R129 selection

[FLYGEEZER]

I've got to clean out my garage. Too many cars & motorcycles. Been thinking on selling my 95 W124 wagon & 1984 944 Porsche and combining my love for MB & a "sporty" touring car. Been leaning towards a SL320. I love the M104 engine in my wagon It's got 174000 miles and other than a wiring harness & a head gasket it has been flawess. Great performer! Can you guys give me any advice on what to look for and to watch out for, on a R129. I'm going to have a hard time giving up the wagon,I love that car! Had this wonderful Mercedes for 14 years. Had the Porsche for 16 Years but its time! Thanks guys.

[JimFreeh]

I've never had a R129, but a good friend has owned both a 300SL and then a 500SL.

His position was that if he had driven a 500SL first, he never would have bought the 300SL. The power difference is simply amazing.

Jim

[tecqboy]

The 300SL's and the 320SL's don't have a lot of torque below 2500 rpm's. ( They do rev quickly to 6K though ). Adding to that the fact that these are heavy cars and the 5 speed automatic transmission starts in 2nd gear, makes these cars feel a bit pokey compared to the V8s. However, the sixs can move quite spritely if you keep the rpm's up by holding back the upshifts of the transmission. You can also manually over ride the 2nd gear start and start in 1st. On the Hwy, my 300SL gets about 26 to 27 mpg. City is about 19 to 20 mpg. The six leaves lots of room in the engine bay for service. The six is known to have issues with the head gasket, but does not have the timing chain problems the 8's have. The later years ( after 1998 IIRC ) have the 3 valve V8 which approaches the 320 in gas mileage. I'd look for a 2000 or later SL500 with lower mileage.

[Will_w202]

Originally Posted by JimFreeh

I've never had a R129, but a good friend has owned both a 300SL and then a 500SL.

His position was that if he had driven a 500SL first, he never would have bought the 300SL. The power difference is simply amazing.

Jim

I've never driven a 300, but why on earth you'd opt for 6cyl torque in a 4100lb 2nd-gear start car is beyond me. And I'm biased...buy a 90-92 like I did. Rates at 322hp, highest V8 HP, non-AMG r129. Sorted out, they are very fun and very fast

[nate300d]

I have put many miles on my 1995 SL320 since I bought it in March. It does not have the snappiest take off from a dead start, but it is a second gear start unless you put it to the floor which is then over kill for my preference. Also, this is a 4000+ pound car, yet does not handle as though it is weighted down. Once it has some revs built it is wonderful. It is a phenomenal highway car. I sometimes wonder what if I would have gotten a 500 or 600 instead, but I must say my 320 is VERY satisfying.

[tecqboy]

You don't have to "floor it" to pull away from a stop in 1st gear. With your foot on the brake, move the shifter all the way down to "2". Next move it back to 4 or D. When you take your foot from the brake and hit the accelerator, you'll start in 1st gear. I find this very helpful when the AC is engaged.

[lynns]

Originally Posted by FLYGEEZER

Can you guys give me any advice on what to look for and to watch out for, on a R129.

I've owned two R107's and loved both cars (MY 88 and 89) but I decided to buy a 20K mile R129, that I've owned for 6 years with NO problems. The car came w/ both the SL1 and SL2 Option Packages. That means that I got the AMG design package with staggered AMG wheels and Xenon HID lamps, etc. If you purchase a MY 01-02 with Xenon's you will get all the latest and the greatest R129 features of a $90K car for a current price of about <$20-$25K for a low mileage R129.

Make sure that you get a PPI and take off the Hard Top and activate the Soft Top (w/ the engine running) 3-4 times (up and down).

2001-2002 SL500 R129.068 chassis, M113.961 engine, 722.624 (W5A580 N-m) transmission, 765.907 steering

M113.961 engine: 303 cid/4,966-cc SOHC/bank 24-valve V-8 high pressure die-cast aluminum cylinder block and heads. Sequential multi-port fuel injection (SMFI), Motor Electronics - Sequential Fuel Injection 2.0 (ME-SFI 2.0), two plugs/cylinder (Bosch Platinum FR8DPP33=7422), Mobile 1 15-50W or 0-40W 229.1 or 229.3

Net Power: 302hp @ 5,600 RPM
Net Torque: 339ft-lbs @ 2,700-4,500 RPM
Compression: 10:1
722.624 (W5A580 N-m) transmission: Driver-adaptive electronic 5-speed with a Summer/Winter switch that allows the car to start in second gear and it has two Reverse gears.
Rear axle ratio: 2.65:1
Front Brembo light weight aluminum 4pot disc calipers + 334x32 mm (13.2") rotors and 300x22 mm (11.8") ATE iron rear rotors. Note: I changed my pads to Akebono Ceramics in order to get rid of that ugly black brake dust, etc.
Curb weight (lbs.): 4125
Acceleration (0-60 mph): 6.1 Seconds
1/4 mile (E.T.): 14.5 seconds @ 97.2 MPH
Top speed: 155 MPH
Fuel capacity (gal.): 21.1
EPA fuel economy, city/hwy/avg (MPG): 16/23/20
Bose Accoustmass seven speaker 200W speed-dependent volume control sound system with fiber optic six CD changer.
Electronic Stability Program (ESP)
Heated Outside Mirrors
Rain Sensing Wiper

1. The M113 was introduced in MY98-08 and has a broad peak torque curve of 339ft-lbs @ 2,700-4,500 RPM and has a great power / weight ratio. With the M113 you have an option to add a supercharger to it.

M113.961 engine: 303 cid/4,966-cc SOHC 24-valve V-8 high pressure die-cast aluminum cylinder block and heads. Sequential multi-port fuel injection (SMFI), Motor Electronics - Sequential Fuel Injection 2.0 (ME-SFI 2.0) with two plugs/cylinder (Bosch Platinum FR8DPP33=7422)

The standard Mercedes-Benz M113 engines were built at the Untertürkheim Germany plant. The M113's have aluminum engine blocks and aluminum SOHC cylinder heads. The cylinders are lined with silicon/aluminum(Alusil), and the heads have 3 valves per cylinder. Other features include sequential multi-port fuel injection (SMFI), fracture-split forged steel connecting rods, a one-piece cast camshaft, and a magnesium intake manifold.

"Using dual spark plugs in a single cylinder creates two flame fronts. The dual flame fronts increases combustion efficiency, allowing more of the fuel to be burned. The resulting combustion forces produce a better piston ring seal and less friction between the piston and cylinder.

The M113 design has a number of interesting features, but the part that stands out is the three-valve cylinder head. This three-valve head has two intake valves and one exhaust valve. the large single exhaust valve has a sodium filled stem. This also helps keep the valve cool. The less heat absorbed by the exhaust valve, the hotter exhaust stream is. Hot exhaust streams result in better cold start emissions. To help retain exhaust heat, the exhaust manifold is a seamless double-wall design. The manifold is fabricated using a high-pressure liquid-forming technology. The results of this type construction are a more durable lighter weight part.

Each head has a single hollow camshaft driven by double roller chains and rubber coated sprockets. This low mass valve train has dual rocker shafts in each head. The rocker shafts hold low friction, roller-tipped, aluminum rocker arms, and the system is maintenance free, as the rocker arms house small hydraulic lifters.

Aside from the increased power, better fuel economy, and reduced emissions, the engine is as much as 25% lighter than the design they replace.

Although the three-valve head is an interesting feature, there's much more to the M113 design than just the head. The rest of the engine has a number of innovations as well. For example, this design utilizes the world's first cast-in cylinder sleeves made of silicon aluminum. This low-friction surface allows the piston ring tension to be reduced by 50%. Using these low-friction cylinders, single overhead cams, the three-valve head configuration, and a number of other friction reduction techniques has resulted in a lessening of the engine's internal drag by 45% in comparison to the previous power plants. This increased efficiency has resulted in both a more powerful and more efficient engine.

The cylinder sleeves were also designed to increase block rigidity, and are a big part of decreasing the weight of the block. In addition to the lightweight aluminum block and cylinder heads, the valve covers and intake manifold are both made of magnesium, which is lighter than aluminum.

At the heart of the engine is a forged steel crankshaft, which is bolted to a pressure cast aluminum block. The crankshaft has the standard V8 five main bearings. The two end caps are four bolt mains, while the center three have six bolt caps. Hollow, forged steel connecting rods are bolted to the crankshaft. To be bolted to the crank, connecting rods must be two pieces. The M113 connecting rods are forged as a single piece, and then hydraulically cracked. This manufacturing process results in rods that are stronger than those that are cut and then reground. Aluminum pistons top off the rods, while a lightweight aluminum oil pan buttons up the bottom end." http://www.marcusfitzhugh.com/CLK/engd.html

2. Exhaust is better flowing with more profound sound. Cosmetically it also adds a chrome oval exhaust tip.

3. Transmission is a driver-adaptive electronic 5-speed with Summer/Winter (starts in second gear)
The Mercedes-Benz 722.6 transmission, also known as the NAG 1 (New Automatic Gearbox 1st Version) is an electronically controlled (shift by wire) transmission. For the R129 SL-Class, it is used in the 1997 – 2002 models. The transmission has five (5) forward speeds and two (2) reverse speeds for those with the S (Standard) and W (Winter) switch at the console.

The 722.6 lines of transmission are designated by W5A XXX, where the XXX is the maximum input torque value (in newton-meters) the transmission can safely handle. Most of the R129s use the W5A 580 version although some are equipped with W5A 300 or W5A 580 versions. Each version has many different models such as 722.624, etc.

Only the “P”, “R”, “N”, and “D” shifting are mechanical (via linkages) and the rest (4, 3, 2, and 1) are electronic (using switches).

In general, models after the year 1999 have updated parts (but lack the torque converter drain plug). The major changes are in the valve body, software, and also mechanical parts in the transmission internals.

4. Front brakes are larger with 334mm x 32mm rotors, lightweight aluminum Brembo calipers. The rears are ATE 300mm x 22mm. You can also add OE factory cross drilled rotors from the 2002 Silver Arrow that improves appearance and brake feel.

SL500 Package Options

SL1 AMG-Sport Package: ($4,995)

AMG designed sculpted lower body aerodynamic enhancements, to include:
Front apron with two separate mesh air intake tow hook covers
Contoured rear apron
Sculpted side skirts with Sport emblem pre 2001
Halogen H3 55W 3100K 12V projector-beam front fog lamps
8.5"x18" front and 9.5"x18" rear, staggered-width AMG I 5-spoke monoblock alloy wheels.
Front 25 mm offset & Rear 23 mm offset, with a 5x112 mm bolt pattern.
245/40ZR18 front and 285/35ZR18 rear, max performance summer tires with a rolled Wheel arch modification for AMG wheels.

Note: Suspension and steering calibrations are unchanged from the Standard package to the Sport Package.

I would suggest that you consider adding a set of H&R Sport Lowering Springs - # 29853 w/ #1 shims on the front and #3 shims on the rear. Lowers 1.25" F / 1.0" R on average

H&R Sport Springs provide a lower center of gravity and reduce body roll for better handling. The progressive spring rate design provides superb ride quality and comfort. If you are only looking to improve one part of your vehicle’s suspension, you cannot go wrong with installing the sport springs.

SL2 Option Package: ($1,820)

Xenon HID projector-type headlights w/ automatic level control w/o headlight washer/wiper
Low beam D2S 4300K HID 35 Watt Xenon 85123 Philips
Integrated trunk-mounted fiber optic 6-disc CD changer,
Buy an extra CD magazine p/n 0028206289
Electrically heated seats

Special Order Options:

Wood and leather trimmed shift knob ($150)
Wood and leather sterring wheel ($1,800)
Multicontour Seats ($710)
Panoramic glass roof ($3,695) 92 lbs. vs. the 74 lb. OE Aluminum Hard Top