Type 4 Exhaust

This page was last updated Friday, May 18, 2007

This subject will try to cover a lot of information. There are a lot of available exhaust systems for the Type 4, and what differentiates them is the application in which the engine will be used. We'll look at the exhaust systems for the stock "pancake" cooling first, and then proceed to engines converted to an upright cooling.

In each of these categories, we'll look at what I call "offroad" exhausts and "street" exhausts. Offroad exhausts are designed for vehicles with little or no bodywork behind the engine and for maximum ground clearance. Street exhausts are designed for stock bodied vehicles, like a Bus, Bug, 411/412, etc. Theses exhausts are designed to fit into the stock body with little or no alterations.

One more thing: all of these exhaust options assume that you are using cylinder heads from a '78 and earlier engine. The later cylinder heads (commonly referred to as Vanagon heads) have different shaped exhaust ports which make it incompatible with the aftermarket exhausts.

Pancake cooling

    Street: Let's start by looking at the combination of the stock cooling system and a stock body. The stock exhaust systems are fine for a stock car, but if you looking for a little bit more power or have really modified your VW, then start looking for a header for your car. Most headers are a "4 into 1" system. That means that the four exhausts meet at a single point into a larger pipe. This conjunction is called the collector. This type of exhaust is commonly seen on the Type 4 engines and the earlier (1.7/1.8) Bus engines.

The other type of header available for a street engine is a "2-2-1" header. This is where the two exhaust ports on each head have their own collector and later on these two pipes merge into another collector and to the muffler. I've seen dyno tests that show that on the Type 1 engine the 2-2-1 headers didn't have the overall powerband that the 4-1 did, so the 4-1 is my personal favorite. This header is usually seen in the later model Busses, as the stock system does the initial 2-2 collection.

Many suppliers sell what is called a Monza exhaust system. Though many people find it attractive with four large chrome exhaust tips, it's not the most desirable. The Type 1 equivalent of this exhaust system was found to flow as well as a stock muffler. Not the best decision if you've made modifications to your Type 4. A well tuned header and quiet pack muffler will give you better gas mileage, smooth drivability, and cooler engine temps from the increased effiecency.

A good resource on designing your own header for a Type 4 is available here: http://myspot.neteze.com/~kdanielson. Ken Danielson did a lot of research, learning about the ins and outs of designing a header. He has a lot of great links to other sources to make you informed. If you are considering fabricating your own header, make sure you spend some time reading this web page and it's links.

If you are looking to do the Type 4 conversion for your Type 3 (Notchback, Squareback, Fastback , or Type 343 Karmann Ghia), these are the exhaust systems to be looking at. I cover this subject in more detail in my technical article on installing a Type 4 in a Type 3.

The best place to get an exhaust system for this application is CB Performance, a Bugpack dealer or Mr. Bug (EMPI) dealer. They offer them in many different applications and are reasonably priced. The only thing I wish they'd offer would be a stainless steel option. Exhaust systems made of stainless tubing don't rust and maintain a better appearance. They typically last years longer than the commonly used mild steel tubing.

It becomes obvious that as you increase the power of your engine, you'll want to run a larger diameter tubing for the exhaust system. Unfortunately, as far as I know, there are no large tubing exhaust systems available for the the Type 4 with the stock cooling system in a stock body car. Any large tube exhaust systems will be need to be fabricated.

    Offroad: In this application, there is only one option. It is available from Eurorace (I don't believe they have a website) and is only available with a stinger (megaphone). The exhaust is only usable with a rear engine sand rail, as the the exhaust pipes are routed towards the transaxle bellhousing, up alongside the bellhousing, and come together at a collector located above the engine. The megaphone exits above the fanshroud. I will see if I can get a picture or illustration of this unique exhaust system. It is available directly from Eurorace or from FAT Performance.

But this isn't the end of this story. I am currently building a fiberglass dune buggy that will feature a Type 4 with the stock cooling system. The body features a large overhang to cover the engine and most of the stock fanshroud. Because of this unique setup, I can't run the above mentioned exhaust. It's only purpose will be for cruising around the roads and highways of Southern California (no dirt trails for this buggy). I am currently looking in adapting a BAS exhaust for a Beetle to place a muffler or two under the body and a discrete exhaust tip. I will post the results when I get to this point.

Upright cooling

Most of the people that are reading this site are interested in converting a Type 4 engine into an upright engine. So, with that conversion, a custom exhaust is required.

    Street: This is probably the most popular application at the moment. There are many people who are looking to install a Type 4 into their street Bug (like me) and they want to know what they can use to finish the installation.

For most mild upright conversions, a very cost effective exhaust system is to use the stock Type 4 heater boxes and a header meant for the Bus. The heater boxes will have to be shortened though, as they will place the header/muffler too far out and interfer with the rear apron. The most common heater box used for this conversion is the dual port used on the early Type 4s. Joe Cali of Next Generation details this conversion in his book.

For those engines who need more flow than out of a standard Type 4 header, there are alternatives. The first alternative is available from FAT Performance. Their ES731 exhaust system includes headpipes, a merged header, and dual quiet packs. When installed in a Bug, it looks real similar to a merged header on a Type 1 engine. Some people have complained about the quality of the fit of this exhaust, but other's have praised it. At the moment it's the only high performance header for a upright Type 4 from here in the U.S.

If these exhaust system don't appeal to you, there are other options. Of course these options are only available from European suppliers. Probably the most well known of the European suppliers is BAS Ahnendorp. They have a large selection of exhaust systems in different sizes and materials. Their exhausts also have more ground clearance than the American offerings. The only downside of these exhausts is the cost. They are quite pricey, though they are the best quality, and the shipping cost must be calculated into the total cost.

Just a note: BAS Ahnendorp also offers an exhaust system for installing a Wasserboxer engine into a Bug.

    Offroad: In this category, there is basically one choice: the excellent TriMil 4 into1 header. This exhaust measures 1 5/8" and includes it's own headpipes. They are extremely popular with the desert racers and FAT Performance even sells one that uses 1 3/4" tubing. Be warned though: this exhaust is loud. It's pipe exits upwards, at about ear level. I'd prefer to install a free flowing turbo muffler to make it easier on the ears.

Footnote: I have intentionally excluded the 914 and 912E from this discussion. The reason for this because of the unique nature of those vehicles, and the common availability of aftermarket exhausts for it, I felt that this information would be of little use for the VW person. With these vehicles, I suggest going with a quality header and muffler from any of the Porsche part retailers (Bursch is a good name in Porsche exhausts).