Background: Have a 2000 coupe MN6 with C6 Z06 sways, metal end links, C5 Z51 springs font and rear, lowered aout 3/4", and C6 Z06 shocks. Also, running 18 inch all around, 275/35 front, 295/35 rear, and the elite tunnel plate. This is a daily driver that may see an occassional track day.

Issue: while it handles very nice I will bottom out the shocks on moderate bumps. small dips, railroad tracks, etc. Not consistently, but on occassion. The ride is firm but not jarring execpting when it hits the stops.

Question: are the C6 Z06 shocks just not adequate to handle the changes? Would either Bilstein HD or Sport shocks be any better? Would Koni FSD's be any better?

Please assume that I will not be entertaining coil overs at this point. I appreciate that they may be the utimate solution, but they are currently not in the budget. Thanks for any input, especially from those actually running the shocks mentioned.

Ok heard from the Bilstein guys, but no one running a lowered C5 on Koni FSD's and how it does?

Looking for some input before making a choice. Thanks for any insight.

 

Stock shocks are not able to handle much lowering. The Bilstein HD's are not good for it either. They are a stock style replacement. The Sports would be good because they are meant to keep damping characteristics on a lowered vehicle.

 

When the car is lowered, the OEM shock begins to operate at the extreme lower limit of it's travel and will bottom out, internally. This is a very dangerous situation, which could cause you to loose control of the vehicle.

I have no personal experience with the Sports, but others have reported that the Sports have solved this problem.

 

vs. Koni FSD for the c6 Corvette?

 

FWIW, I just went down this path. I have a '02 Z06 with 72K on it and felt it was time for new shocks. My decision was based on miles more than anything else. No complaints. I went with the Bilstein sports. The C6 Z06 shocks sound nice, but just not intended for a C5. That narrowed it down to '04 Z06 or Bilstein. From reading on this forum, it sounds like the bilstein are the same on the front shocks compared to the '04, and the rear shocks slightly softer. The main thing that swayed my decision was the quality of Bilstein over GM shocks. I'm sure either would be an improvement over the old stockers, but I don't think you can really go wrong with either one. The bilsteins are slightly cheaper, but not by that much. Hope this helps.

 

No for a C5.

 

I am very happy with my Bilstein Sports

 

From what I am gathering the C6 Z06 shocks are fine on the C5 until you lower the car. Then they run out of travel to handle it. I thought I was not lowering it enough to run into this problem but it seems I am. Thanks.

 

My C5Z is just intended for road use and it looks soooo much better lowered. To be honest, the only reason I still have this car is because my 5yo little boy loves it. Take everything I have to say with a grain of salt

 

Ok heard from the Bilstein guys, but no one running a lowered C5 on Koni FSD's and how it does?

Looking for some input before making a choice. Thanks for any insight.

 

Wow, there are a lot of popular misconceptions about shocks here....

The Bilstein Sport shocks allow no more travel than the stock C5 shocks. If anything, the C6Z06 shocks are slightly longer but not much. You can easily get as much travel with them by taking them apart and cutting the bump stop in 1/2.

None of the stock shocks are damaged by bottoming out. There is a big yellow bump stop that hits first and since it is a bump stop it was put there by the factory specifically to stop the suspension from compressing.

Bottoming out will upset the car just as badly no matter what shock you have.

Now, the reason the Sport shocks can help is that they have more compression resistance. The car won't be as likely to bottom out if the suspension doesn't compress as much when you hit a bump. The flip side of this is that they give a harsher ride. Another thing to note is that the Bilstein bump stop is rather poor. It will fail and allow metal to metal bottoming in short order. I'd suggest using something a little heavier. Try a top bushing for an old school GM shock.

On yet another note, you can increase the travel in the rear fairly easily. Take the shocks out and remove the top plates. Grind the lip around the edge so they fit into the shock mount upside down. Now, assemble the shocks again with the plates on upside down and install again. I'd have to look at one again but I think you also have to swap them left for right. This works assuming your wheels won't hit the fenders with the extra travel.

 

I don't think so....

The plate on the top of the shock has the flange pointing down to start with, and the top of the plate bolts to the bottom of the frame...

There is a pretty big hole in the frame for the top of the shock mount to go into, but the top plate is just sandwiched between the rubber shock mount bushings. You would need to make a new top plate, with the center cut out and an extension to move the mounting surface up into the frame to do what you are talking about. Not that it couldn't be done, but there's a lot more to it than just grinding off the flange...

 

I run the FSD's on my lowered '02 Z. They are very nice shocks, but
I put the stock bump stops back on to prevent harsh bottoming.

 

So, you had a bottoming problem with the FSD's? Adding bump stops would only make it bottom sooner, although, perhaps not quite so harshly.

You may not break anything with the bump stops installed, but any time your suspension has bottomed, it has ceased to function.

How much did you lower the car?

 

Lowered max amount on stock bolts. I would NOT call it a bottoming problem on regular/ nice roads. More a problem going over RR tracks
or thru Chicago's fine construction zones.

 

I think you need to look at that plate again. It has an 3/8" offset where the bushing mounts and the offset is down, just like you're describing. Flip it over and remove the flange and it moves the bushing mounting location up 3/4".

 

Ok so none of the shocks, in original form, will provide more travel (with the possible exception that the stock C6 Z06 may be slightly longer) without some sort of modification.
The Bilstein (Sports) may diminish the bottoming due to a better resistance to compression but at the expense of the ride, as in being stiffer.
The FSD’s don’t seem to have much feedback and they are expensive.
The car is not slammed (rides 4.5” at front jacking point, 5.0” at rear jacking point) so I may try the Bilstein Sport Shocks (with a heavier top bushing) to see if they eliminate the occasional bottom on the deeper pot holes or larger bumps. Hopefully they will not be much stiffer than the C6 Z06 shocks now in place.
A thanks for everybody’s input.

 

I recall checking the C6Z06 shocks against the stock ones and extended they were a bit longer. However, the old shock bump stop was thicker. So, that might have made the length difference a wash. I wasn't looking for the compressed length at the time or I would have done a better job comparing them.

It doesn't sound that bad. What's the concern about occasionally bottoming out on a bump here or there anyways?

 

Here are a couple of pics of the bracket from my 2004 Z06.. Don't know about your brackets, but mine came from the factory flat...

 

It is probably just disconcerting but not hurting anything. I would be only troubled if it did so while in a fast turn. If the Bilstein's will help and not increase the stiffness of the ride too much they are worth a try at a minimum expense. If they dont and I am still that concerned with it I will have to consider coil overs. Which then gets into another whole discussion, LG vs Pfadt vs QA1 vs .......Thanks.