Originally Posted by GMartinez
the only difference I see for the exploded view is the siim engine is not sti modified black coating on the crank modified sleeve is the same other than that the new evo4 comes with ceramic bearrings
The major difference is the mod on the engine, SIIM repacks the SIRIOS and has the modded as per their performance standards, they are impressive.
After the final both cars were temped in at 231 and 228, and the pace was up with the the latest GRP .12 engine who was running at 250+, we personnaly preferred cooler running engines, and less nervous throttle responses where most guys were hitting above 270+.
I'll get a picture of the sleeve, for comparison to the stock sirios..