Yd25 wfitted with 2.5" exhaust reviews

[dmac]

I don't want to start an other 3", 2.75" or 2.5" exhaust debate but unfortunately that's generally how these posts finish up.
Just wondering if anyone has fitted a 2.5" system to their yd25 and if they could share their thoughts and opinions.
I don't want anything loud, want it to be easy to install and want to help the turbo breath.
I'm asking about the 2.5 because of the tight squeeze of the 3" and can be maybe too loud for my likings.
Yes I've hit the search button but haven't found my correct information I'm after yet. Cheers all

 

[308bever]

i`m interested too, i think you could ditch the rear muffler, and fit a sports cat and it would be an improvement, or gut the cat..........

 

[ericcs]

whatever size you fit, as long as you have a muffler, it will barely be louder than the original system.

 

[Rabbid-chop]

I have a 2.5" with hi-flow cat, mandrel bends and single straight through muffler on my zd30. Very quiet. Just get a tiny hint of a manly exhaust note and touch of exhaust whistle.

Im not sure what the std exhaust looks like on the yd25, but on my '04 it was 1.75" or something with nasty crush bends, so the new exhaust was definitely an upgrade in hardware, not that i could really tell the difference in go until i did the egr and butterfly mod which gave it a touch more down low and kept the oil cleaner. Next came the chip which made all the difference.

My opinion; in theory, on a turbo engine, the bigger and more free flowing the exhaust the better, but on these diesel work-pigs with their tiny little turbos anything bigger than 2.5" is a wank, but as long as it is unrestrictive it is a good thing for engine health and future mods.

I would just shop around for a good deal on ebay or whatever, whether it be 2.5, 2.75 or 3", as long as it has a muffler if you dont want noise, but if the existing exhaust and dump pipe look ok then maybe just punch out the cat and swap the std muffler with a straight through or hot dog.

 

[dmac]

Great feedback so far lads, mine's a 2010 model and believe it has a cat but haven't really checked, I know if your car is manufactured with a cat it must have on, but if I put on a 2.5" with out a cat it would it run better, less restriction? I'll be definitely getting a muffler though.

 

[jonney]

my son has a 3 inch system with one only rear muffer [ before diff ] aftermarket dump pipe and high flow cat. he has more power than my stock system gives me.

 

[Jased22]

2.75 is apparently best for the 2.5litres. My best mate had one on his. If you have a muffler and cat in the system it wont be loud at all. Will just have more turbo whistle

 

[Rabbid-chop]

Well i know this wasnt supposed to turn into another 2.5 vs 2.75 vs 3" thread, but i call bullshit on those dyno graphs where the 2.75 won the shootout.
It was so marginal, that the time of day each pull was made would have made more of a difference let alone the actual design of each exhaust they used and the minor differences in workmanship on each one.

We arent talking tuned headers, we are talking turbo exhausts where less back pressure wins the contest, except on these vehicles the output is so small that even a 2.5 is probably overkill.

 

[Teleman191]

Time for another 2 cents worth.
I had a 2013 d22 (I have a d40 now) with a 2'5 inch straight through custom system. No cat, no muffler and only 1 resonator straight from the turbo. It was great. Not loud at all but it was deep and throaty and sounded great when up at 4000 rpm. (Not often though haha)
So 2.5 is good for a straight through kind of thing, if you really wanted a big exhaust, a 3' would fit then just put a muffler on it. It's the whole package that you need to think about, not just the pipe size.
Good luck.

 

[dmac]

Thanks teleman, these are the things I want to achieve with an exhaust.
- Better performance, torque economy, not too noisy and easy to fit. I've got wanka neighbors as it is that sook bout my ute leaving for work at 5am with everything stock on it!
With my set up I was thinking, new dump pipe, no cat, straight through sports muffler and a cannon at the back all in 2.5". Haha minus the cannon! If people can elaborate why a 3" in that same set up would be better I'm all eyes and ears.
Shit, hopefully it's not goin to turn out to an other "debate"!

 

[Jased22]

They can be a pain in the ass to fit. Removing the standard dump pipe is the worst. You have to remove some studs to get the dump out. And there isnt much room in there. I would start soaking all the exhaust bolts with penetrating spray well before you attempt to remove the system.

 

[Teleman191]

Dmac, your ideas are totally fine and would be good, but there will be no real noticeable performance gain until you do an ecu remap or chip the thing. The ecu will detect the extra air flow and work to bring the mixtures back into line with the factory tune. I'm not saying it's not worth doing, but a bigger exhaust is only half the job in reality.

 

[dmac]

Yeah I do intend one day down the track to get it chipped but that one will have to sneak past the wife