Standard Shocks vs Sachs Performance package

[Racecomp Engineering]

A lot of "sport" suspensions at this level of car and beyond are more designed for a sporty feel than actual performance. They way they designed in the handling balance characteristics on these cars is another example. I do think the PP dampers are better on track and a solid improvement in every way over the early shocks for the twins. And definitely an upgrade if your original OEM shocks have 80k miles on them!

- Andrew

[Mike_ZN6]

I don't see why you would go through the effort and cost of switching to PP dampers/springs when you could just get one of the affordable coilover setups out there.

[Mball19]

I installed TRD springs on my car with the Sachs and i think that it rides and handles better than with the stock springs. It seems to absorb impact better with the TRD springs, while being flatter in corners.

[churchx]

Mike_ZN6: imho there might be good deals for used PP ones from someone parting out them exactly because upgrading to something else. So imho instead of choice between PP vs aftermarket coilovers, it's rather OE vs PP.

[Racecomp Engineering]

Originally Posted by Mball19

I installed TRD springs on my car with the Sachs and i think that it rides and handles better than with the stock springs. It seems to absorb impact better with the TRD springs, while being flatter in corners.

Stock has always been fairly overdamped in compression and rebound...gives it that "sporty feel" that ends up being crashy in certain instances and not always the best performance or ride.

Some lowering springs are actually a better match to stock shocks in terms of rebound % critically damped than stock springs. The problem is that most of springs lower too much and there's not enough travel, so it doesn't matter. RCE Yellow (duh), TRD, Eibach Prokit, and Swift are the only springs I would consider.

- Andrew

[N_Raged]

Originally Posted by Mike_ZN6

I don't see why you would go through the effort and cost of switching to PP dampers/springs when you could just get one of the affordable coilover setups out there.

Sure coilovers have come a long way and "cheap" doesn't always mean bad. But not everyone wants to bother with the complexity of coilovers. And some people like myself need to keep the car OEM whether it's to maintain ride height for winter driving, or to stay in stock class at autocross.

[Yoshoobaroo]

Originally Posted by Racecomp Engineering

Stock has always been fairly overdamped in compression and rebound...gives it that "sporty feel" that ends up being crashy in certain instances and not always the best performance or ride.

Some lowering springs are actually a better match to stock shocks in terms of rebound % critically damped than stock springs. The problem is that most of springs lower too much and there's not enough travel, so it doesn't matter. RCE Yellow (duh), TRD, Eibach Prokit, and Swift are the only springs I would consider.

- Andrew

Can you share some information on how the PP dampers match with the yellows vs OEM springs? Are they still slightly over damped with the Yellows?

[Racecomp Engineering]

Originally Posted by Yoshoobaroo

Can you share some information on how the PP dampers match with the yellows vs OEM springs? Are they still slightly over damped with the Yellows?

Background:
1. "Critically damped" or a critical damping ratio of 1.0 means no "overshoot".
2. The "rule of thumb" damping ratio is 65% or 0.65 for sports/race cars for rebound. Some consider more than this to be "overdamped"....some consider more than critically damped (1.0) to be overdamped. For me, overdamped just means too much damping. Lots of factors could lead to more (or less) damping to be "ideal" for a given application and "ideal" will probably be different at each end of the car.
3. The ideal damping ratio also depends on piston speed. A relatively lower damping ratio for high piston speeds (bumps) is generally a good thing for some cars. A higher damping ratio for lower piston speeds (body roll) is generally a good thing for track cars. That's a digressive shock.

Since I have the #s handy....

With the 2013 shocks, the fronts are what most would call overdamped in rebound at both low and high speeds, with both stock and our RCE Yellows. Well over 1.0 in low speed (about 1.15 at 2 inches per second with RCE Yellows), and > 0.80 for high speed. The rears are between 0.60 and 0.70 for both low and high speed with our Yellows.

For PP shocks it's a little better, but not that different. I unfortunately do not have those #s handy. It certainly does not go below 0.60 up front.

- Andrew

[Yoshoobaroo]

Originally Posted by Racecomp Engineering

Background:
1. "Critically damped" or a critical damping ratio of 1.0 means no "overshoot".
2. The "rule of thumb" damping ratio is 65% or 0.65 for sports/race cars for rebound. Some consider more than this to be "overdamped"....some consider more than critically damped (1.0) to be overdamped. For me, overdamped just means too much damping. Lots of factors could lead to more (or less) damping to be "ideal" for a given application and "ideal" will probably be different at each end of the car.
3. The ideal damping ratio also depends on piston speed. A relatively lower damping ratio for high piston speeds (bumps) is generally a good thing for some cars. A higher damping ratio for lower piston speeds (body roll) is generally a good thing for track cars. That's a digressive shock.

Since I have the #s handy....

With the 2013 shocks, the fronts are what most would call overdamped in rebound at both low and high speeds, with both stock and our RCE Yellows. Well over 1.0 in low speed (about 1.15 at 2 inches per second with RCE Yellows), and > 0.80 for high speed. The rears are between 0.60 and 0.70 for both low and high speed with our Yellows.

For PP shocks it's a little better, but not that different. I unfortunately do not have those #s handy. It certainly does not go below 0.60 up front.

- Andrew

That's helpful, thanks! My main worry about PP+Yellows was that the extra spring rate would overwhelm the shocks.

[Ernest72]

Not to thread jack, but it’s related. so do you go rce yellows/ Bilstein b6 or another lower spring with b6 for DD or go to coil overs. Have 50k on my stockers but will be thinking about it in a year or two with my mileage a year (15k a year)

[ZDan]

Originally Posted by Yoshoobaroo

That's helpful, thanks! My main worry about PP+Yellows was that the extra spring rate would overwhelm the shocks.

IMO slightly spring rates (within reason) "overwhelming" shocks is a bit of a myth...

The fact is that critical damping varies with the *square root* of spring rate, not linearly. So a given damper will generally accommodate a fairly wide range of spring rates. If you were at, say 75% of critical damping with stock springs, you'll be at 66% critical damping with 30% stiffer springs.

I don't feel underdamped at all running Swift BRZ Sport springs with the stock PP dampers, and they're 34%F/43%R stiffer than stock. If anything still overdamped in terms of high-speed damping.

My bigger concern is the lack of bump travel with the stock dampers and running 30mm lower than stock...

[Racecomp Engineering]

Originally Posted by Ernest72

Not to thread jack, but it’s related. so do you go rce yellows/ Bilstein b6 or another lower spring with b6 for DD or go to coil overs. Have 50k on my stockers but will be thinking about it in a year or two with my mileage a year (15k a year)

Good question...our first BRZ shop car (owned by Myles) got a whole lot of goodies and was pretty track focused.We ran RCE Tarmac 2s, Ohlins (modified), JRZ, Bilstein, etc.

For our 2nd shop car....which is my personal car...we were targeting a more mild mostly DD build. My initial plan was Bilstein B6 with our RCE Yellows, which I'd spent plenty of time on. That changed because the Bilsteins were out of stock for like 2 years, and then we developed our RCE SS1 coilovers. So I helped develop those and run the final product on my car (and now it's turning into a rally-x car, but that's another story).

The advantage of the Bilstein B6 + RCE Yellow setup is that it's simple. Just put them on, get a good alignment, and go have fun. It rides and handles well, and you can focus on driving. One limitation is that it's not ideal with wide sticky tires. But with a 225 Michelin PS4s or similar, it's great. For roughly $1200, it's a great simple DD set up for a fun street car.

Coilovers can be better, but they're not always better. The damper itself is the most important part of the equation and most options under $1500 have valving that is not as good as a Bilstein B6. More features like height adjustability and camber plates etc., but the shock valving itself isn't always great. They may not have a lot of travel and the camber plates they use can be junk.

That said...there are a couple good coilover options under $1500 with impressive valving for the money. You'll usually get stiffer spring rates than RCE Yellows (which is good if you have stickier and/or wider tires), and sometimes more travel. The good ones at that price point (RCE SS1, CSG Flex, Bilstein B14) will ride at least as good as stock with much better handling. They'll still require a bit more effort to get set up just right, but shops like us will help you with that.

Beyond $1500, most coilovers will be more track focused, but can still be tuned to provide a good DD ride with the right set up.

Hope that helps. Happy to answer PMs too.

- Andrew

[Tanstin]

Originally Posted by Racecomp Engineering

Good question...our first BRZ shop car (owned by Myles) got a whole lot of goodies and was pretty track focused.We ran RCE Tarmac 2s, Ohlins (modified), JRZ, Bilstein, etc.



For our 2nd shop car....which is my personal car...we were targeting a more mild mostly DD build. My initial plan was Bilstein B6 with our RCE Yellows, which I'd spent plenty of time on. That changed because the Bilsteins were out of stock for like 2 years, and then we developed our RCE SS1 coilovers. So I helped develop those and run the final product on my car (and now it's turning into a rally-x car, but that's another story).



The advantage of the Bilstein B6 + RCE Yellow setup is that it's simple. Just put them on, get a good alignment, and go have fun. It rides and handles well, and you can focus on driving. One limitation is that it's not ideal with wide sticky tires. But with a 225 Michelin PS4s or similar, it's great. For roughly $1200, it's a great simple DD set up for a fun street car.



Coilovers can be better, but they're not always better. The damper itself is the most important part of the equation and most options under $1500 have valving that is not as good as a Bilstein B6. More features like height adjustability and camber plates etc., but the shock valving itself isn't always great. They may not have a lot of travel and the camber plates they use can be junk.



That said...there are a couple good coilover options under $1500 with impressive valving for the money. You'll usually get stiffer spring rates than RCE Yellows (which is good if you have stickier and/or wider tires), and sometimes more travel. The good ones at that price point (RCE SS1, CSG Flex, Bilstein B14) will ride at least as good as stock with much better handling. They'll still require a bit more effort to get set up just right, but shops like us will help you with that.



Beyond $1500, most coilovers will be more track focused, but can still be tuned to provide a good DD ride with the right set up.



Hope that helps. Happy to answer PMs too.



- Andrew

Not the guy who asked the question, but thank you. Very informative

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[Ernest72]

Originally Posted by Tanstin

Not the guy who asked the question, but thank you. Very informative

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I echo above. Thank you very much.