Whats wrong with standard 16" cerb wheels?

[spartacus]

:scratchchin:Just getting to the point where have driven the Cerb enough to start thinking about improving the suspension and ride with a mind to fast road and perhaps some track days.

Can anyone tell me why everyone who gets a 4.2 cerb almost immediately gets rid of the 16" standard wheels? does going to 17" Race Lines or 18" Spiders really make that greater improvement to handling with the consequent increasing tyre wall rigidity? I wonder how many people go this route purely for the looks? If I was going to upgrade must admit I would get a set of 18" Anthracite Spiders, but I need convincing they are worth the outlay.

What's the ride going to be like on standard shocks with 18" wheels if one does not upgrade to Nitron shocks immediately?

Has anyone fitted Nitrons and kept the 16" wheels?

[cerbie]

I had new Nitrons fitted to my car in August before I had it delivered. The car is still on the original 16" wheels - I think it handles well but I have little to compare it with.

My car was set up by Noel Flannery at V8 Sports & Classics. Rides height is 125mm front & 140mm back.

The only problem I have had is grounding the car on one or two particularly bad B roads I take to work. Done it twice in two different points on the road so next time I have the wheels off the rears will be stiffened up a couple of clicks.

[spartacus]

cerbie said:

I had new Nitrons fitted to my car in August before I had it delivered. The car is still on the original 16" wheels - I think it handles well but I have little to compare it with. My car was set up by Noel Flannery at V8 Sports & Classics. Rides height is 125mm front & 140mm back. The only problem I have had is grounding the car on one or two particularly bad B roads I take to work. Done it twice in two different points on the road so next time I have the wheels off the rears will be stiffened up a couple of clicks.

Are the springs still standard?

[simonsparrow]

spartacus said:

Has anyone fitted Nitrons and kept the 16" wheels?

Yes, I have. No problems including trackdays. I'm moving to 17" wheels soon, for a number of reasons. The tyre choice is better, the wheels are lighter (not TVR wheels ) and just for a pointless change.

I've been quite happy with the 16", and if I could've got the wheels I wanted in that size would've stick with them.

[cerbie]

spartacus said:

cerbie said: I had new Nitrons fitted to my car in August before I had it delivered. The car is still on the original 16" wheels - I think it handles well but I have little to compare it with. My car was set up by Noel Flannery at V8 Sports & Classics. Rides height is 125mm front & 140mm back. The only problem I have had is grounding the car on one or two particularly bad B roads I take to work. Done it twice in two different points on the road so next time I have the wheels off the rears will be stiffened up a couple of clicks. Are the springs still standard?

I believe they are - waiting for Noel to get back to me to confirm - has has looked after the car since 2000 so knows all the history.

[Toady1]

jonnie5 has that set up mate, ask him... i must say tho, when he took me out in his car it handled very nicely!

[spartacus]

simonsparrow said:

spartacus said: Has anyone fitted Nitrons and kept the 16" wheels? Yes, I have. No problems including trackdays. I'm moving to 17" wheels soon, for a number of reasons. The tyre choice is better, the wheels are lighter (not TVR wheels ) and just for a pointless change. I've been quite happy with the 16", and if I could've got the wheels I wanted in that size would've stick with them.

Just looked at your profile, yours is the cerb with the incredible mileage on the clock, so must do about 10k a year average miles in it and trackdays! very impressive.

[simonsparrow]

spartacus said:

simonsparrow said: spartacus said: Has anyone fitted Nitrons and kept the 16" wheels? Yes, I have. No problems including trackdays. I'm moving to 17" wheels soon, for a number of reasons. The tyre choice is better, the wheels are lighter (not TVR wheels ) and just for a pointless change. I've been quite happy with the 16", and if I could've got the wheels I wanted in that size would've stick with them. Just looked at your profile, yours is the cerb with the incredible mileage on the clock, so must do about 10k a year average miles in it and trackdays! very impressive.

It had about 82k miles when I bought it, I've put another 30k+ plus on

[jonnyw]

So the thread is now, high mileage, Nitrons and 16inch to 17!

My Cerb has done 60,000, going in for an engine refresh at Andy at APM, I have done over 3000 miles on the track including the TVR Speed Challenge and it is a robust old girl!

I moved to Nitrons all round and then 17 inch for two reasons, stiff and low but not quite so low with the 17's, plus tyre tread on the road and a better profile in terms of a balance of control and loosing my teeth through the jarring.

Seems a good balance, wouldn't go back. Car is tighter and doesn't ground as much. Racing springs, big at front, progressive on the back.


Jonny

[spartacus]

jonnyw said:

So the thread is now, high mileage, Nitrons and 16inch to 17! My Cerb has done 60,000, going in for an engine refresh at Andy at APM, I have done over 3000 miles on the track including the TVR Speed Challenge and it is a robust old girl! I moved to Nitrons all round and then 17 inch for two reasons, stiff and low but not quite so low with the 17's, plus tyre tread on the road and a better profile in terms of a balance of control and loosing my teeth through the jarring. Seems a good balance, wouldn't go back. Car is tighter and doesn't ground as much. Racing springs, big at front, progressive on the back. Jonny

So to summarise:

Larger the wheel diameter, and therefore lower the tyre profile, more tread stays on the road but harsher the ride.

RL 17s good compromise but prone to cracking, 18" Spiders prone to bending.

Nitron adjustable shocks a must.

[simonsparrow]

Jonnyw - how come you need an engine refresh?

[gazzab]

So is andy at apm doing the refresh himself ? He mentioned to me that he was going down that route.

[jonnyw]

Oil pressure took a 10Ib dive, idling at 15 and running at 40. Andy's view is that 60,000 is about right to tidy it up for next season's sprinting.

I tend to hold the revs between 6,000 and 8,000 so I don't want anything coming adrift! And with Andy's own racing experience and the fact that he is keeping a few racing cars on the circuits you know that the detail is going to be covered.

Yes, Andy is doing it himself, and I wouldn't have it any other way, going to take 4 to 6 weeks. Few other minor things to do. Top Bloke.

[carl_w]

I have also kept the 16s. Personally I feel that the 18s are too big for the car, and look out of proportion (after all, it's a small car). And the tyres are much cheaper for 16s. Shortly getting the Protech suspension from Joolz, and will be sticking with the 16s.

[simonsparrow]

jonnyw said:

Oil pressure took a 10Ib dive, idling at 15 and running at 40. Andy's view is that 60,000 is about right to tidy it up for next season's sprinting. I tend to hold the revs between 6,000 and 8,000 so I don't want anything coming adrift! And with Andy's own racing experience and the fact that he is keeping a few racing cars on the circuits you know that the detail is going to be covered. Yes, Andy is doing it himself, and I wouldn't have it any other way, going to take 4 to 6 weeks. Few other minor things to do. Top Bloke.

Sounds like you're using your car much harder than me! The oil pressure could just be the spring, mine dropped 10lb after a trackday due to a spring weakening.

Andy does a great job, I'm glad he can do AJP engine stuff now too. I just hope that I get some graceful early warning of when to rebuild mine.

I hope to join you in some sprinting next season!

[purpleheadedcerb]

Slightly off topic, but what oil pressure should you see on a healthy 4.2 engine:

From Cold start?
Once warmed up and at idle?
Warmed up and engine at 3000rpm under load?

Thanks.

BTW. I have the standard 16" wheels but prefer the look of the RL17's. I think the 16's look a bit dated. I too think the 18's look big but each to their own. (Not having a dig at anyone with 18's!)

Scott

[simonsparrow]

On mine,

From Cold start? - up to 80psi in these low temps.
Once warmed up and at idle? - 60psi
Warmed up and engine at 3000rpm under load? - 70psi

[jonnyw]

Simon,

Look forward to seeing you out there.

Unfortunately the spring has been changed twice with only a minor benefit.

Before the "hard" time it's had, it started at 70 plus and ran at 60 and idled at 30 to 40.

Jonny

[purpleheadedcerb]

Hmm.

Ours is 45 at cold start, 40 at warm idle and 50 under load. It's done 55k. I suppose its major fluctuations or extremely low readings that should be a worry. (he says hoping somebody confirms that his engine isn't about to die!)

Scott

[morebeanz]

I've never had an oil pressure reading more than about 40 ever! It seems to build up pressure very rapidly at start up to 40, never wavers until it gets very hot at idle (drops to maybe 35 ish).

I assume that it's the way that the pressure release valve is set up...