Hey all, finally got around to doing the tbody bypass. very easy mod, when ur not struggling to take clips off .

I had to use a piece of (5/16) fuel hose to replace the stock line so it could bypass (stock line not long enoguh) the throttle body. Will fuel hose be ok at the temperature of hot coolant? Am i going to run into problems in the long run?

car feels faster now!

Thanks

 

There is a small possibility though of a problem.

In colder weather with mild to high humidity it has been known for a throttle body to collect ICE inside it due to the pressure drop. Eventually the ice would break off usually at idle and cause stalls or roughness with the extra water in there. I don't think it will really be a problem with the really long runners the scooby's have.

 

hmm, i just used the factory hoses, they were enough for me. Also, how can you feel the car being faster?

 

what is the bypass mod exactly?

 

the throttle body has coolant flowing through it to keep it from freezing in cold weather. well, the coolant as we all know is pretty f'ing hot so, in hot weather, it actually heats up the air going through the throttle body. So what many people have done is disconnected the hoses from the t/b and used a coupler to connect them together therefore bypassing the coolant flow through the throttle body

EDIT: here is a good how-to link. http://www.utm.edu/~gonzalez/TBBypass.htm

 

heh, highly calibrated but dyno. i have a gtech pro but im lazy. Anyways the throttle body definately stays cool to the touch now.

no one answered my question about the fuel hose...comon!

 

Are there really any gains to be had? I mean are we talking 1 hp or so. I would think that in the winter-time, the engine block would heat the tbody enough to keep ice from collecting.

 

I just did it last night. It wasn't as easy as described. They are in the hardest place to get to. After I finally got the two ends loose, it took nearly an hour to get them connected and cinched up to each other.

My butt dyno feels no gains. It shouldn't produce noticeable gains. Maybe some increased fuel economy on long trips of something. my opinion.

luke

 

probably no gains in long trips, as the air at hway speeds is moving to fast to be heated. most gains would be found at the stop light in high heat after your engine has been on. It wasnt super easy for me because it was a tight connection!

 

Its not really the heat but the pressure difference that cuases the ice to form around edges.

Its sorta like how A/C works but with air.

Any piece of rubber hose should be ok. now if it was plastic....

 

I assume this mod applies to any 2.5L-equipped Subaru?

 

yes, and probably all subarus, havent looked really closely though.

 

ok, that all makes sense. Still don't know if it was worth it. O well, something to work on. Not that this has much to do with this mod, but I got 27 mpg on the last tank of gas with everyday driving, whereas I used to get 22-3 stock. I'm impressed with my mods so far.

 

cant expect too much from a mod that was <$5 at most

 

<$2 actually heheh