Get rid of accel/decel pitch
10-04-2017, 12:58 AM
#1
Burning Brakes
Thread Starter
Get rid of accel/decel pitch
2004 C5 with 150K. I'm loving the car but good lord it has a lot of pitch on acceleration/deceleration. Punch the gas and I'm looking at birds in the sky. Hit the brakes and I feel like I'm going over the steering wheel.
The car is currently 100% stock (I'm sure the shocks are shot), so I'm planning to pick up C5 Z06 springs, DRM revalved Bilsteins, and C6Z06 sway bars. Any suggestions/input?
To give some idea of my personality, back in my DD camaro days I ran full spherical bearing suspension front and rear, LG G2 coilovers and big sway bars. So I'm no stranger to stiff suspension and prefer to err on the side of oversteer (I can always get myself out of oversteer, I can't do anything with push).
The car is currently 100% stock (I'm sure the shocks are shot), so I'm planning to pick up C5 Z06 springs, DRM revalved Bilsteins, and C6Z06 sway bars. Any suggestions/input?
To give some idea of my personality, back in my DD camaro days I ran full spherical bearing suspension front and rear, LG G2 coilovers and big sway bars. So I'm no stranger to stiff suspension and prefer to err on the side of oversteer (I can always get myself out of oversteer, I can't do anything with push).
Last edited by ChrisLSx; 10-04-2017 at 01:01 AM.
10-04-2017, 04:02 PM
#2
Melting Slicks
What size and type of tires? This has a lot to do with sway bar thickness. Most people here use c6z51 sways on a c5. That's what I use with 275s up front and 295s in the rear on summer tires. I'm able to induce plenty of oversteer if I want, and the car is balanced pretty neutral in turns. I'm using c5z springs and 04 z06 shocks with c6z51 sways. The 04 z06 shocks are pretty much the best ones you can get for the c5z06 spring rates. The revalved DRM bilsteins are a close 2nd.
The following users liked this post:
ChrisLSx (10-04-2017)
10-05-2017, 09:37 AM
#4
Melting Slicks
Your best bet would be to buy used. I bought mine with 11k on them. Lots of people switch to coil overs and then sell them. New ones are outrageously overpriced and are not worth the price over the bilsteins.
The following users liked this post:
ChrisLSx (10-05-2017)
10-05-2017, 02:42 PM
#5
Melting Slicks
Saw these in the For Sale section. Good price on the C6 Z06 shocks. They're as good or better than the 04 Z shocks from what I've heard.
https://www.corvetteforum.com/forums...es-w-hubs.html
https://www.corvetteforum.com/forums...es-w-hubs.html
10-06-2017, 03:17 AM
#8
Drifting
i put in the 10313647/25819268 shocks and saw nearly no effect. dive surely didnt change. are the 04 shocks any better?
Last edited by romandian; 10-06-2017 at 03:27 AM.
10-06-2017, 09:28 AM
#9
Melting Slicks
It sounds like your Corvette is more of a daily/weekly driver so that would make a large factor in what you use for suspension setup. If you were autocrossing/HPDE and looking for the last possible 0.01 second then a single adjustable shock would be best. You could set it for softer compression/rebound and if you went to the track/lot you could increase or decrease according to the situation. For the other 99.9% of the owners, the 04Z shocks and DRM Bilstein shocks would be the firmest to use on the street, followed by the Johnny O'Connell valved Sach's. After that 06Z would be a good way to go. For the sways, a number of drivers have used a Z06 type bar up front and the standard C5z/Z51 rear bar to induce oversteer. The c5Z springs are would be fine. If you really want expert opinion contact Sam Strano, a forum member, on the optimum setup for you. He is a nationally recognized SCCA champ and car setup specialist and can be found in the Autocross/Road Race section.
10-06-2017, 12:19 PM
#10
Burning Brakes
Thread Starter
Can someone explain how the factory 04 Z06 shocks are better than (ie: DRM or Johnny O'Connell) revalved shocks? I'd think factory shocks would be softer valving (more tuned for ride quality) than an aftermarket valved shock.
Last edited by ChrisLSx; 10-06-2017 at 12:20 PM.
10-07-2017, 12:37 PM
#11
Melting Slicks
Back in 2002, the GM performance group was trying to take the Z06 around Nuremberg faster and found the shocks were under performing at speed. By the time they analyzed all the data and had the valving changed it was time to introduce the 2004 model year. Our local club is fortunate enough to be able to have various GM personal give some tech updates from time to time and one of the chassis engineers gave gave us the info.
If you are an autocrosser, the 04Z shocks give you less body roll and quicker rebound on sharp turns. The JOC shocks are very similar to the 04Z with less rebound, as I recall--been a long time since that was discussed. The DRM Bilstein's were designed more for HPDE and have valving to improve (smooth) transitions but are harsher on the street. The C6Z shocks are designed similar to the 04 but for a car 100+ lbs. more. When I changed from the early Z to the 04Zshocks, my lap times dropped about 1+ seconds on the average at Grattan raceway.
If you are an autocrosser, the 04Z shocks give you less body roll and quicker rebound on sharp turns. The JOC shocks are very similar to the 04Z with less rebound, as I recall--been a long time since that was discussed. The DRM Bilstein's were designed more for HPDE and have valving to improve (smooth) transitions but are harsher on the street. The C6Z shocks are designed similar to the 04 but for a car 100+ lbs. more. When I changed from the early Z to the 04Zshocks, my lap times dropped about 1+ seconds on the average at Grattan raceway.
The following users liked this post:
ChrisLSx (10-07-2017)
10-07-2017, 12:49 PM
#12
Burning Brakes
Thread Starter
Back in 2002, the GM performance group was trying to take the Z06 around Nuremberg faster and found the shocks were under performing at speed. By the time they analyzed all the data and had the valving changed it was time to introduce the 2004 model year. Our local club is fortunate enough to be able to have various GM personal give some tech updates from time to time and one of the chassis engineers gave gave us the info.
If you are an autocrosser, the 04Z shocks give you less body roll and quicker rebound on sharp turns. The JOC shocks are very similar to the 04Z with less rebound, as I recall--been a long time since that was discussed. The DRM Bilstein's were designed more for HPDE and have valving to improve (smooth) transitions but are harsher on the street. The C6Z shocks are designed similar to the 04 but for a car 100+ lbs. more. When I changed from the early Z to the 04Zshocks, my lap times dropped about 1+ seconds on the average at Grattan raceway.
If you are an autocrosser, the 04Z shocks give you less body roll and quicker rebound on sharp turns. The JOC shocks are very similar to the 04Z with less rebound, as I recall--been a long time since that was discussed. The DRM Bilstein's were designed more for HPDE and have valving to improve (smooth) transitions but are harsher on the street. The C6Z shocks are designed similar to the 04 but for a car 100+ lbs. more. When I changed from the early Z to the 04Zshocks, my lap times dropped about 1+ seconds on the average at Grattan raceway.
The following users liked this post:
ChrisLSx (10-09-2017)
10-09-2017, 12:30 PM
#18
Burning Brakes
Thread Starter
Well crud, just called my friend at the dealership and he says the fronts (10339944) are discontinued. I even gave him a vin# to a 2004 Z06 so he could cross reference and no luck. The rears (10339945) are still available ($174.49 each) but without matching fronts, that's kind of pointless.
I'm not big on buying used shocks (unless they are super low miles), so I guess I'll be doing aftermarket.
Bilstein Sports or something better? I'm buying a pair of C5 Z06 springs from a forum member, so that's what these shocks needs to work with.
I'm not big on buying used shocks (unless they are super low miles), so I guess I'll be doing aftermarket.
Bilstein Sports or something better? I'm buying a pair of C5 Z06 springs from a forum member, so that's what these shocks needs to work with.
Last edited by ChrisLSx; 10-09-2017 at 12:31 PM.
10-09-2017, 12:36 PM
#19
Melting Slicks
No, with shocks you have to take the effect of the compression and rebound valving. With non-adjustable shocks it becomes part of the equation of tires, spring rates and shocks. If I were a boulevard driver and wanted some occasional spirited driving I would get the 06Z or JOC shocks, If I was a dedicated HPDE fan and I would have either the 04Z or DRM shocks, for autocrossing the 04Z shocks would be best. When you start changing springs, sway bars, etc, and I was looking for top notch handling, then I would opt for the single or double adjustable shocks like Koni, Penske, etc. Define what is you goal and then set it up accordingly. For the OP, the setup he is suggesting is fine, if he wanted slightly more agressive he has options.
Regarding the 06Z shocks, they were designed to work best with the stiffer springs and larger front sway bar than the stock ones.
Regarding the 06Z shocks, they were designed to work best with the stiffer springs and larger front sway bar than the stock ones.