base vs z51 brakes and trans gearing
10-06-2014, 03:19 AM
#1
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base vs z51 brakes and trans gearing
Hey guys been looking for my c6 and i found a nice one that i like.. it doesnt have the z51 and i really think thats something i want. I know i can easily upgrade the suspension for not to much money to get close to the z51 but the main thing i feel im missing out on are the bigger brakes and the different gear ratios as im going for the manual.
Have any of you been able to try both and see the difference in braking power? Are base c6 brakes good and up to at least the sports/performence car standard?
Also in terms of the different gear ratios would any of you who have driven both say because of the different gear ratios the z51 accelerates noticeably faster?
Ps i heard just the badges add 6-7rwhp. So im really want to make sure i make the right decision
Have any of you been able to try both and see the difference in braking power? Are base c6 brakes good and up to at least the sports/performence car standard?
Also in terms of the different gear ratios would any of you who have driven both say because of the different gear ratios the z51 accelerates noticeably faster?
Ps i heard just the badges add 6-7rwhp. So im really want to make sure i make the right decision
10-06-2014, 07:50 AM
#2
Burning Brakes
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Z51 cars don't have different badging.
The two cars share the same calipers and pads. Only different rotors, which will not improve braking distance or feel. It will only *slightly* help with fade.
If you plan to add power later, the Z51 ratios lose their advantage. At stock power levels, the Z51 will run out a little harder through the first three gears, but the large drop to 4th evens the field.
Basically, don't let the gears and brakes stop you. They aren't worth it alone. Suspension and coolers are another story, but still won't make any difference on a street driven vehicle.
The two cars share the same calipers and pads. Only different rotors, which will not improve braking distance or feel. It will only *slightly* help with fade.
If you plan to add power later, the Z51 ratios lose their advantage. At stock power levels, the Z51 will run out a little harder through the first three gears, but the large drop to 4th evens the field.
Basically, don't let the gears and brakes stop you. They aren't worth it alone. Suspension and coolers are another story, but still won't make any difference on a street driven vehicle.
10-06-2014, 08:31 AM
#3
Le Mans Master
I have a non-Z51 and prefer the taller gearing. Being forced induction, a longer gear helps me. Before having the supercharger, I ran dead even with my friend's Z51 and he had more modifications done than me.
You can get better rotors on a non-Z51 easily. In addition, I upgraded my shocks and swaybars to something considerably more beefy than what Z51 has and the car is as flat as a go kart in the corners.
I know for certain on the non-Z51 here's your gear shift points...
1-2: ~54mph
2-3: ~82mph
3-4: ~ 114mph
On a Z51 I believe it's around....
1-2: ~48mph
2-3: ~77mph
3-4: ~103mph
4th gear is the around the same and rips to almost 150mph on both cars. The 3-4 shift on a non-Z51 keeps you in the better part of the power band going into 4th.
Last edited by Nosferatu; 10-06-2014 at 08:33 AM.
10-06-2014, 09:31 AM
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Thanks for the insight guys. At this point I prob won't restrict myself to just the z51. I am definitely going to mod it. Just hope he can maybe come down on his price! Are the 1lt vs 2lt seats all that much different?
10-06-2014, 09:26 PM
#5
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St. Jude Donor '13
Z51 cars don't have different badging.
The two cars share the same calipers and pads. Only different rotors, which will not improve braking distance or feel. It will only *slightly* help with fade.
If you plan to add power later, the Z51 ratios lose their advantage. At stock power levels, the Z51 will run out a little harder through the first three gears, but the large drop to 4th evens the field.
Basically, don't let the gears and brakes stop you. They aren't worth it alone. Suspension and coolers are another story, but still won't make any difference on a street driven vehicle.
The two cars share the same calipers and pads. Only different rotors, which will not improve braking distance or feel. It will only *slightly* help with fade.
If you plan to add power later, the Z51 ratios lose their advantage. At stock power levels, the Z51 will run out a little harder through the first three gears, but the large drop to 4th evens the field.
Basically, don't let the gears and brakes stop you. They aren't worth it alone. Suspension and coolers are another story, but still won't make any difference on a street driven vehicle.
Anyone have part number(s) to compare?
As for gears, the stick shifts have the difference in the internal tranny gears, the A6 has the difference in the differential. I'm very pleased with the extra pep provided by the A6 performance differential on the highway, though it makes little difference in the standing 1/4 mile.
10-07-2014, 12:05 AM
#6
Race Director
get a car with the F55 shocks has the Z51 brakes. other than that i wouldn't concern yourself with the Z51. I would be more interested in the F55. that was nonnegotiable when i was shopping after driving both..
10-07-2014, 02:11 AM
#7
Find a Z51 option car if that is what you want.
To try to recreate the upgrades on the Z51 option by replacing parts on the base model, you looking at $4k upwards instead (what was around $1500 for the Z51 option instead).
What you are not seeing over just the lower trans gearing, is the added oil coolers in Z51 option as well.
Just brakes alone, since the pads in the Z51 car are better semi metallic pads that in the base car, you in the $800 parts range by the time you buy just the larger Z51 rotors, the Z51 caliper brackets, then the Z51 HD brake pads.
To try to recreate the upgrades on the Z51 option by replacing parts on the base model, you looking at $4k upwards instead (what was around $1500 for the Z51 option instead).
What you are not seeing over just the lower trans gearing, is the added oil coolers in Z51 option as well.
Just brakes alone, since the pads in the Z51 car are better semi metallic pads that in the base car, you in the $800 parts range by the time you buy just the larger Z51 rotors, the Z51 caliper brackets, then the Z51 HD brake pads.
10-07-2014, 02:47 AM
#8
Burning Brakes
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Find a Z51 option car if that is what you want.
To try to recreate the upgrades on the Z51 option by replacing parts on the base model, you looking at $4k upwards instead (what was around $1500 for the Z51 option instead).
What you are not seeing over just the lower trans gearing, is the added oil coolers in Z51 option as well.
Just brakes alone, since the pads in the Z51 car are better semi metallic pads that in the base car, you in the $800 parts range by the time you buy just the larger Z51 rotors, the Z51 caliper brackets, then the Z51 HD brake pads.
To try to recreate the upgrades on the Z51 option by replacing parts on the base model, you looking at $4k upwards instead (what was around $1500 for the Z51 option instead).
What you are not seeing over just the lower trans gearing, is the added oil coolers in Z51 option as well.
Just brakes alone, since the pads in the Z51 car are better semi metallic pads that in the base car, you in the $800 parts range by the time you buy just the larger Z51 rotors, the Z51 caliper brackets, then the Z51 HD brake pads.
But a base car with aggressive pads will out-brake a Z51 car any day. At less than $200 invested.
10-07-2014, 02:47 PM
#9
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C6 of Year Finalist (performance mods) 2019
The biggest difference is actually in the grip of the base vs Z51 tires for stopping distance, not the size of the rotors or the aggressiveness of the pads. Better pads on either car up to whatever the tire adhesion limits are, will reduce stopping distances.However, since both are OEM rated for 60-0 at close to 110' and the 2015 Z06 is the best ever at 98', then if better tires and pads don't get you stopped in enough time, you're going too fast for conditions.
10-11-2014, 04:07 PM
#10
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Are you really going to consistently drive the car hard enough to even feel/ notice the differences between the cars.... doubtful.
Think about what youre going to use the car for... daily driver, weekend warrior, auto-cross, drag? Then think about WHAT YOU ARE HONESTLY GOING TO DO TO YOUR CAR (performance).
Theyre the same car with a few differences. Will you enjoy the $hit out of both of them, yes. Are they both fast, yes. Are they both still Corvettes, yes.
Get the newer car that has the lower milage, better condition, better warranty and better deal. You can make it your own from there.
Think about what youre going to use the car for... daily driver, weekend warrior, auto-cross, drag? Then think about WHAT YOU ARE HONESTLY GOING TO DO TO YOUR CAR (performance).
Theyre the same car with a few differences. Will you enjoy the $hit out of both of them, yes. Are they both fast, yes. Are they both still Corvettes, yes.
Get the newer car that has the lower milage, better condition, better warranty and better deal. You can make it your own from there.
10-11-2014, 05:21 PM
#11
Safety Car
The $1700 Z51 option was a lot of stuff for not too much money- especially transmission gearing which could not be cheaply done after-the-fact.
You get a little more sway bar, shocks, trans gearing, different semi-mettalic brake pads, a little larger rotor, the supercar runflats, a more neutral alignment toe-in wise, oil cooler on manual transmission cars, and different composite monoleaf springs. Probably closer to $1500 if you bought at invoice pricing. I couldn't imagine having a vetter softer than what a Z51 is, but I guess not everybody needs to do 130 mph. The option package doesn't hurt resale either.
You get a little more sway bar, shocks, trans gearing, different semi-mettalic brake pads, a little larger rotor, the supercar runflats, a more neutral alignment toe-in wise, oil cooler on manual transmission cars, and different composite monoleaf springs. Probably closer to $1500 if you bought at invoice pricing. I couldn't imagine having a vetter softer than what a Z51 is, but I guess not everybody needs to do 130 mph. The option package doesn't hurt resale either.
10-11-2014, 08:12 PM
#12
Melting Slicks
Z51 calipers and Pads ARE IDENTICAL to base car. Only the rotors and brackets are different. If they used a different pad formulation from the factory for Z51 option I'm not aware of this. Either way, good ceramic (AC Delco, etc) for the street are the way to go. On the track you are going to run a higher temp rated more aggressive (read noisy and dusty) pad anyway... I got a Z51 car because I wanted all the small differences. I'm glad I did. Of course now after three track seasons, I'm shopping for a Big Brake Kit for the fronts at least. For the Street, the Z51 brakes look bigger and are drilled.. looks "sportier"... my ten cents.
Last time I ordered pads, the parts guys said base and Z51 pads are different. I suspect he's right, because the Z51 pads seem to dust more and I don't think it's just from the holes.
Anyone have part number(s) to compare?
As for gears, the stick shifts have the difference in the internal tranny gears, the A6 has the difference in the differential. I'm very pleased with the extra pep provided by the A6 performance differential on the highway, though it makes little difference in the standing 1/4 mile.
Anyone have part number(s) to compare?
As for gears, the stick shifts have the difference in the internal tranny gears, the A6 has the difference in the differential. I'm very pleased with the extra pep provided by the A6 performance differential on the highway, though it makes little difference in the standing 1/4 mile.
Last edited by franman69; 10-12-2014 at 01:05 PM.
10-11-2014, 09:32 PM
#14
Burning Brakes
Are you really going to consistently drive the car hard enough to even feel/ notice the differences between the cars.... doubtful.
Think about what youre going to use the car for... daily driver, weekend warrior, auto-cross, drag? Then think about WHAT YOU ARE HONESTLY GOING TO DO TO YOUR CAR (performance).
Theyre the same car with a few differences. Will you enjoy the $hit out of both of them, yes. Are they both fast, yes. Are they both still Corvettes, yes.
Get the newer car that has the lower milage, better condition, better warranty and better deal. You can make it your own from there.
Think about what youre going to use the car for... daily driver, weekend warrior, auto-cross, drag? Then think about WHAT YOU ARE HONESTLY GOING TO DO TO YOUR CAR (performance).
Theyre the same car with a few differences. Will you enjoy the $hit out of both of them, yes. Are they both fast, yes. Are they both still Corvettes, yes.
Get the newer car that has the lower milage, better condition, better warranty and better deal. You can make it your own from there.
10-12-2014, 03:41 AM
#15
Melting Slicks
I had same dilemma. Here's some thoughts. It's a used c6 unsure year your after.
Factory tires. Probably not.
Factory brakes. Probably not.
These things have most likely been changed. If not need to be changed.
I can tell you my base car can hang with a z06 all day on an hpde and autocross events. I consistently beat a z51 car everytime at autox.
I have z51 sways. (Cheap) some carbotech pads and slotted only rotors. (Z51s will crack)
And pfadt joc shocks. Only because mine failed and were worn out.
Factory tires. Probably not.
Factory brakes. Probably not.
These things have most likely been changed. If not need to be changed.
I can tell you my base car can hang with a z06 all day on an hpde and autocross events. I consistently beat a z51 car everytime at autox.
I have z51 sways. (Cheap) some carbotech pads and slotted only rotors. (Z51s will crack)
And pfadt joc shocks. Only because mine failed and were worn out.
10-12-2014, 07:52 AM
#16
Racer
I've tried base, F55, and Z51.
Only after I tried the Z51 did I notice quite a difference in gearing from the base. I really liked it! The base 5th gear seemed doggy to me, the Z51's 5th is fun on the interstate (.85 base vs .71 Z51)! The 1st, 2nd, and 3rd are the BEST for around town having fun.
With the F55, I left it in the harsher mode every time anyways. I like the harder ride. Plus I've witnessed owners' frustration with the expensive shock replacements when they go bad. I don't need that.
So the easy choice for me is the Z51, always in the mode I like, the gearing is just right for me, and the added oil cooling seals the deal!
We all have different driving styles. Mine matches the Z51. I'm just the type of customer they built that option for!
Chuck M
Last edited by hotmotorsports; 10-12-2014 at 07:57 AM.
10-12-2014, 08:45 AM
#17
Safety Car
In it's favor, the base suspension rides more comfortably over road irregularities and the Z51 Goodyear Supercar F1 RFs flat out suck and will give up the ghost in about 12K miles.
Obviously the Corvette is going to be a major purchase. You should try both and decide what is best for you. Opinions and observations, (including mine) are no substitute for your own preferences.
10-12-2014, 12:29 PM
#18
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How will you be using your car? Is it merely a daily driver with an occasional straight line blast and/or 'spirited' ride through the twisties or will you use the car competitively? Could you become serious about competitive driving? The Z51 option was created for the parking lot autocross enthusiast. The Z51 option has some nice features but some features may not be desirable for everyone.
Concerning the brakes, according to Dave Hill (the 'Godfather' of the C6) the cross-drilled rotors are there primarily to give the car a "racier" appearance. Although fine for 'normal' use and less severe applications cross-drilled rotors are notorious for cracking under hard use. Serious road racers I know avoid cross-drilled rotors like the plague. IMO you're far better off with solid/solid-slotted rotors. Know also the base brakes can be improved upon considerably. The stock brakes are fine but some quick suggestions to improve them would be to go with more aggressive pads, stainless steel brake lines, improved brake fluid, upgraded rotors and perhaps even stainless steel caliper pistons. Without too much effort or money the base brakes can be improved upon considerably.
Although the difference between the transmissions is not huge (being an avid road racer) the Z51 gearbox was the biggest drawback for me. The wider ratio gearbox of the Z51 option was designed to give the car a slight advantage in parking lot autocross events where a short, relatively low speed blast of acceleration helps. On the other hand, road racing cars typically have a closer ratio gearbox like the Z06 has...same as the base C6 (compared to the wider ratio gearbox of the Z51 option). A closer ratio means the engine can be kept closer to its power peak in all out road racing....particularly in 1st thru 4th gears which matter most. I'm not a drag racer but if memory serves correct the 'granny' gear of the Z51 option will give it a tenth or two advantage over the 'base' transmission in the quarter mile. Someone can correct me if I'm wrong but I'm guessing the Z51 will shift into 4th gear just prior to crossing the 1/4 mile line while the 'base' transmission still should be pulling strong in 3rd gear as it crosses the line. Again, the overall difference between the two transmissions isn't huge but I prefer the closer ratio gearbox of the 'base' C6 (or Z06).
The stiffer suspension of the Z51 option is IMO preferred over the base C6 but (as you mentioned) it's not difficult to modify and improve the suspension. Frankly, if you ever get serious about 'racing' it wouldn't matter which suspension you started with....you'd modify either one. It may be worth noting that I feel the controlled MR (F55) suspension is the best "all-around" suspension offered by Corvette. Additionally, the improved cooling capacities of the Z51 option are great but may not be essential for all practical purposes. You probably will do fine without the extra cooling.
Again, IMO much depends on how you intend to use your car. Without question the Z51 option has some nice features. The wider ratio gearing of the Z51 option was the biggest drawback for me but for others it's just what they want. IMO you can't really go wrong either way but I wouldn't let the Z51 option be an all important, deciding factor. If you find you need to make improvements/modifications, you'll end up with something even better. Good luck whichever way you decide to go.
Concerning the brakes, according to Dave Hill (the 'Godfather' of the C6) the cross-drilled rotors are there primarily to give the car a "racier" appearance. Although fine for 'normal' use and less severe applications cross-drilled rotors are notorious for cracking under hard use. Serious road racers I know avoid cross-drilled rotors like the plague. IMO you're far better off with solid/solid-slotted rotors. Know also the base brakes can be improved upon considerably. The stock brakes are fine but some quick suggestions to improve them would be to go with more aggressive pads, stainless steel brake lines, improved brake fluid, upgraded rotors and perhaps even stainless steel caliper pistons. Without too much effort or money the base brakes can be improved upon considerably.
Although the difference between the transmissions is not huge (being an avid road racer) the Z51 gearbox was the biggest drawback for me. The wider ratio gearbox of the Z51 option was designed to give the car a slight advantage in parking lot autocross events where a short, relatively low speed blast of acceleration helps. On the other hand, road racing cars typically have a closer ratio gearbox like the Z06 has...same as the base C6 (compared to the wider ratio gearbox of the Z51 option). A closer ratio means the engine can be kept closer to its power peak in all out road racing....particularly in 1st thru 4th gears which matter most. I'm not a drag racer but if memory serves correct the 'granny' gear of the Z51 option will give it a tenth or two advantage over the 'base' transmission in the quarter mile. Someone can correct me if I'm wrong but I'm guessing the Z51 will shift into 4th gear just prior to crossing the 1/4 mile line while the 'base' transmission still should be pulling strong in 3rd gear as it crosses the line. Again, the overall difference between the two transmissions isn't huge but I prefer the closer ratio gearbox of the 'base' C6 (or Z06).
The stiffer suspension of the Z51 option is IMO preferred over the base C6 but (as you mentioned) it's not difficult to modify and improve the suspension. Frankly, if you ever get serious about 'racing' it wouldn't matter which suspension you started with....you'd modify either one. It may be worth noting that I feel the controlled MR (F55) suspension is the best "all-around" suspension offered by Corvette. Additionally, the improved cooling capacities of the Z51 option are great but may not be essential for all practical purposes. You probably will do fine without the extra cooling.
Again, IMO much depends on how you intend to use your car. Without question the Z51 option has some nice features. The wider ratio gearing of the Z51 option was the biggest drawback for me but for others it's just what they want. IMO you can't really go wrong either way but I wouldn't let the Z51 option be an all important, deciding factor. If you find you need to make improvements/modifications, you'll end up with something even better. Good luck whichever way you decide to go.
10-12-2014, 01:14 PM
#19
Melting Slicks
Wayne O is right on as usual. Although I can add that the Z51 enhancements have served me well for three track seasons. I have done all the brake upgrades he listed and I'm now moving onto the suspension.