996 - Sports Exhaust Advice

[Rotorhead]

I have a 2002 (3.6) C2 Coupe - perfect in every respect. However, I would appreciate advice on the options and merits of fitting a sports exhaust system, specifically:

* What are the advantages?
* Which system? (would prefer Porsche or recognised alternative)
* Likely cost ? (I don't want to spend silly money)

Alternatively, is there a sound enhancement kit (a la 993)?

Thanks

 

[Guest]

I can only comment on the Porsche system. I specc'ed it and had it fitted from the factory. Cost was £1150 ish, current price for factory fit is £1160 (option XLF if your wondering).
To retro-fit will no doubt be more.

The advantages are that you can have it noisy or quiet at the flick of a switch.
It defaults to noisy every time you start, so you have to conciously select quiet if you want it.
Quiet returns the car to normal volume levels, which is useful to track days and if you want to be a but more discrete or leave at 5.00am in the morning.
It is also nice when you have a long journey on motorways, since it can be intrusive when cruising a steady speed for a couple of hours.
On noisy mode, it sounds great under hard acceleration (as has to be done when pulling away from toll booths). It also sounds pretty good in multi-storey car parks and enclosed spaces, such as tunnels.

Even in noisy mode it is speed sensistive and goes quiet between 35 and 45 mph. As I have mentioned before, I beleieve this is for drive by noise requirements.

It works by having movable baffles in the silencer units. These are electrically controlled.

Other systems will, no doubt, offer the same audio improvements, but I don't think anything else has a switch. So you will be stuck with whatever sound it makes, all the time.

It is of course a toy, not essential and a little pricey, but I would recommend it. EVO magazine reckon it to pretty mandatory equipment.

 

[Kevin Cooke]

Stuarts point on track days is well made, figures for the 996 factory sports exhaust are:

On quiet: 99db at 4,500rpm
On standard (loud):107db at 4,500 rpm.

You therefore won't do many track days unless you have the quiet switch.

Regards

 

[daro911]

ORIGINAL: Stuart Martin

I can only comment on the Porsche system. I specc'ed it and had it fitted from the factory. Cost was £1150 ish, current price for factory fit is £1160 (option XLF if your wondering).

Stuarts description is spot on and if I wasn't a total Boxster convert and obviously don't require 4 seat option I could be swayed into a 996 with factory exhaust option. My neighbour has it fitted to his C4S and the sound is awesome and as impressive as any Ferrari 360 I have ever heard driven in anger [8D]

Just wish Porsche would allow the Boxster boys the same factory choice too [:'(]

 

[Guest]

stick with the Porsche item. even when retrofitted, as I did to my 98 C2, it's loud when you want it and quite when cruising on the m'way. I didn't bother fitting the switch as routing the wires is a major hassle, so it's on loud all the time, but still quiter than some of the aftermarket systems.

sticking to the Porsche item should also not adversly effect the resale of your car, as fitting a max power type exhaust may.

i bought mine second hand from prestige salvage and paid about £450, so not too bad. it was off simon lebons crashed 996 cab (nae luck !!)

 

[JULIAN]

I've just had one fitted to my 03 C4S by OPC Cardiff last week. They had the car all day Fri and Sat morning to fit a full sports exhaust with the dashboard switch for £1850 + VAT.

Well worth it, it sounds brilliant.

 

[ianbanneville]

The Porsche Sports exhaust is the best option fitted to my 4S - I have been told that it makes the 996 sound more like an air cooled car... [8D]

(runs for cover...[])

 

[Rotorhead]

Do the various 'Tequipment' sports tailpipes do anything for 'aural' quality, or are they purely aesthetic?

Porsche Sports exhaust does seem tempting (at a price), but I'd be interested to know what it is like at motorway cruise speeds (75-85)?

At these speeds, in my Coupe, flat frequency road noise (even on the excellent Pirelli N4s) is the most prominent background sound. Would a rumbling exhaust note be better or is it a droning resonance?

 

[Guest]

The tailpipes are just for appearance. I presume you mean the ones with one large circle and one smaller one partly overlapping.

The exhaust is only really significantly louder when under load. With your right foor mashed to the carpet it sounds great and loud, however, at cruise it is quite acceptable.
At motorway speeds it is a little noisier than standard, but is quite acceptable. Obviously it is louder when going up a hill.
Bear in mind that the engine is behind you and noise is going backwards, so I am told it is louder for the cars following. Hence the original comment about being ideal for leaving toll booths.
However, you have the switch to make it quiet, so it really is not a problem.
Of course, if you have the PCM option or the full on Bose, then you can drown out everything with your 11 or 12 speakers anyway.

At speeds up to and above 3 figures, tyre and suspension noise is about the same as the engine at cruise.

 

[Rotorhead]

Following the helpful advice here, and my own research, it would appear that the official Porsche Sports Exhaust System provides a subtle, but crucial, improvement to the 996.

Cost, with a bit of negotiation, is c.£1,390 fitted (inc vat, but excl switch option). This is quite expensive, but it can always be removed and the original system retro-fitted. But, if it injects the 'air-cooled' aural character that is missing from the water-cooled cars, then it will be money well spent.

My car goes in on Weds, so I'll report my experiences.

 

[Guest]

I've also been looking into sport exhausts and got the following reply from Autofarm:

>The exhaust can be considered as 3 separate pieces; the Manifolds(headers),
>Catalytic Converters(cats) and Silencers. They can be changed individually,
>or in any combination. The most usual is to change just the silencers, as
>they make the most difference in terms of the sound, giving a deeper note
>without being too loud. Details as follows.......
>Headers. Cost £995. Possible power increase 15bhp
>Sports "Cats". Cost £995. Possible power increase 10bhp
>Sports Silencers. Cost £895. Possible power increase 15bhp.
>All prices are plus vat + fitting.

This is for a non-Porsche part. Does the Porsche one replace all three? If so the quotation from an OPC for £1300 sounds a much better deal.

Tim

 

[Rotorhead]

I'll let you know later. The system is being fitted today.

 

[Guest]

As far as I am aware, the Porsche one only changes the silencers.
Officially there is no increase in power. I mentioned it when getting insurance and they were uninterested, so I guess they also know it makes no performance difference.

The Porsche one is purely for audio improvement, and does not constitute an upgrade.
The non-Porsche ones are usually oriented towards making some performance enhancement, and this is more commonly achieved by changing the headers and cats (along with ECU etc.)

Given that the Porsche one is only for a sound improvement, it is really a toy and rather expensive, as I mentioned originally, but it makes you smile.
That's the purpose of owning a Porsche - smiles per mile, and on that score it is worth it.

Of course, in terms of smiles per mile per pound spent, then a new(ish) 996 is not really the most sensible option. But who cares - if you are worried about money that much you probably wouldn't have bought it in the first place.

 

[Rotorhead]

Lovetts fitted the Porsche Sports Exhaust System (non-switchable) to my car (3.6 C2 Coupe) today.

Absolutely wonderful - worth every penny.

I'll do a full report under another post when I've run it for a while. However to put it into context; I've owned 911s for 20 years now, (and still have a 73 RS and 88 CS). I love the air-cooled engines. The action on start up and the mixture of induction, mechanical, and exhaust noises always gives me a tingle.

The 996, however, has always disappointed. I had one on test in 1997 and my first reaction was 'great car, but too quiet'. I bought a 3.4 in 1998 and then my current 3.6 more recently. In both cases the engine has always sounded too sterile. For such an accomplished car driver needs to feel closer to the engine.

However, with, apparently, no downside, the Sports Exhaust has transformed the 996. It now has a subtle, warm engine/exhaust tone that sounds delectable, without being intrusive.

It doesn't really sound like an air-cooled car, probably more like a Ferrari V8.

I like my cars pure and simple and I don't like spending money unnecessarily, but I can recommend this system as money well spent.

 

[Guest]

Good to hear your endorsement, I recently bought an '03 C4 with it already fitted and I must say for the grin factor it really is a hit! mine has the switch and auto cut-off at around 30mph - 45mph which is a little sad, however I'm not sure my neighbours would appreciate my leaving in the early morning with it switched to loud! - on the other hand my wife, who is less of a poseur, always switches it off - from the passenger seat!!
I did a solo trip today down the M23 with it on and the great in-gear accleeration combined with the loud warble was quite infectious. Does anybody know how you can disable the 30-45 auto-cut off but still retain the manual switch?

 

[Rotorhead]

Mine doesn't have the switch and, based on my experience so far, doesn't seem to need it.

The 'volume' tends to be rev related. At modest throttle openings, up to 3000rpm, it simply makes a delicious, unobtrusive, growl. Thereafter the sound becomes progressively more involving. It really only starts to become loud with wide throttle openings beyond 4500rpm.

Very clever system.

 

[Guest]

With the baffles affecting the exhaust gas flow less in noisy mode, the effects of the Variocam plus system are more noticeable.

Under low load and at low engine rpm, the intake timing is 'late' and valve lift is 'low'.
Under high load and low engine rpm, the intake timing is 'early' and valve lift is 'high'.

Above 4500 rpm, intake timing is 'late' and valve lift is 'high'. This is to benefit from the ram effect of the intake charge after BDC for better filling of the cylinders.


In 'high' lift (for 1mm valve lift):
'Early': Intake opens 31 deg before TDC, closes 21 deg after BDC
'Late': Intake opens 9 deg after TDC, closes 61 deg after BDC

In 'low' lift:
'Early': Intake opens 15 deg before TDC, closes 35 deg before BDC
'Late': Intake opens 25 deg after TDC, closes 5 deg after BDC

Exhaust opens 4 deg before TDC, closes 42 deg after BDC.

(Note that the turbo anf GT2 use different angles.)

Valve lift (which affects inlet and exhaust):
'High' = 11 mm
'Low' = 3.6 mm

(Just for completeness: intake valves are 40.2 mm, exhaust 34.5 mm. There are 2 of each per cylinder. [])

You also have the Helmholz resonator in the intake manifold. The resonance valve opens at 3120 rpm giving up to 6% more air density in the charge reaching the cylinders due to the pulsations in the air column between the two plenum chambers.