The 850R is completly different to the 740, the 850 use a 5-cylinder alluminium engine with a Mitsubishi turbo and a more advanced injection system and FWD. Mine is a rusty 4-cylinder 2.3 liter iron-block engine, so the T25-T28 should give me faster spool up with a good airflow.

 

I am in the same predicament. im making good very good power with a tdo4h-16t(T2.8+ Hybrid Equiverlent) but could i be making MORE power and have the car pulling harder/running faster times with a t3/t4 kamakazi?

What you boosting the car to? im not sure what the max boost/compressor efficiency of a t2.5 is but the tdo4h's are good for + 2 bars...

 

How is a TD04H-16T good for 29psi when a TD05H-16g starts shitting itself at those boost levels? No way it makes power up there with a turbine that size. No matter what it's not reliable at those levels; IDC if it's forged from titanium. Puny little shaft like that. T3 frame FTMFW!

 

Not going to go too much into it but all the Compressor maps for the tdo4h 15/16T stop @ 1.5 bar Despite them making Postive power upto 2.3 bar after that no more KW just a increase in Torque(Nm) and a blown engine.

2 bar's is alot of boost. car will defiantly be running low compression (8.5-1) 95/8 unleaded petrol and ALOT of Water Methonal/ injection and conservative a tune....

I was a Skeptic too but i have seen great results with these turbo on the dyno and at the track, if your a 1600cc or bigger i would defianlty go t3/t4... cos on these small turbo you really must boost the crap out of it to get decent results and then you stuck on high octane fuels...

 

There's nothing US-spec about your '88 740 if it didn't come with a T3 flange.

 

Dude grow a pair. You have a 2.3 that will realy easy spool a nice size t3.

 

 

I'm running a T67 on my 2.0 liter streetcar. 750 whp spools nice if you pair the cylinders.

 

T88 is where its at.