Performance Upgrades...The big Questions
 

hey all, i'm new to mercedes and new to working on my own car as well. so far it's been great, with a couple little problems. one of which was destroying my ALDA yesterday, as i had read that you should just go ahead and play around with it and see what you get out of the regular CCW turning of the screw, which has lead me to write this to try to get some better, more concise information...

i've been reading through the Diesel Performance Tuning forum (as well as the regular diesel forum) for the last couple of months or so, getting as much info as i can to find out what i can do to get more power and performance out of my 300D turbo diesel. the problem is that, besides removing the egr, every possible upgrade suggestion quickly devolves into an argument about it's benefits or it's disadvantages, that rarely get resolved. or worse, it turns into an argument (usually against ForcedInduction), about how the answer was given, with people actually getting hurt feelings over the tone of someone's typing. (I'm really trying to avoid that one here, by the way, as the information i'm interested in is more important than how it is delivered, so please try to not be offended by someone's typing).

so.... i'm hoping for a list of things to do to increase power and performance (loss of mpg is not that big of a deal to me) with a note on whether it should be done or could be done by a beginner mechanic. this list will probably incur more questions, about how-to's and what not. and yes, i have already read everything there is to read, as stated, so please do not respond with "do a search." try it yourself some time, you won't get that far and what you do get is jumbled, unorganized, doesn't include directions or pictures, and, as stated, devolves into useless arguments. honestly, i was hoping for some stickys in the Performance forum that would have probably taken care of this question. one for egr deletion, one for straight piping, one for intercoolers, etc.

what do you think? those with the knowledge and skill, inform the rest of us! you'll be helping more than just me and maybe we can get some sticky's that will end the constant questions that are similar to this one :D.

so, i'll start, 1. remove the egr: here's a somewhat useful link: http://www.peachparts.com/shopforum/diesel-discussion/92534-egr-blocking-plate-kit.html?highlight=remove+egr

Although there are a number of folks here who can answer your questions much better then I can. But I do want to add a question to your question... What performance level are you wishing to achieve?

Routine maintenance (valve adjustment, timing chain stretch adjustment, IP timing, etc) can improve the performance to stock level for a vehicle that needs it. Then there is above the stock level. If you want go there, then how far above stock do you want to go?

didn't think of that....

i am aware of the routine maintenance suggested, and i should have noted that those things should be done first (maybe we could get a master list of those exact things together with links and/or stickys as well).

so the answer is definitely above stock. if there is a tiered system based on difficulty in achieving the modification, i would say i'm interested in all of the first tier modifications. if performance level differentiation is based on some other system, then i'm not aware of it and am not sure how to describe it. basically, i'm looking for explanations and how-to's, suggestions, and discussions of some of the most common things you see in people like ForcedInductions signature. If that is too complicated or too hard (in the opinion of the forum) for a shade tree mechanic then maybe any modifications that are on the tier before those ones.

does that clear things up?

read sig.

The first two things you should do is to install a boost gauge and a pyrometer.
The boost gauge is a fairly easy install as you can either tap the boost signal tube into the ALDA boost tubes or do as I did and attach it directly to the intake manifold. There is a bung on the intake manifold just for this purpose. Take it out and put in a 1/4inch pipe fitting. Then run some copper tubing around the back of the engine and attach the plastic boost line to it with a compression fitting. The guage sits very well inthe change holder at the bottom of the center console in a W126 I am not sure if that location will work in your car.
The pyrometer needs to be attached into the exhaust manifold. To do this, remove the turbo from the manifold and drill a hole in the manifold about 1 inch back from where the turbo attaches. Tap the hole for the fitting that came with your pyro's thermocouple (the wire that senses the temperature) I put this gauge next to the boost guage and ran power for the puro from the cigar lighter and the guage lights from the ashtray light.

Once you have these guages in place you can see how your engine is running now and what happens when you modify something. It is not safe to modify the engine without monitoring it.

The next thing you should do is to buy a boost controller and plumb it into the waste gate hose. If you have a MitiVac with the pressure feature you can attach it to the boost controller and 'pre-set' the controller to 12~14psi. Once you install the boost controller keep a sharp eye on the boost gauge as you should NOT go over 15psi (the automatic overboost should shut down fuel at this point, but if you have removed the ALDA that won't happen). Also keep an eye on the temps on the pyro as they should still be relatively cool (under 1000)

Once you start increasing fuel the temps will go up.

LUVMBDiesels: that's exactly what i'm talking about! says what to do AND how to do it. if you or someone else could add some pictures, that would make it perfect, and then maybe we could get a sticky: Boost gauge & Pyrometer How To. thanks!

can anyone suggest a certain brand of guage or pyrometer? or any to avoid?

oldsinner111: that's what i do, i read sigs and say, "i want to do that, how do i do that." can you take it to the next step and describe any of those processes, maybe with pictures? that's why i started this thread, to figure out how to do the things guys like you do and post in your sigs.

anyone else?

Pyrometer install writeup: http://www.peachparts.com/shopforum/diesel-discussion/167588-pyrometer-thermocouple-installation-pictorial.html?highlight=pyrometer

If you want faster off the line, you can change the rear differential. Installation is pretty straight forward, but I don't know off hand what models have what gearing and fit.

I haven't done this either, but many people also mod the injectors: http://superturbodiesel.com/std/injector-nozzles-t-28.html

Several people have been installing VNT turbos such as the GTA2056V for a Jeep Liberty. I haven't done this yet, but have one waiting for my time. Do this, and you can remove the ALDA completely. Writeup: http://www.superturbodiesel.com/std/gt2056v-jeep-liberty-diesel-turbo-on-a-617-t-146.html

Also, you can adjust the IP. I haven't done this yet either. Link: http://superturbodiesel.com/std/ip-full-load-adjustment-procedure-for-om61x-series-t-189.html

I think a shadetree can do all tasks, except for the last two which I can't comment on...yet.

Adjusting the the IP is a PITA if your a newcomer to cars. It is certainly easier than messing around with a VNT.

The first thing you do when you have a new to you Mercedes 617 powered diesel is to insure the fluids and filters are new and at the correct level. Change the filters- oil, power steering and primary and secondary fuel and air. Check the brake fluid and coolant- change/flush both if not sure or if needed. If you want to get back to the stock power level- which is the first step to going above that, you've got to make sure many systems are working as designed. Inspect the mechanical linkages from the "gas" pedal to the Injection Pump; are they in the proper location? are they the proper length? and are moving freely? are they functioning properly or are they worn? Check the line coming from the intake manifold to the (alda) IP and make sure it is not clogged as it tends to be. Inspect the path of the air- from the front grill to the intake manifold- are there leaks? are hoses cracked? Is the U-tube seated properly? Inspect the turbo and the exhaust pipes leaving the turbo. Check the motor mounts. Check the vacuum lines in the engine bay for obvious leaks or broken/plugged lines. Check the valve clearances- every 15K miles they are supposed to be check and set to specs. There are more purely mechanical tests but we'll leave those for later and wait for known symptoms to show themselves. (IP timing and injectors are two) Test all of these by everyday driving, listening and observing your engine/car often.
When you can say all of these and other engine related systems are operating properly, then you can start to move into altering the engine to give you more power. The alda unit on top the IP is a common first step adjustment. It's been covered in many threads. Virtually every other modification after this point requires the prudent mechanic to install a Exhaust Gas Temperature (EGT) and a boost pressure gauge where they are easily readable from the drivers seat. More gauges are useful in certain applications- Intake air temp (IAT), Exhaust Pressure are two of them. Gaining power involves adding more fuel and more boost. Each step in either adding fuel or adding boost (and/or when boost is made and the temp of that boost) is discussed here. Remember when you change one parameter on your engine you are likely to effect other parts/systems.

This is by no means a complete list and I hope others will chime in and add helpful advice and/or experience.