2.5 vs 3.0 exhaust for ZD30, opinions.

[scott.a.green]

Hi guys, just picked up a GU with a ZD30, and I'm looking at putting a new exhaust on. I mainly use the car for towing. Was curious as to people's opinions on a 3" system over a 2.5", as in is the extra cost of a 3" worth the extra performance?

Cheers.

[MEGOMONSTER]

Hi guys, just picked up a GU with a ZD30, and I'm looking at putting a new exhaust on. I mainly use the car for towing. Was curious as to people's opinions on a 3" system over a 2.5", as in is the extra cost of a 3" worth the extra performance?

Cheers.

I went with a 3" Taipan exhaust. Reason why I chose this system is cos there is no loud droning at speed. It's said to be only 5dB louder than stock. Much better performance but minimal.
If you do a search on exhaust you should find heaps of info to read through.
I do remember reading on a few threads the the Beaudesert 2.75" exhaust is sufficient.

[scott.a.green]

Cheers for the info mate.

[mudski]

I've heard the same as what MM said. But I went the 3inch Redback system myself. Was only 9hunge and I fitted it myself. Whats the price difference between the sizes anyhow. Surely would be a lot....

[scott.a.green]

I've only just picked up the Patrol, but bigger pipe is no. 1 on my mod list. Only just started looking at systems but seems to be anywhere from $200 to 500 difference in price for the 3" from the same manufacturer.

How did you find the Redback system mate as $900 is a bloody good price.

[mudski]

Goes good mate. Sounds no different to stock aswell. If I get time on Monday or Tuesday I am taking it in to get the muffler removed.
As for different zorst's, everyone can only tell you what they have but remember. Don't too much for a system. In the end they are all the same, well, very close. The major differences will be the type of cat used, muffler, mandrel bent pipe or not, and material used i.e mild steel, aluminised steel or stainless steel.
Material differences will make stuff all to performance, as long as the cat is of good quality and hi flow, rear muffler, just don't bother having one. Mild steel pipe is fine in my opinion, it won;t rust out anytime soon. The Redback system comes painted black too...I saw a Di last week with a complete straight through system with no cat or muffler and even that wasn't loud. No louder than what a TD42 sounds like anyway.

[Hodge]

I do remember reading on a few threads the the Beaudesert 2.75" exhaust is sufficient.

This is what the bloke at beaudesert told me as well hence why I went with this system. They used to do a 3" variant as well, but had way too many after sales phone calls of the car not performing as well due to loss of back pressure and few other things i forgot he mentioned. He also said it's hard to believe that 1/4" makes any difference, but it's actually all it takes to throw off a good engine flow.
Whether it was all horse crap or not, I fell for it and went for the 2.75 and very impressed with the gains so far.

[happygu]

Scott,

Same as Hodge, I have the Beaudesert 2.75" Exhaust, after doing my research for over 6 months on the different sizes on the net and asking around.

When I had already made my decision, I rang Beaudesert and asked for a 3" exhaust to see what they would say, and probably spoke to the same bloke as Hodge.

Mic

[mudski]

The less back pressure the better. Thats why you see drag cars with just the headers sticking straight out. You want the process from intake right through the engine and to the exhaust to be as free flowing as possible. The reasoning behind Beaudesert saying the smaller pipe is better? Who knows. Cheaper and easier to produce? Maybe there is a gain over the slightly smaller pipe.

[happygu]

Mudski,

The main reason for the 2.75 was to stop over boosting issues ...