Exhaust manifold replacement

[dakmon]

Please help. I have a 1990 Talon Tsi with a cracked exhaust manifold. Can it be welded (shop says no). If I must replace it, which manifold would be the best choice? Have heard the 95 manifold is less restrictive, but will that just bolt in or are there mods to do on it? Also two of the studs are sheared off, how can they be fixed? All suggestions are much appreciated.

 

[ProjectGSX]

Welding a manifold is a very short term solution. The weld will not hold very long.

The 95 manifold is your best choice. Don't bother with the EVO manifold - the 2G unit works just as well.

It is not a direct bolt-on to a 1G. You will need to do some grinding on the flange to get it on - not a big deal, however.

 

[dakmon]

Thanks Brian, I will look for a used exhaust manifold. Can you tell me if I will have any difficulty with the size diff. in turbos when I install this in my Talon?

 

[L2RTSiAWD]

No other than grinding the flange it's exaclty the same so any turbo that will bolt to a 1g exh. manifold will work on the 2g.

Later,

 

[1gjohn]

If the studs are sheared of in the head,IF you can get a hold of them with vise grips you might be able to use some wd-40 or some heat to get them out.IF not you will have to drill out the the bolt and use a easy out to extract the bolt.Hopefully you can just use a tap and clean up the bolt hole thread,if the thread are messed up you will have to drill and tap the holes bigger and use a heli-core.You can get these at most auto parts.Its a PIA but good luck.
One a side note Muttedtsiawd is correct you can bolt up a 95 or new manifold to your car.the part you need to grind is the corner that is closest to your power steering pump.If you can port the manifold to match your tubine housing or turbine housing to match your manifold.It will flow a heck of alot better

 

[dakmon]

Thanks MuttedTSiAWD and 1gjohn, the info. provided is very helpful. Would you suggest a OEM 95 manifold or a Buschur (or other) ? Also, can I use my present downpipe etc. or do I have to upgrade?

Thanks

 

[steve]

Conicelli offers a new 95+ exhause manifold MD308197 for $152.85 which is about the cheapest I've seen for a new one. I bought a EVO III Exhaust manifold for my '91 GSX for $190 from Forced Performance. They will grind off the corner id you tell them it's for a 1G. That was the best price I could find that manifold for. You need to order new gasket, studs, washers, and nuts from your dealer or Conicelli. You won't have to change your turbo, O2 housing, or downpipe with either manifolds. I also lost the two left most (driver side) studs but their flush with the top of the manifold, so I should be able to back them out if I'm careful. Look at Turbo Swap VFAQ to get an idea what your going to need and some ideas on how to replace it.

Steve

 

[fast_talon]

You could get a used 95 Exhaust Manifold for $70 or less from a junk yard or the parts trader.

 

[dakmon]

Thanks steve and fast talon, good advice. I will give Conicelli a call and inquire about their products. Can anyone tell me what the 4 bolts on the top of the ex. man. are for. The 2 to the sides are for the upper heat shield but the 4 others appear to be of no use.

 

[steve]

Go look at this VFAQ and you should be able to figure out what goes where.
http://www.vfaq.com/mods/turbo-swap.html

The only four other bolts in the top of the manifold are where the turbo attaches. It that what you were talking about?

Steve

 

[dakmon]

I assume those bolts are for the turbo, yet they are very short and do not seem to hold anything (very loose).
Can anyone let me know why a performance shop would want me to purchase a 1g exhaust manifold. (they say it is a superior product). Everyone else I talk to and hear from say that the 2g is a more reliable manifold. What gives?

 

[steve]

The four bolts in the center of the manifold hold the turbo on. They are actually pretty long (about 80mm) and should be tight. The two bolt on the sides are short and just half the upper heat shield on. The only other bolts are the studs in the head that the manifold hangs on. If you looking at the VFAQ page the turbo bolts (and one stud) are shown as #22 and #41. If there loose and short then they are broken. The replacement part numbers are listed in the VFAQ.

If the shop is suggesting that you use a 1G manifold because it's better, find another shop because they have no idea what's going on. The 2g is a much better manifold and the EVO III is a little better still but maybe not worth the
extra $50. I went with the EVO III because the shop I was getting my new turbo from also had the best price around on them and it saved me having to order a 2g from somewhere else.

Steve

 

[dakmon]

Again Steve, thanks for all your valuable info. and for explaining in such a concise manner. I will order the 2g manifold tomorrow as per your recommendation.

 

[dakmon]

I am going to be installing the ex. man. sometime this week, but am having trouble finding the torque specs. for the man. to engine. I do not see them listed in my Haynes manual and would appreciate it if someone could post them for me. Thanks in advance.

 

[steve]

Remember the VFAQ I pointed you to in post 10.

All the torque specs are shown there in red. For example, the manifold to head stud nuts are part number 15 and the spec is 18-22 ft-lbs, the manifold to turbo bolts are part number 22 and 40-47 ft-lbs.

Everything you need should be there.

Steve

 

[dakmon]

Steve;

I am having great difficulty in removing one of the turbo to ex. man. bolts (they were not all loose). Am I better off just applying penetrating lube or should I use muscle in taking this bolt out? The lube has had no effect over the past 5 hours? The last thing I need is to have this bolt break as I already have 2 sheared off studs to cope with.

Thanks

 

[steve]

I soaked mine with PB Blaster for a week before trying to remove them.
The threads are in the turbo flange for the three bolts and both ends for the one stud. I soaked the gasket between the turbo and manifold in the hope that some would wick into the threads. These bolts have almost 50 ft-lbs of torque on them so ther are going to be tight. Try using your torque wrench set to 50 ft-lbs to undo them. Be careful if that isn't enough and work slowly up in torque.
Mine came loose at about that setting. Get yourself some high temp antiseize to use when putting everything back together. I used the high temp copper stuff available at NAPA. So far all I've done is make sure I could break everything loose, cleaned the threads, applied antiseize, and retorqued. I still have some porting, drilling and taping for my EGT, and maybe ceramic coating before I'm ready to put my new manifold, turbo, and O2 housing on.

Make sure you have ground the exhaust manifold down to fit around the front engine mount. This is shown in the last two pictures in this VFAQ http://www.vfaq.com/mods/porting-exhman.html

Steve

 

[dakmon]

Thanks Steve;

The bolts (and stud) all came out (one partially stripped), but now I am having great difficulty in removing the manifold. I removed the bolt holding the downpipe to the block but the turbo assembly does not want to drop to allow me to remove the turbo ring gasket (I assume the ring gasket is getting in the way of the manifold removal). Is there some sort of trick or am I missing something? Once I do remove the ring gasket, I assume that I discard it and only use a flat gasket?

Thanks

 

[steve]

Your now past the point that I've reached. I'm still getting all my replacement parts ready. The turbo has various hard lines for oil and water supporting it and those will need a little force to deform. Since you have the turbo bolts and stud out and all the head studs unbolted the only thing keeping it connected is the seal ring and the gaskets to both the turbo and the head. I'd try tapping the manifold with a mallet to see if you can free it up a bit to clear the ring and pull it off. Maybe someone who's completed this process can step in with better advice. I'm a couple of weeks away from being ready while I port, tap, and coat my manifold and O2 housing.

I decided the seal ring wasn't a bad idea to help protect the turbo gasket from blowing out. I had my B16G ported to leave in just enough step to support a new 7cm seal ring and I'm porting the EVO exhaust manifold to be the same way. Porting up to the ID of the seal ring is still going to open up the collector quite a bit. (I have to remove 2/3's of the step that cast in)

Since at least one of your turbo bolts/stud was a little stripped, make sure to chase the turbo flange threads with a tap to make sure their clean before putting an new bolt in and don't forget the high temp antiseize. I assume you can find metric taps easily in Canada.

Steve