Hello, I just recently purchased a 2000 volvo S40 with a 1.9t T4. I've been trying to find some further information about modifications and the capability of the T4. So far what I'm understanding is that the T4 in the states is a low pressure version of the T4 in EU. Can the low pressure T4 still handle power without built internals? And if so to what power/torque? I've also been unable to find any detailed information on modification options like tunes etc so do these cars mostly see custom mods?

Sorry about the questions. I've been trying to find out if this car is worth modding since I've seen crazy things done to these cars and a sleeper is what I'm trying for. Thank you!

 

The US 1.9T is a low pressure turbo (LPT) 160 HP design, the T4 is its high pressure big brother that adds about 40HP. There should be no issues with the LPT block being bumped up to 200HP spec'd for the T4 - to do so you'd need to upgrade the 12T turbo to the 14T used by the T4 then get the ECU upgraded to demand more boost. If you wish to go higher, than that, then you'll want to do a few more things - ie bigger downpipe, bigger injectors, bigger oil cooler, bigger transmission cooler, bigger intercooler etc depending on your HP target. The hardest part will probably be finding the ECU upgrade as the 1.9T is not software/flash reprogrammable. Google around and you can find some options however.

Note at 200 HP, that will put you pretty close to the VW/Audi I4 output so if you want to compare performance, look at what a VW Jetta GLI with its 2.0L turbo does. My guess is you'd be in the 6.5 Sec range for 0-60.