Vacuum line/head gasket question

[osswalam]

I just bought a 1991 Turbo Talon FWD that is a kinda a mess. It has a lot of things "rigged" up on it and I'm trying to fix all of this. I was looking at the vacuum diagram today and noticed that all my lines dealing with the MAF, wastegate and turbo lines are totally different than what they appear on the diagram. I have a line going from the throttle body to a T going to a manual boost controller and the BOV, the MBC line then of course goes to the wastegate, is this an alright setup? I was wondering if I should put the vacuum lines back to stock then integrate the MBC. The turbo vacuum line port right now has a screw in it and the port on the MAF canister doesn't have anything on it. I can't really tell if the car is running ok because it has a blown headgasket which I'm fixing this weekend. This brings me to my next question, if I get the Mitsu metal layered head gasket and ARP head studs will I need to have the head/block O ringed? I really don't want to have either O ringed because of time restraints. Any help would be greatly appreciated, I want to get my talon on the road and to the track.

 

[eXploitedGST]

To answer your headgasket question, steel headgaskets DO NOT require O-rings.

 

[osswalam]

Anyone know about the vacuum line question?

 

[eXploitedGST]

sounds wrong to have any source of vacuum going to the wastegate at all, it should be a vacuum line coming off the J pipe on your turbos compressor, to the manual boost controller, then into the wastegate aculator. nothing to do with vacuum.

 

[Defiant]

Originally posted by osswalam
Anyone know about the vacuum line question?

You said you were looking at the diagram. What other question do you have?

 

[osswalam]

I just wanted to know if there would be some reason that anyone would change the routing of these lines around like this and if i should take it back to stock.

 

[candela]

If you are not running emissions than rid yourself of those TB lines, charcoal canister and all that crap and clean up teh engine bay. You can even eliminate the cold start feature to the reg raises FP when cold) but you also live in Ohio so thats up to you to deceide.

The line that the BOV and wastegate and boost controller uses should all be tapped from the INTAKE MANIFOLD. Use good fittings and T's if you are going to be T'ing off. The maf one is probably different because I am guessing that the BCS is probably gone.

Check this out for vacuum line diagrams (screw the FSM) http://www.taboospeedshop.com/emissions.htm

As for running the wastegate and such, its better to run teh pressure source for it (as well as BOV) directly from the intake manifold....

Good luck,

 

[1fast97gsx]

the head and block should be decked however to install the metal headgasket.

 

[coltboostin]

It is OK to have the vaccume line for the MBC comming off the intake manni. In fact, if you have an aftermarket j-pipe// FMIC kit, and a Mitsu style turbo that does not have a nipple, this is how you have to do it. As for the other vaccume lines, most of them lead to junk you and to take off your car anyways, emissions crap, f-it all. It just takes up space

 

[sonicnofadz]

You cannot run a metal head gasket without getting the block and head resurfaced by a machine shop. Just in case you didn't know...

 

[Defiant]

Originally posted by osswalam
I just wanted to know if there would be some reason that anyone would change the routing of these lines around like this

They're idiots. As DSMs continue to get cheaper and cheaper, more low-paid pinheads are able to buy them. Many of whom know all about hotrodding a Chevy 350, and very little else.

and if i should take it back to stock.

Yes.

 

[Defiant]

Originally posted by coltboostin
As for the other vaccume lines, most of them lead to junk you and to take off your car anyways, emissions crap, f-it all. It just takes up space

Yeah, they just threw them on because selling vacuum hose has such a high profit margin.

 

[Defiant]

Originally posted by candela
As for running the wastegate and such, its better to run teh pressure source for it (as well as BOV) directly from the intake manifold....

...because the pressure in the manifold is what you're ultimately trying to control. Running it off another part of the intake tract has more possiblity of introducing drag and/or spikes, as you're trying to monitor and regulate boost levels from "over there" instead of from RIGHT HERE.

When you approach the raggedy edge of engine overuse... er, performance, the little details get bigger and bigger.

 

[osswalam]

Thanks for all the help everyone.