Porsche power upgrade for 996

Guys, can anyone tell me if the engine upgrade for 996 (+25bhp) is retrofitable ?? If so how much ? Anyone out there got the upgrade already that can give me their views ?? Cheers G.

Ahem.....Mr 192MPH wants MORE POWER???????[ ] Happy New Year mate![ ] Simon

It is intended to be a factory fit option. But, my understanding is that it could be, but it is only suitable for a manual car. The changes are not quite so extensive as those to the turbo, but still require a new inlet manifold, new exhaust manifold, new inlet side camshafts with higher lift and larger wider ports on the inlet side, whether this means the inlet manifold, or larger valves which would require a new head, I'm not sure. These bits could all be bolted on, if you can actually order them. I suspect you might struggle to get them from anyone other than Porsche themselves, who may want to limit availability to keep it a factory fit option, but if they will sell them, the prices will be high. The Porsche website (configurator) is not working at the moment, but I seem to remember the factory option price was 5K or more. Aftermarket, it would be more just for the parts, and you need to add quite a few hours labour. (It's not suitable for GT3/TT, but perhaps you have other plans.) One of the other GT3 members, Kevin Cooke, had it on his C4S I seem to remember, so he may be able to help you. My understanding is that the benefits are only really above 6500 rpm, where you get more power. This is useful on the track, but not worth the money on the road.

Good to hear from you Simon, Haven't seen you 'round these parts for ages ??? Where's that GT3 then ???? As for the need for power, well, yes and no, i want to spend a lot of dosh on some Manthey upgrades for the GT3, and to do so i was thinking of downgrading my Turbo Cab to i C4S cab, as i am really starting to think it is way overpriced for what it is, and certainly what i use it for !! Hows the plans for the trip to the ring coming on ???? Ah Stuart, you have come to the mechanical rescue once again, you are truly a walking mind of Porsche knowledge !!! Thanks for the info, doesn't really sound like a good idea then does it. I was trying to see if there was a way of lessening the power defecit between the two, as i know that's one thing i would miss. G.

Well its £20k for school fees for my 3 kids this year or a C4S. (Kids want the Porker upgrade). Might just stay with the 996 C4 and see what my bonus is this year. I'm wondering whether to tag along with your regions trip to the ring in April. Definately going tho. Speak to you soon. Si

Si, My region is going in May. Give me shout if you want details etc. G.

Yep, C4S XL was equipped with the power upgrade, not very noticable on the road but certainly made my old C4S just that bit quicker on the track. Most track day passengers who had ridden in a number of C4S's commented that it felt quick but that was certainly as much down to the fact I was running on Corsa's as the small amount of extra grunt. Was it worth it in cash terms, probably not but then what is. When I sold the car the power upgrade made up for the fact that it didn't have Sat Nav which the dealer said was 'essential to sell a 996'. It shifted very quickly at a lot more than AFN were offering on trade in against the GT3. Would I specify it again? Yes Regards

I have the power upgrade on my recently bought secondhand C4S. As always when buying secondhand, you take the mix of options the previous owner chose and in my case, I didn't really give this car many plus points for having it where others did not. The option cost him £6644.63 and that of course is a factory fit price. An upgrade will be not only be more difficult to install but will also leave you with a bunch of parts you don't need. I've no reference to a car without the upgrade but alongside my other three drives (F355, SL55, Imprezza WRX), the car has plenty of performance for everyday driving and I doubt that the modest power upgrade makes much difference, especially taking into account where in the rev range it acts. Seems to give it comparable engine power to the 997S though the car slower because it's heavier and less aerodynamic. If I was buying a new, I wouldn't specify it. Marginal benefit on the road and you take a bath at re-sale time as the person I bought from did - he lost more than £20k over 19 months and 24k miles.

Carnewal (www.carnewal.com) have the Porsche Original Equipment, +25BHP, X-51 Carrera Power upgrade kit for the 3.6L available for 7095 Euros including shipping and can also supply the required 3rd radiator upgrade to improve engine cooling for a further 395 Euros. Not sure of the fitting cost, but I'm sure a good independent would be able to give you a quotation. Looking at the power and torque graphs for the conversion, (http://content3.eu.porsche.com/prod/911/carrera4s.nsf/gbrenglish/engineperformance_enhancement) there is a loss of low-end torque and all the gain is at much higher rpm. Not sure it would be of real benefit for road use. Ian W

There is an X51 retrofit kit for the 3.6 C2&4, C4S, and targa. The part is 000 044 100 12. The instructions are 13 pages. Do not know anyone who has installed the kit. There is the price of the kit plus the labor to take the engine apart. Lots of money for 25 hp.

Not sure about this logic, but my engine number is 68300828 which suggests that, when my car was made in Feb/March 2003, only 800 customers had gone for the performance upgrade, factory fitted. Don't know when the 3.6 was introduced but if you figure they are making 20 - 25000 911s a year, it's pretty low on the popularity stakes. As Tool Pants says, an expensive option for what it provides.

STOP ! you are scaring me ! [ ]

although back on topic... I thought (?) that Amd up in Bicester did upgrades for the 996 ? otherwise only one I have ever seen is.. http://www.dmsautomotive.com/index.asp?upid=15&msid=3

There are other people who will sell you their own variants and upgrades, but I thought the original question was about Porsche's own upgrade. Without putting turbo's on it, I have not seen any upgrades that give much more than 25bhp. Seems there is not that much than can easily or economically be done.

Who is good in math. The instructions say it takes 2,260 time units to install the kit in a C4/S. There are 100 time units in an hour. My dealer charges $135 per hour. So what is the labor cost. The retail price of the kit is $8,500.

Assuming you aren't joking, its $3051 in labour.

No joke. For the C2 it is 2,590 time units, and that includes installing the third radiator.

Seems pointless doing the upgrade, especially since the benefit is marginal at best on normal roads.

any views on the Torque figures from this 25bhp upgrade ??? as the bhp may not be soo much but it's really all about the Torque !

Well, strictly in the interests of research, I've spent some time in my car today having a play. I don't have a direct comparison with the standard version but what I do notice is that the 911 keeps charging right into the rev limiter. With my F355, the push fades away as you approach the 8500 rpm rev limit and you need to change up to keep the adrenalin flowing. With the 911, because the torque curve is biased towards the higher rev ranges, it is remarkably easy to power right into the rev limit. It feels like the engine will rev for ever and as such, I do like the power upgrade because I wonder whether the normal version would be the same. At the same time, the exhaust note from the (standard) pipes is simply glorious. Add to that the tractability of the C4, the slight but reassuring under-steer and you have a peerless car for cross-country. It's even an accomplished motorway cruiser, just a bit lumpy around town. I love this car!