The £7700 Corvette C6

[Fishy Dave]

Shnozz said:

I admire your attention to detail and some home made modifications in your approach. I remember chasing cooler temps on my old TVR in a similar fashion and water wetter was a great little easy addition! Thought it would be snake oil but definitely helped.

I had thought with the Vettes being run in the USA and in many in the Middle East they would be fine with temperatures.

Thanks, good to hear that Water Wetter helped your car. The standard C6 Coupe is fine in high ambient temps and can cope with autocross type events, it just struggles with trackday sessions. It now appears that the large $1000 oil cooler kit I bought has been redesigned as it blocks too much airflow. Since becoming a Dad I don't have the spare cash to replace this with another oil cooler, so will have to live with it for now.

[Fishy Dave]

firemunki said:

I reckon you could prob cut up the heat sinks and get more on the trans, and like you, I think lots of little bits would add up. Even if it's only a degree or two it could be enough to bring it to a point where the stock cooling is effective again.

Plus heatsinks, and thermal wraps just look cool.

I hope you're right, yes, it might take a bit of time but I could cut up some more of the solid heat sinks and bond them to flat surfaces on the gearbox and diff casings.

[Fishy Dave]

Smitters said:

Anyway, that, and the car aside, huge congratulations to you both on Austin's arrival. Parenthood in your 40's is fine. Provided they sleep perfectly, behave well, never get ill... oh. Bugger. I've been knackered since 2014. You get used to it.

Thanks, I'm really enjoying it so far and he's actually sleeping well. Often he only wakes once in the night for a feed.




He's 3 1/2 months old but is wearing 9 to 12 months old clothes, yikes! I took Austin for a short run along the driveway, he wasn't that fussed, but didn't cry so that's something.

[Fishy Dave]

Janosh said:

Love this thread and the way you’re using the car..

I recently took my VXR8 (LS2) out to Nürburgring and had a valve spring break. Fortunately I didn’t drop a valve or else it’d be time for a new engine.

Apologies if you’ve already done it, but it’s worth considering dual valve springs, especially given the workout that your car gets!

In hindsight I should have changed the springs last year when I replaced the lifters. Good advice. Did you manage to driver the car back?
Two of the exhaust manifold bolt heads have broken, leaving the studs stuck in the heads, so at some stage they'll need to come off to be drilled out, so I'll change the springs then.

[Fishy Dave]

Janosh said:

Love this thread and the way you’re using the car..

I recently took my VXR8 (LS2) out to Nürburgring and had a valve spring break. Fortunately I didn’t drop a valve or else it’d be time for a new engine.

Apologies if you’ve already done it, but it’s worth considering dual valve springs, especially given the workout that your car gets!

Thank you. In hindsight I should have changed the springs last year when I replaced the lifters. Good advice. Did you manage to drive the car back?
Two of the exhaust manifold bolt heads have broken, leaving the studs stuck in the heads, so at some stage they'll need to come off to be drilled out, so I'll change the springs then.

[Fishy Dave]

It's time for another lengthy update, starting from early September.

With a changeable forecast for Scotland with a week to go I made the decision to stick to Yokohama AD08R tyres as a good all rounder. Not as fast as a true semi-slick, but less likely to see me aquaplane in the event of a highland downpour. Adams & Page in High Wycombe tracked down a pair of the last rear tyres in the country (sadly replaced by the disappointing 'RS' version), fitted, with a full geometry check and set up at the same time. The last time I took the car on track I was disappointed with the wayward handling, but put it down to the worn rear tyres. It turns out that the rear toe was off, probably a result of the high loads and kerbs. I could still go for more negative camber, but balancing road manners and tyre life this is an ok compromise.

|https://thumbsnap.com/gEb4rH77[/url]

This was an opportunity to change the tyre pressure sensors (they generally seem to last around 10 years) and fit the polished wheels I'd bought cheaply from the States last year. The corroded chrome wheels will end up being fitted with some track specific rubber and having given up on trying to find anyone who will re-chrome them I will give Plasticote a go at some stage.
I highly recommend A&P, they know their stuff.



The boot can accommodate a pair of wheels, with one in the footwell and one on the passenger seat.

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I changed the air filters again to free up every last bit of power, a few general checks and it was time to head north from Wiltshire to Scotland. Partly it was to compete at Knockhill for the first time and partly to have a bit of a break away, just me, the car and the scenery. I arrived the day before the competition, on Saturday 12th September, it being noticeably chillier than the conditions I'd left behind, oh and wet too.





With my car not having a roll cage I was unable to join in on the test day, but the circuit very kindly allowed me half a dozen laps to familiarise myself with the track. A lot happens in a short space of time, no long straights to relax and plenty of gradient changes, which fully tested the soft suspension. Sadly it bottomed out hard every lap at Duffas Dip, the new rubber lip/under spoiler sections looking decidedly shaved.





The afternoon saw various series racing, it made a nice change for me to spectate rather than organise. The circuit is brilliant for viewing, with far reaching views towards Edinburgh and the mountains.







Sunday, with signing on and scrutineering having been completed remotely and in advance I had enough time to wash the car in the Travelodge car park, apply the number stickers and head to the circuit in time for a video briefing. reduce the tyre pressures and it was time to go out. Superlap Scotland most closely resembles Time Attack, both are best thought of as multiple qualifying sessions through the day. Basically you are competing against your rivals on lap time, not on position, this way you can safely have multiple cars on track and you have plenty of track time too (unlike a sprint). Sure, you lose that thrill of wheel to wheel racing, but are less likely to pick up damage and I don't need to fit a roll cage. The other benefit for my car in particular is letting it cool down with a slow lap, before going at it again to set a fast time, this is far kinder to the car and helps the brakes in particular.



Hard to properly assess the effectiveness of the cooling mods given the lower ambient temperatures, but given that the circuit is known for being hard on brakes with big stops and no long straights I was happy with both the coolant and oil temps throughout the event (220F coolant and 235F oil). the heat haze through the bonnet vent was particularly impressive when coming off the track.



Entered into class D (classes based on power to weight), I was up against an Evo and an Impreza, not what I needed in changeable conditions. The Evo had blown its engine up so it was just myself and the Subaru. The driver and team were very friendly and shared photo and video with me through the day. Great to chat to so many people (at a distance and always with face mask) who were welcoming and seemed to appreciate the V8, a couple of whom recognised my car from this very thread! Hi to the PHer with the Seat parked opposite me.



In order to condense the story, the Subaru was just too fast for me through the day. The damp conditions didn't help, but even in the dry it was still a bit too speedy, all credit to the driver who finished 1.9 seconds ahead of me. Full semi slicks may have helped, but even then it would have been close.

Here's the video summary:


Very charitably I was given a 2nd in class award, being a bit of a tart I'll take that and will display it proudly. I really enjoyed the event, thought it was good value and best of all the car survived just fine ready for a bit of highland exploring the next day.



Here's the result of bottoming out on the front spoiler, this was new just a month before!







I stayed overnight at Stirling, which seemed nice but was a Covid ghost town. Still, I enjoyed a nice curry by myself.

Edited by Fishy Dave on Thursday 15th October 11:05

[Fishy Dave]

Bobberoo99 said:

Fantastic!! Love seeing it being used properly!!

Thanks, I've encouraged a few Corvette owners to take their first steps on track over the last couple of years, with a North Weald event becoming a regular feature now.

[Fishy Dave]

e46m3c said:

Car looks like good fun to drive and well set up. Every time I read your thread I’m back on autotrader

Thanks, it is great fun, there are plenty of cars that handle better, but it's part of the C6's leaf spring charm. I've no doubt it could be better with a bit of money spent on the suspension, but that's true of most road cars.

The exchange rate is back up to 1 dollar 30, about the same as when I bought mine in 2017, so potentially the cheapest way is to pick up your own in the States and have a bit of an adventure. The Corvette Forum, ebay and the various Craigs list regions have a few cheap ones crop up from time to time. I've seen three this year sub $10,000, manual with clean title but high miles.

[Fishy Dave]

Before leaving the circuit Jillian Shedden (wife of Gordon) kindly drew me a map with a suggested route for the next day. There's something exciting about driving new roads (a welcome change from M4!).























I've got loads more, but you get the idea, Corvette in nice scenery. There was a fair bit of traffic on the road to Glencoe, but once I turned south along the shore of Loch Linnhe it was empty. The road surface throughout the journey was excellent, the only disappointment was a lack of places to pull over that still had a view. Many viewing spots either required the ground clearance of a 4x4 or were hidden behind trees or grass banks.

At the end of a long day I stopped overnight in Carlisle and headed home on Tuesday, thank you Scotland.

[Fishy Dave]

Not much time to rest as just three days later it was off to another North Weald handling day, with some members of the Corvette Club UK as part of a Lotus On Track/Car Limits day. A nice variety of Elise, Boxster Spyder, Caterham, a McLaren and more had turned up. The day is a bargain and kind on cars too. My favourite part of the day is the afternoon when the runs are timed on the MSUK sprint layout.









I had three timed runs, all 1 minute 9 seconds, good enough to take the all three fastest times of the day! Chuffed that the old Vette did so well, passing 213,000 miles as it did so.
Had a fun drive in a Corvette C3, what a difference from my car, a proper classic and lively on those skinny tyres (a 1 min 19, I couldn't always find 2nd gear). There were 7 different Corvette's on the day, all did very well against more modern equipment.
The video is from one of my runs.



Once home I gave the car a good look over, all looked well with the rear 1144 pads getting low, but still ok. I was pleased to see that the heat sinks I had bonded to the sump were still intact and must be doing something as witnessed by the poor fly (showing the fins are in airflow).



First weekend in October and I was off to the Nurburgring, just me and the Corvette again. This was supposed to have been a trip in early May before the birth of my son, but it had to be put back of course. All credit to Hotel Zur Burg for being so reasonable at allowing me to rebook later in the year at no cost, when they could have been difficult about it. The hotel was booked later that week by Sauber for the F1. Good to see I wasn't the only C6 there.



October, in the Eifel, it's going to be cold and wet, yes? Yes, it rained on and off every day, the circuit was the most slippery I've known it. I completed two laps only, still enjoyed it but decided it wasn't worth an incident. The Friday evening alone had two motorbikes and seven cars involved in accidents, plus two red flag circuit closures.





So, instead of more lapping I did my usual favourite things, watching from various vantage points, Steak on a stone, hot chocolate at Blaue Ecke, museum, clothes buying in the shop and chatting from a distance with various car mad people from around Europe. I really do love the place, it's like nowhere else in the world.





Not being able to stop properly for a rest in Belgium or France did make a boring journey especially tedious, but I made it back just fine and was ready to spend some time at home with family!

I gave the car a service, this time opting for a lighter 5w30 oil (the recommended weight for a road Corvette), giving Millers Nanodrive a try. i changed the rear pads for a fresh set of Mintex 1144, the discs are fine.





With the rolling and bottoming out so pronounced at Knockhill it was time to do something about my lack of stiffness
As a recap, I have the soft 'base' leaf springs, with slightly firmer Z06 shocks and middle ground Z51 anti roll bars. Not wanting to spoil the ride on the road I decided to buy a used front spring from the Z51 model, these are plentiful on the used market in the States.
Spring rates for those interested are here: https://parsbrorc.com/?page_id=300
You can see that a Z51 front spring is rated at 526 lbs, versus the 420 I have at present. Strangely the base model rear spring is slightly stiffer than the Z51, so that doesn't need changing. By sheer good luck one of the drivers (Chris Tilly) who races in the CSCC was changing to a coil over set up and gifted me his C5 Z51 front spring (same part no. as the C6 Z51), thanks very much.



It's easy enough to change over, with the spring perches in better shape on the new spring. For now I've adjusted the ride height by eye only, at some stage I will corner weight the car (I need to buy new scales).



Visually the springs are identical aside from a part number, so the difference must come from the make up of the composite.



I sadly cancelled my entry to the Snetterton Time Attack round in October; just too busy at work and I needed to spend more time at home too.

Finally, in the last few days the radiator has started leaking, I suspect the pounding the front cradle got at Knockhill and the Carousel when the car bottomed out has probably stressed a weld, so a cheapy, all alloy rad of the same design I have already is on its way ($200).

Edited by Fishy Dave on Thursday 15th October 16:58

[Fishy Dave]

SturdyHSV said:

Forgive my possible ignorance, but I thought the whole point of the Corvette suspension was it's a transverse composite leaf spring, so no need for an upright spring, and handily no need for an anti roll bar?

Or do they add an additional anti-roll bar so you can tweak roll stiffness without changing spring rate? Although again I thought you could do that by adjusting the 2 mounting points of the leaf spring?

Once I took the time to learn about the set-up (as opposed to repeating the Clarksonisms) I thought it was a really impressive solution

Great to see one being used, I'm 50/50 on the vent, but it's a big thumbs up for having the minerals to drill a hole in your bonnet! I'm planning on putting ITBs on one of my cars at some point down the line, so cutting a big rectangle out of the bonnet I'll be sure to think of your bravery

You are right that the leaf is better at resisting roll, but presumably to make the spring stiff enough to eliminate an ARB the ride would be too harsh. The ARBs are quite thin in diameter which further helps with weight. Some good info here: https://en.wikipedia.org/wiki/Corvette_leaf_spring
I hadn't realised that Volvo used this recently.

The C6 doesn't have two mounting points, just the one.

I'm with you, I like the composite leaf, it's a good solution and one I will be sticking with. Adjustable dampers would be nice though, if funds allowed.

I am also 50/50 on the bonnet vent, most of the time I wish I'd not done it, but there is no doubt in my mind it has helped with coolant and oil temps on track. Once all the hundreds of Time Attack stickers are applied the vent will be disguised and more in keeping.

Edited by Fishy Dave on Friday 16th October 10:56

[Fishy Dave]

Don1 said:

Ref Rockingham '18 for the supercar event.... Hello from the Sagaris there. You can see me in front of you on the left from the early morning picture.

It was a good event, a shame my brake discs thought otherwise. I hope they can put on the Goodwood weekend in 2021.

[Fishy Dave]

minipower said:

Really enjoyed reading the update and you are doing a great job of persuading me to try North Weald.

How are you finding the Z06 shocks on the road? I’m going to order the C6 z51 arbs but torn between Bilstein or Z06 shocks. American forums seem to mainly focus on lowering and making the car as stiff as possible which I do not consider ideal with our uneven and broken road surfaces. The C5 already has a tendency to skip over bumps.

Thanks, you should try it, to date I've not known anyone break or damage their car at North Weald: the runs are short and the car gets time to cool down between laps. It's a safe way of perfecting your driving skills, a good laugh too.

The Z06 shocks are comfortable on the road, fractionally firmer than the Bilsteins I had before them, but still smooth. The C6 Z06 has a firm ride, but a lot of this is down to the springs, shocks alone are fine. The editor of the Corvette Club magazine, Mark, has just fitted C6 Z06 shocks to his C5 and commented on the improvement. If you go for Bilsteins be aware there are two types.
I'll probably sell the Bilsteins and Z06 shocks at some stage when I swap to adjustable dampers over the winter if you're interested.

[Fishy Dave]

MrNoisy said:

Great update Dave as always. I am jealous of how you find the time to fit it all in!

Looking forward to Donington in a couple of weeks. Did you manage to persuade any other Vette peeps to come along?

I'm lucky (?) that I work some weekends so build up a fair bit of time in lieu. Oh and having an understanding, car liking wife helps.

Yes, I'm all set for Donington as long as the Radiator arrives in time, no other Corvette's that I know of. A couple of the owners that have enjoyed North Weald are building up to a track day in the next year or so I would guess. Is your car ready? I'll reply to your last email soon, I've got two more race weekends to organise then I should have a bit more time and a little less pressure.

[Fishy Dave]

Accelebrate said:

I was at the ring on Monday for a track day, I’ve never known it to be so slippery. You weren’t the only one finding it challenging!

Any chance of a time goes out the window, what were you driving?

[Fishy Dave]

A very nice highlights video has just been posted on the Super Lap Scotland FB Group.
My car makes a few appearances, at 03:04 and 17:49

Edited by Fishy Dave on Saturday 17th October 12:07

[Fishy Dave]

Don1 said:

Were you there at the last Goodwood one as well?

No, sadly it clashed with work, was it good?

[Fishy Dave]

The radiator arrived, but the brackets that hold the shroud and the fan were squashed. With some heat and prying I was able to get them back into shape, but they are inevitably weaker.





All credit to myus.com they pursued a claim and refund for me, I will probably replace the rad again at some stage, meantime I had to hope that the core was ok as there was no time to order another from America. Once again I took the opportunity of the rad being out to blast compressed air through the A/C condensor, clearing out yet more stone and bugs. The adhesive on the foam insulation strips I had added to the previous radiator had melted, so this time I glued rubber weather seal to various places to seal gaps between the coolers and shroud.
I filtered and re-used much of the few month old distilled water and redline Water Wetter, topping up with more of the same, it takes ages to fill.





The day after working at Mallory Park I made the short drive to a trackday at Donington Park, on the National layout, on Monday 2nd November. This was a bit of fun, but also practice ahead of the planned day and night Time Attack round. Sadly Covid has put paid to that, so we'll have to wait until next year to compete in that. Still, that did mean I could fully enjoy the trackday without having to worry about saving the car.







I was there with car friend Ritchie and his son, bringing along his silver C6. This was his first time to Donington and with the morning starting wet he was understandably sensible, building his speed up over the day. I on the other hand know the place well and was happy to drift around like a loon.



The car was faultless all day, the low temperatures certainly help brakes and fluids. I'm finally happy with the effectiveness of the cooling system, the highest water temps I got to were 210F, with the oil at 260F after a particularly enthusiastic session. The combination of clean rads, sealed air gaps, bonnet vent, newish front air dam, drilled fan shroud and distilled water/Water Wetter have all contributed.

The front Z51 spring has really helped reduce roll and pitch under braking. It has induced more understeer, but nothing a touch more trail braking and heavy right foot can't overcome. I am certain this has reduced lap times, although my drifting around makes it hard to compare last years times with this.

You'll see in the first couple of minutes of the video I was having some fun with a McLaren 720S. It seriously made my car feel slow on the straights, the way it accelerated was remarkable. I had a chat to the driver afterwards, he enjoyed it too, clearly respecting the car and looking after it, he said it produces 780bhp. Having been beaten twice in sprints at Snetterton and North Weald by 720S I know that with a committed driver I'd have never got close to it.

That was the last time the car will go on track in 2020, I have some maintenance to take care of over the winter, with a few of the exhaust manifold bolts having been broken in the heads, probably for years before I bought it (C6's can be prone to this). Before damage occurs I will remove the heads and have the bolts drilled out and probably replaced with ARP studs.

Edited by Fishy Dave on Friday 6th November 12:46

[Fishy Dave]

Hi Ritchie,

Thank you for sharing this, it's not often I get to see my own car. I agree, these private days are superb, excellent driving standards and loads of space.

A few random observations:
My LED brake lights are bright!
Wow your car sounds great, a very different noise to mine, not sure if that's the intake, headers or back boxes?
You definitely got quicker through the day, glad that following helped a bit. Working on your confidence to catch a slide will get you that bit quicker, a drift day and handling day is recommended.
Your driving is neater and tidier than mine (see point above!).
I suspect your sons next car might be rear wheel drive, he's seen the light!

Looking forward to the next one. Cheers, Dave

[Fishy Dave]

A lack of family contact over Christmas does at least gain some extra car working time.

A year or two back I changed the lifters, in the process the heads were removed and out of the car for at least a week. I cleaned them up, not noting anything odd, until I came to one of the final stages when I couldn't get all of the exhaust manifold bolts back it. I had overlooked that three of the manifold bolts had snapped, pretty much flush in the heads (two in one head and one in the other). By that stage I had torqued the heads down, new gaskets, coolant etc. so I left it as a job to do for the future.

Well, that time had come. You can see the hole where a bolt head should be under '243'. It also shows a slight gap between the manifold and the head itself that produces a chuffing sound when the engine is cold.


The questions were how to remove the snapped bolts and whether to remove the heads in order to do so? Removing the heads would make access far easier of course, but then I'd have to buy more parts having disturbed it all. I bought a 90 degree drill head, left handed drill bits, splined stud removers and a gasless mig welder kit from Machine Mart. You can never have too many tools, so even if I didn't use all of the above I know they will come in handy. My limited experience with stud removers has not ended well, so this would be a last resort. The studs themselves are small diameter, so drilling with the heads in place could end in disaster, unless the hole was dead centre. That left me with the welding option. I've only welded about three times before, with supervision, so 'with all the gear and no idea' I watched a few Youtube videos, disconnected the battery and got stuck in.

I had a quick experiment off the car, by building up spot welds on the end of a bolt. Next I moved on to doing the same on the easiest to access head.


With patience and wire brushing between each session of building up the weld I was able to hold a nut in place, joining it to the stub of weld I had created.




On the first and second attempts the weld twisted each time I tried a spanner. Third time lucky and it started to move, woo hoo.



It was out, feeling chuffed I moved on to the harder to reach studs on the drivers side.












A few hours in total and all three were out, with no damage to the heads. I was so pleased, the equipment paid for itself compared to paying for an engineering company to drill and helicoil, plus new gaskets and head bolts, not to mention time saved.

Next job on the list and the cars first upgrade for a while: new engine mounts. As far as I know the engine mounts were original and whilst they felt fine a 20% Black Friday discount was too hard to resist going for these: https://amtmotorsport.com/collections/c6-corvette/...


Because I'd stuck a whole load of alloy heat sinks and a heating pad to the sump I was slightly nervous about raising the engine. The fins held though and I was able to drop the subframe without drama, changing one mount at a time.


From above the mounts looked fine as they are covered in the alloy heat shield.


I was shocked at what I found once the mounts were out though!




They were once in one piece and fluid filled. I like to think I have a pretty good feel for my cars, how had I not noticed this?! Thankfully I don't take hump-backed bridges at speed else the engine could have made a break for it.

These are much nicer, a shame they are hidden away.


I had long decided that I would not spend any money chasing engine power, 400bhp is enough for me most of the time. I would like to improve my lap times, especially as Super Lap Scotland has announced a round at Croft in 2021, as well as at Knockhill of course. So, handling upgrades became my Christmas present to myself. To re-cap, my car's suspension is currently more or less the same as a UK spec C6, with Z51 springs, anti-roll bars and Z06 dampers. It's a nice compromise, but could still be better controlled on compressions (Duffas Dip) and crests (Avon Rise).

I contacted a number of companies, both in the States and closer to home, with my preference being Nitron. However, I couldn't make the numbers work, so opted for KW V3 to compliment the leaf springs (non coil overs), from Co-ordSport (excellent service and price). At around £1400 these are more than I have ever spent on a cars suspension but they have a good reputation, stainless bodies and are double adjustable. Very few seem to have ever fitted them in the States, anyone have any personal experience with them on a Vette?



Next up, to finish off my 2020 Black Friday spending spree I bought a full set of Borg Motorsport Delrin bushes. Another first, although I've replaced the odd bush here and there I've never replaced them all in one go. It seemd daft uprating the dampers but leave the old squidgy bushes.
It appears that in order of firmness it goes Rubber > Poly > Delrin > Steel Monoball.
Polyurethane is much cheaper, but can deform in time and squeeks unless re-greased, whilst the monoballs are harsher riding on the road and may not stand up to British levels of moisture as well?
This is the kit I chose, with Teflon impregnated Delrin: https://www.borgmotorsports.com/collections/c6part...
I'd had some excellent advice from Sam Strano so chose to buy the kit from him, with 20% BF discount and a decent exchange rate too http://www.stranoparts.com/searchbymodel.php?Model...


There are two levels to the box, one for each side of the car, with each part in a set place so no chance of confusion when fitting. These are some of the best made parts I've had the pleasure of handling, decent fitting instructions too.

I don't have a work bench (or the space for one), but knew I needed a Vise, so I bolted it to my Workmate, riding it like a horse to add some weight.



The instructions suggest removing the wishbones off the car, but the various ball joint splitters couldn't handle the size of the Corvette joints. I found that using a 2 leg bearing puller did the job in some case, in others I left the wishbones on the car and used threaded rod to drive the rubber bushes out.





I had marked each eccentric joint before removing, so the settings will be roughly similar. I will get another set up done sometime soon.


All but one bush was in good shape, this one was just starting to work its way out, due to age and track cornering forces.


Access to the rear, top adjusters will be through the boot floor, a bit disappointing the instructions don't describe this. The supplied allen key is woefully short too.


The leaf springs are also going to make adjustment at the lower part of the dampers tricky, but I'll see if I can fashion something suitable.




Everyone can appreciate a neatly finished bush


At the time of writing I have replaced all the bushes, I just need to fit the last damper and start putting it back together. I can't wait to drive it again, in a week or two probably. Here's a nice pile of old bits.