PP shock Dyno?

[Butterman]

Has anyone dyno'd the performance pack shocks?

[Lincoln Logs]

Probably not. What information are you looking for specifically?

[Butterman]

I'm looking mostly for shock dyno plots (speed v time) and gas pressure force. I've got some PP shocks and springs in the garage, I'm curious how they would be on a base BRZ. Considering the unsprung mass on a base model is less than the PP because of the lighter brakes and the base shocks are already critically damped or overdamped, I would assume the PP would be too much damping but I can't any make any decisions without seeing numbers and doing some math first :P

[Leonardo]

Originally Posted by Butterman

I'm looking mostly for shock dyno plots (speed v time) and gas pressure force. I've got some PP shocks and springs in the garage, I'm curious how they would be on a base BRZ. Considering the unsprung mass on a base model is less than the PP because of the lighter brakes and the base shocks are already critically damped or overdamped, I would assume the PP would be too much damping but I can't any make any decisions without seeing numbers and doing some math first :P

The weight difference between a heavy driver and a skinny driver is going to be more than the difference in weight between a PP and a Base. Additionally, the difference in weight between the AT and the MT is greater than the difference between the PP and the Base. AT and MT have the same suspension...

I am not understanding what the info is going to tell you?

[Lincoln Logs]

Originally Posted by Leonardo

I am not understanding what the info is going to tell you?

This is what I was trying to figure out. To the OP: you're splitting hairs here. They are a significantly better shock that the standard ones, install them and enjoy. Don't over think it.

[subaru]

It doesn't matter bc the standard are terrible shits. PP will improve all areas.

[Butterman]

To put it simply, I enjoy numerical simulations.

If you want the long, philosophical answer. It's basically like making a souffle and throwing in some more baking powder and serving it to somebody. You don't know if baking powder is the right ingredient to add nor do you know how much you need to put in, not that you know if the person about to eat it will even enjoy it with more baking powder in it.

Now, an expert chef could probably tell you how much more to put in but how many professional desert chef’s do you know, would they do it for free? I bet you could ask your mom, your grandmother or your sister but are they actually good bakers or are they just good at making cookies? The there are some people that just throw money at the problem and make a million souffles with a variety of spices and quantities. Then you have food scientists that look at statistics and use chemistry in order to predict the changes they are making and pinpoint their efforts; call me a food scientist.

I don’t mean to sound arrogant here but I know how to interpret the data, I can do the math and create a decent guess at how much of an impact my changes will make without ever making the dish. Unfortunately, I need the data.

@ leonardo, it's more about unsprung mass and not so much the weight of the entire car
@subaru I wouldn't say that. Everything on a car is a compromise. Subaru had to compromise on the cost/ride quality (NHV)/high speed performance/ low speed performance.

I've seen a lot of people saying things about these shocks but not one person has presented any data or reason. Just because it's a different shock and it came on the "performance" version doesn't mean it's better. It's important to understand it's use case, it's compromises and how it will affect the other aspects of the system.

[Leonardo]

Originally Posted by Butterman

To put it simply, I enjoy numerical simulations.

If you want the long, philosophical answer. It's basically like making a souffle and throwing in some more baking powder and serving it to somebody. You don't know if baking powder is the right ingredient to add nor do you know how much you need to put in, not that you know if the person about to eat it will even enjoy it with more baking powder in it.

Now, an expert chef could probably tell you how much more to put in but how many professional desert chef’s do you know, would they do it for free? I bet you could ask your mom, your grandmother or your sister but are they actually good bakers or are they just good at making cookies? The there are some people that just throw money at the problem and make a million souffles with a variety of spices and quantities. Then you have food scientists that look at statistics and use chemistry in order to predict the changes they are making and pinpoint their efforts; call me a food scientist.

I don’t mean to sound arrogant here but I know how to interpret the data, I can do the math and create a decent guess at how much of an impact my changes will make without ever making the dish. Unfortunately, I need the data.

@ leonardo, it's more about unsprung mass and not so much the weight of the entire car
@subaru I wouldn't say that. Everything on a car is a compromise. Subaru had to compromise on the cost/ride quality (NHV)/high speed performance/ low speed performance.

I've seen a lot of people saying things about these shocks but not one person has presented any data or reason. Just because it's a different shock and it came on the "performance" version doesn't mean it's better. It's important to understand it's use case, it's compromises and how it will affect the other aspects of the system.

So you are saying that the weight of the PP brakes effects the handling more than the difference in weight between the MT and AT transmissions?

[86MLR]

Originally Posted by Butterman

To put it simply, I enjoy numerical simulations.

If you want the long, philosophical answer. It's basically like making a souffle and throwing in some more baking powder and serving it to somebody. You don't know if baking powder is the right ingredient to add nor do you know how much you need to put in, not that you know if the person about to eat it will even enjoy it with more baking powder in it.

Now, an expert chef could probably tell you how much more to put in but how many professional desert chef’s do you know, would they do it for free? I bet you could ask your mom, your grandmother or your sister but are they actually good bakers or are they just good at making cookies? The there are some people that just throw money at the problem and make a million souffles with a variety of spices and quantities. Then you have food scientists that look at statistics and use chemistry in order to predict the changes they are making and pinpoint their efforts; call me a food scientist.

I don’t mean to sound arrogant here but I know how to interpret the data, I can do the math and create a decent guess at how much of an impact my changes will make without ever making the dish. Unfortunately, I need the data.

@ leonardo, it's more about unsprung mass and not so much the weight of the entire car
@subaru I wouldn't say that. Everything on a car is a compromise. Subaru had to compromise on the cost/ride quality (NHV)/high speed performance/ low speed performance.

I've seen a lot of people saying things about these shocks but not one person has presented any data or reason. Just because it's a different shock and it came on the "performance" version doesn't mean it's better. It's important to understand it's use case, it's compromises and how it will affect the other aspects of the system.

I found the Sachs damper/spring combo really crashy on the street

The valving might be good on a smooth track/road, but on the streets I didn't like them

Mine lasted about a month or two before I replaced them

I use MCA street performance coilovers now and the ride is better, everywhere, and for $2000 AUD they were a bargain

As for data, I haven't seen any, you most likely will need to buy a damper and throw in on a shock dyno yourself

[strat61caster]

I thought race comp put them on a Dyno and posted somewhere that got taken down after a few weeks (pretty common for most vendor posts I've seen), might be able to email them.

Could also buy them and have them dynod at a local damper servicer, might cost a hundred bucks or two but it shouldn't be an impossible service to find.

[Butterman]

Originally Posted by Leonardo

So you are saying that the weight of the PP brakes effects the handling more than the difference in weight between the MT and AT transmissions?

TL;DR: bump control is dependent on unsprung mass and body motion (heave, pitch, roll) is dependent on sprung mass

Long story:
It depends, handling is a complex system of suspension response characteristics that isn't just good or bad. Overall grip is just as important to consider as drivability and transient response.

Shocks dampen a couple different types of motions, pitch, roll, heave, bump. Ideally you'd have 10 specific dampers to individually control each motion. On road cars you'll usually only see 4, manufacturers do this because the it takes up more space, it requires more development and it adds cost. MFGers are able to get good enough performance with only 4 shocks to control all types of motions, critical to this is the split between the high and low speed reaction of the dampers.

Pitch, roll and heave are body motions that are relatively low speed motions
and as such are controlled by the low speed damping of the shock. You'll notice this as the first, steep region of velocity-force plot of the shock dyno. Because this motion deals with body motions it is dependent on the sprung mass (mass of the chassis).

Bump is generally a high speed action and is controlled by the high speed damping of the shocks and is dependent on the unsprung mass. More mass = more momentum. Imagine that you're playing a game of catch with somebody and you're using a medicine ball and that you're trying to catch and throw the ball as fast as possible. Imagine, they're super strong and that they take it easy on you and regardless of the weight of the ball they throw it the same speed each time. You're only so strong but if you guys switch to a lighter ball, it'll be easier to catch and throw the ball right, and so you can do the motion faster. Does that make sense?

Consider hitting a bump at 30 mph with a 20lb brick strapped to your control arm, the bump will always push that mass up at the same speed but now you've got more mass (and thus momentum) that your suspension has to push back down to the road. It's only got so much force (provided by your spring and shock) so it'll take longer than without the weight, right? So you'll notice that with the 20lb weight, the bump will feel harsher and your car will feel unsettled for longer after the bump.

[Butterman]

Originally Posted by strat61caster

I thought race comp put them on a Dyno and posted somewhere that got taken down after a few weeks (pretty common for most vendor posts I've seen), might be able to email them.

Could also buy them and have them dynod at a local damper servicer, might cost a hundred bucks or two but it shouldn't be an impossible service to find.

Thanks, I'll hit em up. ISC is near me but their machine is down right

[RayRay88]

On the flip side does anyone have a new non PP/standard 17+ shock dyno?
I'd be curious to see both and compare.

[Butterman]

Originally Posted by RayRay88

On the flip side does anyone have a new non PP/standard 17+ shock dyno?
I'd be curious to see both and compare.

I don't think the base model shock has changed after 2017. FRS and BRZ have different shocks.

FRS has more compression in the front and less rebound in the rear.


The PDFs are from TEIN but I'm not sure who the data in the image is from. I haven't compared the two so I don't know how well the two datasets correlate. Which would be interesting to know if both datasets are from high quality machines.