[91eclipsegsx16boy]

Ive done lots of reading up on DSM sicne i got mine in Sept, but i stil have some questions.

1. how are the wastegate and BOV different? does the wastegate just bleed off boost, while the BOV releases it when clutch depressed? what can i do to help keep the boost up when shifting?

2. Which cars have 6 or 7 bolt? Those Jap Spec motors sound damn tempting!

3. How difficult would it be for me to switch to a 4 bolt rear?

4. what's this 02 eliminator business and how does that work?

whatever you feel like answering would be much appreciated. pardon my ignorance.

p.s. shop manual finally on the way, only $60 from Satan!

-aaron

 

[91eclipsegsx16boy]

k, i got #1 down except i cant hear my bov really like people talk about it... how do i get it to dump to the atmostphere... im sure there's info for this somewhere else too so ill keep looking, but pease help on 2, 3, &4 if you can

-aaron

 

[Redsand187]

Six bolt I beveive is before most 92's, some early ones have them. I personally do not know about the 4 bolt rearend swap, but I would imagine it would be a full day project with the RIGHT tools. And I belive removing the o2 sensor is for when you remove your cat. so you do not trip the C.E.L. details? I'm not sure about.

 

[4G63Rydah]

1) The wastegate re-routes some exhaust gas around the turbo so that it never reaches it. This is a form of controlling how much boost the turbo CAN make. The BOV is a way of protecting the turbo while u shift. While u have the gas depressed...boost is building up....when u suddenly let go of the gas the throttle plate closes, and the boost that has built up can't go into the engine so it'll actually try to double back and go back towards the turbo...if this boost ever gets back to the turbo it hits the compressor fins and slows the turbo down. This is known as compressor surge...and after some time it can ruin ur turbo. The BOV allows the built up pressure to be vented out (either to atmosphere or back into the air intake right before the turbo).
2) 1990-1992.5 4G63s have the 6-bolt engine.
1992.5+ 4G63s have the 7-bolt engine.

somebody else will have to answer the other two...since i'm not completely sure about those.

 

[Van]

1.BOV releases **filtered boost air** in the intake tract after the turbo, while you are shifting, back into the intake tract before the turbo. A wastegate lets the **exhaust gases** before the turbo; either help spool-up the turbo while at wot or by-pass the turbine wheel of the turbo and go directly into the O2 housing and dp.
Keeping the bov dumptube pointed at the turbo will help keep the boost up "a little." It is like that from the factory.

2. Around April/May 1992 Mitsu changed to a 7-bolt design.
Go here to find out the way to tell them apart.
http://www.vfaq.com/mods/early-late-engine.html

3. 4-bolt rear swap is fairly easy. It is shown at the vfaq's also.

4. I haven't checked into these that much, so can't really answer this one. I've heard good and bad things about them though.

 

[91eclipsegsx16boy]

thanks for all the quick repsonses!

 

[turbolover2]

The o2 eliminator eliminates the o2 sensor housing, I think. Instead of the exahust gases going through the housing after the turbine housing, they dump right into a special downpipe. I think you need an external wastegate for this setup.

-Dave

PS- I spent about a 1/2 hour writing a response to sll 4 questions, and then deleted it by accident. DOH! Oh well, ecetone else answered them.

 

[Turboholic]

O2 eliminator

-This O2 eliminator is made out of steel pipe, so it has better flow then the stock cast iron O2 housing, but I'm not sure the cost will justify the increase flow.
-Also I'd heard it's a pain to install if you get the 1 piece downpipe type, and there might be clearance problem with the oil filter.
-My .02

-Kevin.

 

[Nick 92 TSi AWD]

4. Things a waste of money. It doesn't fit worth crap. If you feel the need for a gigantic o2 housing just get a
EVO III one from Concelli and port it. Should be close to a 3" outlet when you're done.

With one of the first damned 7bolts,