Shock Building

[TwistedFrame21]

What is a good way to learn the trade of shock building? I've always been curious, and been wanting to start building my own stuff for awhile. I just need a little guidance on the do's and donts. Any help is appreciated.

[zeroracing]

There is some info out on the web by different manufactures. Depending on what brand you are going to work on. Bilsiten for example is very easy to take apart and rebuild if you can run a schrader valve.

All of that said, your going to get very limited info on what your curve should look like and how to build that curve. Also anything short of a good dyno will have you struggling to make heads or tails of minor changes. Anymore you would want a higher level dyno that will measure zero force (rebound force as the shock breaks 0). The cheap pneumatic and pen paper graph styles struggle with this. Again, good luck to you but the few guys really in the know try to keep cards close to their vest.

[turtle1hp]

I agree with zeroracing. A dyno is a must and not a lot of people are sharing information. I am in the early stages of building shocks and I find his statements to be true. I am also working with Bilsteins and building the machine to fill non Schrader valve shocks. I have been going back and forth with a rep at Bilstein and they are in the process of putting together classes. About a month ago they were saying that they should be starting the classes later this summer. I am wanting to attend. I will see if I can find more info on dates and locations if you are interested.

[TwistedFrame21]

I appreciate the honest replys, turtle I would definitely be interested. Keep this thread updated

[RCJ]

Bilstein has charts of their shim stacks.Does any other shock company s do this?

[zeroracing]

Ohlins x-stack does as well.

[Matt49]

As it relates to Ohlins, RE Suspension has some useful information on their website:
http://resuspension.com/assets/Ohlins_X_Stacks Book.pdf
Not sure how "current" it is but it's information at least.

[turtle1hp]

When you say "charts" for the stacks, do you mean the dyno graph of the stack, or the shims needed to complete the stack?

[zeroracing]

X-stack book has both, I am not sure how old the book is like Matt49 stated. It shows what the stack should graph like and what shims to use in what order. That said, even on a simple oil change I have my shocks ran on the Dyno to make sure they don't have some other issue or were installed incorrectly.

[Dirt_Buster]

Finding a good flowing piston and properly done body is what we found to be the key. Also the way the piston seals against the body. Also we have tuned our shocks to be fairly the same most tracks and changed the bleed charectoristics for the low speed mainly. Hard to find a very good shock builder that knows anything and everything but we use one that's very good in my opinion and gets what we want exactly In the "feel" department everytime.

[turtle1hp]

Ok. I have been trying to figure out how to ask these questions without sounding like a dumba$$.... "Good flowing piston" Is this to reduce cavitation at high velocity speeds? "Properly done body" and "piston seals against the body" Is this for the least amount of drag without losing low speed sealing/consistency? Is this something that you get in an upper level shock like JRI ?

[Dirt_Buster]

^^^ exactly. You'd be surprised how much smoke a lot of these shock builders will blow up your a$$. They better know about their shock and every other shock on the market and the pros and cons to them all. If they don't they're simply behind. Go ahead and ask them and if they can or can't tell you the difference of theirs and the competitors. If they can't then then I'd say they're not the best to go with.

[turtle1hp]

That whole "smoke" thing is exactly why I started doing mine and my friends shocks. My friend has bought shock packages from a couple of different people and both sets came in labeled LF RF LR and RR. REALLY??? WTH?? How do you tune your car for different tracks and track conditions??? That's kinda like buying springs labeled LF RF LR and RR!!!!! Sorry.... Rant over... I try to understand how everything on the car works and the effects it can have on the corner speed. That whole "smoke" thing gets under my skin... I am "Financially Challenged" and can't throw money at things like some others can do.

[turtle1hp]

I tried to contact my guy at Bilstein and he hasn't responded. He might be on vacation. I did go back through my emails and he stated that the classes would be in Mooresville NC hoping to start late July or early August of this year. As soon as I hear from him I will share the info.

[RCJ]

Might do some search for build front forks or motorcycle shocks.I had found a web site for bikes that explained shim stacks very good.

[Dirt_Buster]

I switched from bilsteins to another brand for a good reason. Piston flow and the seals they use. I like consistency as well as someone knowledgable. I'm very happy with my shock guy now. We understand wants and needs and get it every time.

[RCJ]

What are the advantages of a piston that flows more?

[turtle1hp]

Ok. I was in contact with Jim at Bilstein. I will just copy and paste the highlights of his answers to my questions...... ( Getting close to having the curriculum done, haven't set a date yet.The basic class is one hard 8 hour day. 3 hour classroom, 4 1/2 hours of hands on build and dyno, then a thirty minute classroom wrap-up. Later there will be additional advanced classes available, one balancing base valves then an additional class about building and tuning adjustable mechanisms. Attending the basic class at Bilstein will be a prerequisite for attending any of the advanced schools.Looking into the future I'd like to have the resources to conduct a hands on track class utilizing data acquisition to teach racers to properly analyze handling issues at the track, how to correctly identify and define handling issues, how to decide whether the issue is best addressed with a shock change or a different chassis element, or both, then go through the process of making the change(s) and data testing the new set-up for comparison.Cost: Not sure, but we are trying to make it affordable. We aren't going to look at the shock schools as a profit maker, just need to cover the cost of shutting down our shop for a day and tying up three full time employees.It's been over ten years since we held any of these schools and we charged$250 for a while (going back to 2000), then later $275. I'd guessing now it will be around $300 but it isn't my decision. Whatever the tuition, I promise you your money's worth. It will be a hard day for all of us, we try hard. Not sure of class size, I want to limit the basic class to a max of eight guys at a time, six would be better, but it is a matter of time vs money.Hope this helps, and please stay in touch, looking forward to having you in class.

[Dirt_Buster]

Just ask him how his Pistons flow vs a PENSKE/JRI/OHLINS and heck BSB. See what he says to that one. Hahaha

[turtle1hp]

Trust me. I will be inquiring about that. What you were saying makes sense. I have some Penske stuff and I can see a difference in the design. Smoother flow transitions. I am wondering if that is a reason for running higher gas pressures? To control foaming from the cavitation??