My next step up on the power ladder for my 98 AEB (nDBW/DBC) will be a T3T4.
I could now get my hands on a ATP Mika tuned ECU and 440cc injectors.

a) what T3T4 setup (compressor, trim, turbine) works well considering the tune and fuel combination? What crank/awhp levels can be expected? (no high rpm screemer combo, 3-5k rpm power + drvieability most important)?
- on stock internals
- on upgraded internals (if needed)

b) is the ATP Mika tune for 440cc any good?

c) Is my Southbend stage 3 limiting me?

d) FMIC, 3" downpipe, no cat, Miltek exhaust, AFPR 3-5 bar, Walbro (if needed) already in place.

 

Mika tune = POS
Do not put it in your car.


All T3/T4 setups are going to have its peak hp/tq up highe in the rpms. Even the 50 trim seeing that it flows 46 lb/min which is slightly higher then a GT2871r and the fact that it is a journal bearing turbo. So its going to actually spool up later then a GT2871r and this means full boost after 4k rpm, exactly what your not asking for.

The Elim kits and a GT28rs dont hit full boost till after 3500 rpm, if you want something that hits full boost before that you might want to look at a GT28r. That is the size turbo used in the APR stage 3 and PES T28 kit. Another option would be a 68HTA, 71HTA or 73HTA turbo. The 68HTA flow about the same as the 50 trim but spools up quicker then a GT2871r. But the price tag on those HTA's is $1699.

The SB Stage 3 is rated at 325 ft lbs. So yes you will be pushing the cluch beyond its limits.

 

Thanks Mike, loud and clear: no Mika.

Cost (turbo itself, supporting parts, availability) is the reason for me to stay with T3T4 journal bearings, and therefore I have to live with 4k max boost (but hoping it is starting to come up at 3k to some degree; unintended side benefit is the lower torque (= burden on clutch, gears, shafts, since they are only impacted by torque, not power; check out those on F1 cars; scary thin!)

The mentioned 46 lb/min flow of a 50 trim, .63 T3T4 could be translated into roughly 435 HP? And that in turn represents around 325 awhp? That would be a good match with my power goal.
T3T4 using Turbonetics sizing as example:
54 or 57mm turbine?
Compressor 0.50 trim, 3.00 major, 2.122 inducer, 3" inlet ???
Alternatively compressor 0.46 trim, 3.25 major, 2.003 inducer, 3" inlet? ???

 

You might want to search for any dyno sheets of 50 trim setups on a 1.8t. If your looking for around 325whp on pump gas you are most likely better off with a GT2871r or the HTA if you want quicker spool and a wider power band.

The older journal bearing turbos are going to have more lag and later spool.