Friday 12th July 2013

RPM Technik 911 CSR: Review

Take a 997 Carrera, sprinkle with fairy dust and build yourself a cut-price GT3 chaser - with four seats!

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"As happy going flat through Eau Rouge as it is pottering off to Café Rouge and all at a budget you can afford." So goes the sales pitch for the 997 Carrera-derived CSR from Hertfordshire-based Porsche specialist RPM Technik.

Nothing lairy but intent is clear enough

"We understand that even in this sector it is not always within people's budget to have separate track day and road cars. And that Porsche's purpose built track cars, superb as they are, don't always come equipped with driver comforts, or even rear seats. They are often fitted with cage, race seats and harnesses too so perhaps not ideal for going out to dinner in!"

So says Darren Anderson, passionate Porsche man who, together with colleague Ollie Preston and the team at RPM Technik, has created a thriving business maintaining, selling and now fettling Stuttgart's finest over the last 12 years.

The company has strong sales and servicing departments but it is also known for its fleet of track-prepped machines including a 911 SC, Boxster racer, 944 Clubsport and 996 GT3. Their cars can be hired for track events and they offer full prep and customer support for customer cars and race programmes.

No power boost claimed but razor sharp response

Balancing act
The CSR is RPM Technik's attempt to blend performance and practicality to create the perfect balance between road and track capability. A balancing act that is pretty much the Holy Grail for sports car tuners everywhere and with extensive development at the 'ring and Millbrook, the company thinks it has it bang on.

The base car is a first-gen 997 Carrera S, a car that can be picked up for around the £20K mark these days. From there, RPM has paid detailed attention to every aspect of the machine in creating the CSR.

There is something just right about the car's stance. It looks low and wide over superlight OZ alloys and the carbon fibre ducktail is an immediate head turner. The jawline differs, too, thanks to a modified Turbo front bumper - the foglights now indicators.

Ducktail is a subtle but effective calling card

Creature comforts
Inside there are few bits of matt black trim giving a stealth feel to the interior, along with a red CSR dial taking centre stage. Overall, though, it is pretty much as Porsche intended. No cage, no harnesses, rear seats in situ, pretty normal and nicely comfy.

This car is fitted with a fairly tame exhaust system today to ensure compliance with Bruntingthorpe's strict noise limits. "It's a shame," says Darren, "because the full sports system sounds brilliant and gives the car a much harder edge to the engine note as well as more volume."

There are some terrific back roads in the vicinity so before we take our allotted slot on the proving ground, we try out the CSR's on-road credentials. It takes about 100 yards to realise that this is quite an evolution from a standard 997.

Stance underlines chassis work beneath

Reaction time
The engine feels instantly more responsive and the gearchange requires a bit more concentration, thanks to the lightweight clutch and flywheel. The steering has considerably more weight than the standard car, thanks to the new suspension and those tacky Yokohama tyres. Heftier, yes, but full of feel and feedback.

The ride is firm but not unacceptably so. "We tend to offer three different set-ups: road, fast road or track," explains Darren. "This is what I'd call fast road. We have done quite a bit of track work with it but I have also driven it to and from Spa so I didn't want it to be unbearable. If a customer does more track work, we can set up the suspension to suit. If they want a more compliant setting and a bit more ride height, that is not problem."

The suspension is an Ohlins system, fully adjustable, and the car gets poly bushes, uprated anti-roll bars and then gets a full geometry setup and corner weights checked to ensure optimum performance. The wheels reduce unsprung weight considerably and the brakes are standard discs and calipers but get new pads. "They are more than up to the job on road and track."

Needle fair zings around rev counter with mods

Flatters to deceive
The engine feels brawny: although there is nothing major in the rework under the ducktail, RPM has fitted a high-flow air filter to complement the new exhaust and lightened and balanced the crank. The company isn't claiming a horsepower boost but the 3.8-litre unit seems more responsive and the mid-range feels especially strong. It also revs out with gratifying ease, and you have to keep half an eye on the tacho to avoid the limiter before you get used to it. It's hard to believe there isn't an extra 20-30hp from this blueprinted unit.

The inclusion of a Wavetrac torque vectoring limited-slip differential is one of the more notable things on the CSR spec sheet too. "We have done a lot of testing and we felt this gave us the best combination of handling characteristics, optimising the car on track without sacrificing anything on the roads," says Darren.

Front-end grip matched with epic traction

On the nose
There is certainly a terrific front end on the CSR. It really handles 'on the nose' and that in turn gives great confidence. But there is no sense that the rear of the car is going to get lairy, even when braking deep into a corner.

At Bruntingthorpe we could push that handling to the limit and beyond and the CSR impressed from lap one. Grip levels on hot tarmac are phenomenal and the Wavetrac diff gives a really sweet, neutral feel to cornering. The front bites, you sense the beginning of a rotation towards the rear, sitting the car over its fat rear boots but then it really digs in and fires your out of the turn, reluctant to relinquish its grip on the asphalt.

It is pretty difficult to induce understeer in this car without quite serious provocation. Mind you, it is also fairly reluctant to oversteer. A bit of a lift will do it and really piling on the power will, too. But in general slides are small, well telegraphed through the steering and easily caught. This car is keen to record rapid lap times rather than vaporise its rear boots.

Spangly OZs trim some valuable unsprung kilos

High speed stability is impressive and the brakes proved resistant to fade over several hard laps. It's easy to imagine the CSR is a bit of a giant killer on track days - especially circuits where chassis set-up is more important than big power outputs.

And what of the GT3?
It's a tricky old balancing act, combining road and track performance but the CSR manages to pull it off pretty convincingly. And the beauty of the CSR package is that you can really pick and choose what you want. RPM Technik will happily source you a 997 and produce a fully-finished CSR, including build plaque if you want that. Or, if you already have a 997, you can dip in at whatever level you fancy. So if you just want the suspension, that's fine - £2,340 plus VAT and fitting. Love the ducktail? No problem - £1,400 plus VAT.

CSR realises added potential in stock Carrera

One wonders whether you'd really opt for the CSR over a GT3 but that ability to build your CSR over time and when budget allows makes a lot of sense. And honestly, it really does offer a driving experience worthy of comparison and without some of the compromises. Whether it'll have the status, long term collectability or resale potential of a GT3, however...

But it's a thrill ride, the CSR, no doubt about it, and it takes the stock 997 to a whole new level for driving pleasure and involvement. It looks good, goes better and as summer evening drives go, the one spent at the wheel of the CSR will be remembered for a long time to come.

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PORSCHE 911 CARRERA 2 S 'CSR' (997)
Engine: 3,824cc flat-6, modifications as listed
Transmission: 6-speed manual, rear-wheel drive
Power (hp): 355@6,,600rpm
Torque (lb ft): 295@4,600rpm
0-62mph: 4.8sec
Top speed: 182mph
Weight: 1,420kg (DIN)
MPG: 24.1 (NEDC combined)
CO2: 283g/km
Price: Base car c. £20,000 plus modifications

All figures for standard MY2007 Carrera 2 S manual, before modifications

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997 CSR modifications:
Rebuilt 3.8-litre engine, lightened clutch and flywheel, lightened and balanced crank
Ohlins adjustable suspension
Wavetrac LSD
Powerflex bushes
Solid engine mounts
997 Turbo front bumper and running lights (modified)
Custom carbon ducktail spoiler
Custom sports exhaust
Sports steering wheel
Additional centre radiator
OZ Alleggerita alloys
Yokohama AD08 road/track tyres
H&R anti-roll bars
Castrol SRF brake fluid
BMC high-flow air filter
Full geometry and corner weight setup

For full pricing info contact RPM Technik.

 

 

[Technomatt]

So for a track day focused car on a budget, only the suspension and tyres are most beneficial mods there. Maybe the wheels for the mass savings and as a spare set of rims.

Surprised they have not offered a decent seat and harnesses, much more useful than a carbon spoiler and sports exhaust. Also, lots of expensive engine mods for no real advantage.

[Technomatt]

Modifying a 997S for some decent track pace sounds feasible by just selecting the cost effective performance mods, but trying to fully ape a GT3 from a base spec 997S is a waste of time, money and effort. Buy the GT3.

[Technomatt]

UH-Matt said:

What's the point when a proper GT3 costs £45-50k ?

£25k donor car plus another £25k thrown at it sounds like as bad idea in comparison.

True, when you bear in mind that £20K donor 997S will be a 2004/5 model with high miles and the £50K+ GT3 is probably a 2007 with lower miles and with decent resale potential, then the full package CSR here is a mugs game.

[Technomatt]

Gibbo205 said:

Hi there

I've done a lot of very similar mods to my car, to compare:-

Rebuilt 3.8-litre engine, lightened clutch and flywheel, lightened and balanced crank

- Mine has softronic, X51 airbox, GT3 throttlebody, CF plenum, X51 manifolds, BMC filter - Dyno'd at 376BHP and much more responsive, stock car was 358BHP on same dyno.

Ohlins adjustable suspension
- I'm on stock PASM.

Wavetrac LSD
- Again stock, so open diff.

Powerflex bushes
- Stock

Solid engine mounts
- stock


997 Turbo front bumper and running lights (modified)
- Aerokit on my car, which looks way better!


Custom carbon ducktail spoiler
- Aerokit

Custom sports exhaust
- PSE with PSE mod so always open, no issues at track.

Sports steering wheel
- GT3 steering wheel

Additional centre radiator
- Yes absolute must along with Hartect low temp stat, never see over 110c on track and rarely over 100c on road (oil temps)

OZ Alleggerita alloys
- Lobster Claws, Porsche lightest wheel, OZ will be lighter!

Yokohama AD08 road/track tyres
- Michelin CUP's and Pirelli Corsa's both as good!

H&R anti-roll bars
- 997.2 GT3 front bar on softest and 997.1 GT3 bar set to stiffest.

Castrol SRF brake fluid
- My car has 997 Turbo (PCCB) braking system, but converted to steel with PF08 pads, stock fluid is fine, never had brake fade ever!

BMC high-flow air filter
- yes!

Full geometry and corner weight setup
- Yes! GT3 lower arms so I've got -2.1 front negative camber, neutral front toe. Rear is -1.75 negative camber and total of 25 minutes toe in on rear. Handles perfect, completely neutral and very progressive.


Out of the above if I was to do more to my car I'd probably go with the Ohlins, Wavetrack LSD and powerlex bushes, though I find for track PASM seems great as hard for dry track day and soft for wet track day or road.

Here is a youtube video of a recent Donnington trackday I did in my car, had no problems with far more track focused and expensive stuff:-



http://www.youtube.com/watch?v=8fo4Tnp-W3E&fea...

http://www.youtube.com/watch?v=5V_9e6uYElA&fea...

Sounds like a really sensible set of mods for the track there, bearing in mind a stock 997S would more than likely already have the steel anchors (but no aerokit).

No so sure your engine mods for the extra 18 bhp would be worthwhile for someone on a real tight budget, but I see where you are coming from.

Interesting with your thinking on the stock suspension (neg camber, roll bars excluded) ref the PASM and that ability to switch on a button press and key some degree of compliance for the road.

[Technomatt]

Gibbo205 said:

Yeah engine mods are expensive, your best just doing high-flow cats as they give the biggest gain of all mods and BMC panel filter.

I like the PASM as like you say gives best of both worlds, yes no doubt Ohlins would improve my track times by maybe 1-2s but it could ruin it for the road and I loose that easy flick of a button ability.

I think probably the best mod I've not yet done would be the LSD.

Or a CG-Lock, if you haven't already got one. LAS (Limited Arse Slip)

[Technomatt]

Gibbo205 said:

Technomatt said:

Or a CG-Lock, if you haven't already got one. LAS (Limited Arse Slip)

CG-Lock, whats that?

Paupers harness :

http://www.cg-lock.co.uk/app/performance/

Actually, not bad for what it is and also depending on what seat you are running.

[Technomatt]

CraigyMc said:

Technomatt said:

Gibbo205 said:

Technomatt said:

Or a CG-Lock, if you haven't already got one. LAS (Limited Arse Slip)

CG-Lock, whats that?

Paupers harness :

http://www.cg-lock.co.uk/app/performance/

Actually, not bad for what it is and also depending on what seat you are running.

Personally, I hate them. My mate who has an RB320 subaru swears by his, I just swear at them.

C

If you are used to a multi-point race harness then they can feel a bit lame. However, if you are sliding about on the seat on track under a bit of 'g' with an inertia 3 point, they can be a reasonable option on a budget.