nate1121

Hi all,

Been considering an 08+ for a while now but still haven't pulled the trigger. BLUF, I was looking for a low miles car, M6, Z51... no preference on the LT package and the plit spoke wheels (not a big fan of the 5 spoke style). Anyway, I know the Z51 option code includes brake and suspension upgrades but I've seen other info indicating different gear ratios. I've stumbled across an F55 optioned car which I had never really considered before but it seems like a decent setup and includes the same J55 brakes as the Z51. My only question is if there truly is a difference in gearing between the 2 option packages or is it strictly suspension components? I've done a some searching but haven't seen a black and white answer on this. If there is no other major difference, the F55 and Z51 would be a wash when it comes to finding my C6.

Thanks in advance for the feedback guys.

HOXXOH

F55 is the magshocks and adds the J55 brakes to a base car. The rear gear is 3.42 for both manuals, but the trans has different ratios for the Z51 option. Changing to the Z51 sways is a common thing on F55 cars, so you might want to check to see if that's already been done.

nate1121

Ok... So what is the benfit of the different ratios on the Z51 package? Performance is definately my top priority and like I said, I hadn't even considered the F55 option until I saw this car. I like the idea of being able to select a more forgiving suspension configuration for certain situations... The sway bars are a non-issue as it's relatively cheap to add the Z51 bars (or Z06 if i'm not mistaken). I also know there could be draw backs in the event an F55 shock needsto be replaced but their longer life span seemingly negates that (unless it's a premature failure)... What does the different ratio affect? Top end... acceleration... mid range power? I don't know much about trans and gearing and what kind of difference it would make in the overall performance of the car.

Thanks again for the information!

LR'z-Z06

With the Z51 gear ratios you will accelerate faster or spin the tires more. I think it is one of the best parts of the Z51 package. I've had both.
LR

nate1121

Good info... now I'm torn. Anybody out there owned/driven both? Doubt I could get a good feel for both on test drives. A lot of the F55 guys seem to really like the option... but the Z51 seems like it could be the better performance option.

HOXXOH

It really depends on whether your definition of performance is street, highway, mountain roads, road track, or dragstrip, etc.

Here's a chart for gear ratios part way down the page.
http://forums.corvetteforum.com/c6-c...xle-ratio.html

nate1121

I'd say street/highway and back/country roads would be the majority of my driving. I enjoy a pass or 2 at the trip but it's not a focus and I've never been on a road course.

coryvte

Driven both. Chose F55. In the C6, the z51 gearing will help for autox or drags. You won't needed it for the twistys. Have you driven a c6 yet? More than enough, even in base.

nate1121

Ive driven a base C6 but not hard. last vette was a C5Z so a stiff ride wouldnt be anything new. thanks for the feedback.

AORoads

IMO, you won't go wrong w. either: Z51 or F55. If there is a downside to the F55, it comes w. a benefit, too. Generally, the F55 will feel more comfortable (and for some, more controlled to an extent) in certain situations than a Z51 when set in either mode, touring or sport. There's always the potential for premature replacement of the F55 shocks. Not to compare but I've handled my Z51-equipped car for long and short trips, winding roads, and boring highways and not been unimpressed.

HOXXOH

Smooth surface roads, including road courses, are the best use for the Z51 suspension. The F55 really shines on the rougher roads both at high and low speeds. They both do well on most highways, which are usually pretty smooth.

Nosferatu

Z51 ratios on gears 1-4 are shorter, gears 5 & 6 are the same irregardless on the 6 speed manual. Back when stock ran a stock grand sport we were dead even despite the gearing difference. The grand sports weigh 100lbs more so they need the gearing to make it accelerate similar to a non-GS non-Z51. Take the base model with Z51 it'll accelerate harder (but like others said will spin easier with more power or less grippy tires).

I got a 2010 so there was no Z51 option (basically had to go GS to get it which I refused to do I feel they're are a tacky psuedo-Z06 with extra weight IMO).

I just upgraded to Bilstein shocks and a custom made set of beefy sway bars (way bigger than the Z51). Car is like a go kart in corners there is ZERO body roll. I'm sure it'll take down a z51 in the twisties the way it's set up now.

If you're looking for performance, go for the cheapest options and upgrade the car yourself. The options from the factory will always be a compromise in performance versus what's available in the aftermarket. FYI, if you have suspension problems down the road the F55 is way more expensive to service and more complex than a non-F55.

I know the HUD isn't a good indicator of actual G force but I took a corner easily at a peak of 1.04G and the tires weren't even squealing as the car had more in her. Car was planted flat. It's lovely.

I only went 3LT because of HUD and because daily driver. I like options. I bought used though like you're doing and let someone else eat the bullet for the initial costs.

Happy hunting.