RE: Caterham Seven 310R: Road vs Race

RE: Caterham Seven 310R: Road vs Race

Tuesday 10th July

Caterham Seven 310R: Road vs Race

Ever wondered what the difference is between the road-going 310R and its circuit racer equivalent?



The majority of performance car manufacturers have, at one time or another, made use of the same rather cliched phrase: 'it's a race car for the road'. You know what, though, I don't blame them. Be it Porsche with its GT3 RS or BMW with its low volume M3 GTS, manufacturers pour millions of pounds into high profile motorsport championships in order to develop new tech and demonstrate that there is a clear link between their road and race machines. Therefore, I guess it's fair that a manufacturer like Ford gets to call its GT a Le Mans winner with number plates.

However, if we look past all the marketing hype, even a homologation special like the GT is pretty far removed from the racer. For example, the GT racer uses a different gearbox, a different engine (yes, really), a different exhaust system, passive not active suspension and more extreme aero than the road car - and that's before we've got to the elements that make the production GT road legal.

So where am I going with this, I hear you ask? Well, after spending two rather intense weekends competing in the Caterham 310R championship - as well as chatting at length with Caterham's chief motorsport and technical officer, Simon Lambert - it occurred to me that Caterham may well be responsible for building one of the only true race cars for the road. As far as I could see, my racing spec 310R was only a numberplate (oh, ok, and perhaps some lights and a horn) away from being road legal.

To see if this was indeed the case, we set about getting both cars together so we could perform a back-to-back comparison. The results were rather interesting.


Caterham 310R Road Car

Before we climb behind the wheel, it's worth briefly going over the 310R's unique gestation period. You see, this is one of those rare breeds of road car that was genuinely developed as a racecar first, road car second.

The story goes that Caterham was developing a package for racers looking to move from the mid-level 270R championship to the more competitive 310R category. While doing so, it stumbled upon a setup that delivered such impressive all-round performance that the engineering team felt it was worthy of its own 'road' car.

The changes themselves are surprisingly minor, and aside from the addition of a limited slip-differential, revolve solely around the 270's 1.6-litre Ford Sigma engine. In short, new high-performance camshafts, uprated spark plugs, a tweaked breather system and revised mapping allowed the engineering team to extract another 20hp from the naturally-aspirated unit - increasing overall output from 135hp to 155hp.


Now, 155hp might not sound like a lot, but it's important to keep in mind that this is a car that weighs just 540kg - a detail that becomes immediately obvious the first time you open the throttle. First, second and third gear come and go within the blink of an eye, so closely packed are the ratios that make up the optional £2,495 six-speed manual gearbox. On a narrow and bumpy British B-road, the 310R feels quite a bit quicker than its official 0-62mph time of 4.8 seconds suggests.

And this immediacy permeates every aspect of the driving experience. The steering is so quick that even the most delicate of inputs has the front end diving for the apex; after a few minutes behind the wheel navigating fast corners feels almost telepathic. And because the 'R' comes on a smaller 15-inch wheel - and, therefore, on a skinnier six-inch tyre (rather than the eight-inch rubber of the 360 and 420) - it has the perfect power to grip ratio, allowing you to slide it about at low speeds with relative impunity.

Put simply, the 310R is an absolute riot, being arguably the most balanced and well-judged Seven in Caterham's current line up, something you might not expect from a car designed to live on a racetrack.


Caterham 310R Race Car

Unlike Academy and Roadsport championship machines, the 270R and 310Rs don't have to be road legal. So in order to save weight and reduce drag, the front and rear lights are thrown in the bin, the standard road car windscreen is replaced with a smaller plexiglass aero screen and the passenger seat is removed - all fairly simple changes.

The biggest alteration, however, is the addition of a full roll cage. Now, ingress and egress is never straightforward in a Seven, but the cage makes things even more complicated. Even if you decide to race without doors it's still easier to enter the cabin by climbing over the top of the cage, standing on the transmission tunnel and then lowering yourself into the tight-fitting composite race seat. There's something that feels very Dukes of Hazard about the whole affair.

Thankfully, once you're strapped in, the cockpit environment is very familiar to the road car. Luxuries like the carbon fibre dash and leather trimmed steering wheel are gone, replaced with steel and suede, but the layout of the instruments and the seating position (our test cars both had the £495 lowered floor) are near-enough identical.


Indeed, even when you start the thing it sounds surprisingly similar to the road going machine. Now, I appreciate this shouldn't come as a surprise - mechanically both cars are near enough inseparable. However, with a roll-cage over your head and a stripped out interior surrounding you, somehow you expect it to be race car raucous. Instead, the engine idles away nicely with next to no vibrations (at least by race car standards) transmitted into the cabin. In fact, at low speeds, it's the high-pitched whine from the five-speed gearbox and rear axle that dominates.

But surely the race car will show its unforgiving side once you start to really stretch its legs? Well, not exactly. As I hinted at earlier, all 310R race cars use a Mazda MX-5 sourced five-speed manual gearbox instead of the close ratio six-speed available on the road car. Surprisingly, the reason for this is not performance related, it's simply that the five-speed is a little harder wearing, which is important when you're fighting for a championship week in week out.

However, the five-speed 'box inadvertently brings more to the package than simply improved reliability - it lets you revel in the 1.6-litre Sigma's incredibly linear powerband, all the way to its heady 7,500rpm limit. In a world full of turbocharged engines that force you to short shift through the gears, the 310R's drivetrain is a delight. And unlike the six-speed road car (which, we recommend you spec with the standard five-speed), everything feels less hectic in the cabin as there's no need to keep grabbing gears.


But where the race car really sets itself apart from the road car is in the corners. Where our 310R press car came with sports suspension (standard with the 'R' pack) and Bilstein road dampers, the race car came on track suspension and race dampers, and the difference in body control is immediately noticeable.

Where the road car adopts a bit of lean through high-speed corners the race car exhibits virtually no body roll, which not only allows you to attack corners more aggressively, but it also keeps the car stable through quick direction changes: the result being less weight transfer and therefore less loss of traction. Of course, you can still give it a bung now and then if you want to revel in some gratuitous oversteer, but even when you're over the limit, the race car feels more predictable and better controlled.

All of this adds up to a package that is arguably less taxing to drive - well, on the limit at least - than the road car. Who'd 'ave thunk it?


A race car for the road?

It's easy to become a bit sceptical in a world filled with endless Nurburgring records, spurious advertising and race inspired 'special editions', which is why the 310R feels like a breath of fresh air.

It only takes a few minutes behind the wheel of the racer to realise why the development team decided the 310R was worth transforming into a stand-alone model. All the characteristics that make the race variant so involving make for an inherently well-rounded road equivalent, something that I'm not sure can be said for any other 'race car' for the road.

Factor in that the 310R Championship itself is now one of the most competitive domestic series ever created, and surely the 310R has to go down as one of the all time great road racers.

Find out more information on Caterham here.

Neil Winn


SPECIFICATION - CATERHAM SEVEN 310R
Engine:
4 cyls, 1595cc, petrol
Transmission: 6-spd manual (optional), rear-wheel drive
Power (hp): 154@7,000rpm
Torque (lb ft): 124@5,600rpm
0-62mph: 4.8sec
Top speed: 126mph
Weight: 540kg
MPG: N/A
CO2: N/A
Price: £23,495 (kit), £28,990 (fully built)
As tested options: £2,500 for factory build, £4,495 for R pack, £200 for 13-inch Apollo black alloys on Avon ZZS tyres, £1,250 for full weather equipment and side screens, £95 for side screen arm rests, £80 for hood bag, £115 for fully carpeted interior, £150 for Momo quick release steering wheel, £300 for heater, £300 for Sequential shift lights, £495 for lowered floors, £900 for high intensity lights with LED daytime running lights, £395 for full decal pack, £995 for full paint protection and £895 for on the road package.

SPECIFICATION - CATERHAM SEVEN 310R RACE CAR
Engine:
4 cyls, 1595cc, petrol
Transmission: 5-spd manual, rear-wheel drive
Power (hp): 154@7,000rpm
Torque (lb ft): 124@5,600rpm
0-62mph: 4.8sec
Top speed: 126mph
Weight: 615kg
MPG: N/A
CO2: N/A
Price:£34,095









 

Author
Discussion

suffolk009

Original Poster:

3,772 posts

96 months

Tuesday 10th July
quotequote all
Nice article.

But I don't understand why the 5 speed gearbox would better allow you to rev the engine to the limiter? And surely the difference in suspension is largely down to damper setting and spring rates rather than brand of damper used?

Lordbenny

7,013 posts

150 months

Tuesday 10th July
quotequote all
‘And because the 'R' comes on a smaller 15-inch wheel’.....????

Rob747

183 posts

107 months

Tuesday 10th July
quotequote all
For balance I think the 6 speed box is excellent for the road, it adds another layer of drama and makes the whole thing feel more frenetic than it really is.

steveb8189

177 posts

122 months

Tuesday 10th July
quotequote all
suffolk009 said:
Nice article.

But I don't understand why the 5 speed gearbox would better allow you to rev the engine to the limiter? And surely the difference in suspension is largely down to damper setting and spring rates rather than brand of damper used?
I imagine it's because it revs more slowly so you spend more time towards the limiter and can time you shift more easily.

Jim the Sunderer

1,718 posts

113 months

Tuesday 10th July
quotequote all
I like the use of gaffer tape.
Advertisement

HustleRussell

14,659 posts

91 months

Tuesday 10th July
quotequote all
Jim the Sunderer said:
I like the use of gaffer tape.
Crucial mod- stops your wrist restraint / race suit sleeve / glove from catching on the handbrake

Master Bean

993 posts

51 months

Tuesday 10th July
quotequote all
13 inch wheels on the R model. Great proof reading as always PH. And the 5 speed has a 0.82 top gear whereas the 6 speed is a 1:1.

RacerMike

1,853 posts

142 months

Tuesday 10th July
quotequote all
Lordbenny said:
‘And because the 'R' comes on a smaller 15-inch wheel’.....????
He means 13".....and also narrower. All but the comfort spec cars come with 13s, but the 420R and above have a wider rear.

suffolk009

Original Poster:

3,772 posts

96 months

Tuesday 10th July
quotequote all
Rob747 said:
For balance I think the 6 speed box is excellent for the road, it adds another layer of drama and makes the whole thing feel more frenetic than it really is.
I always enjoyed the 6 speed gearbox in my old Superlight.

wst

2,928 posts

92 months

Wednesday 11th July
quotequote all
I don't know enough about Caterhams to have spotted the cock-ups in the copy... but what's the fking point of reading an article that compares 2 cars that are only separated by tiny details, if the article gets those tiny details wrong?

sfaulds

628 posts

209 months

Wednesday 11th July
quotequote all
RacerMike said:
Lordbenny said:
‘And because the 'R' comes on a smaller 15-inch wheel’.....????
He means 13".....and also narrower. All but the comfort spec cars come with 13s, but the 420R and above have a wider rear.
13" wheels aren't standard on any road cars (except the 620R) - 14" are standard on 'S' pack, and 15" in 'R' pack.

RacerMike

1,853 posts

142 months

Wednesday 11th July
quotequote all
sfaulds said:
RacerMike said:
Lordbenny said:
‘And because the 'R' comes on a smaller 15-inch wheel’.....????
He means 13".....and also narrower. All but the comfort spec cars come with 13s, but the 420R and above have a wider rear.
13" wheels aren't standard on any road cars (except the 620R) - 14" are standard on 'S' pack, and 15" in 'R' pack.
Stu....are you sure?! I can't recall any Seven coming on 14s? All mine (including the new design wheels) where all on 13s, and certainly the two in this article are on those wheels. The Caterham store would suggest that too with the only 14in wheels listed for the 3 Cyl 160. Otherwise, the 'R' pack does indeed come on the 15s.

SidewaysSi

4,352 posts

165 months

Wednesday 11th July
quotequote all
RacerMike said:
Stu....are you sure?! I can't recall any Seven coming on 14s? All mine (including the new design wheels) where all on 13s, and certainly the two in this article are on those wheels. The Caterham store would suggest that too with the only 14in wheels listed for the 3 Cyl 160. Otherwise, the 'R' pack does indeed come on the 15s.
The 14" is standard on the 'S' pack and 15" on the 'R' pack. 13" is a NCO.

RacerMike

1,853 posts

142 months

Wednesday 11th July
quotequote all
SidewaysSi said:
RacerMike said:
Stu....are you sure?! I can't recall any Seven coming on 14s? All mine (including the new design wheels) where all on 13s, and certainly the two in this article are on those wheels. The Caterham store would suggest that too with the only 14in wheels listed for the 3 Cyl 160. Otherwise, the 'R' pack does indeed come on the 15s.
The 14" is standard on the 'S' pack and 15" on the 'R' pack. 13" is a NCO.
When did they introduce a 14? Any pictures of it? You're correct that it lists 14in on the main website, but I can't say I've ever seen a 14in on a Caterham on anything other than the 160, so clearly must be a new style?

sfaulds

628 posts

209 months

Wednesday 11th July
quotequote all
The minilite-style 14" wheel is hardly new!

https://caterhamparts.co.uk/7466-thickbox_default/...

HustleRussell

14,659 posts

91 months

Wednesday 11th July
quotequote all
RacerMike said:
SidewaysSi said:
RacerMike said:
Stu....are you sure?! I can't recall any Seven coming on 14s? All mine (including the new design wheels) where all on 13s, and certainly the two in this article are on those wheels. The Caterham store would suggest that too with the only 14in wheels listed for the 3 Cyl 160. Otherwise, the 'R' pack does indeed come on the 15s.
The 14" is standard on the 'S' pack and 15" on the 'R' pack. 13" is a NCO.
When did they introduce a 14? Any pictures of it? You're correct that it lists 14in on the main website, but I can't say I've ever seen a 14in on a Caterham on anything other than the 160, so clearly must be a new style?
Nah I remember the 14" wheel with Avon ZV3s being an option about 20 years ago. God knows why you'd spec them mind.

Gixer_fan

275 posts

129 months

Wednesday 11th July
quotequote all
The race car is 75Kg heavier ?

HustleRussell

14,659 posts

91 months

Wednesday 11th July
quotequote all
Gixer_fan said:
The race car is 75Kg heavier ?
Not a chance, mine was the same, used to tip the scales at less than 510kg before fuel.

ETA: actually mine had the lighter Ford gearbox and diff rather than the heavier Mazda / BMW combo in the 310R. But still, the race car is definitely less than 540kg

Edited by HustleRussell on Wednesday 11th July 17:45

sfaulds

628 posts

209 months

Wednesday 11th July
quotequote all
The weight quoted for the race car is the race minimum weight, which includes the driver.

Terzo204

372 posts

87 months

Thursday 12th July
quotequote all
HustleRussell said:
Not a chance, mine was the same, used to tip the scales at less than 510kg before fuel.

ETA: actually mine had the lighter Ford gearbox and diff rather than the heavier Mazda / BMW combo in the 310R. But still, the race car is definitely less than 540kg

Edited by HustleRussell on Wednesday 11th July 17:45
So how much will a Supersport with type 9 and BMW diff weigh HustleRussell?