ck_1la@yahoo.com

I came across these two separate test sheets from Car and Driver for a 2008 Z51 and a 2009 Z51. I cant attach it, so I will write them below.

You will notice they have very different times and handling (and weight distribution!), yet on the same tires and similar weather.

I have looked to see if there are mechanical (gearing and suspension) differences between the 2008 and 2009 Z51 through GM to no avail. I thought maybe the 2008 Z51 may have been in "Tour Mode" whilst the 2009 Z51 was in "Sport Mode" (the magnetic ride being turned on that is - but they make no mention of MRC anywhere).

Can anyone tell me if there are truly any differences between an '08 and '09 Z51?

See below test data from Car and Driver for differences (abbreviated).

2008 C6 Z51
Test date: 6/12/2007
Temperature - wet 65 dry 83
Traction Cntrl = Y (no mention of Magnetic Ride Control)
Stability Cntrl = Y (no mention of Magnetic Ride Control)
Tires – GY Eagle S1 Supercar EMT
Weight – 3299 lbs (53.31 front / 46.7 rear)
Road Holding – 0.95g
Accel:
30 = 1.7
60 = 4.0
100 = 9.2
120 = 13.2
140 = 18.2
150 = 23.5
¼ mile = 12.4 @ 116mph
Braking – 70-0 = 161 ft
Sound Level 70cr = 73

2009 C6 Z51
Test date: 9/26/2008
Temperature - wet 59 dry 79
Traction Cntrl = Y (no mention of Magnetic Ride Control)
Stability Cntrl = Y (no mention of Magnetic Ride Control)
Tires – GY Eagle S1 Supercar EMT
Weight – 3273 lbs (51.8 front / 49.2 rear)
Road Holding – 0.99g
Accel:
30 = 1.8
60 = 4.1
100 = 9.0
120 = 12.9
140 = 17.7
150 = 22.2
¼ mile = 12.4 @ 117mph
Braking – 70-0 = 152 ft
Sound Level 70cr = 79

Any input in easy to understand layman's terms would be appreciated.

Last - My C6 Z51 (LS3 motor, 6-Speed w/ Magnetic Ride Control) was manufactured in April of 2008. I bought it used with 11k miles. Is it considered 2008 or 2009?

Furthermore, where do all of the magazines get off saying that a Corvette C6 Z51 weighs 3270-3290 lbs when on the inside of my door it says 3696 lbs? I have a "base model" Z51. That is to say, one power seat, basic trim and NO HUD and NO BOSE. However I DO have Magnetic Ride Control (which comes in handy at the track when I zing past M3's!) and rims that are "brushed steel spoked stars" (for what it is worth, I found ONE SMALL PIECE of paper from GM that said these were apparently a $1800 upgrade above the regular chrome star rims - but they are almost impossible to clean in between the spokes. I have seen very, very few Corvettes with these "brushed star spoke" rims - all Z51's I am guessing bc the brake pads had the holes in them like mine.) I guess I found a "base model" with a strange option combination....

Any input is appreciated. Again in simple terms please.

Thanks - CK (Houston, Texas - 2008 Z51, LS3)

Bat Man

Ls3s and all other engines aren't exact at advertised hp/Tq.

The 2008/2009 are exactly the same. The difference could be driver, engine performance, tire wear/age, etc.

There are some ls3s in the 11s here on forum

Bradl1982

Didn't think 08 or 09 Z51 equipped cars could have F55 option as well. I could be wrong though.

roscoe118

Non GS (prior to '10) F55 cars came with Z51 brakes I believe. At least my wife's '08 did.

haljensen

I can answer the weight question; The door decal is the recommended MAXIMUM weight of the vehicle/occupants/luggage, not the weight of an empty car.

The Front to Rear weight balance will differ on nearly every car, depends on options and whether the car is an automatic with the torque converter in the rear or a stick with the clutch up front.

If the car was manufactured in April 2008 it's officially an '08, I don't think '09 production started until June '08.

Brake pads don't have holes, Z51 and Mag. brakes have cross drilled rotors.

Magazines rarely report the exact figures they get on tests, they all "adjust" the figures to a standard. A different "standard" for every magazine.

SouthBaySurfer

If your car has Magnetic Ride Control, it is not a z51. Check the RPO sticker inside the glovebox for a list of all the options on your particular car.

JohnAE455

Very minor differences in results. Different weight of drivers, amount of fuel, tire pressure, number of miles on the cars (how well broken in), even the slightly cooler temps. for the 2009 test could result in these differences.

Get_UmJ13

It is more likely an F55 that's what I found out about mine when pulled the codes from the glovebox

ck_1la@yahoo.com

I shall check and get back to you. I was not well versed in these minor differences when I bought the car. The GM guy said it was a Z51 and I think that is what the label on the window said too. I must confess that the selective ride control is a nice feature that I would not want to get rid of if it meant going to a Z51. Are the minor differences in gearing and steering worth it? Please tell me your thoughts.

I will say though that I am supposed to buy "Z51 Brakes" and I do have the crossed-drilled rotors (or as I said earlier, the ones with holes in them). Corvettes of Houston said the Z51 brakes stop about 3 to 8 feet shorter (from 60mph and from 70mph) and wear out faster and that is about the only difference. Do you agree?

I will check the glove compartment as you suggested.

Get_UmJ13

I agree with you that the Magnetic Ride control is a great feature and you can definitely tell a difference when its on or off. I have a 07 3LT F55 and I was trying to figure out the brakes because mine are drilled and I was told by the dealership I was at that they are the Z51 brakes and rotors. I believe he ran my Vin# to confirm. I think that would be the safer way to find out.

Let me know how it turns out because I will be in the market for new brakes and rotors.

Good Luck

ncvette_1FUNRIDE

As stated earlier, the Z51 packages on those years don't have MRC. They are exclusive of each other. If the cars have an MRC control on the center console, they are NOT Z51 cars.

That said, I have a 2010 coupe with MRC and that package does include the Z51 brakes.

The suspension is the main difference (and the gearing I believe).

ck_1la@yahoo.com

Got it, thanks....I like the MRC and the ability to stiffen up the suspension WHEN I wish to...thanks for the info!

ck_1la@yahoo.com

Ok - I have not finished moving in yet, so I have not been able to find the owner’s manual and book (I keep anything with my name and address outside of the car at all times).

I can say that if you are going to get brakes - skip the dealership. They charge way too much. Now, I am not an expert, but I do track the car about 3 times a year. In so far as the difference between "Z51 Brakes" and the "Standard Brakes" I don’t think the price increase is justified. The difference in stopping distance is about 3-5 feet from 60 and about 10 feet from 70 to zero. Furthermore, the Z51 Brakes wear out more quickly and cost more. This also means more brake dust on your rims too. It is not so much as being penny wise and pound foolish in this case. Either way the Corvette stops faster than 95% of cars on the road. If you rear-end someone, then you are going too fast and not paying attention, so brakes won’t help much (be they Z51 or Standard). I worry more about stopping too fast and being rear-ended myself!

As for the codes in the glove compartment, one has to be a contortionist to read the sticker in the glove box. So I took a picture of them and they all look Greek to me. Suffice is it to say I will just go with a 2008 LS3 F55 (It sounds cooler anyhow! hahaha) instead of a Z51. I have heard the big difference is the steering (which is more precise on the Z51). I don’t think I would notice much difference on the track as my steering is pretty darn good as it is (and being a good driver helps too). I am not racing at Le Mans or ALMS at 180+ MPH, so the difference in steering and suspension are not going to be noticeable. That said, all Vettes have leaf-springs anyhow (I believe)! Summary - I will take the MRC any day and ride in comfort as I "glide" down the highway on a long trip in TOUR MODE (and switch to Sport when I go to the track 3 times a year)! I heard that to repair the MRC costs in the region of $5k plus, although as an option is costs far less - so I seldom use it.

Best of luck with your brakes. Let me know what you choose.

- CK.

ck_1la@yahoo.com

You have to be a ocntortionist to read those codes! I have gathered that I have an LS3
F55 - which sound cooler than Z51 - but is not in fact a cooler car I guess. That said, I enjoy the MRC and woudl not tarde that for anything. The SPORT MODE does come in handy though when I track teh car about 3 times a year. Thanks for the input!

ck_1la@yahoo.com

Agreed...and I thought much the same after I posted...it stands to reason (what you say).

ck_1la@yahoo.com

Agreed. All I know is that eventhough my LS3 F55 is from 2008, it is still faster than a Camaro SS and any and all Dodge SRT's - although they do give a run for the money on the highway and also most Porsches and M3's...so its good enough for me. Thanks for the input.

ck_1la@yahoo.com

very well said and I did re-read the sticker. You are of course correct - Max weight. I shall be sure not to take Jeremy Clarkson as a passeneger, as he alone would top the Max allowed and he is a crap driver and an aloof butt-head. Thanks for the input!

Corvette Junkie

For the automatics it depended on which rear end you got. And that was only for 08 and 09. The other years you couldn't you couldn't get Z51 brakes and F55.

Get_UmJ13

My 07 has both of those options. Could you elaborate a little more on the "depended on which rear end you got" statement. I'm curious to learning more about my car because a dealer I went to in my area told me I had the big brakes and rotors which I have confirmed but if I purchase after market parts I want to be sure I get the right ones.

Corvette Junkie

If you ordered the automatic transmission it came standard with the GM8 2.56 Ratio Rear Axle. New for 08 they offered an optional GU2 2.73 Ratio Rear Axle. If you ordered the GU2 it also came with the Z51 brakes. Did you buy your 07 new?