Basic question: Can performance be increased in a 300D & 300SDL?? - Page 2 - PeachParts Mercedes-Benz Forum

truckinik · #16 11-01-2009, 10:53 PM

Quote:

Originally Posted by Les Jenkins

Thats all? I'd prefer a 450hp OM606 to any of those poorly built 'merican iron scraps.

The key word here is "ATLEAST", I myself originally installed a 480hp 383 stroker small block into my 79 300CD. It has since been pulled, and installed into an S-10 Blazer, and a more potent 600hp GM LS engine has been installed into the Mercedes. Just that u can buy a complete long block crate small block with 325hp, all day long for $1500.00. I was attempting to keep his budget in mind, because he said he wanted to keep it simple. Anymore than 325hp, and he's now replacing the rear dif, with a Dana 60 out of a Jag, for another $1000-$1500, like I had to. I was just trying to prevent him the hassle of a rear end job too.

Les Jenkins · #17 11-01-2009, 11:16 PM

Right, but you're still stuck with a yankee iron g@sser that are a dime a dozen.

babyjames · #18 11-15-2009, 12:02 PM

Seems like this would be an ideal candidate for your filter/enclosure?? Just copy the setup from the 126.

Jay.

Ian White · #19 11-19-2009, 08:02 PM

Quote:

Originally Posted by Les Jenkins

Thats all? I'd prefer a 450hp OM606 to any of those poorly built 'merican iron scraps.

And you live here why? Lance, maybe you should move to germany then... American and Europeans have different concepts of engine design dynamics. Besides our beloved diesel benzes how many gas old european scrap is still on the road? Not near as much as the American Stuff.

Oldbeaver · #20 12-15-2009, 08:54 PM

Very interesting pieces of advice that of yours.

Do you think these are usefull for a naturally aspirated diesel?

Is there ant way to feedback the guagues info to inyection?

Be easy on me too, please.

Tks.

OldBeaver

Quote:

Originally Posted by rcounts

Welcome.

First step: get everything up to spec. Valves adjusted, injectors cleaned and pop tested. Timing set to spec. Chain stretch checked (and corrected if necessary - by replacing it or installing an offset cam key). Clean the banjo bolt and line from the intake to the ALDA. New fuel filters. Maybe even run a Diesel Purge to make sure things are cleaned out.

Then, once all is up to factory spec, or as close as you can reasonably get it, you can install an EGT guage and boost guage. Once you have these two essential guages, you can start making mods to increase power.

First I'd install a boost pressure controller (if needed) to get the boost back up to 12 PSI (factory spec) or maybe a couple of PSI higher, but you don't want to push it up higher than about 14 PSI.

Then you can also adjust the ALDA and a few other IP settings to get a little more fuel to go along with the additional boost (do a search, there are lots of posts about adjustments you can do). Performance injectors are always another option, though not exactly a cheap one. You can also remove the muffler and/or resonator, though it will make it a little louder. Upsizing the exhaust from the turbo back can't hurt - up to about 3" (anything bigger would be a waste).

Most of these things should have negligable effect on mpg. The biggest determinant of your mpg is driving style and conditions. A heavy right foot and stop and go driving are the mpg killers with these cars.

If bottom end acceleration is what you're after, and you don't mind sacrificing a little mpg to get it, you can change the rear end to one with a higher numerical ratio (like a 3.67 out of a 240D). You probably have a 3.08, or possibly a 2.88 in there now.

Some people attempt to build a more free-flowing less restrictive intake, but the jury is out on that one. Some say the stock cold-air setup is about as good as it is going to get unless you compromise filtration. I've always thought that all the twists and turns of the stock intake setup can't be the least restrictive of all possibilities.

I've wanted to try a really BIG open-element cannister-style filter mounted behind the passenger headlight, and isolated from the underhood engine heat by a partition. Then connect it to the turbo inlet with a smooth gradual-curved intake pipe. Seems to me that would have to make for better intake flow. At least then the airstream wouldn't have to make two 180* turns between the air cleaner inlet and the turbo inlet. Again, the jury is still out on that one.

MTUpower · #21 12-15-2009, 09:42 PM

Quote:

Originally Posted by Oldbeaver

Very interesting pieces of advice that of yours.

Do you think these are usefull for a naturally aspirated diesel?

Is there ant way to feedback the guagues info to inyection?

Be easy on me too, please.

Tks.

OldBeaver

No it really does not apply other than the get it running as close to factory specs as possible part. If you have a NA diesel, adding more fuel without the more air to burn does nothing as far as more power. You must add more air AND more fuel to get more power.

rcounts · #22 12-17-2009, 12:25 AM

Quote:

Originally Posted by MTUpower

No it really does not apply other than the get it running as close to factory specs as possible part. If you have a NA diesel, adding more fuel without the more air to burn does nothing as far as more power. You must add more air AND more fuel to get more power.

In my experience an NA will benefit more from optimization of intake and exhaust than a turbo will - for the exact reason that Brian stated. On the turbo, it will compensate (mostly) for the inefficiencies. Without the turbo to compensate inefficiencies cost you more.

On my first diesel, an NA F250 pickup, I built a custom Y-pipe to a 3" exhaust system (replacing a 2.25" system and the crappiest flowing y-pipe design in automotive history), and installed a straight through muffler.

Then I added a dual intake ram-air setup. After installing an EGT guage I started dialing up the fuel a step at a time until the EGTs started getting out of hand - at which point I dialed it back a step.

I picked up over 15 ponies (calculated HP based on vehicle weight and timed 0-60mph runs vs. stock rating). Not a huge improvement, but almost a 10% increase in HP, and the cost was under $250 - including the EGT guage...

Ezra1234 · #23 11-01-2019, 04:11 AM

So I Just saved a 300d from a junkyard and I'm wondering what's the first mod i should do

VicS · #24 11-01-2019, 08:02 AM

Why mess with a perfectly good time machine?

83w126 · #25 11-10-2019, 01:11 AM

Quote:

Originally Posted by Ezra1234

So I Just saved a 300d from a junkyard and I'm wondering what's the first mod i should do

Adjust the valves, check the timing chain and install an offset key or replace it if needed, rebuilt injectors, new engine and transmission mounts, check the oil cooler lines and replace them if they are showing any signs of failing, other maintenance stuff (fluids and filters, etc), new shocks, 16'' wheels with good tires, brake pads, rotors and lines if needed, etc.

oldsinner111 · #26 11-10-2019, 07:06 AM

propane injection is a fast easy way,,of extra hp.Instead of expensive injection pump work,spray 2 psi or more pre turbo

Ezra1234 · #27 11-13-2019, 02:49 AM

Thanks!

rwd4evr · #28 12-02-2019, 08:33 PM

Quote:

Originally Posted by truckinik

Yes, Performance can be improved in these cars. Here's a quick parts list. A very basic one, and the details are flexible. The list also contains some of the necessary tools, and a quick instruction section.

1. Acquire a good set of Metric, and Standard type hand-tools, Pneumatic tools, etc.
2. 2 good pairs of hd jack stands.
3. A decent welder.

The fun part.....

1. Jack car up, onto all four jack-stands, so it's atleast two feet above the ground.
2. Unbolt everything attaching the driveline, and engine to the car, cut out and toss components such as exhaust system.
3. Drain all fluids into disposal pans, and put car back down on garage floor.
4. Detach everything connecting engine to car topside, flip hood all the way back.
5. Proceed to "Rip-out" all Mercedes built engine and driveline components. Trash them all, except for the driveshaft.
6. Send driveshaft out & have 5.25 inches removed, Have GM "slide in" type U-Joints installed on trans end, and rebalanced.

MOST FUN PART...
1. Acquire a well built "Small Block" Chevy V8, with ATLEAST 325 HP.
2. Acquire a T-56, GM style 6 speed trans, with clutch components etc.
3.Acquire GM, S-10, V8 Small block Conversion kit.
4.Acquire 75-79 Chevy Nova Trans Crossmember.

The slightly more difficult part
1. Use welder, and proceed to install engine mounts for GM V8 conversion for Chevy S-10, 2wd. (They just happen to match the lines of the frame rails in the Benz perfectly, and need no mods- Go Figure...)
2. Drop Small Block Chevy engine into Mercedes Benz, bolt to your new mounts.
3. Jack car up again.
4. Use GM, 1975-1979 Chevy Nova, trans crossmember and install it three (3) inches further back from original Benz crossmember.
5.Proceed to install Trans and Components.
6.Install Driveshaft.
7. Install radiator, and headers from S-10 conversion kit.
8. Install shifter.
9. Connect all electrical, and make necessary mods, such as starter wires locations, and a few simple things like that.
10. Drain all of that Diesel crap outta the tank, install electric fuel pump, and fill that sucker with 93 octaine, install oil & other new fluids.
11. Tow car to local exhaust shop. Have them install a nice custom 2.5", alluminized dual system, and Flowmaster Two Chamber Mufflers.
12. Drive the sucker home, make final adjustments, and cruise town in your ultimate sleeper.

What did you do about the steering that lives where the oil pump and pan on a Chevy would occupy?

Sent from my SM-J737A using Tapatalk

HughO · #29 03-17-2021, 02:18 PM

Quote:

Originally Posted by Hip001

Rcounts,
Thank you for the reply! EGT gauge, Is this exhaust gas temp? Where do I get these and where do I mount them?
I'm in the process of bring the 300SDL up to current maintenance specs. This use to be my Sunday car but think I'm gonna start driving it more.

A boost pressure controller? Where can i acquire that?

I also read somewhere that there was a guy putting a intercooler on his turbo. Is this a good idea? He said he was trying to increase his mpg. I love my big ole Hooptie and am still shocked it gets 30mpg compaired to my 300d's 23mpg. The SDL is the one I would like to keep so I'm leaning toward improvements on it.

This is an old post but maybe people still read it. There are some nice patient answers to this newbie. The SDL is fine. I had an 87 and it got up an ran. He mentions 23 mpg with his slow 300D. That can be brought to over 30 with the usual tips:checking IP timing, chain stretch, injector nozzles with balancing, air filter, turbo checks with all the associated fixes like banjo and alda, valve adjustment. My 85 300 D was fine but got 23-25. After putting in a new chain,reman turbo,bosio nozzles, IP timing and the other stuff I mentioned it has more poop and always gets 29-30 on the hiway. Best is 32.3 at a steady 55 on a long trip. Diesel will use fuel in proportion to the work required and 30 mpg with the sedan is doable.

HughO · #30 03-17-2021, 02:20 PM

Quote:

Originally Posted by Hip001

Rcounts,
Thank you for the reply! EGT gauge, Is this exhaust gas temp? Where do I get these and where do I mount them?
I'm in the process of bring the 300SDL up to current maintenance specs. This use to be my Sunday car but think I'm gonna start driving it more.

A boost pressure controller? Where can i acquire that?

I also read somewhere that there was a guy putting a intercooler on his turbo. Is this a good idea? He said he was trying to increase his mpg. I love my big ole Hooptie and am still shocked it gets 30mpg compaired to my 300d's 23mpg. The SDL is the one I would like to keep so I'm leaning toward improvements on it.

This is an old post but maybe people still read it. There are some nice patient answers to this newbie. The SDL is fine. I had an 87 and it got up an ran. He mentions 23 mpg with his slow 300D. That can be brought to over 30 with the usual tips:checking IP timing, chain stretch, injector nozzles with balancing, air filter, turbo checks with all the associated fixes like banjo and alda, valve adjustment. My 85 300 D was fine but got 23-25. After putting in a new chain,reman turbo,bosio nozzles, IP timing and the other stuff I mentioned it has more poop and always gets 29-30 on the hiway. Best is 32.3 at a steady 55 on a long trip. Diesel will use fuel in proportion to the work required and 30 mpg with the sedan is doable.BTW my engine has 280K miles.