exhaust size 2.3/4 or 3" ??

[SRLUXX]

I have a 3" Scott's Rods mandrel bent with a high flow cat no muffler, sounds awesome with mass turbo whistle, spools at 1600rpm and pulls hard all through the rev range.


If 2.5" was more than enough, why isn't there any exhaust company that makes that size system for the hilux? I wouldn't go any less that 2.75 personally

[JOE21M]

is 3 inch system the go?

[JOE21M]

is 3 inch system the go?

[JOE21M]

is 3 inch system the go?

[mrl]

Yes x3

[FM78LUX]

IMO, I would go 3" Downpipe and 2.75 All the way through with a High Flow Cat and Muffler.
It will not only free lots of flow (and dump it faster) but it is very important to keep a bit of back pressure.
So reducing from a 3" to 2.75" will work good. This way you have the best of both worlds. Big flow starting from the turbo to a 2.75 to create back pressure. I agree with SRLUXX that anything less than 2.75 will be a waste....

This is the set up i am putting on my LUX in the next couple of weeks. I will get some feedback once done if it helps any of you guys.

Cheers

[JustinC]

I've just kept the standard 2.5" mandrel system & changed the cat to a freeflow torpedo muffler & the rear muffler to a freeflow Flowmaster muffler. A slight rumble out the back & a noticeable difference in the low & mid range.

2.5" is plenty for a 3.0l diesel turbo. No need for any bigger pipe size.

I've just had a original tuner box (chip) fitted & got it dyno tuned and it's making 115.8kw (157hp) & 712.5Nm at the wheels. Enough grunt for me on my Hilux.

Cheers.

Hey mate I have been thinking the same about the standard exhaust with a hiflow cat and a 18" hotdog, what are your thoughts

[CamboT]

Trouble with going too big and free flowing is there is not enough back pressure. Then the turbo can overboost or the turbo stepper motor tries to work outside its factory set perameters and then it goes into limp mode.
By all means go 3" but make sure you have some sort of muffler to help with some back pressure.