Exhaust manifold gasket change

Re: Exhaust manifold gasket change (maccardo94)

Mon, 09 Jul 2018 19:56:22 GMT

Awesome good stuff! Nice research too

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Re: Exhaust manifold gasket change (Mrskylighter)

Mon, 09 Jul 2018 13:03:26 GMT

The manifold you have is somewhat rare. It is from a Celica GT4 Group A Rallye/ WRC anti lag setup.

Here's a pic of the complete setup. It is not is use on the production car though. Just fitted for Homologation purposes.

http://gtfour.supras.org.nz/homologation.htm

Anti-Lag
The Group A was the first production car I know of with anti-lag standard, although again not operational. The system uses an ECU signal to switch two VSV's on the back of the block which provide vacuum (via a canister) to the special bypass valve fitted right beside the entrance to the IC. This heavy duty metal valve has a poppet valve which when opened directs some of the air (which usually all goes through the BOV) down four metal tubes into the exhaust manifold. A special manifold has a hole just after each exhaust port. A small heatshield sits between the manifold and the intercooler.

How do you make it work? You don't.

Anti-lag is *very* hard on turbos due to the shockwaves and high temperatures produced. Unless you have a rally team budget, forget it.

Here is some of what you need to do to activate it. My bypass valve seems to be jammed shut, maybe it has an internal spacer to stop it opening. The fittings connecting the pipes to the manifold are also not drilled though. With those aspects fixed the system will mechanically work. The VSV's are wired to the ECU, however an aftermarket ECU is needed to apply 12V to make them work. I'm guessing that (like most systems) the ECU retards the timing while continuing fuel injection. The mixture burns in the manifold, keeping the turbo spinning. This is very harsh on the system, therefore the pipes are just to supply cool air to keep temperatures down (conjecture!).

Re: Exhaust manifold gasket change (stuka)

Mon, 09 Jul 2018 12:13:21 GMT

Im not sure where you download it, someone else on here might know.

The oil lines drain when the engine is not operating

Re: Exhaust manifold gasket change (maccardo94)

Mon, 09 Jul 2018 10:14:01 GMT

No i dont have the pdf. Where can i find this? Also should i drain the oil lines. Or plug them up when i remove them. Or are they only pumping when the engine is going if that makes sense

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Re: Exhaust manifold gasket change (stuka)

Mon, 09 Jul 2018 08:02:02 GMT

Good on you for giving this a go, take your time and you will be alright. Do you have a copy of the workshop manual BGB PDF? It should have diagrams of the turbo and ancillaries in there.

If you don’t undo the turbo oil feed hard line you will be in sorts of strife and you will end up damaging/bending it. This is the combined hard pipe that also returns oil to the sump, it would be easiest to undo the banjo bolt from the block. It’s a big one, maybe 32mm but cant remember exactly.

Re: Exhaust manifold gasket change (maccardo94)

Sun, 08 Jul 2018 21:40:49 GMT

Yes dw i know im far ahead of myself with this. Its my first major work. Just learning as i go. Going to replace the dp with a berk one while im there also with a berk exhaust system. Il keep than oil line in mind. Im at a point where i cant re assemble it easy enough to take it to a mechanic. So it has to be done haha.jokes on me

The car isnt a daily so i have the time to work on it

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Re: Exhaust manifold gasket change (stuka)

Sun, 08 Jul 2018 19:45:13 GMT

The middle section of the stud you mention is the 'shoulder' where the stud 'seats' in the cylinder head. Doesnt matter if these come out with the nut as you undo it.

Im not sure how well you have examined what you have been doing before you dive in, dont forget there is an oil feed hard line from the cylinder block to the underside of the turbo, dont forget to undo this before you try to remove the turbo assembly.

Re: Exhaust manifold gasket change (maccardo94)

Sun, 08 Jul 2018 15:44:58 GMT

Ok so im going ahead removing the manifold,turbo and dp off i one peice as recomended. What is the best way and which end is best to remove the hard lines to the turbo as pictured

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Re: Exhaust manifold gasket change (maccardo94)

Sun, 08 Jul 2018 10:36:49 GMT

Im finding with leaving the vertical and horizontal studs all in. Theres no way i can get it out. Also im buying all me new studs and gssket from primedriven. Heaps of good mr2 stuff

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Re: Exhaust manifold gasket change (mr2pete)

Sun, 08 Jul 2018 08:13:22 GMT

You shouldn’t have to remove the manifold studs to remove the assembly.

I’m also about to also put a new gasket on my engine. Not sure what the besr brand gasket is to use.

Re: Exhaust manifold gasket change (maccardo94)

Sat, 07 Jul 2018 23:16:36 GMT

Also should all the manifold studs be removed for it to be able to be taken of? There a few vertical ones that are fully out, but the very ends are just spinning. Looks like the middle section of the stud is slightly wider than the ring. And wont pass through like the horizontal studs

TAI

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Re: Exhaust manifold gasket change (stuka)

Sat, 07 Jul 2018 19:43:48 GMT

Never seen those bungs before either.

Dont want to complicate things but you might want to consider changing the 2 coolant hoses that are impossible to reach with the turbo in place - affectionately known as the hose from hell and the hose from hell on earth!

Re: Exhaust manifold gasket change (Carmikey)

Sat, 07 Jul 2018 14:45:03 GMT

Timclarkee
I’ve honestly never seen a manifold with those bungs on it before, someone correct me if I’m wrong but would they be for an exhaust sensor for each individual cylinder??
I guess they only need to come out if they are in the way of taking a nut off the stud.

Agree, my gen 3 definitely doesn't have those bungs either.

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Re: Exhaust manifold gasket change (maccardo94)

Sat, 07 Jul 2018 11:48:30 GMT

Really. Oh well there not in the way of anything. But i was just curious as i said i havnt seen any on others. Maybe its gt4 or something

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Re: Exhaust manifold gasket change (Timclarkee)

Sat, 07 Jul 2018 11:46:55 GMT

I’ve honestly never seen a manifold with those bungs on it before, someone correct me if I’m wrong but would they be for an exhaust sensor for each individual cylinder??
I guess they only need to come out if they are in the way of taking a nut off the stud.