Page 1 of 10

Increasing Performance of the H6

PostPosted: Thu Jan 28, 2016 3:36 pm
by Swipez
Hi guys, thought I'd post a quick run down, hopefully answering the debate about mods to have your EZ30 Liberty make more power. This can be considered an expansion thread on JTR's "H6 Performance Mods Do Nothing" thread. Thanks to JTR for putting that together for us, I thought I'd just touch on it too.

On the base tune from subaru, NO mods will increase your engine's output. Changing the air intake will result in nothing but you losing money, and if installed incorrectly, the cops slapping a canary on your window.

An exhaust upgrade, like a catback system will do nothing but make it louder, perhaps change the throttle response depending on the diameter of the piping. Please ensure you don't use anything bigger than 2 1/4 & 2 1/2 inch piping. It will not do you any favours. The only 'gain' you might find with a tuneless mod, is exhaust headers, you'll think that you've increased your power but in fact, you've moved the torque curve slightly lower, so it'll pick up a tad sooner through the rpm range than stock.

A H6 liberty NEEDS a tune in order to make more power+torque. If you want to make power on these cars, acknowledge that you're gonna have to spend cash on supporting mods, in PREPARATION FOR the tune.

You can make more power on a 100% stock car after a reputable tuner tunes your car... Yes. But to make the most of a tune, the following mods should be done -

On a budget:
Catback Exhaust system... That's literally about it.

If you want a bit more out of your tune:
*edit*
Bigger fuel pump, ONLY if running E85 on N/A engine. (This is where the power gains are at)
Catback + headers

Going all out:
Fuel pump,
Full exhaust system including high flow cats,
CAI,
Maybe bigger injectors, but I don't really think are necessary.

Bottom line, you need a tune in order to make power. Don't fool yourself thinking your new mufflers gave you heaps more power, save yourself the money and get a tune from a reputable tuner who can really get the goods out of your engine. :D

Thanks dudes. :) :) :) :) :)

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 10:12 am
by vertix
Good write up! It really seems that after the mods you mentioned, if you still want more power you basically only have the following options:

Convert to e85
Go forced induction

e85 is probably the easiest/cheapest quick win you can do for decent power, though obviously depends on availability.

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 11:00 am
by BillyCorgi
".....Gotta love the smell of E85 in the morning....."

Caltex - Moorebank
Caltex - Casula
United - Yagoona
United - Bass Hill

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 11:41 am
by dr20t
Unless you plan on running e85 and/ or boost, upgrading your stock fuel pump is a waste of money for an n/a car. Sam with injectors

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 8:03 pm
by kiahatsiu
dr20t wrote:Unless you plan on running e85 and/ or boost, upgrading your stock fuel pump is a waste of money for an n/a car. Sam with injectors

Came here to post exactly that.

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 9:06 pm
by RX25SE
dr20t wrote:Unless you plan on running e85 and/ or boost, upgrading your stock fuel pump is a waste of money for an n/a car. Sam with injectors


Yep.

If it cant ingest the air, it cant burn the fuel.

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 9:16 pm
by dr20t
RX25SE wrote:
dr20t wrote:Unless you plan on running e85 and/ or boost, upgrading your stock fuel pump is a waste of money for an n/a car. Sam with injectors


Yep.

If it cant ingest the air, it cant burn the fuel.


I've heard many many workshops and mechanics recommend upgraded fuel pumps to those not in the know - its a joke.

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 9:22 pm
by RX25SE
For some reason people (and I include those that should know better) seem to think that if you can deliver more fuel, you make more power and that is all that is needed.

I have stopped counting how many 'modified' cars I have seen that have black soot spread all over the back of the car.

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 9:43 pm
by HardwareBoB
RX25SE wrote:For some reason people (and I include those that should know better) seem to think that if you can deliver more fuel, you make more power and that is all that is needed.

I have stopped counting how many 'modified' cars I have seen that have black soot spread all over the back of the car.

Increased fuel pressure = increased power. That's not how it works? ;)

Re: Increasing Performance of the H6

PostPosted: Fri Jan 29, 2016 10:15 pm
by dr20t
HardwareBoB wrote:
RX25SE wrote:For some reason people (and I include those that should know better) seem to think that if you can deliver more fuel, you make more power and that is all that is needed.

I have stopped counting how many 'modified' cars I have seen that have black soot spread all over the back of the car.

Increased fuel pressure = increased power. That's not how it works? ;)



Of course - I mean how can you not make more power by uneccessarily heating your fuel which you won't burn that will only be recirculated back to the tank?

Re: Increasing Performance of the H6

PostPosted: Sat Jan 30, 2016 1:40 am
by Housemusic1
New guy here. Not new to the H6 platform, but new to the idea of E85 in my H6. So with that being said.... If I do want to run E85, besides tuning for it, I would need to upgrade the fuel pump, and injectors. Correct?

Re: Increasing Performance of the H6

PostPosted: Sat Jan 30, 2016 8:34 am
by WIDELOAD
If you're staying N/A with E85 upgraded fuel pump is req'd.
If you're boosting it + E85 you'll need both injectors and fuel pump.

Re: Increasing Performance of the H6

PostPosted: Sat Jan 30, 2016 10:50 am
by Housemusic1
Ok thanks. Are there any certain specs I need to look for in a fuel pump? Any suggestions on a good pump? Sorry for the newbie questions, I've never thought about putting E85 in my H6, until I decided I needed more power. Boost would be great, but man its expensive!

Re: Increasing Performance of the H6

PostPosted: Sat Jan 30, 2016 11:07 am
by WIDELOAD
In the vendors section on here Jackson sells a pump under his Kobe brand that is suitable for your needs.
Something in the 265lph range would be fine if you're staying N/A

Re: Increasing Performance of the H6

PostPosted: Sat Jan 30, 2016 11:09 am
by Housemusic1
I'm in the US.