EXHAUST SYSTEMS

BY HOWIE

Non-Turbo Systems


The Nissan EXA is completely responsive to exhaust modifications. It should absolutely be your first performance modification. From the contributions of club members and help from other clubs, i've come up with what I'd say is the ideal system based on a CA18DE motor.

It starts with a 4-1 header system (Hurricane company in Australia can sell you this), through to a high quality flexi-joint, through to a low-restriction sports catalytic convertor, through to 2 1/4" piping until you reach your muffler. Here you have a choice, and this I would say yields the greatest results in power (yep even greater than extractors I'd say, but can't have one without the other in my opinion). My choice was originally a 2 1/2" super flow muffler from Walker. In short this was an absolute piece of junk. It restricted so much of my power under 3000rpm it wasn't funny!

So what's the best muffler? I'd say without a doubt that the Japanese tuning shops have the best exhausts full-stop. You cannot go wrong with a HKS, Apexi, or Trust system. They test their mufflers on a variety of cars and even go as far as providing a recommendation of piping width for their systems.

A member from the club sourced me an Apexi N1 (NA 2 1/4" version) muffler. Immediately the car sounded better, and power went up considerably across the rev-range, especially in the much needed bottom-end. The difference to me was likened to running the car with air-con on high, and without it on. Full day-night effect throughly great results and probably the best money spent on the EXA so far.

 

Turbo Systems

 

Because of the forced-fed-induction nature of this system, the CA18DET requires a completely different exhaust system.

The best setup would be a 3 inch exhaust straight from the turbocharger itself. Have the piping from there-on mandrel-bent of 3" diameter. Mandrel-bending does not allow the pipe to lose it's diameter at corners like normal press-bending, it makes quite alot of difference in a turbo car as it'll have massive amounts exhaust gases flowing through there. From there you know the drill - catalytic convertor, flexi-joint, and a great muffler.

These exhaust systems have a dual benefit on turbocharged cars. One, the exhaust from the turbo exits the turbocharger with minimum fuss - so no choking on it's own fumes (this allows boost to drop rapidly when coming off the gas, blow-off valves usually help prevent this too). Two, modifications to a turbo-charged vehicle's exhaust system will yield more power gains than with a non-turbo vehicle. Some cars will have around 15% power gain without touching boost!

Hopefully, we'll have more information on SR20DET exhausts, and E15ET exhaust systems.