Wade T

Just wondering which headers do you guys recommend for the 16v? Been eyeing the MSDS headers. And second, my car(82) has a Boral catback but I don't like the way it sounds. Below 2k RPMs it's nice and meaty with a good v8 drone, above 2k RPMs it gets so quiet that it sounds like nothing. Is this a characteristic of the Borla or something else, like a clogged cat? Also, what Y-pipe do you recommend? I don't need a cat anymore either.

Many thanks and merry Christmas!

Airflite40

The Borla should scream so I would say ditch the cat and get a Y pipe, but if you want MSDS headers you will have to have a y-pipe fabbed up since no-one stocks a Y or X to go with MSDS headers.

Ideally if you could get Mark A's race headers that would be the best, but I don't think it will be easy, you need to get a group buy together I think.

Wade T

MSDS are the only headers for this car? Also, will the 928motorsports Y pipe be plug and play for the headers and cat-back portion? I guess the smog pump will have to go away. And is there a custom belt made for this?

John Veninger

Think MSDS are the only ones making headers for the 16V cars. They were on my old race motor. They aren't the greatest, but do work for for the under 400hp NA motors.
Don't think there is any plug and play to those headers. Any good shop can attached a Y or X without much effort.
I lIke the Y and single 3" or 3.5" on the 16V motors. sounds great.

VT928

I have an exhaust on my 1980 Euro S that you might like. It has a great sound, you can hear the cam at idle and above 3K it is a angry wail. At several SITM's and a 928oc event quite a few people comented that it is one of the best they have ever heard. It consists of 2.25" pipes off the stock manifolds flowing into dual Inlet/Outlet Magnaflow muffler placed where the US models have the cat located and then twin pipes with gentle bends to the stock exhaust location. There are photos of the system on the 928oc website. Look at the 3rd Tec session in Mass in 07. The car was on a lift and you can see the whole system. Trust me it flows great, after installing it I hit the rev limiterhard several times befor I got used to how quick it reved after the change

Paul

1980 Euro S Red/ Blk Lea

ROG100

The Y pipe that I sell and the 928 Motorsports Y are made by Motorsports SLC and the same pipe.
This Y will not fit the MSDS headers without modifiaction.
Roger

FlyingDog

Mark A said the 928 Intl headers will fit or can be made to fit a 16V. I'm pretty sure 928 Intl headers would be overkill for a 16V without boost or a stroker crank. There is nothing mass produced to fit either MSDS or 928 Intl headers going rearward.

I like my MSDS to Y to 3" exhaust. It sounds awesome and the engine revs amazingly freely.

PS: If you get MSDS headers, get them coated. My aluminized one flake rust everywhere (like in my eyes) when I work under the car.

John Veninger

Yes, the 928intl ones are way to big for a stock 16V engine IMO and would have to be modified.

largecar379

John,

why are the 928 Int'l headers too big---I haven't looked into their specs---?

--Russ

John Veninger

They are a stepped header that starts off with a 1 7/8 primary.
Maybe ok for a race only 16V motor that has been highly modified, but for the street it would seem to be a bit to much for the lower HP engines. Again, just my opinion.

SwayBar

Maybe so, but a well informed one.

Wade T

Great stuff! Thanks all!

Daniel Dudley

Wade, you probably know this, but a header has equal length runners that dump into a collector. If the runners are sized right, the pulses from the exhaust gas from each cylinder will hit the collector in sequence, and effectively extract the pulse from each consecutive cylinder. Large headers need lots of flow or the exhaust gasses lose their velocity and pulse effect. Small headers have good flow characteristics on small displacement engines, or low revving engines, but can only handle so much exhaust before creating backpressure.

Also, think of an X pipe or a Y pipe as an extension of the header, that coincides the pulses from each bank of cylinders and further enhances scavenging. And the purpose of scavenging, as we know, is to empty the cylinder as fully as possible, to enhance intake of air and fuel. With a properly built engine and exhaust, it is even possible to get the exhaust pulse to travel into the cylinder and help pull the intake charge into the cylinder quicker. There are other factors like cam timing that can add to this, but that is the general idea of it.

And of course those long spyder runners on the intake of a 16 valve 928 are also designed to get air velocity up, and increase cylinder filling. In fact, at high rpms, long runners can often achieve so much flow and velocity that air actually keeps moving while the valves are closed and packs the runners with pressure, making a denser charge. Heady stuff.

Daniel Dudley

Also, to go on with the intake tract, of course different sized runners are a compromize. Small ones, like small headers will flow well at low rpms or on small displacement engines. Large ones will flow more on bigger, higher revving engines.

When we look at 85-86 intake runners, we see that they are pretty large, and are compromized to give a better top end, at the expense of some low end cylinder filling and torque. However, in 89, the revised S4 intake has a flappy valve that opens to increase the chamber size on the intake at a certain rpm. This flappy, in effect, gives high flow through small runners at low RPM and high flow through large runners at high RPM.

If you ever get a chance to study a dyno chart of an S4 engine, you will see two distinct torque peaks, at low and high RPMS, with a dip in between them. That dip is where the flappy valve transitions between intakes. Many later Porsche engines had this ''varioram'' effect. And of course some, like the 968 had variocam, to change the cam timing, another big factor in engine breathing at low and high RPMS.

I believe that some 928ers have even installed these 968 heads onto their engines. Neat stuff.

Wade T

Very neat indeed. Think I'm going to go with MSDS and have a custom 3" Y pipe routed to the Borla. The ulitmate goal is low boost custom rear mount turbo, if the compression checks out good.