Front pipe size? Standard?

[benl1981]

Anybody know what size the standard front pipe is on a R33 RB25DET?

Is it 2.5" - 63mm??

Anybody had good results with just changing the front pipe to 2.75 or 3"?

Or is the dump pipe section still a fair restriction?

Some firms sell just the front pipe. I can get a cheap front pipe or get one from the turbo back from Batmbl on these forums,.

Thanks

[benl1981]

Anybody know what size the standard front pipe is on a R33 RB25DET?

Is it 2.5" - 63mm??

Anybody had good results with just changing the front pipe to 2.75 or 3"?  

Or is the dump pipe section still a fair restriction?

Some firms sell just the front pipe.  I can get a cheap front pipe or get one from the turbo back from Batmbl on these forums,.

Thanks

bummp

[benl1981]

[bumpo

[cameron]

Get the full dumpipe from turbo back to the cat.

Other wise its pointless doing half the job. - Yes power gain's are noticable.

Jun

[benl1981]

Thanks Jun - point taken about the half job.

I really don't want any noticeable increase in noise, currently 3.5" cat back but fairly quiet. I was wondering whether just the front pipe maybe good trade off between power and sound..i..e will the full 3" dump/froont increase the noise level?

[benl1981]

Anybody know about this - I'm trying to decide...

would be perfect if somebody had a cat back that was fairly quiet (about 3.5") with stock front exhaust - then swapped to 3" front dump and could tell me how much noiser it was!!!

Thanks

[cameron]

Hey Benl1981,

The noise increase is fairly little for a mild steel dumpipe but with a stainless its a little bit louder. - Nothing much to worrie about as its hardly noticable.

Jun

[ix9]

I've had a 3.5" Front pipe, 3.5" Cat-back (TRUST System)

And have recently put on a 3" split-style stainless dump pipe - and by god it certainly howls on boost now, quicker spool up, and an awesome sound - so yes, just the dump makes quite a bit more noise

[benl1981]

I'm thinking of going a 3" combined front/dump bellmouth style one..will this increase noise you think? Maybe I should just go the front pipe upgrade (without the dump), but then will that be worth doing?

Hmm - hard to know...thanks!

[32vspecII]

i added that a combined 3in front/dump in mild steel and hiflow cat after running with just a japanese cat and the increase in noise wasnt that noticable . certainly nothing like adding the cat back vs the stock catback . on high throttle the midrange was a bit more growly but not heaps louder or droney

[cameron]

Its probrely cheaper to go the full 3" from turbo to cat - one piece. $380 for JustJap I think.

It's not work doing half the job, becuase you'll still have restriction their.

The air flow will go somthing like this:

Out of the engine through exhaust housing on turbo into big 3" dump then into small 2" - 2.5" or what ever size they are standard then back into 3" you get the idea. So its still got a restriction their and that little bit of pipe thats smaller than the rest does make a fair big difference performance wise. If you want to make you'r exhaust more quiet, Put another resonator on their.

Making any change to you'r exhaust - from standard to aftermarket, you will get a little more sound to you'r exhaust note, but nothing drastic.

Jun

[benl1981]

Hey Arkon - did you notice much power gain?? I've got a 4 door like yours

I'm thinking if I fit in and find it too noisy I might put on a standard cat back and sell my cat back...although I would have to source the standard cat back.

The dump/front alone would be more of a gain than the catback right? Is the standard cat back that restrictive?

turbo to cat - batmbl does them on these forums for 250...