CAT SX setup discussion
 

Hey guys - this is a new car and I'm sure it'll be a massively popular one which is new to everyone, so feel free to use this sticky for setup discussion. :)

Are you gonna treat yourself Jimmy ? Must admit im tempted and ive not even raced my B44 as yet !

According the online instruction manual, page 36, I think there's something wrong with first table:
http://img294.imageshack.us/img294/4...iochartmg0.jpg
:confused:

Shock diaphrams?
 

Hi. Just been reading Mr Moss's worksop set up. It says diaphram centres cut out and removed. How,what and why is what I was wondering? Thanks for all the advise. It is invaluable with such a new car. Cant wait to run mine. :thumbsup:

oliv : give us a clue what you think is wrong i'm clearly missing something

the shocks have bladders fitted as standard like most tourers and 1/8th rallycross, cut means the top of the bladder has been removed making the shock more tike the associated 1/10th buggy style, its just another tuning option.

Think he might be thinking that it means the minimum teeth is 99 yet it goes down to 80 on the chart.

But if you look oliv, the total minimum 'combination' of spur+pinion is 99 total, 83 spur + 16 pinion = 99total.
And max combination is 80 spur + 28 pinion = 108 total.

I know it has 80 spur and 16 pinion on the chart, but I'm assuming that this combination can't be used.

So therefor it all looks correct to me.
:thumbsup:

Pretty much spot on. While i have been testing the car all year Ive have tried shocks with full diaphrams and the cut diaphrams. All i do is cut the complete centre out so you are left with the outer ring. You need this so the oil doesnt leak out of the bleed hole at the side. Personally, ive found the shocks with cut diaprams feel better as opposed to the others, they feel more fluid and give less inital pack in my opinion.

Si

Assuming following data:
Diff pulley: 36T
Pulley just before diff: 20T

For the first cell (pinion 16T, spur gear 83T and 34/22 combination) it would be:
(83/16)*(34/22)*(36/20) = 14.43 instead of 14.37 :eh?:

The two others tables are correct ;)

looks like somebody incorrectly calculated the internal ratio to be 2.77.

if i'm honest i hadn't looked that deeply into it as all the numbers appear sensible at first glance.

3 Questions.....

What pinion size should i be looking at for a kit set-up 33/23/83 using an LRP Sphere TC Speedo, and LRP Vector X11 5.5 with a sintered rotor?

What is the rule of thumb when you change a bonded rotor for a sintered rotor with regard to pinion size?

Is Worksop clased as high or low traction?

Cheers in advance.

Ryan

Will you be using Lipo or NiCad ryan ?:lol::lol::lol:

Seriously though Lipo or Nimh ?

3600 Duracel Bunnies going like the clappers :lol:

But if i can't find that many, i'll put the Lipo in :thumbsup:

You might need to put a 6.5 in ryan if your using Lipo it will be rapid;)

Especially with my all or nothing thumbs :lol:





*Note to self: 2 packs of front wishbones just incase* :lol:

Kecky i've heard they are bringing out a maintenance pack for £90 with a load of stuff in it like WISHBONES:woot: etc. If you buy the same parts on there own it would cost you more:)

Due to a change in motor, can anyone help me with the gearing.

I will now be running a Novak Velocity 7.5L Motor, and Trakpower 3600 Lipo cells, with the kit set-up 33/23 & 83 Spur.

The instructions with the motor state you should gear 2 teeth lower than you would use for a 12 or 13 turn brushed motor.

Any help would be much appreciated.

Ryan

I'm guessing here and going from other setups but i'd start on a 21t and go from there ryan. Better to gear low and be safe mate.:)

Cheers Stegger

The motor info sheet says 2 teeth lower than a 12t or 13t brushed motor and 1 tooth lower than the 7.5R motor.

I'll start off with a 21 and take it from there :)

I run Speed Passion 5.5 on 21 pinion, so i'd go up at least a couple if it were me.

Cheers matt, we were just airing on the side of caution:thumbsup:

I ran a Novak 5.5R on 23/83, and it seemed bang on - didn't get overly hot.

Id perhaps sugest 24 or 25 with the 83.

[quote=Chrislong;162750]I ran a Novak 5.5R on 23/83, and it seemed bang on - didn't get overly hot.
quote]

Thats my gearing lol, thief!

Mossy, could you post up your final setup from worksop round 1 please :)

What wings do you use on the cat sx..................:confused:

A lot of driver just ran the kit wings, but some were running the wider wings from othe manufacturers (asso', edit, HB, etc.).

Ive posted my final setup in the Setup thread from the weekend. As for wings, i ran an associated high downforce one with only a small amount removed from the back.

Im looking at putting Ti screws and ball joints on my SX, anyone who has done this do you know how many of each size of screw you need?

Just checking before i sit down and count them myself

Paul

Could someone PM with where to get the orings which some guys have changed too in there shocks

Many Thanks

Paul

http://www.nortechracing.co.uk/ or contact northy on here. whities are the way to go :thumbsup:

Thanks Stegger, found link last night, tried ordering them but came up with an error, have sent email/pm so hopefully get it sorted!

Thanks

Paul

I'm in the process of building my CAT SX. It's a nice return to Schumacher since my very first 4wd was a CAT2000EC.

Since i'll be giving the car its first runs on the Kampenhout track, I'm looking for an astro setup to start with on work from there.

I will be running on an Indoor high traction dirt track in the US. The track is typically pretty technical with maybe on or 2 big jumps and lots of smaller jumps

What would be a good starting point?

What difference does it make on the car switching diff position high/low in their housings :confused:

Thanks mates

High 'should' give more grip at that end, but I think it will be marginal :bored:

G

I have a theory with setting up this car, and being so tuneable it is possible - not possible with ANY other chassis I am aware of.

My theory is also basic because it focus's on single area's of the car to deal with specific characteristics on the track without mixing up one area with another. Therefore the car can be tuned to be perfect as long as you can identify what the car is doing and what you want from it.


1st. To setup the car to go over the bumps, jumps and landings, dial in the shocks to suit. Oil, piston and spring. (wing size for in air)

2nd. To setup the amount of turn in the car has, change the ackerman link to suit. Longer = more initial steering. Don't make big changes at a time. Start with bellcranks parallel. Kit setting ok 8mm leaves the bellcranks pointing in (too short).

3rd. To setup the amount of side bite through & exiting the corner, change the geometry - rear toe in, camber, camber link height & length.

4th. To setup the amount of straight line traction, change Diff height, rear pin height and antisquat. (generally want maximum traction)

5th. To setup the amount of corner exit traction, choose diff, diff + roller, or one way. (generally one way everywhere for maximum traction)

I have setup my car by focusing on 1 then 2, then 3 & 4 together, and finally 5. The result is awesome. Some of the decisions made in early steps will effect the result of later steps, but by focusing sections of the setup on particular characteristics then the result is uncompromised!! ;)

Granted I have skipped a few areas such as wheelbase, camber link length, front castor and width, but like anything - to follow the above you will need an understanding of what does what in terms of setup (in which case, if unsure, copy my setup in the setups section then tell me (PM) how it feels and what you want it to do differently and i'll make some recommendations)

I love setting up this car as it is so easy to understand, and it responds as it should to every change.

Chris

When the diff is spinning it naturally wants to straighten the driveshafts to be level. So having a higher diff means the driveshafts will be straighter - or perhaps pointing down, which will generate more traction mechanically than the driveshafts smiling for the same overall ride height.

Also, having more plunge on a high speed rotating diff adds pack (independent to shocks), so having less plunge in a high diff free's up the corners to allow the shocks to work.... im not sure on the reason for this one, but it seems to be true when I have used it as a setup change.

Therefore, I use high diff on the rear of my SX, low diff on the front.

Thanks Chris for your analysis :thumbsup:

I ran my car in anger for the first tiem at the weekend... and was impressed. couple fo questions I would like to ask if any one has hints and tips...
Front Suspension
Oil: 
 35wt
Diaphragm: Cut out
Piston: Three hole
Spring: Schumacher Red (new)
Track Washers: 2mm front/2mm rear
Anti-Roll Bar: None
Shock Position - Tower: Middle
Shock Position - Wishbone: Middle
Front Rake: 10-degrees
Front Link Bracket: 38.5mm (2mm washers)
Washers on Hub: 2.5mm (hub carrier cut flush)
Ride Height: d/shaft level

Rear Suspension
Oil: 25wt
Diaphragm: Cut out
Piston: Three hole
Spring: Schumacher Yellow
Wheelbase: Short
Toe In: (3.5mm rear/1.5mm front)
Anti Squat Washers: 1.3 degrees (2mm rear, 1mm front)
Rear Link Bracket: 37.5mm (5mm washers under ball)
Shock Position - Tower: Middle
Shock Position - Wishbone: Inside
Hub Camber Link: Middle
Anti-Roll Bar: None
Ride Height: w/bone level

Transmission
Front Diff Height: Low
Rear Diff Height: Low
Layshaft Pulley: One-way
Front Drive: Diff
Gearing: 21/83/Ni-Mh/5.5 with 12.5mm sintered rotor.
Internal Ratio: Kit pulleys

I found the car didn't push enough on power, e.g. going on to the straight the car.. I was thinking of trying more toe in on the rear, also either getting rid of some of the washer under the 'ball' or removing some from the front camber link bracket...

Thanks

I am not sure I understand. Do you want the car to understeer more on power? Or are you saying that it oversteered.

Sorry Chris, it oversteered on power. So exciting the final corner going on to the straight the car would just hang on too much? So I want to make it understeer more on power...

Paul