More BHP required ?
27 November 2011, 06:42 PM
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More BHP required ?
Hi , I have a standard 2.5 sti can anyone let me know how to get more BHP what route to take what can be done DIY and what i have to get done by specialists and do i have to upgrade any of the drive train cheers dave
27 November 2011, 06:54 PM
#2
Hi,
Your drivetrain will be fine for 500+ bhp,
Your 2.5 block on the other hand is not, If it is still standard a re-map will release quite a bit and should see you on 340bhp /350+ torque, Not sure on exact numbers but the 2.5`s can have issues with headgaskets and even piston ringland issues on the 08 plate onwards, Dont hold me to it but i wouldnt suggest going too mad with it unless you change some internals, So in standard barring exhaust,turbo swap i would cap it around the 400 bhp mark, Even this might be a little much for longterm reliability,
Gaz.
Your drivetrain will be fine for 500+ bhp,
Your 2.5 block on the other hand is not, If it is still standard a re-map will release quite a bit and should see you on 340bhp /350+ torque, Not sure on exact numbers but the 2.5`s can have issues with headgaskets and even piston ringland issues on the 08 plate onwards, Dont hold me to it but i wouldnt suggest going too mad with it unless you change some internals, So in standard barring exhaust,turbo swap i would cap it around the 400 bhp mark, Even this might be a little much for longterm reliability,
Gaz.
27 November 2011, 06:57 PM
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All those 2.5 STi engines suffer the same Gaz (the map was a little more agressive on the hatches though), I would cap it at around 350/360bhp unless you want to rebuild the engine?
Tony
Tony
27 November 2011, 07:13 PM
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Had ringland failure on my 06 SpecD running 345hp 385lbft torque (remaped 3 inch exhaust sportscat and filter) Head gaskets were fine, std clutch held up well.
Good excuse for a forged rebuild!
Good excuse for a forged rebuild!
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27 November 2011, 08:36 PM
#8
But isn't there still an issue with the lack of metal between cylinder bores? Hence 'only' running 450 odd. That's why I didn't necessarily mention a rods change (although, I accept that if you were going to forge, most people would do the rods too, as matter of course)... 
Last edited by joz8968; 27 November 2011 at 08:51 PM.
27 November 2011, 08:40 PM
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It has been said to me that a completely standard EJ257 block is good for 600+ , i cant remember who said it but it was definately someone who's opinion is worth trusting, it's one of my past threads/posts, i think any further mods are just insurance, how the open deck block compares to the SCD block i have no idea.
27 November 2011, 08:47 PM
#10
It has been said to me that a completely standard EJ257 block is good for 600+ , i cant remember who said it but it was definately someone who's opinion is worth trusting, it's one of my past threads/posts, i think any further mods are just insurance, how the open deck block compares to the SCD block i have no idea.
Will handle 600bhp,but you will need get block pinned and for this i would suggest too 14mm ARP studs
Jura
27 November 2011, 09:15 PM
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Pinning is a metal rod which is inserted between the outer bore wall and the inner casing wall to provide additional strength/support
i found the post i was talking about aswell...
We don't pin 2.5 blocks, although as we've run them to over 600 bhp without pinning, we don't worry about it too much.
i found the post i was talking about aswell...
Originally Posted by Alan Jeffery
Originally Posted by PaulJC
Cheaper than i thought it would be tbh,do you pin blocks aswell? (Depending on which is better, 257 Semi CDB, Pinned, or Linered?)
I could actually be tempted to build a pre emptive forged short block.
I could actually be tempted to build a pre emptive forged short block.
27 November 2011, 09:16 PM
#14
And this thread hope so will answer your questions
http://bbs.22b.com/cgi-bin/ultimateb...=005745#000032
Jura
27 November 2011, 09:20 PM
#15
Those pic's pain a thousand words, ta.
Yeah, I knew dazdavies had had his done.
But.... surely a 2.5 CDB would sort out any 'weakness' issues, then? But prob too dear for Subaru to produce?
But enginetuner ^^^ doesn't seem to have a problem with their 2.5 builds, anyway!
Yeah, I knew dazdavies had had his done.
But.... surely a 2.5 CDB would sort out any 'weakness' issues, then? But prob too dear for Subaru to produce?
But enginetuner ^^^ doesn't seem to have a problem with their 2.5 builds, anyway!
Last edited by joz8968; 28 November 2011 at 08:55 PM.
27 November 2011, 09:26 PM
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27 November 2011, 09:52 PM
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When you think of it how many people truely run OVER 600bhp and use it all...
27 November 2011, 09:54 PM
#19
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Remap and straight through decat exhaust.
28 November 2011, 07:58 AM
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Last edited by petedotuk; 28 November 2011 at 07:59 AM.
28 November 2011, 01:27 PM
#21
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Ej20 can be stroked to a 2.7 Joz...
http://www.tonyrigoliperformance.com...e_engines.html
http://www.tonyrigoliperformance.com...e_engines.html
Thats cool
I know the ej25 can go up to 2.7 because its slightly bigger.
30 December 2011, 09:51 PM
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Not sure on the new 3rd gen engines though, not that many details about the 2.5ltr v 2ltr on that front as yet
Tony
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