Aftermarket exhaust systems often put a lot of stress on turbo and manifold gaskets because they add extra weight and are much more rigid than the small diameter factory piping.

Hard use, especially on the track, can shorten turbo gasket life to hours!

This exhaust already had an ugly join where smaller diameter pipe had been used to lengthen it in the past, so I was able to cut that section out and replace it with a stainless steel flex joint. This should allow the rear half of the exhaust to move a bit without levering on the turbo.

This car is running a 2L turbo Cosworth engine, and the old exhaust had proven to be a bit too restrictive for the desired power output.

I made up a 3″ stainless pipe and a custom 3″ straight through muffler. The casing is 0.6mm thick stainless steel so save weight (most mufflers are 1.6mm or so) and it’s a lot longer than a normal muffler, to keep the noise levels down.

The front end cap is riveted on, so it can be removed to repack the muffler with new insulation material if necessary in future.

This was a few little jobs on a Kawasaki KLR650.

• A new muffler for a bit more power and sound (the factory one sounds a bit like a lawnmower)
• An upgraded jet kit for the carburettor, to keep the engine in tune with the new exhaust
• and a replacement braided brake line for the front brakes - which improves the braking feel.

The exhaust was a Supertrapp branded one, which is not very common in Australia, but I’ve seen them used on older race cars. They have a unique adjustable baffle setup so you can tune the sound and power a bit.

It went on easily, and takes up a lot less space than the massive factory setup!

Next was the brake line, which was just a simple bolt on job followed by flushing the brake fluid and bleeding the air out. The brake lever feel was improved greatly!

The final job was the new jets for the carby, which actually went together pretty easily apart from the carby being fairly difficult to remove from the bike as it is held in rubber hoses at each end which don’t have much room to move.

Years ago I’d installed an aftermarket exhaust on this 350Z, but it was deemed to be “not loud enough”

The owner had since bought a BuddyClub exhaust, which has larger pipes and very little muffling.

Installing it was a pretty simple job, apart from having to replace all the bolts (about 20 of them in the exhaust system!)

Needless to say, it’s loud enough now!

This 180SX exhaust system had been poorly modified in the past, with some bad welds that were now leaking, as well as a mount that wasn’t reinforced - causing the pipe to crack where it was welded on.

I removed the old exhaust mount, cleaned up the rusty pipe, and welded up the cracks.

I then welded an extra metal plate over the damaged area, and replaced the mount with a stronger one attached in two places on the new reinforcing plate.

The leaking welds at each end were cleaned and re-welded, and then the whole section given a coat of paint to protect it.

You can see the reinforcing plate and mount in this photo. The big ugly weld was already there

Today I replaced a bunch of turbo gaskets, installed braided flexible coolant and oil lines, fixed up some vacuum plumbing and installed a boost controller in a Nissan 200SX (Silvia).

The turbo gasket had blown, which often happens when people run an aftermarket exhaust which isn’t supported properly. The extra weight and missing bracket in the middle puts a lot of stress on the turbo mounting bolts and they tend to loosen off.

This starts the gasket leaking, and eventually it burns through and leaves the turbo hanging loose, dropping performance and making a loud exhaust leak sound.

While the turbo is loose and able to move around the metal coolant and oil pipes are constantly flexing, and they eventually crack and you have a coolant leak as well as an exhaust leak!

So, a new set of gaskets, replacing some damaged manifold studs (and retapping the thread in the engine!), a set of braided lines, and it was good as new

Another problem this car had was that the boost control solenoid was hooked up to the wrong vacuum line, which meant the boost control system didn’t work properly, causing overboosting.

That was fixed up and a new boost controller installed, allowing in cabin adjustment.

Unfortunately I didn’t get a chance to take some photos!