The Porsche 911 acquired their reputation in competition where most of the models of the brand have distinguished themselves, whether in rally or on circuit: 911 RSR , 911 SC , 930, 934 ... have harvested many successes. The 911's trump card is undoubtedly its famous "flat 6" air engine, which combines flexibility, power and torque while giving the 911 a very low center of gravity.

Nowadays there are many possibilities to prepare a Porsche 911 engine, the mastery of technical processes has evolved and allows the use of parts of modern design and realization.

Since 2011 LORRTEC has prepared more than 60 Porsche 6-cylinder flat engines in atmospheric and turbo versions: Porsche 906, 914, 911, 930, 935..., through the 3.0l SC and RSR, or the 3.6 of 964, and finally the Porsche 956 & 962 (Group C) twin-turbo water-cooled engines, one of the expertise of our workshop.

How much power can we get?

It is possible to reach 80 to 100 horsepower per liter on 911 engines with the modifications listed below. Beyond that, it is necessary to have the skills of a professional motorist.

Power level according to the level of preparation:

Porsche 911 2l engine : 180hp to 220hp
Porsche 2.5 ST engine: 250 hp to 260 hp
Porsche 2,8l RSR engine : we get from 260 to 300 hp
Porsche 911 SC 3.0l and 3.0l RSR engine: 280 to 330 hp
Porsche 964 3.6L engine and more : 340 to 400 hp
Etc...

If you WISH to improve performance without dismantling the engine:

The first step to improve a 911 engine is to work on the peripheral parts of the engine block: the intake and exhaust.

At the intake level, the engine will gain power by straightening the ducts to better supply the engine with air:

On a 911 engine and for a use on circuit with a rather free regulation, it is possible to opt for triple body carburetors or electronic throttle bodies of injection:
- PMO or Weber for carburetors
- PMO or JENVEY for electronic injections with MOTEC caMOTEC® calculators
For historical competitions with strict regulations, it is possible to mount Weber carburetors or a mechanical injection such as BOSCH (with butterfly or guillotine)

The exhaust system is also a component that improves engine power and torque. In this case, the size of the collector must also be taken into account to avoid having a collector that frequently comes into contact with the ground and deteriorates during use. We have designed many custom-made collectors for rally or circuit. Contact us for more information.

WEBER IDA mounting on Porsche 911 flat 6

To go further: prepare the lower engine

The next step for the preparation of a Flat 6 is to strengthen the lower engine and lighten the mobile crew:

Crankshaft balancing
Lightweight flywheel
Use of forged H-rods
Forged pistons for reliability and increased volumetric ratio
Etc...

prepare the top engine

For even more power and torque, it is necessary to work on the upper engine: camshafts, springs, cups and valves. It is also possible to machine the cylinder head ducts in CNC in addition to the assembly of specific parts. Contact us for more information.

The case of the Flat 6 with dual ignition - 964 and 993 engines:

When it is possible in terms of regulations, or for leisure use, a MOTEC electronic management system coupled with PMO or JENVEY throttle bodies allows you to get the most out of the engine preparation by maximizing power and optimizing consumption.

For 911, Boxster, Cayman with water cooled Flat 6 engine

We also offer a large number of parts for Porsche water engines with the following displacements: 3.4l, 3.6l, 3.8l

H-shaped forged connecting rods
forged pistons
valves, cups and springs
lightweight flywheels
Etc...

Changing pistons and connecting rods Porsche

We have three brands of pistons in our store for Porsche engines: CP-CARRILLO, WOSSNER and MAHLE MOTORSPORT. Two brands also supply connecting rods: CP-CARRILLO and WOSSNER. We have a large choice of products depending on the technical characteristics required. Do not hesitate to call us for more information depending on the application.

Changing the connecting rods and pistons makes it possible to gain in lightness on the mobile crew, and thus to obtain more lively revs and an engine more at ease in the turns. In addition, the parts we sell provide a gain in robustness and reliability. Replacing the pistons also increases the volumetric ratio and thus improves power and torque.

Change the cylinders of the flat 6

When the ovality of the cylinders is greater than 0.02 mm, a new Nikasil treatment is required or the liners/cylinders must be replaced.

New Porsche flat 6 cylinders are for sale in our store. You can use them in case of heavy wear or if you want to change your displacement.

Change the flywheel?

As with the forged connecting rods and pistons, the lightened flywheel assembly allows for lighter weight, resulting in faster acceleration and revving.

Beware! For this modification we recommend to balance the whole crankshaft and flywheel.

Mount a competition clutch.

For all 911 and all engine sizes:

Competition clutches allow for much lighter mechanisms than the original ones and are more resistant to intensive use.

If you do not have any regulatory constraints and you wish to use your engine intensively on track, the best is to install a Tilton-type aluminum dual-disc clutch.

For use in historical competitions, we offer clutches of the same type as the original but reinforced to better withstand the stresses.

Change the camshafts ?

We distribute the brands WEBCAMSHAFT and CATCAMS

We have many profiles, opening times and lifts available depending on the desired preparation levels and the pistons chosen, offering various compromises. Porsche camshafts are available in 47mm and 49mm bearings depending on the engine generation, with or without end drive (injection pump ...).

We recommend that you contact us so that we can advise you on the best camshafts for your application.

Caution: the camshafts are linked to the types of valves and pistons, contact us for the compatibility of the various parts. For the most "powerful" camshafts, the change of the valve cups and springs is mandatory.

For Porsche camshafts with high lift, we recommend using our reinforced rocker arms.

Cylinder head ducts according to wind tunnel profiles

Porsche cylinder heads can also be machined in our workshops.

Our machining is done on numerically controlled machines. We can machine cylinder head ducts on all 911 engines.

The machining programs and profiles of the cylinder head ducts were defined from wind tunnel tests.

We also install beryllium valve seats with wind tunnel optimized shapes.

Install reinforced rocker arms.

The rocker arms we offer for Porsche engines are reinforced, more rigid and compatible with high lift camshafts.

Change valves, cups, springs ?

These parts are available for Porsche 911 2l, 2,2l, 2,4l, 2,7l 3,0l 3,2l engines etc...

Replacing the springs and cups is imperative for camshafts with racing profiles.

We also offer reinforced valves with better aerodynamics and lighter than original for the same diameter.

It is also possible to increase the diameter when allowed by regulation.

We use and supply beryllium valve seats with wind tunnel optimized shapes.

Tips for preparing a 911 engine

We recommend that you set a budget and make changes that are consistent with your usage. For example, it is useless to buy high-lift camshafts without planning to replace the pistons... Do not hesitate to contact us for any information request.