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2.0ltr to 2.5ltr Conversion Q...

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Old Oct 4, 2012 | 04:56 PM
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Default 2.0ltr to 2.5ltr Conversion Q...

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?
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Old Oct 4, 2012 | 05:15 PM
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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.

Last edited by KAS35RSTI; Oct 4, 2012 at 05:26 PM.
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Old Oct 4, 2012 | 05:41 PM
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how do they pin and how much?
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Old Oct 4, 2012 | 06:08 PM
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Looking at 450hp
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Old Oct 4, 2012 | 06:11 PM
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https://www.scoobynet.com/subaru-par...rankshaft.html

Just add rods, pistons and bearings.
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Old Oct 4, 2012 | 06:11 PM
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Then dont bother pinning or doing 14mm head stud conversion. Some uprated ARP's will do the job.
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Old Oct 4, 2012 | 06:15 PM
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Why on earth would you want to go down that route in acheiving 450bhp
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Old Oct 4, 2012 | 06:17 PM
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Originally Posted by rickya
Why on earth would you want to go down that route in acheiving 450bhp
2.5 punch is fun
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Old Oct 4, 2012 | 07:29 PM
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the engine you have currently is 450bhp capable why 2.5?
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Old Oct 4, 2012 | 08:04 PM
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Why on earth....?

Very different attributes....
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Old Oct 4, 2012 | 08:07 PM
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Just add rods, pistons and bearings......

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

Any traders welcome to add input!
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Old Oct 4, 2012 | 08:29 PM
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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
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Old Oct 4, 2012 | 08:37 PM
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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
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Old Oct 5, 2012 | 06:19 AM
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Give Andy Williams a call, WMS racing on here.
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Old Oct 5, 2012 | 07:56 AM
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For a usable road engine its all about torque not power! You cant beat a 2.5!
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Old Oct 5, 2012 | 08:13 AM
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Driving both is a very different experience. I love my 2.5.
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Old Oct 5, 2012 | 08:33 AM
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Your current block, inc rods and pistons will achieve 450bhp.
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Old Oct 5, 2012 | 05:18 PM
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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.

Last edited by rickya; Oct 5, 2012 at 05:19 PM.
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Old Oct 5, 2012 | 05:27 PM
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Hve you ever driven a 2.5?
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Old Oct 5, 2012 | 07:43 PM
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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.

Last edited by rickya; Oct 5, 2012 at 07:44 PM.
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Old Oct 5, 2012 | 08:12 PM
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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.

Last edited by dazdavies; Oct 5, 2012 at 08:14 PM.
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