An upgraded exhaust is one of the more common modifications done to four wheel drives. Most four wheel drives are manufactured with exhausts that somewhat restrict airflow. By fitting a slightly larger sized exhaust the vehicle breathes better, thus potentially producing more power and improving the economy.
Why replace your exhaust?
- Reduce back pressure
- Improves economy
- Increases power
- Improves the sound
- Remove the rusty or damaged existing exhaust
- Allows the turbo (where applicable) to spool up earlier
- Reduce engine and turbo temperature
What size is best?
The exact sized exhaust should be determined by a proper exhaust shop. If you fit one that is too big, you will potentially get worse fuel economy, and a droning noise. A lot of bigger four wheel drive engines need a 3 inch exhaust, but the smaller engines will take a 2.5” or 2.75”.
The likes of Beaudesert can give you quality advice and tell you what systems are best, as you can easily go too big and that’s not great either.
Stainless Steel exhausts
Original exhausts are made of mild steel. These can corrode quite quickly (especially in petrol engine cars) especially if you are doing lots of beach work. Stainless steel has the advantage of never rusting, although it is nearly double the price.
To give you an idea, the exhaust swapped on my 80 series was 23 years old and still in reasonable condition (minus where it had been squashed). It is however, a diesel and this prolongs the exhausts life!
My Land Cruiser 3” exhaust
As some of you may know I recently purchased a Factory turbo diesel 80 series Land Cruiser. It was recently rebuilt, and is running a safari front mount intercooler. I looked underneath at the exhaust and found a section that was seriously squashed.
These exhausts from stock are too small in the first place, let alone more restriction.
Beaudesert had the best reputation and I received great service from them. In under a week a box arrived at my house. About 5 hours (with some help with a mate) of mucking around (most of the time was spent removing the original exhaust) and it was fitted.
The kits are perfectly designed, relatively easy to fit and work extremely well.
I haven’t done enough driving to know whether it has improved economy, but it definitely pulls better and has more low down torque. I love the new note, and the turbo whistle sounds great. I can’t say it made the turbo come on any earlier, but it was already coming on at about 1600RPM anyway, so you can’t complain!
To give you an idea on price, the standard aluminized mild steel 3” exhaust was $960, plus $30 for packaging, and $100 for freight (from Queensland to Perth). A stainless steel one would have been $1800.
Update June 2016
It’s been 3 years now, since I fitted the Beaudesert Exhaust to my 80 series. The exhaust has been flawless, and I’ve since compared it to several other exhausts made at local exhaust shops, and those mandrel bent from other companies.
The mounts, thickness and quality of build on the Beaudesert Exhausts is still the best I’ve seen. The mounts are made of roughly 30 x 5 flat bar that is welded extremely well, and the whole exhaust feels much stronger than many I’ve seen. I still wouldn’t hesitate to recommend them!
I did measure the noise levels, approximately a metre back from the vehicle (inside a garage) at exhaust level. The stock exhaust was as follows:
Idle: 70 dB
1600RPM: 82 dB
With the new exhaust, it changed to
Idle: 80 dB
1600RPM: 84 dB
The exhaust doesn’t drone at any speed, and certainly isn’t much noisier. I love the sound though! Have a listen below.
Why Beaudesert Exhaust?
Beaudesert Exhaust has one of the best reputations in Australia for aftermarket exhausts. All of the exhausts are mandrel bent, aluminized (or stainless steel), CAD bent (they fit perfectly every time) and extremely high quality. The kits come with everything you need including bolts, nuts, new mounts and the gaskets in between each join.
Beaudesert states online that the increase in power and economy is roughly 12%, and I would have to agree. Couple this with a snorkel and you will have the engine running better than ever. They can install the exhausts for you if you are local ($300), or if you aren’t local you can have the complete kit shipped to your door!
Mandrel bending vs press bending
If you are going to get a new exhaust, make sure you stipulate that it is mandrel bent, not press bent. The exhaust shops that really know what they are talking about will advise you of this. When you bend tube, if it isn’t supported the curved piece reduces in size.
This means even with a 3” press bent exhaust, the bent section is smaller. The flow is restricted by the smallest size, which is always in the bend. A mandrel bent exhaust however, is supported inside the pipe when it is bent, which means the diameter does not change throughout the whole exhaust.
A 3 inch press bent exhaust has a cross sectional area of 5.65 inches. On the other hand, a 3 inch mandrel bent exhaust has a cross sectional area of 7.06. That is a 20% difference in size!
Final thoughts about Beaudesert Exhaust
There is a reason that companies build up such a solid reputation. I looked online for reviews, and couldn’t find anyone complaining about Beaudesert. They have brilliant customer service, extremely well built products and come highly recommended from me!
If you are looking to fit a new exhaust, you can’t go past Beaudesert Exhaust!