Liberty GTB MY07 - AM Exhaust Required?

[widowm4k3r]

Hey Guys,

Just a quick question about a (Sports Auto) Liberty GT Spec. B MY07.

I really don't want to change my exhaust, trying to keep my car stealth and I have had bad experience with AM exhaust systems in the past.
I hear from every Tom, Dick and Harry I talk to about exhausts say that the stock Exhausts are too restrictive etc etc, but am I really limiting THAT much power by not changing the OEM exhaust?

The mods I have booked in for my car to get done are as follows;

AVO;
Radiator Shroud
TMIC
Panel Filter
15PSI Actuator
BOV

AEM;
Water\Methanol Injection System to keep the engine cool, clean and eliminate the knock Auto Libs are highly prone to from high Boost Levels (Plus Detonation of course)

And a Dyno Tune to 120RON (Octane) (95RON+Water\Methanol Mix @ 51/49)

I ask because the stock exhaust isn't exactly small and I like how quiet it is, I am hoping that I don't have to touch it, but I'm curious to see what other's opinions on the matter are, my goal with these upgrades is low end torque for faster acceleration over top speed (It's not a track car)

Cheers!

[Rome_BRZ]

If your goal is low end torque you would achieve more from a full aftermarket turbo back exhuast than you would from all of the above mods put together.

It's not just about the extra power you can get from a full TBE, it's also the increased airflow, responsiveness, breathability etc.

You can still get a stealth-ish aftermarket exhaust which isn't that much louder than stock and will give you all the benefits!

[B4ITZUP]

have you consider this?

http://www.jayracing.com/index.php?main_page=product_info&cPath=1_58_376&products_id=16557

front part of the dump, only issue i can see is it might hit the steering knuckle as it's design for US market. (a fix for this is to replace it with a sti steering knuckle)
This can be installed on both auto and manual

only change the dump pipe will make a huge different without hurting the noise level

[widowm4k3r]

@Rome_STI: Thanks for the info I was that wouldn't come to that, I'm not keen to replace the full exhaust so unfortunately it's kind of out of the equation for the time being.. I still value your input though.

@B4ITZUP: Awesome! That's what I like to see, cheers mate, that I can do. The downpipe apparently is where most of the restrictions occur with liberties
(According to this guy anyway http://youtu.be/oacHbJV4YRI)
I Guess I'll have to check out the steering knuckle too, make sure I can get one of the STi's before getting a pipe. Thanks for the info!

[widowm4k3r]

FYI, After doing a bit of digging I found this info on the MRT website;

EXHAUST
(Some traps for people here, unless carefully chosen.)
Single scroll turbo engine pipes with split collector to fit wastegate is necessary and will add throttle response and is good value, with the correct complete design. High flow cat in the downpipe is best. All this adds up to a huge decrease in back pressure and a big increase in performance.

Flex joint is needed as well, with correctly located O2 sensor.
Get this wrong and the car will suffer CEL lights, deactivate the Cruise control and cause poor fuel economy.

On Sedan model the replacing the twin mufflers adds no value and should be completed as a part of a whole turbo back exhaust kit.
In some cases depending on final tune the twin mufflers in sedans can be re used with a complete exhaust.

[B4ITZUP]

personally the splitter in the dump pipe for a vf46 isn't necessary, this is because the waste gate port is opening from the bottom, so it won't interfere as much.

as appose to other turbos, it open from the side which is facing the turbo outlet



in regards to sti steering knuckle, I'm not 100% certain that the front dump requires it, however the complete 1 piece dump from invidia do required it
I remember Troy from prospeedracing had some for sale. send him a pm or email from his site, if you can't find any

or Phat...

[stew07gt]

... youre not taking it to mrt are you?

[blacktop™]

please dont take your car to MRT. and please dont take any information from their website or youtube videos.

for proof, a flex joint is not necessary in a dump pipe or the whole exhaust.

as for your initial question: yes a dump pipe (along with a tune) will get you decent results with hardly any increase in exhaust noise.

im unsure why you want to change your BOV when your trying to keep your car quiet?

[kiks]

lol water/meth..

And not 2000hp

[widowm4k3r]

Haha nah I'm in Melbourne, taking it to JJM turboworld, didn't realise MRT were that bad =\

OK downpipe has made the list, I thought having the wastegate divorced may help a little bit, I guess manufacturers will spin their products to sell them, I'm thinking for the wastegate divorced downpipe the Invidia with Hi Flow Cat and from what I've looked into it is Auto compatible and will clears the stock steering knuckle.

The Exhaust sound is the one I am trying to suppress, I actually like the BOV air rush sound, as long as it doesn't sound like a VL or that kind of ridiculous crap anyway lol.

As mentioned before the water meth kit actually has quite a few benefits to me in particular, it's a knock suppressant for high PSI tuning and I tend to drive very short distances so it works great to clean carbon deposits that are usually cleared after a bit more driving. Plus the theoretical air temp reduction you get means the engine will stress a lot less, Coupled with a bigger more efficient TMIC you can get a pretty extreme reduction air temps, I've done quite a bit of research on it. Plus If I want to I can Use 91RON fuel and still get 112RON rating just using distilled water so If I'm long distance driving and the petrol station in the middle of nowhere only has low octane fuel I can still use it, but that's just a small perc if anything else.

[widowm4k3r]

Oh the Invidia needs the STi steering knuckle? Damn, I'll have to track one down then, the Invidia Dumppipe looks pretty awesome

[PoidaGT]

Don't get the invidia downpipe like i did.

Replacing the steering knuckle was a pain in the arse and expensive.

Get a dump pipe designed for RHD cars.

Also get a decent 3 inch centre and y pipe but keep the standard mufflers.

This will give you all the power benefits without the noise increase.

I just got a mild steel 3 inch centre and y pipe fitted for $350. (X force)

I got a reasonable increase in low end and mid range torque just from the centre & y pipe.

[KiDo_Tuning]

$65 for the knuckle and takes under 10 minutes to fit while the dump pipe is off... I know, I have fitted quite a few of them

The Invidia dump needs to be the right one to suit auto, there is a part number on the USA Invidia website

Don't get the invidia downpipe like i did.

Replacing the steering knuckle was a pain in the arse and expensive.

Get a dump pipe designed for RHD cars.

Also get a decent 3 inch centre and y pipe but keep the standard mufflers.

This will give you all the power benefits without the noise increase.

I just got a mild steel 3 inch centre and y pipe fitted for $350. (X force)

I got a reasonable increase in low end and mid range torque just from the centre & y pipe.

[blacktop™]

Sorry to get off topic but how much does an invidea dump cost? And are they better than an xforce dump?

[PoidaGT]

Sorry to get off topic but how much does an invidia dump cost? And are they better than an xforce dump?

I think I payed about $800 for the Invidia dump pipe.
I really regretted it though.
I bought the STI steering knuckle for $95, couldn't fit myself, got a mechanic to fit it for $90 and then he had to get a wheel alignment for $50 to straighten the wheel.(teeth didn't align).
I now get extra vibration through the steering wheel which annoys me.
I should have got a locally designed dump pipe (Phat, AVO, X force etc)
It's very debatable to which is better.