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Timmo
17th June 2013, 07:06 PM
Hi guys,

can any one tell me in simple terms if a 3 inch exaust is any better then the standard 2.5?

boots
17th June 2013, 07:51 PM
Hi Timmo . If yours is a ZD30 then they are 2 inch only factory and the section of pipe from turbo flange to cat is only 1 3/4 inch .

happygu
17th June 2013, 07:56 PM
Extremely happy with the 2.75" exhaust from Beaudesert.

Really good gains, and much better to drive.

Mic

boots
17th June 2013, 07:56 PM
^^ x2 with happygtu

MEGOMONSTER
17th June 2013, 08:02 PM
I put in a 3" Taipan exhaust.
Definitely have a power boost. Especially when at speed.

93patrol
17th June 2013, 08:03 PM
And you had a few dramas as well didn't you megomonster


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MEGOMONSTER
17th June 2013, 08:06 PM
And you had a few dramas as well didn't you megomonster


Sent from my iPhone using Motorculture mobile app

Yes I did, it came down to the fitter not aligning correctly then forcing the mounting bracket upward causing it to break.

Hodge
17th June 2013, 09:10 PM
^^ x2 with happygtu

x3 . I'm going down this road at the moment. Getting a beaudesert 3" . Just a heads up, in the curent 4wdaction issue, their ad has a keyword to 10% off and a discount on shipping. Just mention "4WD200". Gonna apply that discount as soon as my quote comes through.

kevin07
19th June 2013, 01:55 AM
some people are getting overboost issues with 3" I would suggest the 2.75 no issues with that one

happygu
19th June 2013, 06:51 AM
some people are getting overboost issues with 3" I would suggest the 2.75 no issues with that one

That is also one of the reasons I went for the 2.75" exhaust ...... and I can't imagine that after installing it and feeling the gains driving around, that going 3" would give better gains anyway.

Mic

june
19th June 2013, 07:36 AM
i have 3inch stainless from taipan, with no problems. welds and fitment are good. made a big difference performance wise.

kevin07
19th June 2013, 08:43 AM
i have 3inch stainless from taipan, with no problems. welds and fitment are good. made a big difference performance wise.

june your not getting overboost issues as you have a di with a dawes fitted but this is a common rail so some are getting overboost others not me personally I read all the info and decided on the 2.75 as a no problem exhaust vs the 3" where some are having issues not worth the risk of creating a whole lot more dollar issues than what any extra gains that maybe achieved from that little bit extra size

threedogs
19th June 2013, 09:14 AM
My system is 3" all the way,no noise, did over boost but sorted with the NADS set up;
Would it overboost with a 2.75" we'll never know. Can't be any happier with mine ATM.
To answer your question anything that helps get the exhaust out quicker has to be a good thing
be that 2.75" or 3" .From my take on things some sizes benefit one motor more than another,
Talk to your exhaust guy, one size may give better economy, or other better low down torque Etc Etc

Steve4wdin
19th June 2013, 04:03 PM
I fitted a 3" turbo back, high flow cat. Had endless amount of trouble. Over boosted, Fixed that, than huge turbo lag. only just recently got it sorted out. I tow a big camper and the car performs well but it was painful to sort out. The 2 3/4 " system seems to be a lot less trouble.
Steve

june
19th June 2013, 06:12 PM
yes I did have over boosting and yes nads fixed every thing. still happy with out come. its one of those mods that some like 3inch and some like the smaller 2.75 inch. its like 3d said talk to your exhaust guy, but they are only going to tell you what they sell is best. [good luck]

Timmo
19th June 2013, 07:59 PM
ok so how do I tell what size my exaust on a 2009 st is? I went and measured the thing and came up with 2.25 inch so I guess and brand new 2.5 inch for free will not give me much gain at all?

happygu
19th June 2013, 08:07 PM
Timmo,

The standard exhaust is quite restrictive, and gains achieved will be dependent on the new exhaust fitted.

Is it 2.5" with mandrel bent bends, which keep the pipe bends to the full 2'5" sizing, or are they just normal bends which then collapse the pipe down to around 2"?

If they are mandrel bends, it is probably good for free - if not, then don't bother. You will probably then get the same gain by just removing the main muffler.

Mic

Davesgu
19th June 2013, 08:33 PM
I've just fitted a 3" mandrel bent system to my Zd30 (nads previously installed) and have a noticeable power difference and its sounds good too.
I bought my set up through "Scott's Rods" in QLD and they fitted the bung for my EGT probe before shipping it to me in NSW.