Flashback – Thema 16V Turbo Swap

Before I get too far into the V6 project, I thought it would be of interest to outline my Scorpion’s history and describe its previous incarnation.  I bought my Scorpion in 1981 with 25k miles from the original owner in LA.  I drove it stock for a while, then bought a 2.0 liter twin cam from a Montecarlo that met an untimely end here in California.  Although rougher running and not as rev-happy, the extra torque was sure nice.  By then I was participating in track days, and was getting tired of pulling over on the straights to let faster cars go by.  Barry Waterhouse (now deceased) in the UK told me about his 8V Thema turbo conversion, and found an engine/transaxle for me.  That was fun, but it was more of a quick & dirty swap, and I wanted a better planned implementation, with a 16V that was boosted to 300 or more HP, since that sounded like a lot of fun.

I found a 16V turbo engine/trans in the US that had been brought over by a FIAT employee in Michigan, but was too slow on the trigger and ended up spending 2x to buy it from the person who moved faster.  Here’s the engine after all the updates:

16V on cart

The header is TIG welded from 321 stainless steel which feeds an oversize Garrett GT28RS ball bearing turbo with 1.2 bar wastegate into a 3″ exhaust.  Intercooler, throttle body, injectors and cams are all uprated.  The engine has forged, oil-cooled pistons, peened rods, a 3 stage dry sump oiling system, 12mm head bolts, and racing head gasket.  The flywheel was lightened, and joined with a competition clutch and pressure plate.  A programmable ECM provides engine control closed loop via a wide range O2 sensor.   The transaxle is from a Thema 8.32 (which has a Ferrari V8) to which I added a Transtad torque-sensing limited slip differential.


All the above added up to 285 RWHP and 284 lb-ft  of torque as measured on the chassis dyno at 034Motorsport.  Performance exceeded my expectations, and was amazing for passing slower traffic on 2 lane back roads, but total overkill for any other street use.  It was also a great track setup, except that all the heat back there takes its toll.  The turbo alone becomes a 25 kilowatt heater at full tilt, so fair warning to those looking for the High Boost experience!

burnout_2007 no plates



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