[Z06] What makes 2004 Z06 shocks so good?
11-23-2013, 08:04 PM
#41
Yes, they have the Sachs name from Germany.......but the GM shockes are made in Mexico...pick your quality level.
11-23-2013, 08:18 PM
#42
Race Director
typically made in the usa, canada, europe or japan means top tier everything
honestly...i really don't know if the new shocks are the same as the usa made ones that were actually used in 2004. i'm sure they are made to the same specs but it's hard to say if the materials are the same level
11-23-2013, 08:45 PM
#43
Melting Slicks
Rolling /driving normal speed on a street and punching it. I've learned long ago to be very smooth with the throttle application.
Last drove it more than a month ago, its cold now but wasn't that cold back then, plus I drove all late Summer with these tires.
Mexico these days is doing some very good work, they are even making many aerospace parts these days and turning out a fair amount of engineers.
Last drove it more than a month ago, its cold now but wasn't that cold back then, plus I drove all late Summer with these tires.
Mexico these days is doing some very good work, they are even making many aerospace parts these days and turning out a fair amount of engineers.
11-23-2013, 10:12 PM
#44
Drifting
As Solofast posted earlier, Dennis Grant had dyno'ed the Bilsteins and the 2004 Sachs OEM shocks. Furthermore, Dennis dyno'ed both the Bilstein HDs and Sports. See link below.
http://farnorthracing.com/autocross_secrets18.html
It is important to note that Dennis dyno'ed the shocks on the same dyno, with the same procedure.
If I recall correctly, Dennis used a Roehrig shock dyno. Where he worked was only a couple of miles from my office, so ATI (his employer) did some work on my car. ATI has moved out of the motorsports arena and returned to their core business of measurement equipment, and Dennis ventured off several years ago into other fields of endeavor.
Last edited by acrace; 11-23-2013 at 10:15 PM.
11-26-2013, 11:48 AM
#45
2nd Gear
Member Since: Nov 2013
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Yup. That was me.
I see that OP ripped off my graphics and stuffed them on photobucket, and that a big chunk of the text is also stolen directly from A2W... but hey, plenty of other people like to rip off material from A2W so why should OP be any different?
The dyno was actually a SPA. I had a mid-level model with a prototype power preload motor. It was a pretty nice piece of kit.
Those Z06 shocks are excellent. In fact, if you bought the ~$2000 a corner high-zoot Penske Coilover kits we sold, part of the QA process before those shocks were shipped was to run a full sweep of the shocks on the dyno and then I matched them to the OEM shocks.
As a customer you were free to twiddle ***** to your heart's content, and those Penskes had *awesome* control authority and pretty good linearity, but the default setting as-shipped was 100% OEM. And boy howdy, the number of times I got feedback from customers about how much better my shocks were than OEM... "I just bolted them on and went faster" - placebo effect demonstrated.
Leaf springs vs coils - car doesn't care. Only real advantage to coils is better/easier rate selection. Race tires coils are better because you need stiffer springs to offset the grip increase and higher max roll angle; how much depends on tire, and it's hard (or used to be at least) to get the kind of granularity in leafs that you can in coils. 25 lbs stiffer is easy in coils, not so much in leafs.
Street car, street tires? Keep stock springs, keep stock shocks. No need to upgrade at all. Drop car an inch and be done with it. GM did their homework on that car.
"Other fields of endevour" - yup. A field outside Kandahar City, a field outside of Gagetown, a field outside of Wainwright....
Hey Al. Sorry I didn't get a chance to say goodbye before I moved out of town.
Folks - listen to Al here. He knows his **** and can drive. You can take 90% of what he says to the bank.
DG
I see that OP ripped off my graphics and stuffed them on photobucket, and that a big chunk of the text is also stolen directly from A2W... but hey, plenty of other people like to rip off material from A2W so why should OP be any different?
The dyno was actually a SPA. I had a mid-level model with a prototype power preload motor. It was a pretty nice piece of kit.
Those Z06 shocks are excellent. In fact, if you bought the ~$2000 a corner high-zoot Penske Coilover kits we sold, part of the QA process before those shocks were shipped was to run a full sweep of the shocks on the dyno and then I matched them to the OEM shocks.
As a customer you were free to twiddle ***** to your heart's content, and those Penskes had *awesome* control authority and pretty good linearity, but the default setting as-shipped was 100% OEM. And boy howdy, the number of times I got feedback from customers about how much better my shocks were than OEM... "I just bolted them on and went faster" - placebo effect demonstrated.
Leaf springs vs coils - car doesn't care. Only real advantage to coils is better/easier rate selection. Race tires coils are better because you need stiffer springs to offset the grip increase and higher max roll angle; how much depends on tire, and it's hard (or used to be at least) to get the kind of granularity in leafs that you can in coils. 25 lbs stiffer is easy in coils, not so much in leafs.
Street car, street tires? Keep stock springs, keep stock shocks. No need to upgrade at all. Drop car an inch and be done with it. GM did their homework on that car.
"Other fields of endevour" - yup. A field outside Kandahar City, a field outside of Gagetown, a field outside of Wainwright....
Hey Al. Sorry I didn't get a chance to say goodbye before I moved out of town.
Folks - listen to Al here. He knows his **** and can drive. You can take 90% of what he says to the bank.
DG
11-26-2013, 02:15 PM
#46
Drifting
Hey DG - it is good to hear from you. I'm not big on Facebook and other social media. I PM'ed to you my e-mail addresses. If you feel like it, drop me a note from time to time.
Keep safe, buddy.
Keep safe, buddy.
11-26-2013, 03:27 PM
#47
Racer
Thread Starter
I just copied them to Photobucket so I could link them in the thread.
I didn't rip off any of your text though.
I've always enjoyed your website, and I was just trying to be helpful here to the C5 Corvette community.
11-29-2013, 01:33 PM
#48
Racer
What is also not kinda shown is that hysteresis can effect how a shock acts. The dyno plots shown are force average.
at lower shaft speed, you tend to see more divergence due to hysteresis. Depends how much bleed is in the stack.
An average force dyno doesnt show everything. Also, note that static nitrogen pressure, length of shock, bump stop material can materially affect handling.
at lower shaft speed, you tend to see more divergence due to hysteresis. Depends how much bleed is in the stack.
An average force dyno doesnt show everything. Also, note that static nitrogen pressure, length of shock, bump stop material can materially affect handling.
12-02-2013, 10:46 PM
#49
Safety Car
Member Since: Sep 2007
Location: Sunniest city on Earth
Posts: 4,169
Likes: 0
Received 21 Likes
on
20 Posts
12-23-2013, 11:42 AM
#51
Instructor
12-23-2013, 06:25 PM
#53
Race Director
rock auto or gm parts direct, local dealer may even price match another gm dealer online. rock auto has these shocks under the ac delco part number. the 5% discount code for dec-jan is 1872513816251248
12-23-2013, 06:27 PM
#54
Team Owner
Member Since: Aug 2005
Location: Riverside County Southern California
Posts: 34,988
Received 501 Likes
on
342 Posts
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
If I mod/swap these shocks with Bilsteins; What can I expect?
12-23-2013, 07:54 PM
#55
Melting Slicks
If you go with the Bilstien Sport shocks you won't really see a difference. If you look at the shock curves, the fronts are so close to the stock shocks that they are for all intents and purposes interchangeable.
The Bilstien rears have a bit more high speed force, but you will only notice that on very sharp bumps. In that case it will be a bit harsher, but again, unless you have a well calibrated bum you won't really notice it.
The Bilstien rears have a bit more high speed force, but you will only notice that on very sharp bumps. In that case it will be a bit harsher, but again, unless you have a well calibrated bum you won't really notice it.
12-23-2013, 08:24 PM
#56
Team Owner
Member Since: Aug 2005
Location: Riverside County Southern California
Posts: 34,988
Received 501 Likes
on
342 Posts
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
If you go with the Bilstien Sport shocks you won't really see a difference. If you look at the shock curves, the fronts are so close to the stock shocks that they are for all intents and purposes interchangeable.
The Bilstien rears have a bit more high speed force, but you will only notice that on very sharp bumps. In that case it will be a bit harsher, but again, unless you have a well calibrated bum you won't really notice it.
The Bilstien rears have a bit more high speed force, but you will only notice that on very sharp bumps. In that case it will be a bit harsher, but again, unless you have a well calibrated bum you won't really notice it.
Thanks
12-23-2013, 11:04 PM
#57
Race Director
that part about the high speed damping out back is also a big negative on the street. the car is faster over uneven terrain which you typically find on the street with the 04 shocks simply because they are more compliant and allow the car to react faster. the nurbugrng is really similar to the average street which may be why gm chose to set the valving there
the bilsteins are almost identical to the 02 shocks
the bilsteins are almost identical to the 02 shocks
12-24-2013, 03:09 PM
#58
Le Mans Master
I have the Bilstein DRM shocks on now, they are nice, less harsh. Will have to put more miles on to really see how they handle better, been doing SC upgrades and have not driven much. The car tends to spin a lot so have to be careful, especially in winter or in curves. I want to see if it has any wheel hop when I really get on it.
12-25-2013, 05:24 PM
#59
Instructor
I'm considering these 04 Z shocks, but my 03 is lowered on C6 bolts in the front and extended bolts in the rear. I reversed the rear shock mounts to stop the back end bottoming out. I know lowering will have an effect on the effectiveness of the shocks, but will I still see an improvement with the 04Z shocks? It is pretty harsh now..
Is anyone running the shocks on a lowered car?
Is anyone running the shocks on a lowered car?
Last edited by JoeJ; 12-26-2013 at 10:42 AM. Reason: typo
12-25-2013, 06:14 PM
#60
Le Mans Master
Depends how much you are lowered. Mine is lowered, from what I have read the Bilsteins work better for lowered cars. Mine was slammed, raised it some, but still low compared to stock, road a lot better, then switched shocks, road even better.