Bolt on more performance from 560SL?
 

Is there a way to get more torque from a 5.6 liter engine? Perhaps a bolt on turbo or supercharger? I need more torque!

There are supercharger kits available from either:
http://www.tdi-plc.com/Merc500SEC.SELclass.html
Or if your feeling more extravagant
http://www.koenig-specials.com/mercedes/mercedes.html

I'm sure there are more kits available, but these are the ones I know of.

Kind Regards

Why do you need more torque? Is 279lb/ft not enough? Are you utilizing first gear start?
Just curious, as my '88 560 in first gear will leave plenty of black rubber from BOTH tires at will...

Get some euro manifolds on there, that'll really uncork the motor. Also, remove that resistor so you get full timing BTDC. Aside from that, the motor is going to be about maxed out torque wise... higher compression pistons will help as US ones are dished. Comp is ~9:1 I recall on US ones. Heads/intake manifold already have large ports you won't gain anything with porting... polishing them will help with higher RPM gains.

279tq isn't that much anymore... BUT when you have ~3.9:1 first gear, a 25.5" tire, and a 2.47:1 rear diff, it should scoot very well from the hole.

Higher RPM power? Pick up some Euro cams or get a set of the AMG ones, one of the members here has a set of them he's going to have made into more. Should put another 25-35rwhp down with those alone.

I have found myself two Euro 380s I plan to swipe the valve bodies from both of the trannies. If their WOT shift points are 6000, I'm going to bolt one to my stripper 560 and take the other apart passage by passage and find out exactly what is the difference between the US and Euro VBs. I bet it's a spring added or something.

There have been some attempts to put superchargers and turbochargers under the hoods of the 560SEC and 560SEL. Very expensive, and mixed results. I believe their was a Willy MOSSELMAN in Holland who had a company doing it (not sure of that.)

The forum archives and search engine at www.mbcoupes.com might be worth checking for more information, that has been discussed quite a bit there, it is a performance oriented group there.

What is your rear diff, is it a stock 2.47. That is what the stock 560 SL came with... A first gear start and a 2.82 or a 3.07, would give more low end grunt for sure. A 3.07 or higher would I think you'd rev a lot higher at high and top speeds. Carl Genberg of Bergwerks in LA owned a SEC with a 2.82 and the first gear start, and boy could that thing take off.

Also, whatever modifications you contemplate, is there a way to be assured there won't be a droning sound at 65-70 mph?

Are smog tests a worry? Some modifications could be extra legal in your state? ( Or is it for Off Road Use Only;) ?

Also, engine bay and hood clearance is a real issue to address before you even start. Gee, I have more questions than answers for you (sorry)

Can the motor even take the stress of turbocharging and superchargers:Again, I don't know. Would you need J & E pistons etc.?

K & N filters are supposed to get the air in faster, but they don't filter quite as well as stock, is the downside, so a little more dirt and airborne crud could get into the motor. That's why I would forego them.

You could get a little more performance with a good set of mandrel bent headers, and a wider exhaust system, and lose the exhaust crossover (it's skinny and restrictive) at the rear of the engine, (is reconfiguring the exhaust ahead of the CAT legal in your state?

Remus mufflers and tips should bolt right in. But don't expect more than 3 hp more with that.

Truth is, the Mercedes V8s, and sixes, any of them, will walk away from a pre 1991 560 engined SL SEL and SEC. The SEC only had 238 hp, the SL had 227. 0-60 times were about 7 seconds, which these days is nothing to write home about.

Low boost would be fine on 9:1 compression, I wouldn't run past about 9-10psi even with good fueling. Stock crank and rods are plenty stout, those break due to RPMs almost always. JE pistons I've seen come apart a few times, I'd never run a set. Venolia is my top choice, then Ross, Diamond, etc.

The same member with the AMG cams picked up only about 9rwhp with a K&N on his SEC. That's near margin of error for a dyno between runs. So I'm on the fence to get one for my stripper 560 or just run a quality paper.

Large gains will come from uncorking the exhaust. If you keep the resonator section with rear muffler (both of which flow pretty well as I understand), I don't see why you couldn't pick up 25rwhp/25rwtq...

Without spending a lot of money, a first gear start and pulling the timing resistor (and from then on, 92-93 octane always, only) helps a lot at lower, "street" speeds.

I just don't think the entire drivetrain is really built for high power; the flex disks are there, the transmission is kind of small, anything can be done with lots of money, but the cost/benefit ratio doesn't look very good. I suppose that if I were willing to spend a few thou, I'd look at AMG cams and exhaust work; but a lot of the exhaust benefits are high-RPM, and the cams might make a marginal engine fail pollution tests, and depending on where you live, this could be nasty.

I have the parts to do a dual-cold air intake air cleaner housing on my car; this might explain the mysterious few extra horsepower (again, at peak RPM) this engine has in an SEC; but I'll have to relocate/replace the windshield washer bottle and overflow tank.

Yes, I forgot SLs didn't have the same intake the SELs did. I'd be suprised if Euro cams pass the sniffer, I doubt the AMG ones would.

All it takes is money, how much do you want to spend?:D $100? $1,000? $10,000?

Certainly a 6L 4 overhead cam AMG V8 could be located, purchased and fitted.

I have also seen a pretty decent number with forced induction.