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Gen 1 997 GT3 wants more power

Bigfra

Well-known member
Joined
22 Aug 2012
Messages
215
As title chaps, fancied the parr 3.9 conversion but 450 bhp doesn't sound much if I'm honest. Any other options besides sending the engine to the states ?
 
Speak to Ken ay 9e. I'd be asking for a 4.0 or 4.2 litre 500bhp revving out to 8500 rpm :D

Black Friday tomorrow so a good day to have chat to him :wink:
 
Big step. If you have to have n/a engine and it's a keeper then that's one route.

Downsides are it'll be expensive, won't add value to the car and would make it harder to sell being more niche than a standard GT3.

You could always sell the GT3 and get a GT2 or turbo.
 
Bigfra said:
As title chaps, fancied the parr 3.9 conversion but 450 bhp doesn't sound much if I'm honest. Any other options besides sending the engine to the states ?

Yes, as these engines are maxed out the only real way to improve performance is to open up and increase capacity if you want to keep NA. You then need to decide whether you want to use Porsche parts or install after market bits. Porsche parts will let you get to 4.0, but I've read about conversions of 4.25 in the states using after market parts.

Personally I decided to stick to Porsche bits 3.8 conversion with modded cup cams, made 475bhp and 350 ft lb torque on the rollers. Go talk to o Fearnsport.
 
Thanks lads, Defoe want to keep the car na. I'll call around and see what people think
 
Bigfra said:
As title chaps, fancied the parr 3.9 conversion but 450 bhp doesn't sound much if I'm honest. Any other options besides sending the engine to the states ?

Or make it lighter ?
Add ceramic brakes, lighter wheels, lighter exhaust, lighter interior, other RS lightness touches

makes a difference
 
Power figures sell cars, torque wins races.

Bore and stroke on the 3.6-litre engine is 100mm x 76.4mm; on the 3.8 they changed it to 102.7mm x 76.4mm. On the 4.0, they kept the same piston size of 102.7mm and increased the stroke by 4mm to 80.4mm

According to Andreas Preuninger, Porsche motorsport manager for high-performance cars: "We have finally really reached the bore limit with this engine. This is the maximum before we need to create a new engine blueprint." Wall thickness between bores is in fact so thin now that steel cylinder liners have been added for durability as with the GT3 RSR racecars.

In my experience of doing a 3.9 conversion (using 104mm pistons) but retaining the standard crank & rods, going over the 102.7mm bore of the 3.8 results in the piston flopping around inside the cylinder because they have to allow for the piston to expand and the cylinder expands much less than the piston; the greater the diameter, the more the piston expands when hot and this larger cold clearance increases wear. Not to mention sounding like a bag of nails until fully up to temperature. I don't have that engine any more due to piston / ring failure after 42K miles. There's a reason that Porsche don't use a larger piston & chose a longer stroke for the 4.0 ...

AFAIK, nobody has made a N/A Mezger engine of over 4.0 produce reliable big power for hundreds of hours on a track. Claims of 50K miles on the road in big bore cars are out there but that's not really stressing the engine. Just because it's possible doesn't automatically mean it's a good idea...
 
NXI20 said:
Power figures sell cars, torque wins races.

Bore and stroke on the 3.6-litre engine is 100mm x 76.4mm; on the 3.8 they changed it to 102.7mm x 76.4mm. On the 4.0, they kept the same piston size of 102.7mm and increased the stroke by 4mm to 80.4mm

According to Andreas Preuninger, Porsche motorsport manager for high-performance cars: "We have finally really reached the bore limit with this engine. This is the maximum before we need to create a new engine blueprint." Wall thickness between bores is in fact so thin now that steel cylinder liners have been added for durability as with the GT3 RSR racecars.

In my experience of doing a 3.9 conversion (using 104mm pistons) but retaining the standard crank & rods, going over the 102.7mm bore of the 3.8 results in the piston flopping around inside the cylinder because they have to allow for the piston to expand and the cylinder expands much less than the piston; the greater the diameter, the more the piston expands when hot and this larger cold clearance increases wear. Not to mention sounding like a bag of nails until fully up to temperature. I don't have that engine any more due to piston / ring failure after 42K miles. There's a reason that Porsche don't use a larger piston & chose a longer stroke for the 4.0 ...

AFAIK, nobody has made a N/A Mezger engine of over 4.0 produce reliable big power for hundreds of hours on a track. Claims of 50K miles on the road in big bore cars are out there but that's not really stressing the engine. Just because it's possible doesn't automatically mean it's a good idea...

Nice concise summary...and anyone out there thinking of investing in a 3.9
conversion i'd take real heed. If you're in need of more power for your 997,
your best bet is find yourself a nice gen 2 car, that has a useful edge of extra
bhp and a better and slightly fuller torque curve.

The other remedy.....a 997 RS 4.0...maybe not !. :roll:
 
Nick is the man to know as he has tried different route and really used the car to extreme. would always vouch n trust what he says.

what about taking out some weight from the car? far cheaper than doing the engine conversions.

change the rear glass to polycarb and maybe side windows? will increase the sound effect of the mezger too ;-)

Carbon rear spoiler and carbon bonnet.

you could go for much lighter wheels as the OEM wheels are very heavy.

you could easily save 50KGs with that set. maybe RS flywheel to rev quicker and maybe lightened pulleys too.

not just about power....look at what ELA done with his std 996......3.4 engine with nearly 200 KGs out of it. has oem GT3 power to weight ratios.
 
nick w said:
Nice concise summary...and anyone out there thinking of investing in a 3.9
conversion i'd take real heed. If you're in need of more power for your 997,
your best bet is find yourself a nice gen 2 car, that has a useful edge of extra
bhp and a better and slightly fuller torque curve.

The other remedy.....a 997 RS 4.0...maybe not !. :roll:

I thought Gen 2 cars were around £40k more than Gen 1, until I had a look on the OPC network this morning. The price gap between 7.1 and 7.2 997's seems to be closing, based on the current stock anyway. There's a 997.1 GT3 for £84k, 997.1 GT3 Clubsport for £90k, and a 997.2 GT3 for £99,950

Previously I would have said go for a 3.9 rebuild (I like the idea of modding, plus more power than a Gen 2 3.8, and around £20/25k ballpark so relatively cost effective), but now I'd consider looking at a gen 2, which previously wouldn't have been an option

Creating a GT3 outlaw type thing by throwing out weight also sounds like a good option... combine that with a 3.9 and you'd have a monster :grin:
 
How about this conversion for FVD

997 GT3 / RS 3.6L ( to 4,1L ) Level 3 (485HP/354TQ)
FVD 997 100 83B

8.995 €
Add to cart
SRP: 9.748 €
11.600,12 €
FVD 997 GT3 4.1 Level 3 Kit

- Max. Power - 485 HP (357 kW) @ 8100 rpm
- Max. Torque - 354 lb ft (480 Nm) @ 5650 rpm
- Max. Speed - 198 mph (320 kph)
- Max. RPM - 8600 rpm
- Acceleration 0-100 kph (0-62 mph)* - 3.7s

* Based on German tests done with kph. 100 kph = 62.137 mph

The FVD conversion kit includes:

MAHLE Piston & Cylinder set 4.1 L (106mm), 997.1 & 997.2 GT3/RS x 1
FVD Software upgrade for 3.6 L to 4.1L with My Genius Flash tool x 1
BMC sport air filter for 997.1 GT3 x 1
Intake manifold 4.0 L x 1
Engine gasket set 997 GT3 x 1
Cylinder head gaskets for 4.1 L FVD conversion x 2
Cylinder base gasket for 4.1 L FVD conversion x 2
Intermediate shaft bearings x 2
Intermediate shaft thrust bearings x 2
Connecting rod bearing shell x 12
Spark plug GT3 x 6
Crankshaft pulley washer 997.1 GT3 x1
O-ring for thermostat housing x 1
Pan head screw x 2
Hexagon head bolts x 2
Washers x 2
Screw x 2
O-rings for actuators (small) x 2
O-rings for actuators (large) x 2
O-ring for oil tube x 1
Gaskets for exhaust manifold x 2

Further additional parts/work required:
- Connection rods (22mm pin) FVD10397520
- Modification of the customer's original water housing - 2 Qty.Needed (Right and Left) FVD10303905WKA
- Modification of the customer's original crankcase FVD10303905MG
- Modification of the customer's original crankcase to 2 oil jets (or purchase 3.8 crankcase)
We recommend the use of an M&M Exhaust System BES99701260S with 200 sport catalytic.

The labor for the engine conversion is approximately 65 hours.

TàœV-Approval is only possible for vehicles converted by us and equipped with a valved exhaust system.

TonyMac.
 
tonymac3 said:
How about this conversion for FVD

997 GT3 / RS 3.6L ( to 4,1L ) Level 3 (485HP/354TQ)
FVD 997 100 83B

8.995 €
Add to cart
SRP: 9.748 €
11.600,12 €
FVD 997 GT3 4.1 Level 3 Kit

- Max. Power - 485 HP (357 kW) @ 8100 rpm
- Max. Torque - 354 lb ft (480 Nm) @ 5650 rpm
- Max. Speed - 198 mph (320 kph)
- Max. RPM - 8600 rpm
- Acceleration 0-100 kph (0-62 mph)* - 3.7s

* Based on German tests done with kph. 100 kph = 62.137 mph

The FVD conversion kit includes:

MAHLE Piston & Cylinder set 4.1 L (106mm), 997.1 & 997.2 GT3/RS x 1
FVD Software upgrade for 3.6 L to 4.1L with My Genius Flash tool x 1
BMC sport air filter for 997.1 GT3 x 1
Intake manifold 4.0 L x 1
Engine gasket set 997 GT3 x 1
Cylinder head gaskets for 4.1 L FVD conversion x 2
Cylinder base gasket for 4.1 L FVD conversion x 2
Intermediate shaft bearings x 2
Intermediate shaft thrust bearings x 2
Connecting rod bearing shell x 12
Spark plug GT3 x 6
Crankshaft pulley washer 997.1 GT3 x1
O-ring for thermostat housing x 1
Pan head screw x 2
Hexagon head bolts x 2
Washers x 2
Screw x 2
O-rings for actuators (small) x 2
O-rings for actuators (large) x 2
O-ring for oil tube x 1
Gaskets for exhaust manifold x 2

Further additional parts/work required:
- Connection rods (22mm pin) FVD10397520
- Modification of the customer's original water housing - 2 Qty.Needed (Right and Left) FVD10303905WKA
- Modification of the customer's original crankcase FVD10303905MG
- Modification of the customer's original crankcase to 2 oil jets (or purchase 3.8 crankcase)
We recommend the use of an M&M Exhaust System BES99701260S with 200 sport catalytic.

The labor for the engine conversion is approximately 65 hours.

TàœV-Approval is only possible for vehicles converted by us and equipped with a valved exhaust system.

TonyMac.

I would be concerned about reliability with this. Been speaking to Matt at Fear sport after Nick's advice so let's see what happens over the next few months. A gen 2 car would be ideal as well but no CS spec cars about at the moment
 
Bigfra said:
tonymac3 said:
How about this conversion for FVD

997 GT3 / RS 3.6L ( to 4,1L ) Level 3 (485HP/354TQ)
FVD 997 100 83B

8.995 €
Add to cart
SRP: 9.748 €
11.600,12 €
FVD 997 GT3 4.1 Level 3 Kit

- Max. Power - 485 HP (357 kW) @ 8100 rpm
- Max. Torque - 354 lb ft (480 Nm) @ 5650 rpm
- Max. Speed - 198 mph (320 kph)
- Max. RPM - 8600 rpm
- Acceleration 0-100 kph (0-62 mph)* - 3.7s

* Based on German tests done with kph. 100 kph = 62.137 mph

The FVD conversion kit includes:

MAHLE Piston & Cylinder set 4.1 L (106mm), 997.1 & 997.2 GT3/RS x 1
FVD Software upgrade for 3.6 L to 4.1L with My Genius Flash tool x 1
BMC sport air filter for 997.1 GT3 x 1
Intake manifold 4.0 L x 1
Engine gasket set 997 GT3 x 1
Cylinder head gaskets for 4.1 L FVD conversion x 2
Cylinder base gasket for 4.1 L FVD conversion x 2
Intermediate shaft bearings x 2
Intermediate shaft thrust bearings x 2
Connecting rod bearing shell x 12
Spark plug GT3 x 6
Crankshaft pulley washer 997.1 GT3 x1
O-ring for thermostat housing x 1
Pan head screw x 2
Hexagon head bolts x 2
Washers x 2
Screw x 2
O-rings for actuators (small) x 2
O-rings for actuators (large) x 2
O-ring for oil tube x 1
Gaskets for exhaust manifold x 2

Further additional parts/work required:
- Connection rods (22mm pin) FVD10397520
- Modification of the customer's original water housing - 2 Qty.Needed (Right and Left) FVD10303905WKA
- Modification of the customer's original crankcase FVD10303905MG
- Modification of the customer's original crankcase to 2 oil jets (or purchase 3.8 crankcase)
We recommend the use of an M&M Exhaust System BES99701260S with 200 sport catalytic.

The labor for the engine conversion is approximately 65 hours.

TàœV-Approval is only possible for vehicles converted by us and equipped with a valved exhaust system.

TonyMac.

I would be concerned about reliability with this. Been speaking to Matt at Fear sport after Nick's advice so let's see what happens over the next few months. A gen 2 car would be ideal as well but no CS spec cars about at the moment

I love that FVD list. The headline price seems very attractive until you factor in the need for new rods at €1K each, the machining of your crankcases & water jackets + the 65 hours of labour. Oh, and a new exhaust. Plus all the "while you're in there" bits such as chains & tensioners, cam buckets, springs, etc. etc. Then it becomes at least 3 times as much :floor:
 

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