Ok, so i got a 2.0ltr STI on a 2005.

If i want to do a 2.5 ltr conversion with forged rods and pistons.... Just rods and pistons...

Talk me through it? What do i need?

 

How much power do you want

You will need EJ25 block, EJ25 crank, 99.5 pistons or 100mm oversize. I would also pin the block if you are planning on going over 500, along with 14mm headstud conversion.

 

how do they pin and how much?

 

Looking at 450hp

 

https://www.scoobynet.com/subaru-par...rankshaft.html

Just add rods, pistons and bearings.

 

Then dont bother pinning or doing 14mm head stud conversion. Some uprated ARP's will do the job.

 

Why on earth would you want to go down that route in acheiving 450bhp

 

2.5 punch is fun

 

the engine you have currently is 450bhp capable why 2.5?

 

Why on earth....?

Very different attributes....

 

Just add rods, pistons and bearings......

Make it easy on me... which ones, where from, how much....?

Any traders welcome to add input!

 

http://www.ebay.co.uk/itm/SUBARU-WRX...item3ccb00be7e

http://www.ebay.co.uk/itm/SUBARU-IMP...item51a20e7271

http://www.ebay.co.uk/itm/SUBARU-COM...item3ccb1cbfdb

 

the standard crank and rods are capable of withstanding 450 however forged pistons are needed. Lateral performance will be able to satisfy ur needs for a reasonable price. If i were u i wud purchase one of there 2.1 stroker kits for 1495 +vat and build the stronger 2litre block

 

Give Andy Williams a call, WMS racing on here.

 

For a usable road engine its all about torque not power! You cant beat a 2.5!

 

Driving both is a very different experience. I love my 2.5.

 

Your current block, inc rods and pistons will achieve 450bhp.

 

I understand people have preferences of 2.0 or 2.5, but it doesn't make sense in my book changing a perfectly good 2.0 to a 2.5.
PS my current ver9 jdm sti 2.0 on simple mods is making 370 ft/lbs torque at 3200rpm.

 

Hve you ever driven a 2.5?

 

Yes. They'r good but if I already had a 2.0 engine and wanted to upgrade then I would go forged 2.1 stroker. Or if I wanted to replace the engine then Id go for a 2.35 CDB instead.

 

I guess I have a good perspective on this.

I had a 600bhp forged pinned 2.5 Classic with AVCS heads and all the trimmings. It was mental and I thought it would take some beating. It was a phenominal engine and the car was absolutely ballistic., insanely quick infact.

That said I now have a 2005 Widetrack JDM STI with a factory engine but with a Litchfield LM450 and some other nice bolt on mods. It's the best car I have ever owned.

It's not a brutally quick as the other one but it makes for a fantastic road car. The other whilst it was proper quick it was an animal on the road, a proper handfull.

450 in a well set up New age is just about perfect for a road car. With the JDM being a forged 2.0L I was expecting it to be a little laggy. It's not. I havent stopped smiling since i first drove it.

Save yourself some cash and rebuild the 2.0L. Keep the current crank, new bearings, new rods new pistons and for a couple of £k you should have a great base to start from.

One word of advice though is do it properly with all the supporting mods otherwise you will have problems on the way.