sothpaw2

Last week there was an interesting thread regarding C5Z vs C6 Z51. I think this topic had come up many times before, but this time there was a lot of opinion that the C6 z51 in stock trim didn't handle nearly as well as the C5Z and also had some nasty reliability issues (the engine, and I think the diff etc). In particular, there was vid showing the C6 Z51 going into somewhat unpredicted oversteer after hard braking.

So my question: Does the C6 GS still have this same oversteer characteristic which the C5Z does not? Which is the better handling car?
The dry sump of the C6 gS should fix the LS3 oilling issues, but what about the diff, etc?

Above are not serious, immediate need questions but I find it a very intersting topic in that I see the C6 GS as a likely upgrade at some point to my street C5Z that sees a few track days per year. Most of what attacted me to the C5Z is its proven track prowess and in particular its praised handling characteristics.

Thanks,

Andy

trapp

I would go with the GS.....Wider tires..bigger better brakes...dry sump...

sothpaw2

C5Z can have wide tires and AP racing brakes for relatively little money in the grand scheme of the cost of a track car. However, upgrading suspension (to fix the oversteer) and replacing diff or axle parts repeatedly would be a pain. Plus I'm not sure if LS3 w/GM dry sump has actually proven reliable in the last 3 years.

Has it? Does the stock GS suspension still have the oversteer?

redtopz

GS would be the way to go now IMO. The C5Z is a great car, but all the parts are obsolete including the engines. GM no longer carries most of them. Grandsports can be made to handle however you like with simple mods plus they come with factory coolers, dry sumps, and wide tires.

VatorMan

I've been tracking my GS since it was new in 2010. No problems at all with the drive train.

hklvette

Doesn't the GS use the same exact hardware as the C6Z? Don't recall hearing about any rear driveline issues with them...

QUIKAG

Yeah, first time I've heard of rear diff issues. I never had an issue with my '08 Z51. I added the extra quart of oil, pads, tires, and brake fluid and pounded the car for 3 years on track with no problems.

The C5 Z is a sweet ride, but at this point, I would think the GS with the LS3 dry sump and the Z06 goodies would be the way to go. Plus, it should have a warranty.

93Polo

Which car had oversteer?

skyavonee

I love my C5Z... but would prefer a C6 GS.

As others have noted: stronger powertrain, dry sump, bigger tires/brakes. Any supposed balance issues can usually be dealt with pretty easily with adjustable sway bars and a proper alignment, both of which are fairly cheap.

cleanerPA

The only C6 that has differential issues is the 2005 due to the bad design of the mounts.

As for oversteer, that's a new one. I know that my C6 had some oversteer when cornering hard on a bumpy surface as the rear shocks could not maintain traction. That was fixed with Callaway/Eibach shocks. Any good aftermarket shock with good valving should fix that issue.

trapp

I have an 2011 and it has been solid for 2 years going on 3 years of hard tracking......no problems whatsoever.........

JeremyGSU

Just curious but what parts are obsolete? I've bought some parts in the last year without issue. And even if the dealer doesn't carry them the parts are out there. Check out Eklers.

redtopz

What I mean is that GM is no longer manufacturing many (or most) parts for the C5. You have to find used or remanufactured parts.

Supercharged111

Does anyone have back to back experience? I think this a great topic, just leave price out of it. I see a lot of satisfied customers on both sides here.

Scooter70

Steering rack is a big one. Also the earlier C5s have some computer modules that are no longer available. It will only get worse as the cars get older.

93Polo

EBCMs on the 97-00 have generated plenty of talk. 01+ have been repaired and are available, last I read.

Even when I had my '00 7 years, key fobs were much less expensive for 01+ than the earlier ones.

crimlwC6

I had a 2008 c6 base and then got a 99 frc. I pulled the pfadt shocks and swaybars from the c6 and put them on the frc. The frc did have the carpet removed and lighter seats when I got it (it was a track school car). It is difficult to compare since I've improved as a driver but 2 cents.... I will say I love the c5 (I've now taken about 250 lbs or more out of it and done some other things). I miss the motor of the ls3.
The c5 feels like a smaller car to me and seems to rotate easier (factually it is a bigger car). This could be car to car variation or just bad memory on my part or ghosts in the c6 code that never truly lets the car 100% free of electric nannies . The ls3 pulls like a hoss compared to the ls1 but my ls1 has 91k miles and 7k of those are track miles and has never been refreshed to my knowledge.
I'm very happy with my choice but I was not happy at the (un)expected costs I ran into getting a 12 year old car track worthy. Steering rack, front main seal, torque tube bushings...
I don't recall seeing any issues with the GS motors (plenty of debate on the LS3 w/o dry sump). I do feel like the C5 rotates easier. I do think getting newer typically means less surprises once you start tracking. My youtube channel has the two cars running on the same tracks. http://www.youtube.com/user/awlittle13?feature=guide

ZedO6

The C6 electronic nannies and TPM issues were a factor for me. Plus...the price difference between a C5Z and a C6 GS can buy a lot of upgrades...

Bill Dearborn

I only know of one failure that can be repaired in the 01 and up EBCMs. That is the replacement of the relay in the power feed to the BPMV. Any failure outside of that they can't perform. If you send your unit into them for repair of a non relay issue and they send one out of stock you may get lucky and get one that didn't have that failure but that wasn't because they had repaired the unit. Just luck. If the repair facility has no way to detect what the problem is (requires test equipment with far more capability than a Corvette or Tech 2), no way to buy a proprietary replacement component if they do know and no way to test (see test equipment requirement) if the repair worked there is no way to get a good replacement module other than magic. When you get a C1251 which I think is the code for a general internal failure inside the EBCM electronic components your module is toast. If GM hasn't stopped purchasing these modules from their supplier they soon will as the internal components are more than likely on the component suppliers obsolete list. When the component supplier does that the module becomes obsolete and GM doesn't purchase any where near the volume of components for the component supplier to consider changing its mind. Just the nature of business in the electronics world.

Bill

JeremyGSU

I would stick with the C5 Z. Everything I've read says the LS6 is pretty much the most reliable track motor that has been in a Z. Hard to beat that if you're on a budget, even if parts are getting harder to find.