Inexpensive shocks dyno'd...

[Jenson May]

Originally Posted by EarlQHan

Wouldn't you want to use the lower rubber mount as that's how it will act on the car? Just asking for clarity.

The ideal way to get raw data out of a damper on the dyno is to use solid mounts. Using rubber bushings will skew data.

One can obviously mount a shock on the dyno with rubber fittings/bushings, you just have to take that variable into account and when analyzing the data.

[EarlQHan]

Originally Posted by Jenson May

The ideal way to get raw data out of a damper on the dyno is to use solid mounts. Using rubber bushings will skew data.

One can obviously mount a shock on the dyno with rubber fittings/bushings, you just have to take that variable into account and when analyzing the data.

Understood. Although it adds another variable to the graph, I figured since it more accurately reflects real world conditions with the bushings on that it would be preferred. I understand why you test it with your method though since it's more about showing the damper. Thanks.

[thinkdigit]

The rubber bushing has nothing to do with this plot. If you look at the jig used on the dyno, the base plate is pushing against the lower bracket. There's nothing connected to the rubber bushing of the lower bracket.

[Jenson May]

Originally Posted by thinkdigit

The rubber bushing has nothing to do with this plot. If you look at the jig used on the dyno, the base plate is pushing against the lower bracket. There's nothing connected to the rubber bushing of the lower bracket.

If that is the case then something was loose (which is common)
That graph is not normal, I dyno these for a living so I know what the graphs are supposed to look like

[thinkdigit]

Originally Posted by Jenson May

If that is the case then something was loose (which is common)
That graph is not normal, I dyno these for a living so I know what the graphs are supposed to look like

Pretty sure JRZ knows how to dyno shocks.

[Jenson May]

I am pretty confident that they do as well. However mistakes can happen.
Also each of the 500 series shocks are serial #'d. So if I can get those serial #'s I will have the dynos on file and post them up for comparison.

[fatoni]

Originally Posted by Jenson May

I forgot to address cross talk. When looking at the Novak racing dyno plot, you notice that the lines are extremely jagged. As previously stated the reason why this particular graph looks like this is because the shock was not mounted to the dyno in an ideal fashion.

If you look at the football graph I posted (which is very clear) you can see that there is cross talk but its very minimal. For a entry level coilover kit, I am pretty confident in saying that all brands will have the same level of cross talk or higher.

If you look at a JRZ, Moton or Penske sweep graph you will notice even less cross talk. These companies accomplish this by very high end machining tolerances of the their jetting assembly. This is one of the main aspects that separate a $1000-3000 shock from a $4000-$14000 set of coilovers.

Another thing to look at is damping adjustment accuracy.
In the realm of ALMS and professional racing teams, it is crucial to have a very linear damper force adjuster. You want each adjustment force to be equal to the next. On more entry level setups, the adjustment force is more progressive. This is not ideal for a professional race team, however its absolutely fine for your weekend and grassroots racers.

why do you guys offer adjustment at all on entry level coilovers? it just seems to me that the money could be spent better or kept in my pocket. the only reasons i can think of doing that (not just you guys but the whole entry level market) would be to have something fancy to talk about in a sales pitch or to tune out the differences from shock to shock to balance out the set.

im not trying to offend anyone, im just curious as to what something like this has to offer over something like a rebuilt bilstein with gc sleeves.

[Calum]

@Jenson May

Awesome info. Thank you very much for sharing and being so open.

How do these damper force ratings relate to ideal spring rates for the damper? Is a critically damped system ideal? At what part of the curve would you measure the damper to compare to the spring, the slow speed or the high speed?

I'm also curious about @fatoni's question.

And, could you post plots for the FRS coilovers?

[Jenson May]

Originally Posted by fatoni

why do you guys offer adjustment at all on entry level coilovers? it just seems to me that the money could be spent better or kept in my pocket. the only reasons i can think of doing that (not just you guys but the whole entry level market) would be to have something fancy to talk about in a sales pitch or to tune out the differences from shock to shock to balance out the set.

im not trying to offend anyone, im just curious as to what something like this has to offer over something like a rebuilt bilstein with gc sleeves.

Excellent question, having rebound adjustment does not hurt things. On Fortune 500 shocks you have 100-150lbs of rebound adjustment range. This helps with suspension tuning to an extent.

In all honesty, marketing also plays a pretty big role in how "adjustable" a suspension is. This is where things start to get a little ridiculous in my opinion. You would be surprised at how many people purchase coilovers in the entry level market based on 1. Color of the shocks and 2. Supposed "adjust-ability" of the shocks.

I put adjust-ability in quotes because there is a pretty large chunk of entry level coilovers that adjust absolutely nothing. The adjustment knob is there for looks, or to make you believe that you are adjusting something when you are really not changing a thing.

Then there is the "how many adjustment clicks you have marketing". The higher the amount of clicks the better. So something that has 40 clicks of adjustment is better than something that has 10 clicks. This obviously is absolutely ridiculous.

If it were up to me, Fortune's would be 10-click adjustable. However, I am not involved with the marketing aspect of things and understand that since the entry level coilovers are the largest segment of the coilover market, so you have to fulfill what most people are looking for.

[CSG Mike]

Originally Posted by Jenson May

In all honesty, marketing also plays a pretty big role in how "adjustable" a suspension is. This is where things start to get a little ridiculous in my opinion. You would be surprised at how many people purchase coilovers in the entry level market based on 1. Color of the shocks and 2. Supposed "adjust-ability" of the shocks.

I put adjust-ability in quotes because there is a pretty large chunk of entry level coilovers that adjust absolutely nothing. The adjustment knob is there for looks, or to make you believe that you are adjusting something when you are really not changing a thing.

Then there is the "how many adjustment clicks you have marketing". The higher the amount of clicks the better. So something that has 40 clicks of adjustment is better then something that has 10 clicks. This obviously is absolutely ridiculous.

If it were up to me, Fortune's would be 10 click adjustable. However I am not involved with the marketing aspect of things, and understand that since the entry level coilover market is the largest segment of the coilover market. So you have to fulfill what most people are looking for.

This is one of the best posts I've seen on this board. Props sir.

[Jenson May]

Originally Posted by Calum

@Jenson May

Awesome info. Thank you very much for sharing and being so open.

How do these damper force ratings relate to ideal spring rates for the damper? Is a critically damped system ideal? At what part of the curve would you measure the damper to compare to the spring, the slow speed or the high speed?

I'm also curious about @fatoni's question.

And, could you post plots for the FRS coilovers?

My pleasure!

Critical damping is very important. For a particular application (spring rate dependent) we like to set critical damping roughly at the middle of the damping range (actually a bit closer at the soft end of the range - i.e. jet open) This then allows the user to over or under damp the shock absorber.

Both the low and high speed force of the shock are extremely important and are taken into consideration. I would be more than happy to post some plots up of the FRS dampers. I probably can make a video of it as well.

Let me try and see if I can get to it mid next week as we have been extremely busy these past few months.

[Calum]

Originally Posted by Jenson May

My pleasure!

Critical damping is very important. For a particular application (spring rate dependent) we like to set critical damping roughly at the middle of the damping range (actually a bit closer at the soft end of the range - i.e. jet open) This then allows the user to over or under damped the shock absorber.

Both the low and high speed force of the shock are extremely important and taken into consideration. I would be more then happy to post some plots up of the FRS dampers. I probably can make a video of it as well.

Let me try and see if I can get to it mid next week as we have been extremely busy these past few months.

I look forward it!!

[Jenson May]

Originally Posted by CSG Mike

This is one of the best posts I've seen on this board. Props sir.

Hahah thanks

[Racecomp Engineering]

edited. This is a pretty good thread.

- andy