Sebring Exhaust Part 1
A Sebring style exhaust is something that I have been planning for a long while. Whilst it's not the best style of header to use from a performance perspective, it does have that iconic Porsche racing style to it and so is the perfect choice for a period looking car.
I've been carefully taking note of all of the different styles of Sebring exhausts, both real and replica, trying to work out the best way to make one for the speedster. There are a variety of different designs, even between the various Porsche works cars. I think that exhaust header design was an emerging field of development at the time and so there was much experimentation carried out. As such there is no one 'correct' design, but rather a range of different designs which form an overall aesthetic to how they should look. Some of the Carrera exhausts were pretty wild, in fact it almost seemed like they grew in length every meeting.
There are a number of modern Sebring-style exhausts available, like those on offer by Vintage Speed and CSP. For me I think that the CSP is the more accurate design but at well over AU$1500 without shipping it's a bit too expensive for my taste, plus it's stainless so it's too shiny.
So the only real solution for me, being the cheap-skate that I am, is to make my own.
A critical aspect of the exhaust design is the engine that it attaches to, so finalising the engine choice is an important aspect of the exhaust build. The car came supplied with a freshly built 1600 that's never been run, but to be honest, judging from the quality of the other work carried out on the car, I'd prefer to not try to run it without tearing down to check it. It's supposedly built from new components, it would be a shame to grenade it.
I do have another stock 1600 and a set of twin spark heads that I built. Those could be a nice combo paired up with a pair of IDFs from my carby stash, or even better the nice pair of DLRA 36's that I have. I also have an Okrasa 36hp big bore engine that I was building for my salt car. This is a twin spark 1625cc and is probably similar power to a nicely tuned dual port, plenty of steam for a lightweight Speedster and now 'spare' seeing that I have sold the race car.
In either case the capacity is about the same, and even if I ended up fitting a blower to it (in all probability a fairly likely eventuality) a small sized 1 3/8" system would be just about right.
So with the size decided I went off to the local tube makers where I buy all of my blower manifold tube from. I had quizzed them some time back about perforated tube and luckily they still had some in stock. I also bought up the necessary mandrel bends and flanges needed to make the headers.
The perforated tube is so that I can make my own silencers ('Mufflers' for my Yankee friends). There's nothing small enough available off of the shelf, so the only option is to make them from scratch. At least this way I hopefully get to build a system that fits perfectly. (Perfection is a relative term of course ;) ). The main issue is the available ground clearance and the short length required to fit in between the rear valence and the engine.
The silencers will feature the same twin parallel straight through tubes that the Carrera exhausts featured. I'm hoping that they will not be too noisy although it seems that people often run an additional silencer in the tip so I'm guessing that my hopes may be wasted on that point.
So now that I have all of the parts I now need to put it together. I'll make a start on the 4-into-1 collector and once I've picked up some packing, the mufflers, but final assembly will have to wait until I've fitted the rear bumper. I've managed to score a steel rear bumper to match the front so want to wait until that's in place first so I can tuck the tip right up underneath it.