
thickness turns and lenght ???

mvh isobarik

maybe email schumacher

Thanks, that makes sense. The length must be in inches.

Good, the AE blue springs I've got are 1.66" long / rate 4.2 and I can get the AE silver springs, which are 1.3" long / rate 3.85

Will the shorter springs be more progressive?

Voila!

http://www.oople.com/forums/showpost...&postcount=215

That was so much better ..........

i didnt like the herse back in the days and still dont like it.....

I´m bidding on some xls bodies 3 to be more precise and one undertray.
They are used but will do for now.

mvh Isobarik

new video "drop test"
 

Thanks for your comments. Think I got the dampers nearly sorted...

Front: 2 hole piston 1mm dia, 30wt oil, AE blue springs 4.2 rate, short Schumacher ball cups

Rear: 2 hole piston 1.3mm dia, 30wt oil, Losi yellow springs 2.0 rate

Got spacers on shock shafts to limit downtravel and both roll bars are back on. Still seems a bit hard but I'm hoping it will handle Stotfold better (astro turf track with jumps) and won't bottom out or roll too much.

Here's a video of me doing a "drop test" whatever value that is, have a look...

http://www.youtube.com/watch?v=DFlLTH4p13o