To Forge or not to Forge?

[Ryan]

Rebuilding my EJ20 in my V2 STi, going to run my standard TD05 turbo with a 18g wheel, my big decision: is it worth putting forged pistons in?

[gotasuby]

are you changing computer and injectors?

[Markmcrs]

It would be cheaper, easier and quicker to just buy a brand new EJ207 short motor.

I did this for a mate with a V4 WRX.

Pulled the motor out, removed the heads and had them tidied up/faced and bolted them plus all the bits off his old motor (new water pump and oil pump though) onto the 207 and dropped it back in.

He's very happy with it.

They are a very strong bottom end.

[nt_a_foz]

+1 for the ej207....

Iv run a big end and am researching quiet a bit before i decide what i do.

Basically knocked forging on the head straight away the $$$ it cost out weight the benifets when the cost of a ej207 block is only 2.5k... Seem to be the goods and be a proven block..

[GregNZ101]

ej207 had factory boost levels of at least 18 psi i think. With that kind of boost most people are happy, and even with forgies its not best to go much further. Forgeis are going to cost more and are noisier

+1 for the ej207

[gotasuby]

if you are doing all the labour your self then forging will be cheaper. I built my own engine complete for 2500 incl full balancing. the ej207 short block is that price

[Markmcrs]

He's running a TD05H with a 18G, where is the benefit in building your own bottom end?

There is very little a built forged bottom end is going to achieve over an EJ 207 to warrant all the work involved in doing it yourself.

[Guest Rugged_RS]

So sounds like its the ej207 short block FTW!

[BC5RA]

If your going to go with the EJ207 You'll require the manifold to suit as your V2 intake manifold will not bolt up.

[Markmcrs]

If he was to use an EJ 207 long motor that would be correct, but the advice is to just buy a new short motor from Subaru and fit his heads to it.

Thus his inlet manifold and everything else will still bolt up.

[Guest Rugged_RS]

I wish i knew all about this lol

[Ryan]

Cheers for the suggestions, just going to stick with the standard block for now altho I'll keep the EJ207 in mind for the future..

[PhatRS]

Id forge it cos it gives you scope for the future, IF you wanna go for more power or race the car youve got the engine to handle it already, save doing it all over again.

[Ryan]

Yeah good point, I don't think I can afford to forge both pistons and con-rods, which takes the most beating? Thinking pistons..

[PhatRS]

Wait and do both if you ask me, if you are going to the lengths of forging pistons then do the rods too, you can get forged rods now for little more than factory ones. They both take a beating for one reason or another, if you make one strong then you end up with a weak point in my eyes.

[Markmcrs]

My 2.2 had completely stock rods...

Engine saw 24-25 psi reguarliy and with a 1/4 mile MPH of 121 was making around 260-270 kw's ATW.

Engine also saw several track days too.

So I'd be inclined to say that the stock rods hold up pretty well.

Also, if your going to the length of forged pistons and rods then building a 2 litre is a bit silly when you could build a 2.2 for the same price, with the potential for more power and for quicker spool and more torque too.

[Guest]

Where can i find this motor??? sounds like a cheap alternative for mine now that its gotta knock. possum bourne motorsports are selling a high performance one with all forged for 3800. would that be a good option to keep the motor forged and closer to the original?

[pl0x]

 matty981 said:

Where can i find this motor??? sounds like a cheap alternative for mine now that its gotta knock. possum bourne motorsports are selling a high performance one with all forged for 3800. would that be a good option to keep the motor forged and closer to the original?

personally i dont see the point in fully forged block unless it huge power or piece of mind your wanting

a v7 short block from wingers is 2.5k which has better rod design (i think) which means they dont run big ends

this also could be because of there different sump design (again i think)

what version engine is the possum one? is it only a short block?

(Edit) also a v7 block from wingers is semi forged so should handle 20psi with ease

no matter what short block you get your still going to have get seals, gaskets etc which is gna be 1k at least

and your still going to need to get the heads cc'd to make surte you get the right compresstion

[Guest]

If your engine is a v2 sti it should have factory forged pistons so no need to buy expensive aftermarket pistons, find a good closed deck block and forged rods, either eagle, scat or m&h, etc and your got something alot better then an ej207 v7 sti short block.