My Poor old P1 has bigend failure, the knock is very slight, but im told its fooked, the cars standard apart form center back scoobyworld pipe

to start with i was looking at a new 2.5 short block with forged pistons, but as it would be still on the vf28 how would this drive, im aware i'd need it remapped, going this way i was thinking its a good base for more power later?

then after much thought i thought of going for a new sti8/9 short block from subaru £1500+vat

now im told rebuilding the P1 block will be fine, with new crank ect, if i went this way i'd like to use forged pistons and rods, now if the bores were ok would i still need a rebore or just fit new forged standard size pistons??

also i see there is alot of cheap forged rods out there, how much and what pistons and rods would be best for my needs, i would say 400/400 would be the most i'd be going for at a later date

cheers mark

 

If your going for 400/400 then I'd suggest the 2.5. Even on the VF28 it would be very responsive and 330 would be achievable. For 400 you'd need a bigger turbo.

All that would need doing to your current engine is the replacement of crank and bearings. The p1 already has forged pistons but the rods are shyte.
So you're looking at a set of rods too.

The rods in the 2.5 are far stronger and I ran my stock 2.5 at 452 bhp for 7000 miles without problems. Its only being replaced for a stronger block and I'm aiming for 550bhp with similar torque levels.

Cost wise if your having to buy a crank and rods for your existing engine and considering short motor assembly labour costs. You're already into new short motor territory cost wise.

As I said the 2.5 conversion would be my choice. Just choose a tuner with a good reputation to do it for you. RCMS, Zen, Tracktive and API would be my recommendations

 

so if i went for the 2.5 would i really need forged pistons at the power levels im going to be at?? or is it worth doing just to be safe

its not easy making the right choice is it lol

mark

 

2.5 will be fine at 400/400 as it comes out of the factory.

Its upto you, at the end of the day its what power you want and what budget you have.

But a 2.5 will p*ss 400/400 all day long providing its based on the semi closed EJ257 bottom end as opposed to the oped deck EJ25

 

sounds like the norm with a p1, all i done when my ends went was a crank, uprated oil pump, acl racing bearings, seems fine at the mo, 10k since rebuild, hope this one lasts, had 3 other bocks already

 

You wont know if your bores are ok until it has been stripped,cleaned and measured with a bore gauge.
If rebuilding the engine( P1 with Subaru HF Forged Pistons or a EJ257 ),it's always wise to go for Forged Rods and Pistons to make it "future proof" because you will have peace of mind that the botom end will handle all your future mods.

Mick

Mick

 

Speak to David @ API for options .........


Daz from experience knows his stuff though.