Shock Oil Information

[JeremyH]

I had been having trouble finding the right shock oil for my super (was running Losi 100wt, but needed something heavier) and in my search, I came across some information that I thought others might find quite useful.

I did not know that there were differences in the classification of shock oil weight between different manufacturers. Some manufacturers (for example, Losi, Associated and Traxxas) use a numerical system of "weight values" to represent the different viscosity levels of their oils. This threw me off when I asked the LHS about heavier oil and he suggested diff oil of 1500. In my mind, that was 15 times heavier than what I had in there, but, as the guy at the LHS explained, that isnt so.

He explained to me that the Losi 100wt oil is about 900 CTS. Now it started to make sense!

I searched around on the internet and found some useful information so I thought I would post this here for others that might be as confused as I was. This website also gives information about how the shock oil changes with ambient temperature.




Silicone shock and differential oil and more

In the beginning of the 80's cars were equipped with small shock absorbers 1/4 of the current size. The shock fluid used was normally a kind of transmission oil.
These oils always changed in viscosity (thickness) during use and temperature and a stable shock oil was not there. Therefore all kinds of products were tried.
Even STP oil was used, you then had to warm up your shocks before racing with a hair dryer before you could use them.
Fortunenatly silicone oil was introduced in the mid 80's.
This type of oil has an better constant viscosity over a wider temperature range then other fluids but still is not complete temperature stable!

The thickness of the oil is officially rated in Centi Stokes "Cts".
Centi Poise (nowadays called Pascal per second) is the result of the Centistokes value magnified with the density of the oil.
Normally for silicone oil this value is 0.9875 = almost 1.0

An other known and used American rating is WEIGHT "WT".
This WT or W rating is a non world standard and is introduced by Associated and not comparable between brands using this W or WT rating.

Thanks to Casper who found this remark on the net about SAE WT:
"Correct measures of viscosity are centi-stokes, N/m^2, or poises, depending on how you define it.
SAE WT is not really a measure of viscosity. The SAE scale was designed for classifying motor oils. For example SAE 30/40 means that the viscoity is one value (30) at one temperature and an equivalent (40) at the engine running temperature. When the number has WT after it this means "winter" so that the oil will have a particular value at I think 0 degrees Celsius.
The main problem with using the SAE scale oil is that each SAE band can encompass a large variation in viscosity. For example one manufacturers SAE 5 can be anothers SAE 10 and both are within limits. Using the SAE scale oil is best only to compare one manufacturer. "
Concerning Cts the thinner the oil (fluid) the lower the number, the ticker the oil the higher the number.
For normal shock absorber use, this rate may vary between 100 Cts until 900 Cts.
Nowadays we use O-ring sealed diffs, so we can use silicone oil in the diffs instead of thick grease.
For diffs the rate may vary between 1.000 Cts (loose) up to even 500.000 Cts (very, very, stiff).
Some USA based companies still are using the "WT" weight rating, where Japanese and European companies use the better linear industry standard Centi Stokes or Centi Poise rating.
A lot off people think that the ratings between the "WT" and "Cts/Cps" ratings are linear but this isn't the case.

If there is a factory that can provide oil for testing we can arrange this to see if the product reaches the specification claimed or convert to Cts!

Which manufacturer use which rating?
Which manufacturers you can use same rating oil?
Only manufacturers using Cts as rating are using a world standard and can be mixed used.
Other ratings like W and WT differ from brand from brand as WT or W is not a world standard!

	shock oil
Brand	bottle values	label rating	linear values in Cts
Kyosho	100 - 900	numbers	yes
Mugen	100 - 900	numbers	yes
Associated	10 - 80	WT	no
Losi	10 - 100	WT	no
Orion	10/100 - 80/800	numbers	no
Xray	100 - 900	numbers	yes
GS-Racing USA	20 - 60	WT	no
GS-Racing Europe	200 - 900	Cts	yes
Crono	?	?	?
Serpent	20 - 50	W	no
Thunder Tiger	?	?	?
Trinity	?	?	?

[JeremyH]

	differential oil
Brand	bottle values	label rating	linear values in Cts
Kyosho	1.000 - 60.000	numbers	yes
Mugen	1.000 - 60.000	numbers	yes
Associated	not available	not available	not available
Losi	not available	not available	not available
Orion	not available	not available	not available
Xray	1.000 - 60.000	numbers	no
GS-Racing USA	1.000 - 50.000	Centipoise Cts	yes
GS-Racing Europe	1.000 - 50.000	Centipoise Cts	yes
Crono	?	?	?
Serpent	not available	not available	not available
Thunder Tiger	?	?	?
Trinity	not available	not available	not available

If you have better information let us know

For shock absorber use, this is the comparison table when using LOSI, ASSOCIATED and SERPENT some others silicone oil rated in "WT" "W" or are not labeled with a rating but just a number like 30/300

unofficial conversion values provided by Gene Hickerson USA
Cts	Losi WT	Associated WT
100	10	7.5
150	15	12.5
200	20	17.5
275	25	22.5
300	27.5	25
350	30	27.5
400	32.5	30
425	35	32.5
450	37.5	35
500	40	37.5

The 50 Cts steps between "Cts" rating are linear, where the 5 "WT" steps used in the "WT" rating are progressive compared to the real thickness of the oil.

No one can tell TEAM TWF8 how "WT" OR "W" rating is measured!!!!! If you know it let us know! info@twf8.ws

[JeremyH]

Serpent oil (04-01-2005)
rating W	Cts
20	107
25	207
30	370
35	626
40	1070
45	1449
50	2250

We tested this oil supplied by Serpent Benelux on 04-01-2005 in our labaratory and compared them with a calibration oil.of 100 Cts.

Conclusion:
Serpent oil is way of linear with Cts rating

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Xray silicone oil with Rheometer 09-10-2005
Rating	Cts
100	106
150	179
200	248
250	292
300	354
350	381
400	441
450	475
500	542
600	625
700	702
800	799
900	913
1.000	1020
Differential usage
2.000	2490
3.000	4270
5.000	9000
7.000	10500
10.000	13000
20.000	30000
30.000	39600
60.000	65000

Use the values above for your benefit and as a guideline.
TEAM Xray has improved their oil line values from December 2006 onwards.
They now have a new silicone oil supplier.
Xray oil provided by TEAM Xray Slovakia

[JeremyH]

Kyosho
rating	Cts
250	244
300	302
350	351
400	411
500	506

Use the values above for your benefit and as a guideline.

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Associated silicone oil measured with Rheometer 09-10-2005
rating WT on bottle	Cts	Cts*
10	108	100
15	--*	150
20	208	200
25	286	275
30	373	350
35	454	425
40	525	500
45	-	575
50	707	650
55	-	725
60	725	800
70	960	900
80	1040	1000

Use the values above for your benefit and as a guideline.
* The value 15 Weights we measured was like water thickness and is probably a filling fault at the factory.
Altough the contents was silicone oil it was to thin for the 15 WT specs and can not be used for the shocks.
Associated oils were provided by Kendall Bennet from A-mainhobbies and Tony Penzincka from Tony Screws

*T he cyan colored values collum are provided by Kurt Menger from Team Assosiated R&D and are the values that will be curerntly mentioned on the bottles to give comparising with Cts values. (18-10-2007)

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Trinity silicone oil measured with Rheometer 09-10-2005
rating	Cts
30	337
35	376
40	505
45	497
50	658
55	568
60	799
70	757
90	974

Use the values above for your benefit and as a guideline.
Trinity oils were provided by Kendall Bennet from A-mainhobbies and Tony Penzincka from Tony Screws

[JeremyH]

Losi silicone oil measured with Rheometer 15-12-2005
rating	Cts
15	110
17.5	158
20	243
22.5	243
25	294
27.5	345
30	381
32.5	397
35	459
37.5	477
40	546
45	657
50	886
60	844
70	970

Use the values above for your benefit and as a guideline.
Losi oils were provided byVolker Gerdes from BUGGY-SPORT.INFO

---

Currently we are measuring our oils with a RHEOMETER.
A sample of such a machine can be found here

This device is able to measure more accurat regardless the viscosity.

From September 2006 we measure all oils with a RHEOMETER.

---

SILICONE SHOCK OIL AND TEMPERATURE

Although everybody thinks silicone oil is not affected by temperature, we can wake you up out of that dream.
When the same test is done @ 10 or @ 30 degrees Celsius we get other values!
Test result from our laboratory provid us with the following fist rule:

Below some examples.

Silicone shock oil measured in Centistokes at various tempratures in Degrees Celsius (Rheometer)
Shock oil temperature	Losi 40	Trinity 40	Associated 40
5	754	688	747
10	677	622	685
15	605	555	598
20	539	492	536
25	501	467	502
30	455	420	456
35	409	377	410
40	373	345	375
45	345	320	346
50	319	294	319

To estimate your needed viscosity we made a XLS spreadsheet which you can use for calculating the correct viscosity.
You can download it here.

Team TWF8 special thanks goes to Jacco Koch our Chemicals specialist from The Netherlands for testing the fluids and the pictures.

[JeremyH]

Sorry for the multiple posts, but there were a LOT of characters on the original page and it wouldnt let me put them all in one post.

Anyway, I hope this helps some folks out....

[EGRESSor]

a converter
CPS in WT und umgekehrt umrechnung - Viskosität von Stoßdämpferölen und Diffölen

[The Violator]

I would say if you need that thick of oil, there are other issues. I say toss those red shocks in an envelope and I will trade you for a set of plastic traxxas shocks that do not even need oil. I will even throw in a $5 to cover shipping your to me.

[JeremyH]

Haha! I tried some 1500 cts as well as some soft internal springs (along with my external springs) and it is getting there. I plan to try some medium internal springs in the front and hopefully that will do the trick.

[EeePee]

Different shock pistons? Always worked for me.

[Robbob]

I would recommend a sticky on this thread.

I use the same link Egressor for tuning my touring car but having all this in front of ya can really help dial a rig in.

Great post Jeremey, thanks for taking the time.

[JeremyH]

Originally Posted by EeePee

Different shock pistons? Always worked for me.

My super is quite heavy...the leverage on the front end is ridiculous and these 1/10th scale shocks and springs just aren't up to the task. I am currently using 2 hole pistons.

Originally Posted by Robbob

Great post Jeremey, thanks for taking the time.

I did nothing but copy and paste so that the folks using the search function on this forum can find it easier. The real work was done by the folks who wrote the article.

[WIDELOAD]

Thanks for finding the info Jeremy. I always knew that there was variance between different companies. Now i realise how big that is...Hmmm....Sticking to one brand more often now.

[team3six]

Im not 100% positive but I believe I have Mugan 700wt in my shocks on the teenycar. War Pig seems pretty knowledgable about that stuff.

[EeePee]

Originally Posted by JeremyH

I am currently using 2 hole pistons.

Well, one hole it.

[JeremyH]

Originally Posted by EeePee

Well, one hole it.

I'll go extreme.....no holes in the pistons! Or hell, just replace the shock with a sold link!

[meanbgreen]

So the lower the number the softer the oil? How's the softer; harder affect the shock travel? Harder oil rebounds quicker, better for high speed?

[JeremyH]

Higher number means the fluid passes more slowly through the pistons.

[AlexG]

Here's everything in one chart



Hope this help someone.

[JeremyH]

Originally Posted by alexus

Here's everything in one chart

Awesome! Thanks for typing that up!