Exhaust Work for 81 Euro 911

[EuroTargaJim]

I am exempt from emmissions because I rarely drive this car.  I thought "Why not get a killer exhaust and boost horsepower."  I have purchased a pair of Bursch tuned racing headers.  Now I need to install them!  The factory exhaust goes toward the front of the car then bends around and goes into a single inlet cat then muffler.  The headers are designed to go straight out the back.  I need help designing a "cris-cross" muffler system.  I also need the manifold bolts drilled out and re-tapped.  Should the engine be pulled out for this project?  The existing bolt heads are all rusted.  I don't believe I can get them off without destroying them.  The car is a true Euro-Spec.  Am I foolish for attemping this?  Will the car be more valuable left "as-stock"  All you 911 air-cooled experts give me some advice....please!

[Tony356993]

I would leave it alone and drive a bit higher up in the power band for some more driving thrills.

[Brian Minkin]

I did the Bursch headers and a Bursh exhaust on a 2.4 litre targa a number of years ago. The positive was that it increased the torque at low and medium RPM.  Car was certainly noisier then stock but not unpleasant. If you have an oxygen sensor on your car then it will have to be tapped into the header as they do not provide a port for the oxygen sensor.

The negative was that it eliminates the heat and defroster.

Bursh makes an exhaust that will bolt right up to the headers.  Dansk also makes an OEM type sport exhaust that will bolt right up. 

Dansk also makes a Pre-Muffler that replaces the cat and will also give a performance boost without going to headers and allows you  to continue to use the stock exhaust or go to a sport exhaust for greater performance.

So you have a number of options. 

If you are concerned about value the Dansk pre-muffler and sport exhaust since they keep the system basically stock are the way to go.

If you go with the headers the manifold bolts you speak of are bolts that go into the heads and mount the heat exchangers.  Although they are very rusty there are some super penitrants made today that may free them up. If you dont want to do this DIY then any of the shops that service AIR Cooled 911's have been through this zillions of times and can get them out. 

[Porshagod]

Another more cost effective option may be to leave the manifolds alone and just do a Cat bypass and/or performance muffler. Vertex.com  has a nice SS Cat bypass for around $150. You can find a nice used performance muffler on eBay for around the same price. I would recommend Meineke in Berwyn, Pa to do this and/or any other custom Porsche exhaust work. Ask for Chris, tell him I referred you.

[michael lang]

I believe in what Tony & Brian said, leave it alone and as Brian stated go with a euro pre-muffler or bypass pipe if you feel the need to change something. Porshagod had a good idea of going with a used bypass pipe but I can tell you after years of watching the classifieds on Pelican Parts I can tell you that (ab)used parts that sell for almost retail are pretty beat up by the time they go up for sale. Buy new! Why pay someone to work on your car for you, that is probably one of the easiest project to take on. I'll give you a hint, PBlaster.

Now if you are dead set on changing the heat exchangers to headers, then I would suggest going with a set of SSI's. Mostly because if you ever sell the car those will help you retain your car's value. Plus they are the easiest to mate up to just about any performance muffler that is available for your car's engine. Do your homework, you will have oil line issues to deal with as well since they will have to be changed also. I'll give you a hint, PBlaster.

Your car is now 26 years old, SOAK the bolts for atleast a week before your attempt to break them free. I'll give you another hint, Heat.

Good luck!!

[michael lang]

EuroTargaJim, I'm curious, what did you decide to go with?