172 replies to this topic

[XXB4XX]

All these power mods you people are doing, are cool but useless.. Direct piping, intakes, filters, mufflers etc, will not make any noticeable difference to a N/A AT ALL! Im not being a dik, im being honest, your wasting your time.. the only way you will ever get more power from an N/A is to do internal engine work, which will be more expensive then just putting a turbo kit on.. If you want any power difference there are some things that need to be addressed which are the basics to more performance. 1st - Why isnt there anyone here with an N/A that has played around with different types of cams?, a good cam set will get you more intake and exhaust which = more power!! pod filters = 0.000001kw power! 2nd - Why dont you people continue with the group buy and get some extractors!! extractors = atleast 3-5 KW's if not more!! CAI = 0.00001KW 3rd - Why not do some cheap headwork?? for about $400 you can get your heads ported, polished and shaved 40thou to increase compression and flow! this = atleast 5-10kws at a minimum! 4th - Port match your heads to your exhaust! this will increase the flow without restriction!! = atleast 2kw's. 5th - Valve springs, harder valve springs ensure no leak from the cylinders and more even fuel combustion, along with a good set of cams this = another 2kw's if not more + better driveability and torque. 6th - all you Auto's, go install a shift kit in the gearbox, $400-500, will give you firm and hard shifts from each gear without that dreaded wait time from gear to gear! 7th - look at larger throttle bodies with other subi's that give you more flow! there is more power gained here and cheap! 8th - Diff ratios, this is one of the most important, a good high revving set can awaken your car like you wouldnt believe Im only doing this thread as a reference point for you N/A people, too many people are posting questions about things that cost a fortune with NO or little power difference. feel free to tear my post or me apart, but all of the above is the truth and WILL make a difference. If anyone wants to add something I have missed, feel free. Brendan.

[SUBARU]

I reckon we lock this thread down and sticky it. What you've written is pretty spot on and doesn't really need to be added to in the case of the NA Subaru's.

[Not Marv]

Something needs to be added: For all the great info in the post above, you'd be wiser to just convert the car to a turbo set-up. It should have more power and be nicer to drive around town than a worked NA. Don't get me wrong, I love NA engines (more than turbo engines), but I don't see it as making sense to pour all that money in where a better alternative is going to be cheaper.

[SUBARU]

That info was put together purely to help slow down the amount of topics being posted about "How do I get more powa out of my NA?" We all know that it's an expensive venture to mod an NA to the level that indicated above, but it's merely a resource, not a suggestion of what should be done.

Edited by SUBARU, 29 August 2008 - 02:07 PM.

[fatcat67]

Something needs to be added:

For all the great info in the post above, you'd be wiser to just convert the car to a turbo set-up. It should have more power and be nicer to drive around town than a worked NA.

Don't get me wrong, I love NA engines (more than turbo engines), but I don't see it as making sense to pour all that money in where a better alternative is going to be cheaper.

I think that is the only conclusion that can be drawn from reading through that post Ian.
But as you've heard some people just need to be different, so we'll always be subjected to the Supercharge, stroker, bla bla bla my N/A is hot shit.

[Mav]

well said still suggest a nice zorst and extractor setup ifyour just starting out

[Mav]

or cant get into a turbo due to licence / insurance restrictions

[Not Marv]

I think that is the only conclusion that can be drawn from reading through that post Ian.
But as you've heard some people just need to be different, so we'll always be subjected to the Supercharge, stroker, bla bla bla my N/A is hot shit.

I have to admit I got a few lines in and went... "yeah ok, great way to spend $5k to get a 300rpm powerband, 150km less to a tank of juice and a whole 20kW more".

NA Subarus?

zzzzzzzzz...zzzzzzzzzzzz.....zzzzzzzzzzzzzzzzzzzzzzzzzzzzz...

[boost]

Buy my RS!! IT'S CHEAP!!

[XXB4XX]

Well said all yo, especially SUBARU, your right, it's just a resource to stop the ultimate spammage of "Will a pod get my 2.5L N/A 10 kw's??"

[Soop]

This is a controversial topic always.

Brendan, I agree that modifying an NA seeking peak KW outputs is down right dumb.
But telling people "Don't bother, it will result in 0kw extra." is telling half truths.

No modification will result in much more than 5kw@w, what i mean by this is. Out of all the extra things I've done to my car, this is very little difference to be seen on the rollers.
BUT, The way the car responds to throttle adjustments and the rate at which the car accelerates has greatly improved.
In stock form, you could depress the accelerator to the floor and the rev's would slowly build and then the transmission would kick back and it would go a little.

Now as you accelerate the revs move with the throttle and the car does actually speed up. If simply mash the pedal to the floor, the gearbox kicks back immediately and will pull you back into the seat a bit. On the odd occasion it's managed to chirp the tyres and torque steer has become a wee problem (in the wet its atrocious).

Compared to stock, my sedan is a totally different vehicle to drive. Much more enjoyable.
Having said that, it will never get the adrenaline pumping, or make you actually work to drive the thing. Which is what you'll get with a performance turbo Subaru.

I need to put it back on the dyno next dyno day we hold (Jarrod!), and run it while its healthy (Last time it had a mcrooted AFM and fouled spark plugs) to confirm how much difference the modifications don't make on the Dyno. But in any case you will notice a changed in the performance of the engine.

Now a few comments on issue's you posted in your first post.

1st - Why isnt there anyone here with an N/A that has played around with different types of cams?, a good cam set will get you more intake and exhaust which = more power!! pod filters = 0.000001kw power!

Primarily because they're are no aftermarket cams available for the NA EJ's. I looked into regrinding a set of EJ25D cams. And was going to cost around $500 for all four.
Then you have fitting costs, and the cost of new valve springs.
Is it worth it for 10-20kw?

2nd - Why dont you people continue with the group buy and get some extractors!! extractors = atleast 3-5 KW's if not more!! CAI = 0.00001KW
I find it hard to believe that they gain you 5kw's.
The bottom end torque is substantially improved, by the seat of the pants test. But with a standard exhaust in place i seriously doubt the engine could run efficiently enough to make more power.
Neither the CAI or the extractors will have much benifit by themselves.
Combine to two how ever and it all adds up. Open up the intake and free up the exhaust and the engine will love you for it.
It will respond faster and rev quicker.

4th - Port match your heads to your exhaust! this will increase the flow without restriction!! = atleast 2kw's.
The Subaru heads flow quiet well for the needs of the engine. The primaries on the extractors are far bigger than the ports of the engine.
That coupled with the costs of doing this make it a moot point.

6th - all you Auto's, go install a shift kit in the gearbox, $400-500, will give you firm and hard shifts from each gear without that dreaded wait time from gear to gear!
Seriously not worth it.
You can buy and fit an NA 5spd manual for around that if not less (Fitting by yourself + mates.)

7th - look at larger throttle bodies with other subi's that give you more flow! there is more power gained here and cheap!
EJ257 uses the same diameter throttle body as the EJ22NA. 'Nuf said.

8th - Diff ratios, this is one of the most important, a good high revving set can awaken your car like you wouldnt believe
Auto's use a 4.11 final drive.
Manuals are 3.9.
You could convert to a WRX 4.11 manual or STi 4.44 if you wanted, but it wont get you much really.

5th - Valve springs, harder valve springs ensure no leak from the cylinders and more even fuel combustion, along with a good set of cams this = another 2kw's if not more + better driveability and torque.\
The standard cams wont rev past 6500rpm anyway.
So unless you get custom cams made, this is a waste of time.
As i stated before, custom cams are quiet expensive.

It's not like the old holden V8's and 6 banga's mate. These things run just about as good as they're going to from the factory.

I hope this is somewhat useful, like always this is just my opinion which i have formed after a fair bit of research and practical tests. Take it or leave it.
Cheers, Paul.

Edited by Soop, 01 September 2008 - 10:53 PM.

[Mav]

nice write up soop. good to see you put some thought into it hehe,

[Not Marv]

Keep in mind that when you want to put a turbo gearbox in an NA car you need to change quite a bit as the clutch type is totally different (hydraulic vs cable)

[Blaeven]

mmmmm.... high revving boxer engine... now to source me some monies... the cops will never know... i'm joking... i'm not going to pour that much money into an NA lib... if i wanted something fast and NA then it would involve 6 cylinders... (damn p plate laws)

[SUBARU]

if i wanted something fast and NA then it would involve 6 cylinders... (damn p plate laws)

You can drive a car with 6 cylinders on your P's...

[Soop]

Technically your not allowed to do engine conversions. But i reckon you could get away with a H6 in a Gen2.

[SUBARU]

Technically your not allowed to do engine conversions.

But i reckon you could get away with a H6 in a Gen2.

Not sure that he was talking about a conversion, but talking about driving a modded 6 of some description.

A conversion to an H6 would be a ball breaker!

Miles did one didn't he?

[Soop]

Al did. But being on P's its a no no. But they don't care. So long as it doesn't go PTSHHH, they're happy.

[Mav]

or rumble like a nice v8.

[Soop]

One question i will ask. Why has no one looked into a stronger ignition system? More bang = hotter burn = more efficient burn = theoretically more power. I'll have a squiz into whats involved.