525 Tds Tuning

Hi, Has anyone out there carried out any DIY engine mods to a 94 525 tds?? Or can they reccommend any aftermarket devices. Is there a chip available to alter the auto box shift characteristics? ( 5HP18 Box i think...sealed for life type ) What sort of boost pressure do they run? ( can i increase it safely myself ) Does an exhaust help? I am new to diesel tuning, and automatics....
I am in the UK..Thanks !!!

Hi
I am far from be a specialist but I have a '95 E34 525tds Touring and the only way I know to improve the engine is without modifications is by a chip, BUT... the chip you might want is one that affects the diesel pump and NOT... the turbo if you increase the turbo pressure by a chip you will reduce is lifetime dramatically. There are a lot of manufacturers of tuningchips for the 525tds but in my opinion the bests are the ones that don't need to open the DME (where the original chip is), they have a separate box with plugs (e.g. POWERBOX) that are connected between the cables that came from the DME to the diesel pump, they usually increase the power by 30bhp but where they really excel is on the torque figures.
Hope this will help you. Best wishes from Portugal

Cmoura

hi there,

I have a 325td 1993 manual gears

I am also looking for the same answers as you are meaning:

Increae bhp and torque.

This I have been told by both specialist and enthusiasts can be achieved in a few ways:

1. Chiptuning - as the oter reply n the thread suggested, this is better if it is done without interventing inside the computer of the car, but rather by a lug and play method like Tuning Box does or Van Aaken chip.
2. Cold Air intake for the diesels also improves performance. The kit from K&N for my diesel should also fir yours since they are basically the same engines but mine is with a smaller turbine and lacking an intercooler like yours should have. The exact product ID for the kit, shall be differet so i suggest you contact K&N and ask them about your make. they were very helpful with my inquiries.
3. Alterpower - cutting of alternator power when it is not needed is said to give and extra 2 - 10 hp. I personally prefer to go without the extra 2 - 10 hp, but be sure to have enough electricity to power my AMP and lights in case the alternator suddenly drops dead (happened to my twice already)
4. Exhaust - on the diesels, the benefits are very little felt if at all. Sure it makes a difference, but i guess it is more of the smoothnes of the ride and sound of the engine than a real HP or torque gain
5. Speed delimeters - some cars have a limit for the max speed. This device takes that away. You decide if this is what you need. Not really sure how this interacts with torque and hp, but it is said to give you an extra 5 - 10 mph over standard max speed.
6. Light allow pulleys - i have read a lot of controversial information. So I suggest before you go on for that option - read carefully.

Well I think that is about it with my research so far.

I drive another Bimmer, 1992 525tds but decided to experiment on the 325td.
Now I am looking for information on excahngign the turbine of the 325td with one like teh 525tds and installing an intercooler. Theoretically this should not be a problem since bothe engines are identical. But still doing research on that one.

hope this helps.
hit me back if you have found something else besides these or if you have found other relevant info for the diesel :)

cheers
from Bulgaria

Every tuning part, INCLUDING a power box DOES affect the turbo...

A diesel is great to tune and get about 30 to 40bhp an about 100Nm torque because of tuning the turbo... If the turbo wouldn't be affected, you would NEVER get these results!!

I drive a 525tdsA Touring from 1992 and mine will be proffesionally chipped at the end of this year. This will be done by 1 of the best tuners here in Holland. www.boltuning.nl Believe me... He knows what he is doing...

I'm now looking for possibilies about building an open air system...

also am I looking for the possibilitie to make it a bi-turbo... IF that's gonna work, I will get about 240bhp and about 550Nm...

BTW... The turbo of a M51D25T and the M51D25TU (325/525td and 325/525tds) are the same... the only difference is the intercooler and computer...

Bit of an old thread this....

I havent had that car for a long time. It was one of the worst purchases I ever made in cars..

Anyway.
As for your twin turbo idea. it would be a total waste of time, money and effort, when a single turbocharger could easily give you as much power as you need, and be almost a direct bolt on upgrade, along with appropriate fuelling adjustments.
Making manifolds/exhaust and various other plumbing required for 2 turbos would be a load of hassle, for no reason, and little benefit.

No question on the hassle and without getting into a 'free-will' discussion everything has a reason. The benefits of a twin turbo system [ being smaller units usually ] when propery engineered are the great improvement in 'spool-up time', the increase in the low end of the torque curve which is what diesels, for the most part, are all about.

On such a relatively small engine, that would also have a relatively small turbocharger in order to reach the power levels needed, a twin turbo setup, would offer little, or no improvements.

My most humble apologies.