How do you make a 300d-T go fasTER ? Like, really FAST
 

guys, simple question: how do you make a w123 300d-t go faster? The exhaust is pretty restrictive, and so is the exhaust manifold. How about some custom headers with a turbo bung, and a completely different kind of turbo? what kinds of aftermarket turbos have people tried, how much boost have they run with them, and what internals needed to be replaced?

this car is like, waaaay too slow for my taste, but i know it has potential

Mild performance improvements can be made to a 300D Turbo for reasonable amounts of money and effort. BUT you're not going to make a W123 go really fast without spending a buttload of cash.

For the same money you'll get a lot more of what you're looking for by trading up to a newer model with the 6-cylinder turbo and selling your W123 to someone who appreciates their other fine qualities.

Just my 2 cents.

You should sell the w123 and get a w124 500E with the hand built porsche engine, burn some rubber with that bad boy :D

LOL. Its not going to go much faster. If your 0-60 is between 12 and 14 seconds, that is about all you're going to get unless you spend about 4-5k on mods....even then, the increase would be minimal....could buy a second 400E to have fun with for that amount.

The stock exhaust is not restrictive at all, it is free flowing. A straight pipe gives a very small performance increase in low end torque because the turbo spools a bit faster, but otherwise no difference.

The problem with the 617 is that it is not a cross flow head, and only has 2 valves per cylinder. This makes performance mods pretty much moot for the motor. A better motor to mod is a 603 or 606...they can make serious power.

The boost is already as high as it needs to be. With more boost you put more strain on the engine, bearings, head gasket, everything. And there will be no additional power unless you also increase the fuel, which means fancy injection pump tuning and changes ($$$$$)....and if you increase the fuel, it will run too hot at high load and your EGT could become a big problem very quickly....once again limited by the head design.

The 617 already has a free flowing air intake and exhaust....changes to that are pointless....and modding the engine would cost a fortune to make any additional power.

If you want Speed you bought the wrong car, simple as that. Go buy a 280e if you want speed. ;) Don't ruin a perfectly good 617 with mods that won't work.

Do a search in the diesel performance section. There is plenty to read about there and you'll get an idea.

There is a sub-forum called diesel performance tuning. As you shamelessly don't seem to let things be I'm sure you'll find alot of fun stuff to do there.

Also:

http://www.youtube.com/watch?v=czV3fwZ73gc

From what I've been able to glean so far, after doing many mods to a w123 617 you will still have slower car than a stock 280E.

An 87 300D has decent performance right out of the box. The w201 190D 2.5 turbodiesels have excelent performance as well. Nice examples are available for between $2 and $3k, which is less that you will have invested in a modified 617, which is still going to be slower.

I love the 617 and I'm satisfied with the mediocre performance it provides. It's old tech now, but for the late 70s early 80s, especially in it's 126 chassis iteration, it seemed pretty high tech in it's day.

so, guys. what can i do to get some mild performance gains, without breaking the bank, and without taking apart the engine and messing with pistons?

so far all i've done is delete the egr, and install a K&N air filter. how about an aftermarket air intake? perhaps going with the half-sized oil cooler (for models without A/C, presumably), and using the area above the small cooler for a cold air intake? course this will reduce the oil cooling capacity. or maybe re-route the stock oil cooler (or a larger one) to underneath and behind the bumper?

my only other thoughts are light weight CLK wheels, which will only save me a pound or two per corner, which is not bad for a start.

i'm willing to entertain any suggestions or links to what others have done (on a budget)

:deadhorse:

No need to spend any money. Just shred some dead weight. Remove passenger seat, back seat, spare tire, clean out the trunk, remove compressor and belt, condenser, evaporator, blower, radio, antenna. 1st aid box etc etc. That is what a F1 car is like.

If you are looking for a sport car's performance then you bought the wrong car.:D

Installing the K&N was pointless, unless your goal is to maximize dirt intake into the engine. Put the stock paper filter back on, the engine will thank you for it. The K&N offers no performance gain, only a wear-out-the-engine-faster gain.

hahaha. guys. i knew i should of expected replies like this. no doubt i'm beating a dead horse on this one. i'm not thoroughly convinced about the K&N filter though. I regularly clean, oil and rotate it. but forget about the filter and cold air intake for a sec...

let me re-phrase it this way: if you had $1K to spend, and you wanted to eek out a bit more performance out of this engine, what would you do, specifically?

i'm keeping the car essentially stock on the interior, so nothing will be removed to save weight. i already have a 190e which is set up as a track car, i couldn't fathom trying anything like that on a w123 unless it was a beater to begin with

buy yourself a nice set of wheels and tires and a smaller diameter steering wheel. new bilstein sport or hd shocks unless you are sure they are not worn out. Absolutely anything else you do you will not be able to feel any difference....not for a grand anyway.

It sounds like junior, like, needs a, like Honda...... :rolleyes:

http://i29.photobucket.com/albums/c2...ff/Ricebag.jpg

A highly modified Big Block Chevy under the hood would fill the bill.

You can install the torque of a honda into a TDI with just a chiptune and nozzles. :D

Your 300D Trubo isn't really that slow. It will get you where you need to be. Just relax and enjoy the ride. You've never driven a slow car (NA300D, improperly tuned VW 1.6... I drove one for a while that had probably 40 hp. I ended up being a lot less stressed that week... the car just did its thing at its pace and I was along for the ride)

-Jason

Okay for $1000 you could do the VNT turbo swap and put a proper air filter back on. Again if you are trying to make this thing go fast you are on the losing end of the game. Find a running V-8 mercedes and have fun! That would be my honest suggestion

A VNT won't get you anywhere unless you add more fuel first. The stock turbo should be more then enough to do 15 PSI, but at those pressures I would want an intercooler.

-Jason

For $1000, a V8 swap would be the most bang for the buck. That's my vote, sell the 617 to someone who can appreciate it.

hmmm how about a GM 6.2 or 6.5 turbo swap?
weight would be an issue, and boost would be limited to 8 or so psi, but you'd get another 60 to 110 or so HP... much faster motor,,, SBC swaps have been done, heck, throw in a 5 or 6 speed manual tranny, and you could do some serious moving in the car... and still be under the 1000$ budget... it'd be a crappy car at that point, but if you want to stay diesel, and have speed in your 123, that's the way to look at this point...
a 4bt is too rough, and expensive, the better MB motors won't fit easy or cheap in the car, NO WAY a powerstroke would fit in the car, cummins are just huge and pricey too...

x2. A K&N filter can potentially provide performance gains on certain motors. A turbo-diesel is not one of them. You are getting ZERO added performance from that K&N. None. Not even 1 hp. Nothing. Is there some way we can make this clearer?

With that K&N perfectly brand new and freshly oiled and performing exactly as it is intended, it is still letting a LOT of dirt into the engine. A LOT. Way way more than the factory paper filter. If you're "not thoroughly convinced" then you're not thoroughly educated.

Did I mention it doesn't increase performance AT ALL on this engine?

Further, the original intake as delivered from the factory is a cold air intake. I'm afraid to ask what sort of "cold air intake" you planned to replace it with.

Really? Are you actually suggesting to reduce the oil cooling capacity on a turbocharged motor and trying to increase output at the same time?? :freak: You need a new hobby because quite frankly, you have no understanding of how an engine works.

And your performance budget is $1000? Really? You can almost buy a nice bicycle with that. ;)

If you want a fast diesel, sell your car and buy a new CDI.

I seriously still say go with a 500E, the w124 is a classy and sporty chassis and you have a hand built porsche engine for possibly under 5 grand.. You could have some serious fun with a car like that, but still maintain that Mercedes look.

I am wondering, if you are not happy with your 617, if it is running right?

Some members have seen marked improvements from installing new nozzles. Also, a proper valve adjustment can make a huge difference.

Also, are you getting full accelerator pedal travel?

Is your transmission adjusted correctly?

The only simple mod I can think of that might make a difference is to install the 2600 rpm stall converter from an '85 model, if you haven't already.

My 617 turbo cars run as well as anything on the highway, they have adequate power and are not slow by my standards.

Maybe some basic maintenance would change the feel of the car for you.

Here you go - swap already done & for only $2800.

http://nashville.craigslist.org/cto/1395058811.html

Looks like a waste of a good SD.

I can guarantee that no matter what you do to the 300D short of installing a rocket booster on the back, my 300E will take it down every time, stock. It is just not a fast car. You need to accept this at some point. :D Preferably before you fully destroy that poor 617. Get that K&N Junk off of it!

If you want fast buy a different car.

Well if you are set on leaving the interior stock your other best option is exterior mods. It's a power to weight game in ANY vehicle. So pull the doors, my god they wiegh a ton. Trunk lid and hood with front fenders. Discard sun roof. Then as others suggested strip the motor. No spare tire and only a gallon of fuel. No wipers or mirrors.

Then get a set of street slicks and go the the track. Easily mid 13's if you really get serious. Sounds like you have a car set up for the track so you should know all these tricks already. Good luck. Thanks

That is a gorgous w126. I can fathom how some one could destroy a car like that!

woah, woah, guys. ease up on me a bit. i'm sure everyone has strong feelings about this engine, and others believe you shouldn't mess with a good thing from the factory. it's got decent power for its age, but every engine can be tuned.

as a disclaimer, I'm an m102/m103 guy--this is my first diesel car, i hardly drive it more than a few miles every few weeks or so, when i go to my dad's house, where it's parked. i was basically hoping to get some advice on well-known, well-documented tuning that's been done to these cars to eek out some more power without breaking the bank. i'm not asking these questions to instigate you or piss you off. and i'm certainly not into hondas, although I do own an ae82 toyota, and am into the mid-80's 16v scene (190e 2.3-16v, ae86, etc.)

so, having said that, take no offense to my questions. instead think about how you can EDUCATE me, rather than bag on me.

but you know what, forget i said that--keep the flames coming (just don't tell craig about this thread)

by the way how about having the head re-worked, and port-matching the intake and exhaust manifolds to the gaskets? has this been tried before with decent success?

you know what, in all seriousness, if i did all that, i could prolly shave a sec of my quarter mile. the doors DO weigh a ton, and so do the sunroof, so that's all something to think about--i'll take it into consideration. while i'm at it, why not cut out the spare tire well--that thing weighs a ton, too

actually larry, i have seen a 190e with a corvette engine in it. anything is doable. if you have a nice body, you can strip out the wiring harness and ancillaries off the engine bay, and have a fresh canvas to work with, and do whatever you want to, including a big block chevy 454 ss engine.

i can appreciate this engine. i've been a fan of it for a long time. i've disassembled hundreds of w123's, finally i decided i would pull the trigger when the opportunity for a nice one, on the cheap, presented itself. i wouldn't of bought the car if I didn't like the chassis and the engine. you can't go wrong with a simple engine that's proven to go forever, rather than an m117 which is complicated and expensive to have people work on

nah, just thinking out loud, on the oil cooler. you can increase the size of the oil cooler, and just put it under the bumper with a cleverly installed bracket. then you've got the space to the left or right of the radiator for an air intake which can bring in more air than the stock intake. and i do agree the stock intake is cold air.

regarding the air filter, if it's a well-known, well-documented fact that the K&N is worse than the paper filter for this car, i'll go along with that. i don't claim to be an expert, but i do know that it helps for my m103 engine

this is already my initial goal. i've installed the 1991-1994 steering wheel with the airbag (non-functional, just there as a horn, really), the CLK wheels are in the works, and so are some sport shocks if I can get someone to make them for me--otehrwise bilstein hd's. some cut-down w126 springs are also in the works. we all know how everyone hates lowering a w123, so let's not go there again.

just thinking ahead to the future

it's not that i'm not happy, it's just that i'm never satisfied--always want to yank some more out of the car somehow, if it's possible.

i don't think my transmission is adjusted properly. sometimes as it shifts into second, it slips, and the rpm's go up for a second, until it finally kicks into gear. in that one second, i lose throttle response. so there is definitely either a cable that needs to be adjusted, or a new vacuum modulator in the works for me, but the slip isn't bad enough to justify throwing money at it just yet.

i will search for this stall converter--have no clue what it is though

realistically, the w123 is slow by modern standards. it may be a weight issue, and, i don't want to start a discussion about this in this thread, but i doubt there are 3.0l diesel engines brand new from the factory by any brand out there today, that produce only 130hp or less, and the chassis weighs over 4K pounds, give or take. this is a recipe for 'relative slowness', but we can all still appreciate the car for what it is

What are you hoping to achieve by altering the intake? Have you ever owned a turbocharged vehicle before? Playing with the intake will gain you nothing. Even porting and polishing the intake manifold will do very very little, so little in fact, that it is pointless. A turbo charged diesel engine works very very differently from your normally aspirated gasoline m103.

It is a well documented fact that a K&N is bad for ANY and ALL turbo diesel engines. Period.

This is not an m103, and your m103 tuning does not apply. If you only walk away with ONE piece of knowledge from this entire thread, it should be to put that K&N into the trash and install a paper filter instead.

Edit: I second kingdoc1's recommendation on maintenance. Questions for you:

1. When is the last time this car had a valve adjustment?
2. What kind and weight of engine oil are you using? Last changed when?
3. When is the last time the fuel filters were changes?
4. When is the last time the transmission was serviced?
5. When was the brake fluid last flushed and changed?
6. Are the injectors original? Have they been rebuilt?
7. When is the last time a Diesel Purge was performed?

ok, dude. i'll walk away with that and hopefully more. i fullly realize this isn't a gasser and not all mods are transferrable. but i also think you should consider changing your approach.

for the record i did state above that this is my first diesel car, so i'm new to all this tuning, even though i'm not new to this engine or chassis, having dismantled many a w123 before (almost completely)

Trying to instill a sense of urgency because it seemed like you weren't willing to accept the advice give to you by multiple folks who do know this engine very well. But since you are, I'm more than happy to help.

If your familiar with the w123 chassis that will help you in performing the required maintenance. See the list of questions I just edited into my post above. The valve adjustment and fuel filters in particular can have a very noticeable impact on performance.

Blasphemy. VNT does wonders for the low end. Stock turbo can do more than 15 but it just turns into a heatpump.

ah, i see. yeah, i did a new clear fuel pre-filter going into the back of the injection pump--i guess the next thing to do is the filter on the gas tank. valve adjustment might be out of my ability range, and i prolly don't have the tools to do it, either. i might be able to follow a step-by-step if it's been well-documented with pics though

Aside from the clear pre-filter and tank filter, you have the primary fuel filter. It is a metal spin-on canister type. I change mine every 12k miles or once per year.

Valve adjustment is not hard, and it's very inexpensive if you DIY, but requires very precision adjustments and attention to detail. It must be performed every 12k miles or once per year.

Also, if you have 150k miles or more, I'll bet your injectors are worn out and in need of a rebuild. This can have a very noticeable affect on performance as well. This is not a DIY, you'll want to take them to a diesel injection shop.

I wouldn't even be thinking about performance modifications until you've addressed all the items 1-7 on the list above. Who knows, getting it properly maintained may very well give you the performance boost you're looking for.

Agreed, so hopefully you've decided to not complicate matters for a negligible gain. Removing items such as seats, doors, sun roof, spare tire and well negate the attributes of a car. (tongue in cheek)
Folks are trying to let you know there is very little available to "hop up" this engine. I would think porting and polishing would help, but again, how much for such a time consuming task? Yet, by all means, knock yourself out.

I'll put my vote in for an SBC conversion. A Vortec 5.7 in one of these cars would probably return the same mileage as the diesel and be a lot more fun to drive. The conversion is pretty straight forward.

There is a guy on here (forget his name, out in Texas) that had a 70's 280 that was converted to a SBC. Nice car. Good mileage and the engine parts are cheap and widely available.

I think the swap is a great idea. Too many purists around here. The diesel is OK... The V8 swap is just sounds like fun!

Why is everybody bad mouthing the K&N air filter? I see them run all the time on Cummins,Duramax and Powerstrokes pick-ups many with over 300,000 miles on original motor. Are you saying they are bad just on Mercedes Benz or are these people ruining their 40,000 dollar trucks because they don't know any better? Just wondering what there is to support this?

Yes, they don't know any better or have fallen for marketing hype. Oiled gauze filters rely on electrostatic charge to draw dust out of the air, but it passes a lot of dirt. If you want longevity, use a paper filter.

Sounds like somebody didn't read the whole thread before hitting the reply button. :wallbash: From page 1:

So to answer your question, yes, those people are fools who saw a TV commercial and they don't know any better. They are letting dirt into their $40,000 truck engines and they are not gaining any power at all, not even 1 hp.

Load it on a C-130 or the airplane of your choice. :D

listen to these guys pal, they know their ***** allright

Welcome back...

So so you think he changed his ISP so they couldn't check his IP address? Just to get back on the forum. Sure sounds like one of Lance's replies.

do you have a lot of dosh to play with? just curious dude--you sound like the rich type