Installing Rb25 Turbo In Rb20

[ACTIV32]

hay guys i need some help im Installing a 25 turbo in my rb20 my stock one blew up last nite i need my car for next week and ive been told that i need to weld a nipple on my intercooler piping for a boost line but im not sure were to put it and which line goes to it and if i need to do anything to make it fit anything you guys know to help me out will be great thanks

Daniel

[R338OY]

You mean a nipple that you connect to a boost controller? On my RB25 the boost line goes from a nipple in the intercooler piping leading to the intake plenum, goes through my manual boost controller, and connects to the wastegate actuator on the turbo.

If you've done some welding it's a DIY job, but should be cheap for a workshop to do.

Try this thread: http://www.skylinesaustralia.com/forums/In...st-t185848.html

Do a search for some entra info, and check the DIY thread.

Good luck mate.

Edited February 7, 2008 by R338OY

[Baz]

Reason for needing to do that is that on RB20 turbos the wastegate line is connected to a nipple that reads vacuum from the compressor housing. Not entirely the smartest idea. While the RB25 turbos having an updated design that reads vacuum from just before the throttle body. ie. a vacuum line runs from the actuator to the intercooler piping.

Some A/M intercooler piping, mainly the 20/25 type already have a vacuum line nipple installed on the piping that sits just before the factory hardpipe (which the factory BOV sits on). Anyway by far the easiest way is to drill a small hole on the intercooler piping and then buy yourself a fitting that screws into the piping which has a nipple on the end. No need for welding when there is an easier alternative. Just to be sure to use some thread tape to ensure it seals completely. Then you can run the vacuum line from the wastegate actuator to the nipple.

[r32woohoo]

Reason for needing to do that is that on RB20 turbos the wastegate line is connected to a nipple that reads vacuum from the compressor housing. Not entirely the smartest idea. While the RB25 turbos having an updated design that reads vacuum from just before the throttle body. ie. a vacuum line runs from the actuator to the intercooler piping.

The wastegate actuator doesn't 'read' vacuum pressure.....it needs positive pressure so it knows when to open the wastegate

Why isn't a good idea to get the pressure from the comp housing?

Isn't that where it would be most accurate? no pressure drop through all the piping

[R338OY]

As long as there's no boost leaks it's more accurate for the nipple to be before the throttle body. It's a truer measure of the amount of boost being used by the motor. If there are boost leaks then the wastegate actuator will need more boost to open the wastegate, and that means making the turbo work too hard, which can be dangerous at higher levels.

That said, if there aren't boost leaks whether it's at the comp. housing or not should make little difference.