cudaeh

I got to looking at the similarities between the GM LS1 throttle body and the 2000 Subaru 2.5rs one. The conclusion I came to is that they have the same type of sensors and the LS1 is a whole heck of a lot bigger. After taking a look at it I have come to 3 conclusions.

1: the idle air control valve for the ls1 has a bigger valve head, but the exact same throw and mounting as the 2.5RS one.
Solution to 1: I am going to find or make a washer with the same inner diameter as the 2.5rs port but with the outer diameter of the LS1. This way I can just press it in and call it a day.



2: The throttle positioning sensor on the LS1 is a key style where as the 2.5RS is a bar style (see pics for clarification).
Solution to 2: Luckily because of the difference the LS1 shaft is longer and protruding from the mount surface of the TB. This will allow me to make an adaptor plate and punch a hole in the shaft to accommodate the bar.


3: the LS1 TB is way bigger than the 2.5RS and has a different bolt pattern to it.
Solution to 3: Easy, I am using the WRX intake manifold which has a mostly a flat mounting surface. All I have to do is mill down the old mount surface, blend and smooth it into the manifold face, punch the new TB hole, and the new screw holes.

1sicwrx

iTrader: (5)

I have no idea if it will work but good luck man and let us know what happens.

SubyN00by

iTrader: (15)

be sure to get a tune after it's done (=

cudaeh

Yeah maybe I should explain my entire project.
STI short block with forged pistons, and TWE wrist pins
2.5RS SOHC heads with TWE springs, retainers, stage II cams, and porting
WRX intake manifold
Turbo (no idea what one yet)
Various fuel rail upgrades
There is no way I would run this thing without some type of management, I am just afraid the SMT6 won’t be enough!!

Well, didn’t get much of a chance to poke at the bits tonight but I did pick up a roll of aluminum wire for my mig welder.

I will post progress as I go so this will either work and I will look pimp, or it will fail badly and Ill look like a tool. Either way it should be fun for a laugh or two.