F456M
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- 127
I guess his Spyder was with late 2L 220hp or 2.8 18v heads. 2.5 turbos where real small and not sure they were water cooled.
You don't need better chips: just move SEM restrictors to the Ghibli position, you'll get 1bar boost instead of 0.8bar. Not sure EFI 2.5 had late heads with two big intake valves. Also find a short 3.73:1 Ranger diff (your 2.5 is 4 bolt I guess so it's a Sensitork).
I'm convinced the 18v heads are almost as good as 24v ones, while they are much cheaper, smaller and lighter. Intake valves are smaller however ports and are larger than on 24v, intake seats are same size as on 24v. I'm currently rebuilding my 2.8 18v (222E) and doing lots of mods: forged pistons (about 8:1CR), bigger unshrouded valves (BMW 30mm), many changes. Stock turbos, they should be enough up to 320-340hp at 1.2 bars with a better mapping (stock ECUs). It's a fun (and expensive) pastime. Also bought the ASMotor struts.
He had the original turbos and had 320 hp. on the real wheels at 1,3 bar. They are bigger than those of the 2,0 18v. They are tiny small. That engine was taken apart in the early 90ies and ported and done many tricks to. The smallest intake valve was changed to one bigger than the big one! The "bottle neck" lately is that the injectors can't deliver enough fuel, so bigger injectors are soon going in. It runs out of fuel at only 5.000 rpm. He want it to run 7.000. Max torque is now at 5.000 instead of 3.500.