snake eyes

It is so close its all driver at the track..
Older video of me chasing a 991.1 C2S with power kit.
skip to 1:14
I was on cold tires..than we were pretty darn even.

I suspect you really need a high speed track to pull away.

vern1

How do you come up with 25 to 45 HP? Feel?

vern1

Agree

I believe people:
1. wildly over estimate the power increases they "feel" they get from a bunch of bolt-ons; and
2. wildly over estimate the effects that an extra 20-30 hp will actually produce

Frank996

I was going to check this as well, but don't think so tbh.

I'm really happy with all the replies here as it seems like there are quite a few of you (who seems to much more on the subject than I ever will) that maybe it's not worth it.

If I was going to splash the money, I should have bought a 997 GTS4 instead as the total cost would come to the same I believe...

Edgy01

Thanks for including this video! I've gone through a fair amount of rubber over the years a long time ago at Hallett and enjoyed it very much!

Am guessing your lap was about 1:35.

Will have to drag out my old records to compare to my 911SC-Turbo.

One other factor that you have to keep in mind is that the X51 mod assumes that the starting engine is in great shape. They don't want to do this mod on a car with miles on it. Check with them to see what exactly is their concern.

:-)

JAGMAN1

I would consider the power kit upgrade. But first I'd see what it would cost to buy a gts (as others have suggested) which I think would be very expensive given the tax you would have to pay. Assuming the financials don't make sense then do the power kit upgrade. It is a solid and reliable modification.

I would NOT do a tune, if you drive the German Autobahn. Especially not a tune from a U.S. Tuner. The fuel aggressive fuel mapping/timing changes, and resulting air/fuel ratios could be damaging if they're not designed for that type of driving. Specifically, part throttle sustained high rpm cruising. U.S. Tuners don't have to worry about that as it isn't really possible to cruise at 5-7K rpm for extended periods at part throttle.

Again, the X51 power kit is a good price at 11.5K CHF. Yes it's expensive, but it is a solid product with no mystery oils used.

DC911S

oh yes it is......you just have to be careful where you do it. I've had mine cruising at 110 MPH for long periods.

snake eyes

Yup, lap time in that video was around 1:34ish.
Here is another video for comparison (new pdk software and brake pads + plus much more experience at this track)
1:28 was the fasted lap - tires were not happy! average 1:29- 1:30 on clean laps without traffic... This is moving for Hallet and was awesome to break that 1:30 barrier.
for reference the the Black 997.1 S is my friends car and he was averaging 1:34 on clean laps.

Fined

whether the upgrade is worth the cost or not depends largely on your reasons for doing it. With money as no object, or shall I say, money as a reduced importance object.. yes definitely do it.

you'll notice a difference, but primarily north of 5500rpm. I think the sound may be a bit nicer, but I haven't spent enough time around non X51 cars to say for sure.

I imagine that spending the same money to tune the suspension of the car and buy lighter wheels would get you further.

____________
the idea that you get an ECU tune and put on the air filters for $1500 total and are just as good off as the changes from X51 is just silly. try actually reading (from the manufacturer) what is done to get the power difference and that should be plain to see.

MaximumA

I don't think you can add much meaningful power and torque to what is already a very high compression engine, but you can always improve the breathing a little bit with some free-flow filters and new manifolds/headers (to the extent there is any room under there to improve the design). I just added the rear centre muffler delete (mostly for the noise, who knows if there really is an additional 15hp?) and the filters, which may bump me up a couple of horses at very high revs, so instead all my performance changes have been to tyres, rims, chassis and brakes. I'd use your budget for these kinds of modifications.

JAGMAN1

My point was that most tuners only tune at or near WOT and use a rich air fuel mix to protect the engine and keep the exhaust gas temps under control. Where those modified maps intersect with the factory maps is the risk zone.

Beyond that, 110 mph is likely below that threshold, nor is 110 particularly hard on a 911 in terms of thermal management in the cylinders and around the exhaust valves. Cruising at 125+ is where those challenges become more acute. Long term engine durability for these cars is dependent on effective thermal management of combustion temperatures in this more extreme regime. The motor is not under significant load at 110mph, that duty cycle increases exponentially at higher speeds.

If you are cruising at 110mph (175kph) in a 911 on A81 north of Singen, you are doing it wrong... and should not be worrying about the X51 power kit.

swoardrider

Take that $12k and put it into a set of super lightweight wheels. That will yield the best results in terms of feel. Better acceleration, braking, and handling.

Frank996

Thanks all for your replies...

I have given a little more thought and maybe it's not worth the extra $ (or rather CHF's) as I honestly already have a super fast car as it is. I was just the victim of my Porsche dealers marketing ploy and I'm a sucker for these things.

For the record, this is what's on offer:

"Teilenummer: 997 044 100 11

Leistungssteigerung auf 300 kW (408 PS).Beinhaltet modifizierte Zylinderköpfe, Luftfiltergehäuse mit Oberschale in Echtcarbon, neu entwickelte variable Resonanzsauganlage mit 6 schaltbaren Klappen sowie eine optimierte Motorsteuerung".

This said, I could never ever EVER get the green light from my better half to spend that kind of money on a set of wheels so I'm not even going to bring it up with her

JAGMAN1

That parts list has the full engine kit, but not the sport exhaust. Which makes the deal you are seeing a fair one, not a great one.

Fabspeed Motorsport

Hey Frank! I was reading through this thread and wanted to jump in, as I have some valuable information that might make your decision making process a bit easier. The X51 power package is definitely a draw with the promised power gains; however, you can achieve the same power gains and give your car a boost in power and sound by spending less than half that money! A set of Sport Headers and a tune will give you around 20-25 additional HP and costs only 4100. Here's a dyno graph from a stock S and an S with Sport Headers:



The power curve is not only smoother but you can see the increase in power. Our tunes give you another 15 HP, so in conjunction they would produce around that 20-25 HP number. Definitely something to consider. Power gains are sometimes subjective, as everybody's butt dyno gives a different reading based on their experience behind the wheel, seat time in other cars, etc. That being said, this combination of our performance upgrades will give you a noticeable increase in power based on proven results, and the Sport Headers will give your exhaust tone a bit of a throatier, sportier nature.