Up next on my hitlist, is the straight through, side exit exhaust system a PO decided to fit to my 90 with a 300tdi conversion.

My god it's loud. Really loud.

I do often enjoy the sound, but when trying to creep past a farmer's house when out green Laning, it's a bit embarrassing.

So my question is - what's the real benefit of having it, when I've driven other people's 300tdis, I'm certain mine is a bit more pokey, but I have no idea if that's anything to do with the exhaust.

If I'm not going to see a noticeable performance decrease, I might just get it back to the standard exhaust system.

Thoughts?

Less restricted air flow in and less restricted exhaust gases out will always be best for performance, thats why race cars and performance cars are always loud as they have no resonators nor exhaust silencers/mufflers.

Car enthusiasts and race car owners go to great lengths to facilitate this, using headers, bigger and shorter exhaust pipes etc. Believe it or not, I found that even a snorkel with the flat mounting design slightly reduced performance. Having said that, what you have will be best for exhaust flow and performance from an exhaust stand point but the balance between reduced noise pollution and reduced performance is up to the owner.

Except for a dyno pull you cant tell how much gain you will get from a stock 300tdi with a 113HP with a free flow exhaust as opposed to stock exhaust, but there will be some.

If this Landy is your daily driver I would say install a less restricted muffler than stock, will be a good balance between noise pollution and flow, if it is a weekender I will leave it as it is.

I have ported and polished my 300tdi head for better flow, re-bored then engine to 40 thou OS, have a full width inter-cooler and will be installing a MB VNT Turbo all for increased HP, I will install a 3" exhaust pipe with a free flow muffler to make this a great package.

Cheers.