3" or 3.5"? Whats better?

[Gester]

Just wondering what would be better. A full 3" exhaust or 3.5"? Is it worth getting a 3.5" exhaust?

Would I notice much difference?

[maximumrpm]

since you have a turbo car a 3.5inch would be better for top end power...but it depends what your goal is...top end you would get a few extras kws

[Sydneykid]

3 inches from the turbo back is fine, and definately better than a 3.5inch cat-back alone.

By the way, its not all about top end and kw's....

Son of Sydneykid

[maximumrpm]

yeah you lose bottom end power with a bigger exhaust system but you gain mid to top end power

[sLo-32]

What about 3 inch from the turbo and 3.5 from the cat back?

Thats what i got....is this a reasonable setup?

[Sydneykid]

thats a good setup slo-32.... does the turbo back have a separate dump pipe??

Son of Sydneykid

[doxximus]

cool my exhaust is 3.5 cant wait to see how my car is i like more top end than bottom end most of the time

[Sydneykid]

Try it with a full exhaust, notice the difference...cat back is only half the job

[sLo-32]

Son of Sydneykid: Do u mean a seperate dump pipe that comes off the wastegate? Because i'm pretty sure its one pipe Covering the turbo housing and the wastegate ( i'm not sure whether thats the right way of putting it ) Basically...its a 3 inch dumpipe from the turbs....3 inch cat and from the cat back a 3.5 inch.

[Sydneykid]

Slo-32 - 'zactly what i mean.

[sLo-32]

Nah...I dont have the seperate dump pipe....well i'm pretty sure i dont

Is it actually worth getting the seperate dump pipe for the wastegate on the stock turbo? Dont mean to hijack the thread

[Sydneykid]

Well, it is, its still more efficent, but the more power you make, the more in need it becomes

[Gester]

Yeah im probaly gonna get the twin dump pipe so it has a seperate pipe from the wastegate. Is this much of an improvment cause its like $700 just for the twin dump alone.

[Guest SXU29T]

ive been told by exuasht shops it doesnt make a diff...

[Ronin 09]

i've got a separate waste dump, 3" front pipe, 4" cat back. Definetly more top end. Sydneykid, how much louder is a screamer dump, and what does it sound like?

[aybee]

screamer pipes are very loud!

sounds like a scream

[Guest 382 GZV - 4 Door R33]

How much rwkw are you expecting to get gester??

I would have thought that a 3" was fine for standard size turbo and over 300rwkw.

I even heard of a VL turbo (has an RB engine so it's acceptable) doing 8 sec 1/4 miles was using a 3" system.

The note's probably louder if that's what you want - or else you can do what I do and have a 3" exhaust with no muffler. That is loud enough ........ well it's been getting softer lately, I think it may be me going deaf to that frequency though :zap:

[Gester]

Yeah just that I have a choice between 3.5 and 3" so if its pretty uneccesary then I'll just stick to 3" as lower range power is better for me. Im aiming for around 180-200kw.

With the muffler I know usually they dont make much of a difference but surely a twin tip muffle would be different then say a 4" tip? What would be the best sort of muffler to get with a 3"?

[Ronin 09]

180 - 200 rwkw? mine only has the full exhaust and cold air intake and it makes 174.

Twins look good on a skyline, it is a bit different to the generic 4" tip like mine.