full exhaust for sti v7? 3inch 0r 2.5 ?

[ROYALS STI]

Hi there looking at getting a full exhaust for my sti and have been told to go 2.5 inch all the way but have found to be a lot more expensive than a full 3 inch? 2.5 system is suppose to be better for a standard turbo ? any thoughts or recomendations would help ?

[Scoobydoo]

2.5 cuts down a lot on noise, and for factory (or a bit more) power levels would be fine. 3" is better for flow but get a good muffler so you aren't picked up for noisy exhaust issues by WOF's or traffic enforcement.

A medium approach would be having 3" off the turbo, into either a 2.5 or 3" mid section, then a 2.5" muffler. Better flow from turbo, but not a huge increase in noise.

[pl0x]

3" down pipe to 2.5" rest with a decent muffler is a good setup imo.

Where are you getting your prices from?

[boon]

 pl0x said:

3" down pipe to 2.5" rest with a decent muffler is a good setup imo.

This is what I'm running, can't say what it does for power but definitely brings the turbo on boost a lot earlier than the factory setup.

[Scoobydoo]

Yes it will because there is no restrictions in the downpipe with the Cat gone.

[ROYALS STI]

Redline doing a full stainless 3 inch system for 600 bucks at the moment,out of stock at the moment but have been told thats very cheap,has a big rear muffler which you have to put that horrible looking insert in for a wof.Dont wont the car to loud just wont the power gains really.

[GC8E2DD]

Just replace the downpipe then and leave the rest.

[pl0x]

Or cut the cat out

[ODB]

imo a 2.5" full mandrel bent system is sufficient if you plan on doing only minor mods.

3" will net you higher peak gain and work with large scale mods ie changing turbos etc but with a smaller system you will have more lower down torque for factory turbos etc.

if its not a mandrel bent you are prob better keeping the factory item.

[funkytown]

ODB speaks the truth.. on this occasion ( lols.. couldnt resist :-*)

[ODB]

 funkytown said:

ODB speaks the truth.. on every occasion and he is my god and I bow down and worship him

Fixed for ya jonny boy!

[funkytown]

baha! if it makes someone feel betterer you can think i bow down

nah on most occasions (not that i always agree) you lay it out pretty straight which is fine with me.

[spark_38]

2-3/4", I think that's what's on mine. 3" downpipe. Not too loud.

Had a 3" on my wagon is it was bloody loud! Didn't have that car dyno'd, but it made it on the track and a unofficial 1/4 mile.

[richm]

My ten cents worth....

Replacing the downpipe makes a big difference, but does increase boost levels (of course). Sound, however, stays the same, so I went for a sti genome muffler which increased power levels even more and the sound is incredible.

Don't recommend the $600 system from RLP, although they have sold 300 + of them.

Then, you get what you pay for...

[Simon C]

I have a full 3" exhaust on my V7 from turbo back, although the muffler itself is 2.75". I needed three resonators to keep the car from being droney and loud. 2.5" is quieter and has a nicer note, but 3" to future-proof yourself if you plan on powering the car up.

[Pappu1]

on the stock turbo i have had a 3inch and 2.5 inch - didnt notice any difference in performance.

the 2.5 was bit quieter i suppose

if u like me and dont really plan to get into the whole turbo swap thing then 2.5 is better as it will get u same sort of gains for a lower price.

note that not all downpipes fit the v7 sti as the older model ones hit the steering knuckle so get something v7 specific

[Guest]

im planning on getting the RAGE 3 inch downpipe to replace stock. everything else is already 3 inch from previous owner. Is the Rage Product good ? Previous owner had everything Fujitsubo.

[Johnnynz]

My first WRX had a full rage system, I liked it but it was very loud. No way it would pass noise laws nowadays.

Holy thread resurection btw...

[runrabbit]

i have a 3 inch tbe, no cat, and it is loud. Usually drive it with the silencer in as not to attract too much attention and to pass warrants.

The worse part is the can on the back is probably close to 6 inch diameter, with a four inch tip. any very shiney - so it sticks out like dog nuts.

Whats a good brand (muffler only) replacement that is smaller and still in the canon style?? ((noting the earlier comment about the STi genome)

(sorry for the hi-jack)

[sultan]

i recommend the redline performance kit even ignoring the fact it's priced really cheap. i dunno about the downpipe, as i have a twisted setup, but the rest of it is really good. sounds awesome and isn't too loud, especially with only the one reso!!! vtnz wof'd it no worries

[johnny5]

Damn old ass thread Im rocking the redline exhaust dumppipe fits good bit shonky on the rest few of the brackets didnt line up and i needed to lengthen it by 100mm but other than that its pretty good at a sharp price

[sultan]

i've had probably 8 different different exhausts on my car as both 2.0 and 2.5, twisted and non twisted, brand name and non brand name, and the redline kit is my fav

[TypeR rated]

If you are worried about sound, then get exhaust made from mild steel. Stainless steel resonates alot more and gives you a rasper note. mild steel is a softer material so absorbs some of the sound on its way through. I have a rage 2.5 siamese down pipe with my own made 2.5" stainless system after that and it is very border line on being legel haha ( have had it tested tho ) , but sounds choice when its on song. I was very keen to try and make a titanium system but autobend said they couldn't bend the pipe I had

[johnny5]

Titanium has a tendency to straighten itself thats why most titanium exhausts are lobstered