1973 911 RSR Racer With 3.8L DME G50 6 Speed Conversions In Martini Livery
Posted by PATRICK MOTORSPORTS on
This 911 underwent a complete rebuild to RSR specification. We incorporated a 6-speed G50 Short Bell Housing transmission (G50 SBH). We machined and performed a blueprint rebuild here at Patrick Motorsports.
Engine and Transmission fitment required extensive chassis modifications due to the longer transmission length. The engine displacement has been increased to 3.8L. Oil cooling has been updated with an RSR oil pump, our special Setrab front mount oil cooler and the original equipment 930 radiator style front fender cooler. The specs for the racing class allowed us to use PMO Carburetors with a high output ignition system. We also built a new wheel set based on original Fuchs centers to maximize traction.
|1973 Porsche 911 RSR Martini Livery at Cal Speedway for the 2009 PCA California Festival of Speed
At Phoenix International Raceway (PIR)
We always choose Mahle Motorsports piston and cylinder sets for our 3.8L engines. The case bore and other machine services are done in our in-house machine shop.
The piston & cylinder set we used is for RSR connecting rods - 22.60mm piston boss spacing - yields 3.8 liter - 12.5:1 compression ratio - machine operation on case to bore I.D. 109.00mm - 6 qty. pack - Mahle Motorsport
We chose Pauter Rods for this 3.8L engine. Pauter Rod's years of hands-on experience, working with rods of all shapes and materials, of all types of racing and racing-related abuse, with design failures (and successes), has resulted in a fairly comprehensive file on just what works - and what doesn't - on the subject of high performance Pauter connecting rods.
From this body of knowledge Pauter Rods have selected and incorporated the elements into what it is we think a great rod should be.
For starters, the simple Pauter beam design completely eliminates thin and non-uniform cross sections over the total length of the beam. This feature greatly improves resistance to crack-induced metal fatigue. In addition, the non-tapered profile of the Pauter rod beam helps to spread potentially harmful stress over a larger area, dispersing instead of concentrating these destructive loads. The design also efficiently places needed material in critical transitional areas, giving maximum support exactly where it is needed (such as directly under the wrist pin). The streamlined contour also provides subtle benefits in the form of windage reduction. The main beam rib itself continues around the wrist pin boss, perfectly integrating the beam to the pin boss, a small, but important contribution to overall structural unity. Pauter rods are indeed different by design.
•E4340 vacuum melt chromoly forging – CNC machined
•Heat-treated to Rockwell C36; full coverage shot peened; end-to-end balanced in sets.
•Each rod comes standard with ARP 2000 bolts rated at 220,000 psi tensile strength.
•Aluminum-bronze wrist pin bushings (standard.) EDM pressure-fed oiling to pin (available at extra cost.)
•Custom pin diameters and center-to-center rod lengths can be ordered.
We also chose the Porsche 911 GT3 Cup / R / RS 2000-2005 / Porsche 911 Turbo GT2 2001-2005 oil pump - Porsche Genuine - part number 996 107 007 94
Building
For this project we found limited wheel size options available. So we decided to make our own using original Fuchs alloy wheel centers. Special machined centers with the proper offsets.
Mounting of the Setrab oil cooler with Goodridge stainless steel lines and fittings.
When a fuel cell is wanted or required there is no finer choice than a fuel safe fuel cell. They are used and approved by all sanctioning bodies in every racing application from off road to Indy. If you are looking for a fuel cell, fuel safe should be your first and only choice!
Part number FUE SA101 Fuel Cell - Porsche 911 / 930 - Pro Cell 27 gallon (100L) - 0.063" TIG aluminum case - black powder coated container - includes belly pan tray - fitting and sender utilize OE hook up locations - includes standard 6 x 10 OE hook up remote style filler plate - fittings and hardware included - fuel safe - *note: this unit is also available with the standard screw on filler neck
This shows the balanced lightweight RSR flywheel with the clutch package ready to install. We use the Centerforce clutch disc and pressure plate package.
This package starts with a new Sachs 240mm aluminum pressure plate 1976-1977 (short type), modified to high clamp load 934 / 935 specifications, with triple drive straps, this is the key element to the performance of this clutch package.
the triple drive strap technology allows the pressure plate to handle the high torque load of large displacement engine like the n/a 3.6l, 3.8l & 3.3l 3.5l turbo applications, but equally important is the ability of this clutch to handle the opposite load associated with down shifts in race or autocross abuse. this pressure plate mated with the Centerforce patented dual friction carbon/kevlar spring hub disc make for the most reliable performance street / race clutch package we sell.
we need to remind you this is a very street-able clutch, with little to no additional pedal effort.
To maximize engine power output and efficiency, we needed to build a tuned exhaust manifold and rear exhaust. This system features T304 stainless steel construction, high flow merge collectors and purged TIG welding.
Porsche Club Of America Rennsport Reunion 2007 Paddock
Corner balancing and final weigh in.
This shows our fender mounted Setrab oil cooler, Porsche 993 Turbo Big Red brake calipers and cross drilled brake rotors. The coilover suspension is comprised of Bilstein RSR struts with Eibach main springs and tender springs installed. Anti-sway bar system front - 1965-1989 Porsche 912 / 914 / 911 / 930 - 25 mm hollow lightweight (stiffness of solid 22 mm bar) heat treated 4130 chrome moly - includes: fully adjustable 6061-T6 aluminum bearing blocks, drop links and arms with zinc plated steel hardware **1974-1989 models also use: u-bracket adaptor - SUSSBRFADP2 & nut plate adaptor SUSFSB1950 ** The lightweight hollow sway bars are half the weight of a 22mm solid bar with the same stiffness. They are fabricated from aircraft-quality 4130 chrome moly alloy steel and heat treated to maximize strength and reliability. Part number SUSFSBA22F
We also used the anti-bump steer kit - Porsche 914 / 911 / 930 - steel and spherical rod ends with aircraft quality hardware - sold as left and right set
part number SUSBUMPKIT
This shows our fender mounted Setrab oil cooler, Porsche BIG RED calipers and cross drilled rotors. The suspension is coil over struts with Eibach Tender springs installed. Anti-sway bar system front - 1965-1989 Porsche 912 / 914 / 911 / 930 - 25 mm hollow lightweight (stiffness of solid 22 mm bar) heat treated 4130 chrome moly - includes: fully adjustable 6061-T6
aluminum bearing blocks, drop links and arms with zinc plated steel hardware **1974-1989 models also use: u-bracket adaptor - SUSSBRFADP2 & nut plate adaptor - SUSFSB1950 ** The lightweight hollow sway bars are half the weight of a 22mm solid bar with the same stiffness. They are fabricated from aircraft-quality 4130 chrome moly alloy steel and heat treated to maximize strength and reliability. Part number SUSFSBA22F
We also used the Anti-Bump Steering Kit - Porsche 914 / 911 / 930 - Steel And Spherical Rod Ends With Aircraft Quality Hardware - Sold As Left And Right Set
part number SUSBUMPKIT
On the grid at Cal Speedway for PCA Festival of Speed!
Here you can see the dash layout with the stock gauges. in place of the clock we add our low oil pressure warning light- dash mounted clock replacement - Porsche 911 1965-1998 - includes black anodized aluminum bezel part number PMPSLOPWL
Don’t destroy your engine by missing the drop in oil pressure when you are busy on the road or track this light will catch your attention so you can shut down before you damage your engine
- Another Patrick Motorsports exclusive --
To the right of that you see the pull for the fire system - 10 lbs. aluminum fire bottle - halon 1301 - pull cable kit & 3 nozzles with aluminum tubing kit - dot approved - meets SCCA / NASA requirements - non SFI certified - SAFECRAFT
part number SAF LT10AAA
Fuel Safe fuel cell and dual brake master cylinder in the front trunk compartment
Here we are torqueing the pressure plate bolts to spec. This is critical, if the pressure plate bolts are not torqued properly it can cause problems later. The bolts get stressed if too tight, they can break, and if they are not tight enough they can work loose.
Either one is devastating as there is no room for the broken part to fall out and the damage they will do to the transmission case will shock you. Also ALWAYS use new bolts for the flywheel and pressure plate every time it is removed.
You can also see our Camshaft Block Off Plate - 1989-1998 Porsche 964 993 3.6L Engines - Conversion Or Power Steering Delete - Low Profile For Additional Clearance - Includes O-Ring Seal - 2 Per Car - Part Number PMP36CAMBLOCK
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- Tags: 1965-1989 Porsche 901 / 911 / 912, 3.6L / 3.8L Builds & Conv, 911, ARP, CALIFORNIA FESTIVAL OF SPEED, CENTERFORCE, EIBACH, FUCHS, FUEL SAFE, G50 Short Bell Housing (SBH), GOODRIDGE, Long Hood, MAHLE / MAHLE MOTORSPORTS, PATRICK MS EXCLUSIVE PARTS & PKGS, PAUTER, PMO, PMO CARBS, Race Cars, RENNSPORT, RS / RSR / IROC / IMSA, SETRAB