jmcrides03@yahoo.com

i just bought a airesearch/garrett m10 .42 .48 turbo from a chrysler and i am a turbo noob . but my question is i have 2 holes on the 02 housing i know one is obviously for an 02 sensor but what is the bigger hole oppisite the 02 sensor for is that for a dump tube? it looks like if it were vented to atmosphere there id have a constant exhaust leak. sorry if this is a dumb question but i did my googling first and didnt have a whole lot of luck finding anything quite like mine. i could upoad pics if neccesary. thanks for any help

jmcrides03@yahoo.com

ok i asked the seller and he said that i was correct and that is for a dump tube. so now my question is how does this work since it will be a hole thats constantly open on the bottom of my 02 housing? do i need to recirculate it? will i have a problem if i vented it to atmosphere since there isnt a valve or anything there? again sorry if these are newb questions but any help would be greatly appreciated.

i should have mentioned its internally wastegated

busa4

the wastegate dump tube needs to be recirculated into the downpipe. dumping it to the atmosphere is the cheap way of doing it. not a fan of it.
if your turbo has an internal wastegate then fill the hole with steel and weld it closed.
if your using an external wastegate then you obviously will need the hole as thats were your wastegate tubing will tie into.

jmcrides03@yahoo.com

it has an internal wastegate. so i should weld that hole shut? thats weird because its off of a turbo 2.2 chrysler and it has the factory 02 housing and wastegate how would they have had that hooked up factory? also would adapting that hole to use for an EGT probe be a decent idea? it would cap it off and ive read on a dsm forum that alot of them are drilling and tapping their 02 housing for the same reason. any opinions would be appreciated

busa4

if you dont need it then weld it shut. you can also use it for an 02 sensor as well. you should need two 02 sensors anyway. one for the engine computer and another for your wideband.

janus

i'm into turbododges and i know that some of them came with a second port on the o2 housing (swingvalve) that was used for the EGR! If you don't need it just plug it. The other one is the standard port found on every TD swingvalve and is used for the narrowband o2. i wouldn't put a wideband o2 sensor in there because it's just too hot, or so i've heard. most recommend to put it at least 12" downstream of the turbine (somewhere in the downpipe)!
oh and as for the dump tube port, those turbos are internally gated.. and anyways, the port is after the turbine anyways as said we usually call it the swingvalve.
for the EGT i would prefer a pre-tubo location, e.g. exhaust manifold collector.

jmcrides03@yahoo.com

cool thanks man i think i figured how im setting everything up just gonna weld the extra hole already have my narrow band in the other one im gonna leave it internally gated for now. do you know what the stock wastegate is set at on the turbo II dodges?

boosted86

The turbododge 2.2/2.5 turbos came in 3 flavors, a TI "Log" style turbo, a TII style turbo, and a mitsubushi turbo, on 89+ cars.

From what it sounds liek, you haev a turbo from an 84-87 Turbo I car. That second port is a port for the EGR, like posted above. The other is for the o2 sensor. Also note, if the wastegate can has 2 ports on it, it came from 84,a nd you will need a different vacuum can ot effectively use it correctly. 84 cars were "mechanically" controlled, using bleeds in the vac lines.

The compressor housing will need "slight" modification to work like a normal car. Also, the Chrysler turbos were regulated with a computer controlled vacuum solenoid. Without using either the stock setup, a vacuum bleed setup, or a manual boost controller, you can't regulate boost beyond what the internal spring can hold (which is approximately 16-20 lbs).

For you, regulating boost is easy. Get a manual boost controller, and hook one vac line from your intake to the boost controller, and the other line to the wastegate can. Then set it low, and work your way up higher in boost till you find a spot that is comfortable.

What car are we working on?

boosted86

Do not weld the wastegate hole on the turbocharger, you will not be able to regulate boost whatsoever, without custom making an exhaust dump before the turbo.

boosted86

Also, that factory wastegate housing will be a 2.25 housing. You can but a 3 inch housing, though not cheap. Also can get an internally gated V-band housing for 175 IIRC.