Shock Building

[MasterSbilt_Racer]

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??

I am not a shock guy, but I do know there is a mechanical reason, due to construction, that the bilstein requires more gas pressure. Something inside can move if the pressure is too low. That said, the ASN shocks perform well.

[RCJ]

On the l/r with a lot of compression I've seen the divider piston move.That was with low gas pressure(50lbs).I've never been inside other shocks, but you would think they all would do that to some degree.
With higher flow pistons don't you have to run more shim stack to get the same rate?What are the advantages or disadvantages?

[Dirt_Buster]

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??

Nailing all them nails on the head.

[zeroracing]

To answer Masters_built, they do require a decent gas pressure, many guys that rebuild them do not put the clip right under the rod guide back in them, makes rebuilding easier. That said at low or no gas pressure during compression that may move inward.

To respond to Dirt-Buster, I do think there are shocks out there many times better than Bilstien, however, that may be why one piston on my JRI cost more than the whole shock from Bilstien. For a low budget racer, or guy wanting to have fun Bilstiens are not a bad option, but yes I will agree there are many better options on the market overall.

[Renegade Cust Susp]

To answer Masters_built, they do require a decent gas pressure, many guys that rebuild them do not put the clip right under the rod guide back in them, makes rebuilding easier. That said at low or no gas pressure during compression that may move inward.

To respond to Dirt-Buster, I do think there are shocks out there many times better than Bilstien, however, that may be why one piston on my JRI cost more than the whole shock from Bilstien. For a low budget racer, or guy wanting to have fun Bilstiens are not a bad option, but yes I will agree there are many better options on the market overall.

Beat me to it

[Wizard 05]

Integra Shock (which is part of Port City Racing) in Coopersville Mi. Has a very nice shock school..It is either one or two days depending on what YOU want to learn. 1-800-472-2464

[turtle1hp]

To answer Masters_built, they do require a decent gas pressure, many guys that rebuild them do not put the clip right under the rod guide back in them, makes rebuilding easier. That said at low or no gas pressure during compression that may move inward. To respond to Dirt-Buster, I do think there are shocks out there many times better than Bilstien, however, that may be why one piston on my JRI cost more than the whole shock from Bilstien. For a low budget racer, or guy wanting to have fun Bilstiens are not a bad option, but yes I will agree there are many better options on the market overall.

Beat me to it

I was thinking the same thing. BUT.... The higher end shocks have high flow pistons for a reason. Are they really necessary for a typical dirt track shock? I have been more concerned with the 3" - 6" per second velocity range for tuning the chassis. What are the typical velocities seen on an average racing surface? I was "assuming" around 10" - 20" per second range when hitting bumps or the cushion. Has any anyone done some data acquisition tests on this? At what velocity does the high flow piston become an advantage?

[Renegade Cust Susp]

I was thinking the same thing. BUT.... The higher end shocks have high flow pistons for a reason. Are they really necessary for a typical dirt track shock? I have been more concerned with the 3" - 6" per second velocity range for tuning the chassis. What are the typical velocities seen on an average racing surface? I was "assuming" around 10" - 20" per second range when hitting bumps or the cushion. Has any anyone done some data acquisition tests on this? At what velocity does the high flow piston become an advantage?

Have actually discussed this first hand with a group that did some R&D with Fox and they numbers are much higher than you would expect, which is why I think the flow rate of the piston comes into effect. But I have my own opinions on what this changes and effects as far as being a builder and the resolution it allows. That being said, shocks are becoming more and more critical because the information on the rest of the car is so wide spread. It makes the sciences behind damper tuning much more specific.

[Racer96m]

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

I run Bilstein XVS. I build my own shocks. Noboby runs stock pistons in anything. Every corner of my car has a different piston in it. All the top guys have custom built shocks, no one I race with just puts a stock out of the box shock on and does any good no matter what brand shock.

Dave

[Dirt_Buster]

Fox piston is basically a bilstein one. They don't flow either and have to gas them up. Masking a problem if you ask me.

[Renegade Cust Susp]

Fox piston is basically a bilstein one. They don't flow either and have to gas them up. Masking a problem if you ask me.

They aren't all that similar, orifice size and location is different and there digressive bleed set up is completely unlike the Bilstein stuff.

But you keep referencing flow of the piston, what exactly are you refering to? Volumetric flow rate? and there is some trade off in that high flow

[Dirt_Buster]

The flow charectoristics are very similar to each other. They both don't flow. They also both aren't consistent on a dyno. Just throw them on there at 3-6" per second and go ahead and see how long it takes for that shock to start Cavitating. Then mask it all by throwing more gas into it.

[FourDeepInTheFluff]

Where are you guys getting your shock dynos at? Does anyone provide a leasing option? I looked at AccuForce Dyno and just dont have that kinda money to throw at one at once. But could come up with the monthly fee to lease/finance one.

[Dirt_Buster]

Unless you're doing a lot of shocks and for a lot of different divisions don't waste your money. There are plenty of shops around who fronted the bill already.

[turtle1hp]

Where are you guys getting your shock dynos at? Does anyone provide a leasing option? I looked at AccuForce Dyno and just dont have that kinda money to throw at one at once. But could come up with the monthly fee to lease/finance one.

I was lucky enough to find a used one. Before that I was looking into the Performance Trends dyno. It is moderately priced and I do believe they do offer financing. Keith Berner owns AccuForce. Did you speak to him and see if there were financing options available? Most businesses will use an outside company for the financing.

[Renegade Cust Susp]

Where are you guys getting your shock dynos at? Does anyone provide a leasing option? I looked at AccuForce Dyno and just dont have that kinda money to throw at one at once. But could come up with the monthly fee to lease/finance one.

Personally I am partial to Roehrig Engineering

[zeroracing]

If your going to buy a dyno get a Roehrig or intercomp maybe a maxwell. You want to be able to measure the zero point easily. That said if your not going into the shock building game as a real business then I would say just get with a good shock guy and use them. The tools including dyno and knowledge needed is too much for the average racer to keep up with. Guys that do 100 shocks a year collect so much more knowledge and data than a guy that does 10. I tried it some, realized this and gave. It up.

[FourDeepInTheFluff]

Hey guys, thanks for the replies. Awesome information. So here is the idea, I have been in contact today with Maxwell. I have priced out a 3HP Shock Dyno and Spring Dyno. At first, the use will be for myself and a group of close friends. Probably around 6-8 different drivers with various classes of cars be it Modifieds, Latemodels, Stock cars, and sprint cars. Looking to try different valvings and numbers to see how things work and react. Is it for business purposes? Eh, maybe not immediately, but I am open to it. Its really more for my own knowledge.

I am a college student, so if I could use it to make some part time money and work my own schedule at night then that's a plus. I know that wont come over night and probably not for a few years. I am okay with that. Eventually, (within the next 4-6 years) I plan to turn my shop into a full fledged race shop. Offering fabrication, shock, car building services. But for now, while my own racing is being (and has been) pretty much put to the curb to focus on my education, I am just looking for something to keep me involved on the inside and challenge myself to learn a side of the business I have always bought because it was alot easier.

Thanks again for all the advice!

[Dirt_Buster]

If I have any advice at all in this it would be as follows. Get a job that makes you enough money to afford the good shock guy and work and learn with him. You won't make a lot of money in this game doing shocks at these levels. Trust me

[FourDeepInTheFluff]

Thanks guys! I am taking everything into consideration. As of now, it seems like it is a lot easier to just basically have a shock guy on payroll. Although I am still interested in learning on my own. I just may not be financially set up for that right now.

My questions I currently have is this... Purely going by what I see in pictures and prices it would seem that the Performance Trends dyno is a cheaper option. I am sure there is a reason for this... Would this set up be good enough to "potentially" use to try and get a little small time shock game going if thats the route I choose since it seems to be in a college kids price range?

Also, if I am doing coil over shocks, will I need a spring dyno? And what does the spring dyno do other than spring rates? Basically it just tells me that my spring is still within the rate stamped?

Also, can one point me in the right direction of how to gas fill shocks work, as in what kind of machinery is used to charge/recharge/service/etc.... can all this be done on a regular shock dyno?

Apologize for all the questions, but the info is not really out there...... and that is understandable.