Has anyone taken a Rancho RS9000 shock apart?

Let us know what you find.

I can tell you that the Rancho and Bilsteins don't suffer from lack of compression. But an overabundance of rebound. Flip the piston over, I bet it'll ride better.
 
Well changing engine oil is tuning I guess? Again I have not tried this or even seen what will happen. It’s an experiment. Who knows? It may fail?

To be the devils advocate... yes changing engine oil can be tuning... modern engines use such advance alloys that engine oil can be thinned down to 0w20... This maximizes economy but still adequately lubricates spiny thingies. When I supercharged the 3.6 in my Gladiator, I changed the oil weight to 5w20 per the recommendation of the supercharger company. This supposedly reduced ring blow by and helped keep things lubricated under boost.

Race teams often use pressure to alter a shocks performance on the go. Its a band aid, because they don't always have the time to pull all of the shocks and properly re tune. The driver says "its a little soft on the big stuff" and the tuners will add x amount of nitrogen pressure.

What your doing may be silly, but I say hell yeah. Lets Learn something.
 
Higher nitrogen pressure isn't a bandaid. Can be I guess, for too small of shocks. But it's a requirement on some setups due to shaft speeds, amount of valving, and reservoir size.
 
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Well the easiest reason is I’m not actually getting inside and changing anything. If I wanted a a tunable shock I would buy one I could tune.

If that's how you need to rationalize what you are doing when you try to tune these shocks. It isn't like anyone is accusing you of being gay because you are doing gay stuff, not that there is anything wrong with that. 🤣
 
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Higher nitrogen pressure isn't a bandaid. Can be I guess, for too small of shocks. But it's a requirement on some setups due to shaft speeds, amount of valving, and reservoir size.

Sorry, I meant relative pressure. Meaning everything is set, but the shock tune isn't working exactly as expected. They can "band aid" tune in just a few seconds with pressure.

That being said, you know significantly more about tuning shocks than I do. I've tinkered with mine a few dozen times, with fantastic results, but nothing race worthy.
 
Well changing engine oil is tuning I guess? Again I have not tried this or even seen what will happen. It’s an experiment. Who knows? It may fail?

Your going to a lot of trouble to mimic an overheated shock without the heat. Low speed might be bearable, but above that its going to act like hot garbage and blow through the compression travel.
 
To be the devils advocate... yes changing engine oil can be tuning... modern engines use such advance alloys that engine oil can be thinned down to 0w20... This maximizes economy but still adequately lubricates spiny thingies. When I supercharged the 3.6 in my Gladiator, I changed the oil weight to 5w20 per the recommendation of the supercharger company. This supposedly reduced ring blow by and helped keep things lubricated under boost.

Race teams often use pressure to alter a shocks performance on the go. Its a band aid, because they don't always have the time to pull all of the shocks and properly re tune. The driver says "its a little soft on the big stuff" and the tuners will add x amount of nitrogen pressure.

What your doing may be silly, but I say hell yeah. Lets Learn
If that's how you need to rationalize what you are doing when you try to tune these shocks. It isn't like anyone is accusing you of being gay because you are doing gay stuff, not that there is anything wrong with that. 🤣

Thank you your input has been very insightful I’ve learned so much from your comments. 😂
 
Your going to a lot of trouble to mimic an overheated shock without the heat. Low speed might be bearable, but above that its going to act like hot garbage and blow through the compression travel.

I haven’t gone through any trouble. This is theory haven’t done anything. Worst case I swap the same oil back into my shocks and I learn something?
 
I haven’t gone through any trouble. This is theory haven’t done anything. Worst case I swap the same oil back into my shocks and I learn something?

But the fact that you want to is perplexing claiming to have been around shock tuning. This experiment is the equivalent of hitting your hand with a hammer to see if it hurts to hit your hand with a hammer.

Throwing in the troll card on this thread.
 
The valve tuning is poor I agree! A thinner oil should pass faster through the orifice on the adjuster and the shock. If 5 wt is the oil used a 2.5 wt oil and the same nitro pressure should make some difference. It’s all theory tho.

Not to beat this horse much more but anything done to alter the characteristics of how a shock performs is in fact tuning it. Yes, you can tune with oil weight. If we can tune with gas pressure, no reason you can't either. We don't keep it tuned with pressure, but we do use it to figure other things out that we need to know.
 
The two very best shock tuners I have ever met in my life don't ride in the car to tell you exactly what you need. And I have never seen them make any adjustment with oil.

This experiment seems like extreme turd polishing with no true measured result.

The two best I know do 3 things. Watch the car go over specific events, ride in the car over specific events, and listen to me when I tell them what the car does that I do and don't like.
 
I am resistant because I respect the people that actually tune shocks as a job professionally. By no means what I am doing is what they do. I am just experimenting. Worst case I learn something from a shock that I’m not gonna use anyway.

Just because professionals tune shocks doesn't mean backyard hacks are not tuning when they change the behavior of a shock.
 
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Not to beat this horse much more but anything done to alter the characteristics of how a shock performs is in fact tuning it. Yes, you can tune with oil weight. If we can tune with gas pressure, no reason you can't either. We don't keep it tuned with pressure, but we do use it to figure other things out that we need to know.

Thank you for this. To be clear again it’s an oil change lol!
 
Well changing engine oil is tuning I guess? Again I have not tried this or even seen what will happen. It’s an experiment. Who knows? It may fail?

Semantically, you are tuning the engine to start easier in a colder climate by changing to a lower viscosity oil. You can also tune it to start worse if you so wish.