Questions about tb bypass

[bongchild]

So I looked under my hood today to see which hoses to disconnect for the tb bypass mod and I ran into a problem....
There's 2 sets of hoses going into the tb! One set is big with clamps on it, and the other set is small without clamps on it. Which ones are the coolant hoses? If it helps any, I have a 1.8L engine.

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[NicEJ25]

biggest one that get hot are the coolant ones...

[Legacy777]

here's some pics

http://www.main.experiencetherave.co...tb_bypass1.JPG
http://www.main.experiencetherave.co...tb_bypass2.JPG
http://www.main.experiencetherave.co...tb_bypass3.JPG


you can see also in this pic

http://www.main.experiencetherave.co...s/DCP_2508.JPG

[bongchild]

OK, gotcha. Thanks for the info! The pics really helped.

[Legacy777]

no prob

[bongchild]

Got another question... Where can I get a bigger throttle body that will fit my car? Are there any other cars that I can rip one off of??

[Kostamojen]

Bigger tb? Isnt it a 60mm already? (IE rather large)

And I didnt think the TB mod worked for older engines like ours... I dont think they actually run the coolant the same as the RS TB's.

[Legacy777]

You can get the current TB bored.....but don't know if it'd be worth the money.

The TB mod works the same for the old & new cars.

[Kostamojen]

Are you sure? I could never find any actual coolant lines running into my 1.8 throttle body...

[Legacy777]

what does the TB look like on the 1.8l motors? I know the 2.2 is the same.

Here's pics of the TB from the 2.2 liter motors.

http://www.main.experiencetherave.co...b/DCP_1505.JPG
http://www.main.experiencetherave.co...b/DCP_1508.JPG
http://www.main.experiencetherave.co...b/DCP_1510.JPG

[xfrickx]

This thread reminds me I gotta reconnect mine for the winter.

[cvalle-sd]

I had to reconnect mine for a smog check, and to be honest, I think it runs better with. Considering the coolant temp, and the brief time the air actually spends in that area, I think it really just helps maintain a predictable intake charge temp for the ECU. I'm running 89 octane with no ignition mods, and I can't remember the car ever feeling better with the bypass. I use the stock airbox drawing air into the fender well from the front fascia. If you have a good source of outside cool air, then the TB isn't going to lose you any power, and the heat soak from the block will reach the TB anyway. The hoses just bring it up to temp faster, so you don't run all funky at startup, or in cold weather. (ice) By the time the air reaches the TB, and starts to absorb a littel heat, it's already in the system anyway. Whatever degree of thermal expansion you get is probably insignificant against the benefit of having a properly diffuse A/F mixture. If the air is too cold (not likely, either) the gas isn't going to vaporize properly.

PS - it is a pretty damn big throttle body - It's the same size as my exhaust tubing. I can't imagine it presents any restriction that could be practically reduced.

[Kostamojen]

Originally posted by legacy777
what does the TB look like on the 1.8l motors? I know the 2.2 is the same.

Here's pics of the TB from the 2.2 liter motors.

http://www.main.experiencetherave.co...b/DCP_1505.JPG
http://www.main.experiencetherave.co...b/DCP_1508.JPG
http://www.main.experiencetherave.co...b/DCP_1510.JPG

Heres the 1.8 engine bay: http://community.webshots.com/photo/...78363775zAHidh
Its a bit different.

[Legacy777]

Interesting......you wouldn't happen to have pics of the underside of the TB?

what year 1.8l is that?

the new 2.5's have the same TB with the IAC on the top. The underside coolant lines are the exact same as mine however. I've done two of my buddys' 2.5 RS's

[Kostamojen]

Sure, heres a shot from under the TB on the 1.8, its a MY95 btw:

[Kostamojen]

And heres the top up close (Are the coolant lines the two small hoses?):

[Kostamojen]

And this is where those two small pipes on the TB go to under the intake manifold (I dont know what it is though):

[Legacy777]

I believe this is how it is



Not sure about that one I labeled possible coolant line. There should be an output/another line somewhere.


The last picture is the canister purge solenoid valve.

[Kostamojen]

I think that the two lines that you point too might be coolant lines, but they run to that part that operates with the throttle so I dont know if thats actually effecting the TB temps like the other TB's on the newer cars.

As for that other line coming from the intake manifold, i think thats some sort of emisions part, as it runs to another odd thingie connected to one of the intake manifold runners:

[1 Lucky Texan]

just a guess but one of those may be the PCV line.

Also, maybe feeling the temp (before and after about 10-20minutes running) of them would pinpoint the coolant lines.

Carl
1 Lucky Texan

[Legacy777]

actually looking at that line labeled "possibly coolant line" it's not a coolant line, because of where it taps in. it is a weird location....


Carl, if you look down slightly and to the left you'll see the pcv valve hose.


The two lines I do have labeled as coolant are coolant. That thing they are going into is a form of idle control for when the car's cold. The older cars have something similar to this built into the IAC valve. The new cars don't seem to have this. This must have been one of those in between steps subaru used.

[Kostamojen]

My car is just so wierd, lol

[Hawk296]

Kost- the lines legacy 777 labeled coolant lines are in fact the coolant lines. the other two on top (line and plugged one) are vacuum sources, they are actually on the manifold not the throttle body. so is the tiny little one on top of the throttle body.

[Kostamojen]

So I presume that the TB bypass with my car is pointless.

[Legacy777]

yeah, the coolant lines on your car and how they're routed serve a different purpose then what they do on the other cars.

You'd mess up your cold idle or normal idle by bypassing that valve thingy.