3 inch exaust

[june]

i have 3inch stainless from taipan, with no problems. welds and fitment are good. made a big difference performance wise.

[kevin07]

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]

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]

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]

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]

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]

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]

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.