MY09 4GEN GT-B Auto - Most Cost Effective Upgrades?

[newbie_liberty]

Besides a K&N panel filter from a previous owner, it's a completely bone stock car. It's so quiet that I even hear any squeaks or rattles....!

Want to get it sounding a bit better (boxer rumble and some turbo woosh noise) and maybe extract a bit more performance out of it.

Is a tune worth it on the stock turbo?

I'm planning on getting an Xforce 3" catback exhaust, but is there any significant power benefit to going with a turbo back system instead?

Will be keeping the car for a year at most, so have set a budget of $2k max for mods.

[Yowie]

Welcome. Good pickup too.

Is a tune worth it on the stock turbo?

Yes, but do it straight after you install the other breathing modifications.

I'm planning on getting an Xforce 3" catback exhaust, but is there any significant power benefit to going with a turbo back system instead?

The power benefit comes from the forward section (dump pipe to cat). The iconic/better sounds come from the cat-back section. If your budget does not permit a tune, just get the cat-back section. If you want a power increase, go the full exhaust (or even a larger front section adapted to stock cat-back) AND get a tune.

...sounding a bit better (boxer rumble and some turbo woosh noise)

For intake noises some people go for a so-called "cold air intake". Design and quality vary. A lot of them turn out to be a hot-air-sucking pod filter in the engine bay. With the stock turbo you will not be making any more power, but the intake sounds will be louder. Almost certainly requires a tune after installing. Probably the worst "bang for buck" modification in my opinion [*braces for incoming disagreement from others*].

A much cheaper way to get more intake noise is removing the "3 litre milk bottle" white plastic resonator from the bottom of the stock airbox. If you stop there it will suck a bit of hot engine bay air but sound better. If you extend that bottom section (pictured below) with a 76mm silicone hose (and/or aluminium and/or bends) so that air is being drawn from a cooler area near the foglight you might draw some cooler air.

Will be keeping the car for a year at most, so have set a budget of $2k max for mods.

That budget will be tight, so either the budget or the wish list will need to be flexible. If cash is king, just throw on a cat-back, delete the milk bottle resonator, spend any change on replacing worn items (and/or tightening up suspension) and be done with it.

Good luck with it all.

[Stifull]

I agree with Yowie. $2000 is an awkward amount because the upgrades that provide the most increase need a $1000 tune which doesn't really leave enough for the performance upgrades like, as mentioned, down pipe etc. Removal of the resonator milk bottle is always a good one because it's only reason for being there is to make the car quieter...LOL.. What were they thinking. I think the issue is that you are not keeping the car. Personally I buy cars with no though of ever only keeping them for short periods of time. My GT is built to last and go fast for as long as I live.. Same as with my Rex..No plan of ever selling either.. Or my 4wd.. I spent $5k on GT on new and 2nd hand goodies for my GT and achieved a 50% power increase at only 16lb of boost.. In your case I would just do a cat back and resonator delete and as mentioned spend the couple of dollars left from $2k on maintainance.

[newbie_liberty]

Yeah, I know what guys mean!

I'm just trying to restrain myself from spending big $ on this when overall, it's going to still be slower than my previous few daily drives.

Besides being a bit laggy when off boost, it has adequate power (...for now)!

I'll give the 'milk bottle' mod a go over the weekend.

As for the exhaust, I think I'll grab the Xforce catback for now and have a go at fitting it myself.

[bigBADbenny]

I recommend Btssm app, for monitoring engine tune, virtual gauges/alarms eg coolant temp, datalogging and ecu learning view, diagnostic codes and ecu reset.

viewtopic.php?f=56&t=27506

Because it’s always good to know if the engine is running properly whether tuned or not!

[dmhc]

if you're going for straight up performance, get a downpipe and a tune -- it will cost you the entire budget, but will turn a sluggish auto into something much quicker. talking from experience, this was the best bang for buck mod i've done and it made a huge difference in how the car drives. good luck!

[Yowie]

Based on my recent experience, replacing an old (200,000km+) or suspicious knock sensor can wake the car up a fair bit under most driving conditions if the current sensor is worn & possibly giving false positives.

if you don't have a way to check for the regularity of knock, it's up to the individual owner whether it's worth the $150ish and and afternoon to replace a sensor on general suspicion/hope only.

[newbie_liberty]

Bit of an update.

Have the exhaust fitted and it sounds great. Exactly what I wanted.

I’m so tempted to get a tune/remap. Is it worth it without replacing the downpipe?

[Stifull]

Enjoy the new sound while you put a few more dollars aside to get a good down pipe, maybe a high flow air filter for the stock air box, they are not a big expense and then get the tune but don't wind up the boost to make too much power or you risk all you careful, thoughtful effort..

[Yowie]

I’m so tempted to get a tune/remap. Is it worth it without replacing the downpipe?

You'll get a performance (actual and perceived via throttle mapping) benefit if you do a tune with the stock down pipe. So much was true tuning my wife's stock (incl. stock dump pipe and smaller turbo than yours) Forester for 98 octane and more "go" generally.

If you're replacing the down-pipe anyway, do the tune after but if you're going to keep it as-is for a while then "tune now" makes sense. Assuming the tuner stays in business and is contactable, re-tunes after replacing dump pipes won't cost nearly as much as the first tune.

See my comments on the knock sensor above. If it's going to the tuner you don't want the tuner's hands tied behind his back because the car is pulling timing due to false positives from an old knock sensor.