C5 Z06 vs C6 base

C5 Z06 vs C6 base

Author
Discussion

Benbay001

Original Poster:

5,795 posts

157 months

Sunday 7th April 2019
quotequote all
Hi,
Ive been looking for a while now (2 years) at getting myself a Corvette if I get taken on after my apprenticeship (September).

I was initially looking at C5s, with my ultimate aim being a Z06.

But ive recently starting considering spending a bit more to get a base C6.

Price aside, what areas do each car excel over the other? Does anyone have experience of both?

The car in question would have to be manual.

Thanks in advance.

LuS1fer

41,133 posts

245 months

Sunday 7th April 2019
quotequote all
I had a C5 Z06 and it was a strong performer and good handler but was ruined by the gearbox.
Though not a terminal issue,, being 5'6", the shifter was not ideal for me and the quality of the change was abysmal, even by tractor standards.
The long and the short of it was that when you wanted tp press on and swop the cogs down, like when approaching roundabouts, it was far more a chore than a pleasure....and that was with a shorter throw Breathless shifter.
I sold mine, mainly as I needed 4 seats but my Mustang's gearbox is far, far better and that is far from being great.
A friend of mine still has his C5 Z06 and seems to find it OK so maybe with the seat further back, it might be easier.

I am told the C6 gearbox is better but as I never liked the styling, I never bothered trying it.

Benbay001

Original Poster:

5,795 posts

157 months

Sunday 7th April 2019
quotequote all
LuS1fer said:
I had a C5 Z06 and it was a strong performer and good handler but was ruined by the gearbox.
Though not a terminal issue,, being 5'6", the shifter was not ideal for me and the quality of the change was abysmal, even by tractor standards.
The long and the short of it was that when you wanted tp press on and swop the cogs down, like when approaching roundabouts, it was far more a chore than a pleasure....and that was with a shorter throw Breathless shifter.
I sold mine, mainly as I needed 4 seats but my Mustang's gearbox is far, far better and that is far from being great.
A friend of mine still has his C5 Z06 and seems to find it OK so maybe with the seat further back, it might be easier.

I am told the C6 gearbox is better but as I never liked the styling, I never bothered trying it.
That's the sort of insight I was after.

Thank you smile

Anyone else?

Z28DUNC

155 posts

150 months

Monday 8th April 2019
quotequote all
Best of popping a post on the corvette club uk forum. Lots of people on there will be able to give you there experience of both.

The T56 box is a bit of a pig compared to modern 6 speeds thats for sure but I never found it a problem as long as I shifted smoothly. However this was in a Camaro so probably a different driving positon plus its not a transaxle and that might change the feeling too.

Fishy Dave

1,026 posts

245 months

Monday 8th April 2019
quotequote all
I was looking at both models too, in my mind they both have their advantages and disadvantages:

C5 Z06
+
It was the top model at the time (pub bragging rights only)
More of a race car feel
Titanium exhaust
Only available in manual transmission
Simpler electrics (non Canbus)

-
Fixed roof only, no open air thrills
More dated appearance, although pop up lights are cool
Larger dimensions
Boot space is smaller (still big though) and still less useable

C6
+
Newer car (any age related issues)
To my eyes the nicer looking car inside and out
Non Z51 option is more softly sprung and damped on the road if you want a road only car (all UK cars are Z51 spec)
Smaller exterior dimensions (yet longer wheelbase)

-
The non Z51 option is too softly sprung and damped for a track day car
Gear ratios are too long on the non Z51 cars.
Slightly heavier than the C5 Z06

For me it came down to looks, size, the removable roof panel and that my C6 came up at a bargain price, I have no regrets. smile



minipower

897 posts

219 months

Monday 8th April 2019
quotequote all
LuS1fer said:
I had a C5 Z06 and it was a strong performer and good handler but was ruined by the gearbox.
Though not a terminal issue,, being 5'6", the shifter was not ideal for me and the quality of the change was abysmal, even by tractor standards.
The long and the short of it was that when you wanted tp press on and swop the cogs down, like when approaching roundabouts, it was far more a chore than a pleasure....and that was with a shorter throw Breathless shifter.
I sold mine, mainly as I needed 4 seats but my Mustang's gearbox is far, far better and that is far from being great.
A friend of mine still has his C5 Z06 and seems to find it OK so maybe with the seat further back, it might be easier.

I am told the C6 gearbox is better but as I never liked the styling, I never bothered trying it.
Interesting comments on the shift. I similarly found the standard C5 box awful and very difficult to find reverse. It didn’t help that they fitted the most horrible stock gear knob as well.

This was until it was swapped for the MGW short shifter. It really has transformed the gearbox and made the car far more enjoyable to drive.

anonymous-user

54 months

Tuesday 9th April 2019
quotequote all
Bear in mind that all Corvettes from C5 onwards have been "transaxle" cars with the gearbox at the back, which inevitably entails a longer linkage with various joints in it. In comparison Mustang has its gearstick directly into the gearbox. On cars with auto transmission it makes no difference.

Two thirds of all Corvettes built/sold are auto so likely to be easier to find than a manual and may have more price flexibility.

Bear in mind that if you're looking at the cheapest C6s the early auto cars have a 4-speed box carried over from C5. The 6-speed auto was introduced a bit later and is a lot more modern. I'm no C6 expert but there's also at least a couple of different base engines through production - LS2 and LS3.

Any of the modern Corvettes are fantastic real-world cars. You won't be disappointed!

wildoliver

8,777 posts

216 months

Thursday 25th April 2019
quotequote all
I can only speak for our c6 against a background of European sports and semi super cars.

You want the z51 option. Our suspension is a perfect match for UK roads. Any stiffer it would be uncomfortable, any softer it would lose focus. The brakes are better, the gearing suits UK roads far better (your still cruising along at barely over tickover but the acceleration is savage).

There are also a load of other little improvements the z51 package includes that are worth having.

We nearly bought a C5 z06 before we got the c6.

I prefer the C5 shape in some ways (it's a pretty car) I also like the titanium exhaust/mag wheels. But a c6 imo is a better car. The ls2 engine is basically a bigger version of the engine in the z06 (C5) it's a more modern and really good looking car, the interior is light years ahead. C6 interior is similar in feel to 90s Porsches, albeit not quite as solid feeling, C5 interiors are a more acquired taste.

The c6 electrical system is a pain. It's not hard to work on but there are a few gremlins and stupid design ideas (door handles I'm looking at you). It's can bus so jobs have an extra layer of complexity.

The gearbox. Maybe we are just lucky with ours, but it's lovely. It's a moderately heavy shift when cold but what powerful car with strong gearbox isn't. It certainly isn't worse than the Porsche or Ferrari boxes. When warm it's just a perfectly normal shift. It warms up quickly. I usually rush to change gearbox oil but haven't on this as the shift is fine (and the cars low mileage).

The clutch slave is a pain. You can't realistically bleed it in the car. The fluid burns due to the pipe albeit lagged running past a header. So you get gritty black fluid. When I do change the slave and clutch one day I'll fit a remote bleeder to make changing fluid easier. It does self bleed to a point so "the ranger" method of changing the fluid in the reservoir does tend to over time change it.

Did I mention there are a lot of electronics? Fitting a stereo needs a break out box. I fitted a modern stereo and rear view camera to ours. These cars are super sensitive to voltage drop. Ours had a persistent voltage drop which threw loads of annoying fault codes, eventually the alternator died. A cheap but half days work to change it, the wiring loom and the solenoid to make sure all the charging system was tip top. Since then it's been perfect. Fitted a higher output alternator as the original is borderline.

Heat management. The engine bay gets hot. Fine when driving but just like a Ferrari, lotus, tvr or air cooled Porsche they do not like sitting stationary and running for long. It cooks the alternator, clutch line, starter and anything else in the vicinity. The cooling system is excellent so the engine won't suffer but everything round it will. What finally killed our alternator was sitting on the mot ramp trying to get the cats hot enough for emissions test.

Get the glass roof it's great. Wrap or paint the halo/roll hoop black to match, it changes the look of the car hugely.

I think the import cars are better cars personally, but check out how well the conversion has been done. Ours was horribly bodged and I've just got it right. The UK spec cars are nice but don't feel you need to go for one.

Npp exhausts are well worth looking for. The standard exhaust (or npp valves closed) are quiet. Open the valves on the npp though and it sounds like thunder. Basically it's a standard exhaust and a tuned exhaust all in one. Don't worry if you don't have the wiring in your car it's not a big job to fit.

wildoliver

8,777 posts

216 months

Thursday 25th April 2019
quotequote all
I can only speak for our c6 against a background of European sports and semi super cars.

You want the z51 option. Our suspension is a perfect match for UK roads. Any stiffer it would be uncomfortable, any softer it would lose focus. The brakes are better, the gearing suits UK roads far better (your still cruising along at barely over tickover but the acceleration is savage).

There are also a load of other little improvements the z51 package includes that are worth having.

We nearly bought a C5 z06 before we got the c6.

I prefer the C5 shape in some ways (it's a pretty car) I also like the titanium exhaust/mag wheels. But a c6 imo is a better car. The ls2 engine is basically a bigger version of the engine in the z06 (C5) it's a more modern and really good looking car, the interior is light years ahead. C6 interior is similar in feel to 90s Porsches, albeit not quite as solid feeling, C5 interiors are a more acquired taste.

The c6 electrical system is a pain. It's not hard to work on but there are a few gremlins and stupid design ideas (door handles I'm looking at you). It's can bus so jobs have an extra layer of complexity.

The gearbox. Maybe we are just lucky with ours, but it's lovely. It's a moderately heavy shift when cold but what powerful car with strong gearbox isn't. It certainly isn't worse than the Porsche or Ferrari boxes. When warm it's just a perfectly normal shift. It warms up quickly. I usually rush to change gearbox oil but haven't on this as the shift is fine (and the cars low mileage).

The clutch slave is a pain. You can't realistically bleed it in the car. The fluid burns due to the pipe albeit lagged running past a header. So you get gritty black fluid. When I do change the slave and clutch one day I'll fit a remote bleeder to make changing fluid easier. It does self bleed to a point so "the ranger" method of changing the fluid in the reservoir does tend to over time change it.

Did I mention there are a lot of electronics? Fitting a stereo needs a break out box. I fitted a modern stereo and rear view camera to ours. These cars are super sensitive to voltage drop. Ours had a persistent voltage drop which threw loads of annoying fault codes, eventually the alternator died. A cheap but half days work to change it, the wiring loom and the solenoid to make sure all the charging system was tip top. Since then it's been perfect. Fitted a higher output alternator as the original is borderline.

Heat management. The engine bay gets hot. Fine when driving but just like a Ferrari, lotus, tvr or air cooled Porsche they do not like sitting stationary and running for long. It cooks the alternator, clutch line, starter and anything else in the vicinity. The cooling system is excellent so the engine won't suffer but everything round it will. What finally killed our alternator was sitting on the mot ramp trying to get the cats hot enough for emissions test.

Get the glass roof it's great. Wrap or paint the halo/roll hoop black to match, it changes the look of the car hugely.

I think the import cars are better cars personally, but check out how well the conversion has been done. Ours was horribly bodged and I've just got it right. The UK spec cars are nice but don't feel you need to go for one.

Npp exhausts are well worth looking for. The standard exhaust (or npp valves closed) are quiet. Open the valves on the npp though and it sounds like thunder. Basically it's a standard exhaust and a tuned exhaust all in one. Don't worry if you don't have the wiring in your car it's not a big job to fit.

Our car is a 2005 c6 ls2. The car most people would say to avoid. Got to say though compared to say a tvr it's been trouble free. Given a bigger budget and the choice again? Probably a manual ls3 gransport. Gransport took over from the z51 package and added the wide body which is nice. It's basically a z06 without the LS7. But on manuals it gets a dry sump ls3 which would be lovely.

You'll be happy with any of them though. Great cars and very practical. Huge boot, comfy but supportive seats, cruise control, hud if fitted is great, mpg are incredible for the type of car.

LuS1fer

41,133 posts

245 months

Thursday 25th April 2019
quotequote all
The C5 is old school electrics and I did the SVA work myself. I fitted a Breathless shifter to my C5 Z06 but it was still poor.

The battery does need to be kept in a state of good charge as one day, none of the door controls worked and I had to restart it after a few miles to restore the power.

On the Z06 watch for cracks in the trim round the door but more particularly the seat runners can get a bit wobbly.

The C5 ZO6 had a short run. The 2001 had less power, harder suspension and oil issues. The revised 2002 onwards 405hp is the one to get, which ran to 2004.

300bhp/ton

41,030 posts

190 months

Thursday 25th April 2019
quotequote all
wildoliver said:
The ls2 engine is basically a bigger version of the engine in the z06 (C5)
It is and isn't.

The LS1 is 5.7 litres and used in the base model C5 Corvette as well as the Fbody Firebird & Camaro models. These make circa 345hp +- depending on year and exact spec.

The LS2 is an update to the LS1 with 6.0 litre displacement and a different intake manifold.

The C6 Z06 uses the the LS6 engine, this is based on the LS1 and is still 5.7 litres (the same 346ci). But it technically has a different block, it also uses better heads with different valves sizes and a higher compression ration. It has sodium filled valves and a titanium exhaust. As well as the LS6 intake manifold (which looks like the LS1 intake, but is different internally). The LS6 manifold has generally outperformed the LS2 manifold.

There are probably other changes I've forgotten about too. The main difference is the LS6 will feel far more racey and lively and revs higher, with PEAK power higher up in the rpm range.

The LS2 makes approx the same power, but the power delivery is different and more akin to the regular LS1.

Both fantastic engines however. As is the latter LS3 (6.2 litres).

The higher CR of the LS6 makes it less suitable to adding boost, although you still can, but you'll have to run less. But only an issue for those intending turbo or blower kits.

300bhp/ton

41,030 posts

190 months

Thursday 25th April 2019
quotequote all
Fishy Dave said:
I was looking at both models too, in my mind they both have their advantages and disadvantages:

C5 Z06
+
It was the top model at the time (pub bragging rights only)
More of a race car feel
Titanium exhaust
Only available in manual transmission
Simpler electrics (non Canbus)

-
Fixed roof only, no open air thrills
More dated appearance, although pop up lights are cool
Larger dimensions
Boot space is smaller (still big though) and still less useable

C6
+
Newer car (any age related issues)
To my eyes the nicer looking car inside and out
Non Z51 option is more softly sprung and damped on the road if you want a road only car (all UK cars are Z51 spec)
Smaller exterior dimensions (yet longer wheelbase)

-
The non Z51 option is too softly sprung and damped for a track day car
Gear ratios are too long on the non Z51 cars.
Slightly heavier than the C5 Z06

For me it came down to looks, size, the removable roof panel and that my C6 came up at a bargain price, I have no regrets. smile
Some good points.

The only other thing to mention is long term residuals. The z06 is akin to the ZR-1 for the C4 model. And is likely to be the most desired and expensive C5 model to own as the years tick by. While a base C6, even with the z51 package will likely be the cheapest C6 to buy.

wildoliver

8,777 posts

216 months

Thursday 25th April 2019
quotequote all
300bhp/ton said:
Fishy Dave said:
I was looking at both models too, in my mind they both have their advantages and disadvantages:

C5 Z06
+
It was the top model at the time (pub bragging rights only)
More of a race car feel
Titanium exhaust
Only available in manual transmission
Simpler electrics (non Canbus)

-
Fixed roof only, no open air thrills
More dated appearance, although pop up lights are cool
Larger dimensions
Boot space is smaller (still big though) and still less useable

C6
+
Newer car (any age related issues)
To my eyes the nicer looking car inside and out
Non Z51 option is more softly sprung and damped on the road if you want a road only car (all UK cars are Z51 spec)
Smaller exterior dimensions (yet longer wheelbase)

-
The non Z51 option is too softly sprung and damped for a track day car
Gear ratios are too long on the non Z51 cars.
Slightly heavier than the C5 Z06

For me it came down to looks, size, the removable roof panel and that my C6 came up at a bargain price, I have no regrets. smile
Some good points.

The only other thing to mention is long term residuals. The z06 is akin to the ZR-1 for the C4 model. And is likely to be the most desired and expensive C5 model to own as the years tick by. While a base C6, even with the z51 package will likely be the cheapest C6 to buy.
Very true.

wildoliver

8,777 posts

216 months

Thursday 25th April 2019
quotequote all
300bhp/ton said:
wildoliver said:
The ls2 engine is basically a bigger version of the engine in the z06 (C5)
It is and isn't.

The LS1 is 5.7 litres and used in the base model C5 Corvette as well as the Fbody Firebird & Camaro models. These make circa 345hp +- depending on year and exact spec.

The LS2 is an update to the LS1 with 6.0 litre displacement and a different intake manifold.

The C6 Z06 uses the the LS6 engine, this is based on the LS1 and is still 5.7 litres (the same 346ci). But it technically has a different block, it also uses better heads with different valves sizes and a higher compression ration. It has sodium filled valves and a titanium exhaust. As well as the LS6 intake manifold (which looks like the LS1 intake, but is different internally). The LS6 manifold has generally outperformed the LS2 manifold.

There are probably other changes I've forgotten about too. The main difference is the LS6 will feel far more racey and lively and revs higher, with PEAK power higher up in the rpm range.

The LS2 makes approx the same power, but the power delivery is different and more akin to the regular LS1.

Both fantastic engines however. As is the latter LS3 (6.2 litres).

The higher CR of the LS6 makes it less suitable to adding boost, although you still can, but you'll have to run less. But only an issue for those intending turbo or blower kits.
The LS1 became the LS6 in the C5 z06 with the improvements you mention (although later ls1s got the LS6 inlet too).

Ls2 carries the LS6 heads on a new 6.0 block. There seems to be some debate about the ls2 inlet but it's generally accepted that even if it isn't the same as the LS6 inlet the LS6 inlet isn't worth fitting. Ditto to a degree the camshaft, while the LS6 cam is possibly livelier (although even a standard ls2 is hardly sluggish) there are far better cams. Don't know about exhaust manifolds, I suspect ls2 uses different manifolds to LS1/6 as I do know the ls3 manifolds are the same as ls2. Mainly due to having both here. I can't see Chevy keeping an inferior design for the ls3 after all the work they did on the ls3 head.

About the only bit of the LS6 I do wish the ls2 had retained are the valves. Purely for bragging rights, I'm not aware of any ls2s suffering even when seriously abused from any kind of valve failure but sodium filled valves are always good for bragging rights.

However all the ls engines are great even the LS1, it might be the baby of the range but it's a hell of an engine. The LS7 has more than it's fair share of issues but once sorted what an engine.

They are all great cars, whatever you buy you will have a blast. There is also a good degree of parts interchangeability between the models so to a degree pick the car you like the look and feel of you can always upgrade things later. Parts are cheap in America but the shipping/customs can be a killer.


LuS1fer

41,133 posts

245 months

Thursday 25th April 2019
quotequote all
300bhp/ton said:
Some good points.

The only other thing to mention is long term residuals. The z06 is akin to the ZR-1 for the C4 model. And is likely to be the most desired and expensive C5 model to own as the years tick by. While a base C6, even with the z51 package will likely be the cheapest C6 to buy.
I'm not entirely convinced. The higher residual will come from having 405hp vs 350hp but, to my eyes, the C5 is not as pretty as the ordinary C5 which has the big bonus of a hatch and a removable roof, something I sorely missed from my previous C4.

The ZR1 has better collectability as it had a lot more power than the 300hp C4 and 330hp Gran Sport and had the unique LT5 engine (also starting with 375 and being raised to 405hp) but you have to remember the car cost TWICE what the standard Corvette sold for whereas the Z06 was just a top model in a proportionately priced range.

wildoliver

8,777 posts

216 months

Thursday 25th April 2019
quotequote all
LuS1fer said:
300bhp/ton said:
Some good points.

The only other thing to mention is long term residuals. The z06 is akin to the ZR-1 for the C4 model. And is likely to be the most desired and expensive C5 model to own as the years tick by. While a base C6, even with the z51 package will likely be the cheapest C6 to buy.
I'm not entirely convinced. The higher residual will come from having 405hp vs 350hp but, to my eyes, the C5 is not as pretty as the ordinary C5 which has the big bonus of a hatch and a removable roof, something I sorely missed from my previous C4.

The ZR1 has better collectability as it had a lot more power than the 300hp C4 and 330hp Gran Sport and had the unique LT5 engine (also starting with 375 and being raised to 405hp) but you have to remember the car cost TWICE what the standard Corvette sold for whereas the Z06 was just a top model in a proportionately priced range.
God yeah you've just reminded me of the C5 z06 shape I'd totally forgotten about that. The notchback shell was the biggest put off for me behind the interior. I imagine some people like the shape but for me once I saw it compared to the prettier coupe (targa?) I couldn't unsee it.

At least they learnt on the c6 and the z cars carried the standard shell albeit with the targa top bolted in and not easily removable (indeed recommended to never be removed as it's allegedly necessary for stiffness with the alloy chassis).

300bhp/ton

41,030 posts

190 months

Thursday 25th April 2019
quotequote all
The C5 z06 was actually a development of the C5 FRC (fixed roof coupe). Which is probably the rarest C5 variant. It was the notchback body but with regular C5 engine and running gear. I believe the FRC weighs less, which is why it was used as the basis for the zo6.

Personally while the targa top appeals of the regular coupe. Visually I love the look of the notch back styling.




ExitLeft

930 posts

224 months

Wednesday 8th May 2019
quotequote all
I bought a C5 Z06 new in 2003, used it in the USA where I live till 2008, then imported it to the UK for summer use. I bought a new C6 Z06 in the USA to replace it. I got rid of both in 2013 (one of those mid life moments).

Couple months ago I tracked down the C5 Z06 in the UK and bought it back. New tyres, all fluids changed and ready for Le Mans. Couldn’t live without it.

I have many other cars that cost ten times as much but the simplicity, purity and sublime experience of the LS6 engine in a lightweight but comfy package is the best! Mine is completely stock except shift knob (not shifter).

C6 was great but for me the extra stuff and electronics diluted the purity of the C5.


Benbay001

Original Poster:

5,795 posts

157 months

Wednesday 8th May 2019
quotequote all
A vague question but can I ask what you think is a reasonable price for an average condition C5 Z06?

Suitably vague answers are accepted smile

Silver C6

252 posts

145 months

Wednesday 8th May 2019
quotequote all
What a buyer is prepared to pay for it? Is that vague enough? Sorry, couldn't resist.

Edited by Silver C6 on Wednesday 8th May 13:16