New on here 🤝

[AltFuelMan]

Hello group,
Thanks for accepting me to this awesome forum.
I live in England & bought myself a very first 940 2.4tdi
I'm still learning about it so please be patient with me if ask too many questions.
Many thanks 🤝🍻

[v8volvo]

Welcome! Glad to have you here and we look forward to hearing about your car and what your plans are with it.

Ask any questions you have, we are happy to share any help we can.

[AltFuelMan]

Hi, I'm planning to get a lil bit more poke out of it
Was thinking of bigger turbo but not sure where to start
Many thanks

[v8volvo]

Where to start -- for these cars (and more or less all others also), always valuable to start with a good basic freshen up, what many people call a "Stage 0".

In other words, before going after upgrades, modifications, etc, especially those that require serious investment and/or could add extra stress to an aged engine and its aged supporting systems, it always is a good idea first to make sure all the basics are squared away back to 100% condition. Things like fluids, filters, compression test, fuel system checkup and injector testing/rebuild if warranted, check/adjust valve clearance if mechanical lifters or test/replace as needed hydraulic lifters if equipped. Also a thorough checkup and refresh of cooling system components to make sure you can get rid of any heat the engine produces so that you can actually use whatever power it makes without leading to trouble: at minimum new high quality 80C thermostat, sometimes new radiator is a good idea if the car has its original, and pressure test, look for and fix any suspect hoses that could fail, check operation of viscous fan clutch. Test glow plug system and refresh as needed. Check operation of cold start timing advance system, particularly making sure it is not stuck in the cold position due to a dead wax thermostat.

And of course on the D24T and related engines, maybe most important of all: the replacement of the timing belts, unless you have rock solid evidence it was done very recently on a known date and mileage AND done correctly by a qualified individual using the proper special equipment and methods. Nothing less than this is good enough. If in any doubt whatsoever, plan on doing or re-doing the job correctly yourself.

Oftentimes just the steps above will gain a great deal of power and efficiency. Run stronger and cleaner, start quick and smooth, stay at stable temperature so you can get the most out of the engine. This alone might provide the performance increase you are looking for.

Also worthwhile: checkup of basic safety aspects of the rest of the car to make sure it's ready to be driven hard, especially if you plan to eventually increase engine performance above stock. Brakes, tires, suspension bushings, shocks/struts, front end and steering components, alignment. Rest of the drivetrain too -- transmission and differential fluids, condition of clutch if it's a standard trans car. Check driveline u-joints and carrier bearing/support.

Then finally, you're ready to consider upgrades. But remember these two things that many folks have found to be true:
1) Performance parts bolted on to an engine that is not in a correct basic state of tune (for a very common example, injection or cam timing not right due to shortcuts taken during a botched timing belt replacement attempt), or an engine that is not at full basic health in terms of cylinder compression or deferred maintenance, will be wasted as neither the upgrades you add, nor the engine as a whole, will perform to their potential. Sometimes can lead to damage as well, especially if timing is off and leads to excess smoke and sky high EGT (overly retarded timing) or sky high peak cylinder pressures that blow the headgasket or damage the engine internals (overly advanced timing).
2) The engine is a system, not just a sum of parts, and thus the components used need to be well matched to work their best together. Bigger turbo alone might not make any extra power: in fact it could well cost you performance or response at lower engine speeds, unless it's one part of a carefully designed compatible package to help the engine efficiently move more air, fuel, and exhaust gas. And cooling system ALSO needs to be matched to the upgrades, to be fully up to the task of removing the extra heat that comes with increased power, otherwise the effort and cost of upgrades will not be of any benefit since you will not be able to operate the engine continuously at the higher power level.
Keep in mind that ~70% of the energy from the fuel is turned into waste heat and only ~30% into crankshaft power, so if you want to make more power by burning more fuel and air, you will need to deal also with more heat in a roughly 2:1 proportion!! And this is in an engine that sometimes can push the limits of its cooling capacity even at the stock power level. Unless you only want your added power to be usable for extremely short bursts of a few seconds at a time, increasing cooling capacity *before* adding power is considered the best safest practice. And of course a good set of gauges including oil and exhaust gas temperatures is essential for monitoring your modified engine's operation closely and ensuring you stay in the safe zone.

Good luck with your project and let us know how it goes. And if we can help!

[AltFuelMan]

Wow thank you for such a massive reply

[v8volvo]

Haha, well said. I could and should have been more brief but I guess I had nothing better to do at that moment and just kept rambling. Hopefully some worthy ideas there, maybe some not.

Bottom line/short version: have fun and ask any questions you have on here, we will all be happy to help if we can.

[AltFuelMan]

Ma y thanks 🤝🍻