Over a year ago, I was quoted almost £1400 for a custom handmade stainless exhaust system. I’d have to trailer the car to them and leave it for a week. Since then, although not much progress has been made, I’ve changed my requirements and added an extra pair of back boxes.
This car is a ‘fluid’ design. Many aspects of the car have been changed more than once. That left me thinking; if I splash out on a professionally made system, within a couple weeks I’d want to cut it up. With the total build cost so far, being roughly £1500, a DIY system seemed a much better bet.
Therefore, I started gathering the parts from the auction sites.
- A pair of stainless catalytic converters,
- 2 off 5″ x 30″ mufflers,
- 2 off 5″ x 18″ mufflers,
- 2 off flexible sections
- 6 off machined flanges
- 2 metres 2.5mm 2.5″ stainless tube
- A box load of random 2.5″ bends.
Some parts are British and the rest are Chinese imports. In terms of quality, to a non-expert they all seem very solidly constructed. Certainly much better than what the local exhaust centre fitted to my hatchback. All the parts are unused, although some parts like the cats and large boxes had been sitting on somebodies shelf gathering dust for a couple years. The bill so far, approximately £115.
If I’d bought the parts at ‘buy now’ prices I’d be looking at over twice that, but still a bargain.
My exhaust is 2.5″ or 63mm, which coincidently is a dimension used by sanitary fittings. If you add the word ‘sanitary’ to your search criteria, you can buy identical parts for half the price and unlike car parts, often there are bulk discount options. Plus, when it comes to brackets, clamps and V-bands you can find some very posh CNC machined items designed for the bathroom.
I know some professional exhaust fabrication shops fill the exhausts with gas as they weld them; so that the weld is perfect on both sides; but I simply gas welded mine with oxy acetylene. Given I haven’t gas welded for 30 years and by medical advice I’m not supposed to weld at all, it was surprisingly easy. The tricky part was rotating them quick enough to weld. I could have done with at least 2 more sets of hands.
Unlike most Haynes Roadsters and Locosts, this V8 will have a single, 8″ wide, oval rear exit exhaust pipe. There will be 2 more smaller boxes behind the rear axle. The exhaust pipes will pass in-between the rear driveshafts and A-Arms. With the cantilever shocks mounted to the top of the rear hubs, so this is easier than you’d think.
The purpose of the extra boxes is to give a nice V8 rumble without having the ground to shake around me.
The catalytic converters were originally destined for a Nissan Skyline and luckily have a threaded mount for a Lambda sensor. This will be handy when I come to get my megasquirt ECU running.
I’d been quoted £500 for the headers and after a couple attempts they came in under £130. If you add the cost of Gas that’s £250, all in, for a complete handmade stainless exhaust system. That’s a saving of £1850!