Are there any performance upgrades available for diesels? anything i can do myself to make it faster?

Try to go downhill most of the time. When you get to Florida, put it on the train and send it home. Point being that this appears to be one of the premier passenger car engines of all times. It can run all day long, it can pull a load, and it can make a half-million miles with average care and attention. However, it will only deliver decent 0-60 times with significant gravity assist. Remeber Fred Flinstone's car? I think that was the old 200D. Thank the powers that be that the turbo got into the mix.

I agree with TXBills post except I prefer blown Chrysler Hemi as my engine choice.

Seriously though, the nature of a diesel engine does not lend itself to performance modifications. In the case of a gas engine, there are three main principals involved in power increase, these principals are:

Increase the flow
Increase the flow and
Increase the flow

A gas engine is an air/fuel pump, when you increase the air/fuel that is pumped into the cylinders, you increase the power. In the case of a diesel engine, the only way you increase power is to inject more fuel into the cylinders. Any improvements done to increase flow such as turbochargers and resonance intake systems provide more air in the cylinders which allow more fuel to be injected without injecting too much for the volume of air present in the cylinder.

These kinds of modifications are not such that lend themselves to the hot rodder.

Enjoy your fabulous, rattling diesel and get used to your lesson in patience that you get every time you strategize the passing of a slower car on a two lane road.

Have a great day,

Would there be any gains by reducing the amount of exhaust back pressure on a diesel? Say by removing the resonater, increasing exhaust pipe diameter or putting on a less restrictive muffler.

Aivars

As far as a less-restrictive exhaust goes, I would imagine the setup on a Benz diesel is pretty much optimized in its stock form.

Having said that, I've heard more than once that you can't have too large an exhaust on a turbocharged engine. That's why many aftermarket companies sell absolutely HUGE (4 in. and larger) exhausts for turbodiesel pickups. However, the guys driving these pickups are turning up the boost and fuel delivery substantially beyond factory settings. A stock Benz diesel probably wouldn't benefit much from an uncorked exhaust.

It's interesting to note, though, that semi-tractors with single turbochargers often have massive dual air filters and dual exhausts. However, a 120 hp, 3 liter Mercedes-Benz diesel is not a 550 (or more) hp, 14 liter Caterpillar.

Aaron

Bill, when you modified your exhaust system, did you find the exhaust tone a lot louder?
(Kind of tractor-like? )

Aivars

Great car, This is the fastest mb diesel engine until the 98 and 99 E300 Turbo's came out. Its plenty fast when you get on it.. But it is what it is.. not much can be done..

Put trap doors in the floorpans and when you want to go faster have everyone open the trapdoors,stick their legs out and run to push your diesel faster (like Fred Flintstone)!!

Actually, you'll get the best performance by setting everything to factory spec. (valve adj., turbo adj., new air cleaner, make sure the intake/exhaust manifolds are tight and don't leak, check the timing chain for stretch, do a compression/pressure test, new fuel filters, trans. adj. etc., etc.), and if everything checks OK your turbo diesel should perform better than many others on the road. The official M-B manuals and the Haynes manual will provide lots of info - both can be found on eBay. I prefer the print version over the CD for the M-B manuals. If you have problems - then do a post and you'll find a wealth of knowledge and experience here to help you.

Good Luck!
Tom

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How about taking your original engine fan off and replacing it with an electric one?

On your 86 300sdl, make sure you have the latest trap oxidizer, the 3 inch diameter one, not the large 9 inch diameter canister. That change on my 87 sdl gave me what seemed like 20 HP, and added 3 MPG to my fuel economy. The upgrade was free from the MB dealer. Other than that, make sure all the filters are clean, and you might pull your injectors and have them tested.

It doesn't apply to you but on my 240D, the fan is direct drive with no fan clutch. I've heard of guys putting a fan clutch from a 300D on their 240D to gain what must be about 3 HP.

Joe

I think that speed and acelration are relitive . I took my 74 240 d out for a spin today to cirulate her fluids and bring the basttery up to charge. Then I put her battery in my 81 2wd 454 powered Blazer ( 2 batteries for three cars = hillbilly heritage) and took her for a spin ,both are a lot faster than walking.....
William Rogers.....

As diesels are basically big air pumps, would a wee bit of an improvement be had by going to an oil-soaked air cleaner such as an Amsoil or K&N item? I have also thought that perhaps some improvement can be had by using one of those air cleaner lid things with filter elements in the top (I do not know what K&N calls that product). I have read posts here that argue pro & con for oiled filters vs. stock paper elements. Even if a stock paper air filter flows as much air as an aftermarket Amsoil/K&N item, would not the aftermarket item offer better filtration of particulates?

Personally, I do not want to "Soup Up" my diesel - the car is saving my drivers licence; however I do want to make it as efficient as possible, in addition to enhancing its already excellent reliability & longevity.
Now, about those damn rotten switches & electrical glitches...

Wow, there sure are a lot of posts to this thread with no actual performance tips! OK, here goes:

1- As someone mentioned, make sure the trap oxidizer is removed. This picks up 5hp (more if it was plugged.) The dealer will replace it free as part of a factory recall, and also replace the turbo free if any damage is observed.

2- If the car is very sluggish off the line, you can try adjusting the ALDA to correct this (assuming the engine is otherwise in good condition.) This is not easy to do on an OM603, the ALDA has to be removed to access the adjustment setscrew. Post a new topic specifically on this if you want further help (I haven't done it personally, YET!) This will NOT increase top-end power, just the off-idle response, and only if it's poor in the first place. If it's good now and you adjust it, it will be worse, not better.

3- You can adjust the turbo wastegate to increase boost. HOWEVER, fisrt make sure it is reaching factory boost spec, which is 0.85-0.95 bar (13-14psi). Plumb in a pressure gauge with a "T" fitting, route the hose out the hood seam through the window, and go for a drive - max boost will be at full load & high RPM. If less than the above numbers, you're not getting what Mercedes intended. If you are, and want more, you can tweak it a LITTLE bit, say up to ~1.1 bar (~16psi). That's when the overboost sensor cuts in. Any more than that and you would have to disable the overboost safety, which is a bad idea, and you also risk serious engine damage. The extra HP also puts a strain on the transmission, so be warned if your tranny is old and stock...

4- A K&N air filter won't help at all. Save your money. Diesels run with an excess of air, more airflow won't help. Use an OEM (Hengst, Knecht, Mann) filter and make sure it's clean.

5- Reduced friction is always good. Use a top-quality diesel-rated synthetic oil. I use Mobil Delvac-1, which is a super-duty diesel version of Mobil-1. Most full synthetics are fine but per Dr. Booth's comments, stay away from Castrol Syntec. I found Shell Rotella Synthetic at the local Wal-Mart for $19/gallon, but haven't tried it yet. The price is pretty good though, for a diesel-specific synthetic, and a lot easier than getting Delvac-1 at the Mobil distributor!


So, yes you can get more power from your 6-cylinder OM603 engine, just not a lot more! BTW, my 1987 300D's have the same engine as your 300SDL (yours is an OM603.961, mine are OM603.960)


Good luck,

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Boise, ID
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I had a car manual that speced the power of the fan. It was rated at 7 hp.

Jim

If it is 7hp, maybe I should try to put a fan clutch in my 240. Hey, 7hp is 10% of what I have.

Joe