Minimum Non Strangling Exhaust Diameter, 33 Rb25Det

[diante]

good evening.

was wondering what experience people have had with not going overboard on pipe size with GTS-T R33's. the motor will be left standard and i'm more into sensible decibel levels than droney/blaring exhaust notes. what did they come with from factory as around here i haven't spotted a one without some monumental drainpipe hangiing out the back.

room is at a premium and i'm thinking a 2.5 inch system reincorporating a cat as what came with the car is 3 inches through a hotdog finalizing into a 4 inch exit genie cannon with a welded on dummied catalytic outer casing. never heard the thing running through it but i can't see it being subtle.

i know that diameter means flow but surely theres an acceptable compromise to be had on a daily driver.

thanks for your time, glen.

[DVS JEZ]

3inch with 2 big mufflers. Will be free flowing and still be quiet

[R31Nismoid]

3" is the "norm". As long as you get a system with two mufflers, kakimoto as an example - it'll be right on legal which is 89-90dB

Simply on a cost basis this would be cheaper 2nd hand than making a new 2.5" system. Not sure if that is a concern or not.

3" /w 2x Muffler is pretty quiet and rarely any drone at all.

Once my car doco/video is done (it has sound) i'll post it up and you can hear it as there is incar sound and that is a 3.5" straight exhaust around

the 91-92dB marker with 2 mufflers.

If you wanted quieter again you could always get the rear muffler swapped out say, and a 2.75" or 2.5" one put on as exhaust gas would have cooled a bit.

Sound is definitely a personal preference as i said in the thread just below this. Depends on you as a person

[diante]

cost isn't a concern just yet but a lack of a cat convertor will make getting it on the road a non event so it's going to need to be started with fresh. also may need to go over a live axle as it isn't being fitted to another skyline.

i'll do some measuring and see if i've clearance for a 3 inch system. though not being a straight pipe application it's gonna wind up expensive whatever diameter i use.

thanks fellas. cheers, glen.

[R31Nismoid]

So it's not going on a R33?

I got that impression from your first post - although i did read it a few times and wasn't 100% sure

[diante]

nah sorry matey, i've picked up the heavily written off R33 purely for it's motor, box and electricals. going to be fitting it into an aussie ute i've had in spasmodic build since 2000.

i've not seen any of these engines installed in non 33/34/cefiro applications, and never one with the factory exhaust intact. was hoping a 2.5" would be sufficient as it will definitely clear but if there's no other way i'm sure a 3 inch can be accomodated. the car weighs in under that of a 33 so less than massive power is required and it'll be treated gently for the most part. i just don't wish to leave the poor thing constipated.

original plan was for a RB26 but this GTS-t fell into my lap at the right price.

thankyou again.

[discopotato03]

Well if by standard engine you mean standard turbo I'm not so sure 3" all the way through is absolutely essential .

The std turbine and turbine housing isn't real big and while 3" to a 3" cat could be ok I think you would find it easier to keep quiet with 2.5 down the back . As Nismoid said the gas cools and contracts on its way south and you don't want it to lose too much speed along the way .

Noise doesn't necessarily mean power though some think its an easy substitute .

A .