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Hey everyone .

Just wondering on your thoughts on wether I should get a 3inch or 3.5 inch system for my GTR .

Plans are mild mods , HKS GT-SS or 2560r lowmounts and support systems to match that sort of setup . no internal changes at this stage.

Obviously bigger is better but I have found a big price jump in the 3.5 inch system so is it worth it ?

It really relies on what power goals you are after with all the mods you plan to put into it.

If its say under 300rwkw then a 3inch should be fine without restricting air flow.

Im guessing the the difference between a 3inch to a 3.5 inch is something like an extra $500?

3.5" :D

If using twins, just run a twin exhaust of a smaller size :O

i don't get it...... . .. . .

" if using twins " you mean if your putting it on a twin turbo car?? like his gtr??

sooo on a gts-t *single turbo* 3.5" is quite desirable

sooo can i go for a 3.5 on a gts-t with less than 200rwkw's?

better spooling right?

aaand quick question cuz u'v help't me sooo much in the past 2 weeks..

* iz turbo fluttering bad for my turbo? because i block't the bov off and i LUV the sound it makes

plus doesn't it increase spooling because the pressure aint going away completely?

dont hijack my thread dude!

:D

i dont remeber of the top of my head what other people with gt-ss/2560s are making but i dont want more than 3-350 max rwkw and i dont think those turbs will get to 350 anyway

it was about 700$ extra fitted for the custom 3.5inch system over the 3

but bear in mind that for a gtr that system is only going to be 3.5inch from the cat onwards , the twin fronts will probably be about 2.25 on both systems . so it seems like a lot for just a bigger cat and catback . especially given some of the 3inch metal cats are flowing huge numbers , far greater than a traditional ceramic cat in even 4inch

Hey,

As someone else said a long time ago, oils ain't oils ;) Not all 3" and not all 3.5" exhausts are equal. If you

can find something that expands from the turbo outlet at 7deg angle to the sizes you want (say expanding

to 2.5" on the dual pipes, merging to 3.5" then through a 3.5" high-flowing cat), you are in luck.

A turbo will work the best with pretty much nothing behind it - you of course can't do that, so the bigger, the better.

Bigger usually means more noise, so you need to factor that in - my old 4" is 95dB@3500 - and that's with the turbos,

twin cats, a resonator and muffler to shut it up. My old exhaust isn't really suitable for a road car - very deep, nice

note - but very loud.

Personally if you can put up with the noise I'd go for 3.5" - it depends what your needs are. The difference in top end

between 3" and 4" is noticeable - so I'd guess this would apply to 3.5" too (all other things being equal).

Given that you're concerned about cost a dual 3" is probably not an option for you? If the price difference is so big

you might want to ask about that...

Regards,

Saliya

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