cheftrd

What Stony is trying to say is for the money it's going to cost you to swap in the RB 20 or 25, the same money spent on the L will kick the stock RB's butt. And......at the risk of offending those with RB20's (I've been building RB's since they came out), the 20 isn't worth spitting on. When the RB20 was all to be had, we were swapping L motors into the R31 skylines and pitching the RB20. The cost is small to bring the L28 to 3 liters and all the RB20 mods in the world won't make up a 1000cc deficit. With an efficient turbo system, at around 17 pounds of boost you will double your power, so you're looking at around 150hp gain, not 40. If you're going for the "wow" factor of having an RB in an old Z car. Stick with the 25. I don't know about elsewhere, but in Japan, people will laugh at you for swapping in an RB20. No joke. Matt

That's correct, and yu can use the same line as long as it's large enough and short enough not to cause a delay in pressure change to the regulators. As far as the other question, running two FPR's in sequence won't change anything. The pressure will only go as high as the highest pressure setting on the regulator with the highest pressure. With a rising rate FPR, it should to go in line after the standard type regulator to work properly. That said, FMU's are not a good choice for fuel enrichment. To double the fuel, it requires four times the pressure; bad for the pump, bad for the injectors, bad for the car if something fails and you have a fire. The EFI system was not designed to run that kind of pressure. Matt

The heads were originally around $12,000. That's with header, intake, timing chain, cams, cam cover, and all the necessary hardware. That's cheap for a limited run of this type. A new plastic mold for car interior parts can easily reach $50,000. OS will not make them anymore as they no longer have the tooling. I know someone who has two complete set-ups, but they've been siting on the shelf for 20 years. I'll check to see if he will part with them, if they're still good, and for how much. The reason he abandoned them was because the factory N42 or P90 head could be made to produce more power as cam selection for the OS head is limited. Matt Hutchens Motorworx Race Systems Japan