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-   -   500bhp from a standard 2.5 (https://www.scoobynet.com/scoobynet-general-1/828369-500bhp-from-a-standard-2-5-a.html)

Shaun 09 May 2010 03:40 PM

2ltr engines do not have proper "forged" pistons as OE, however, as you suggest some OE 2ltr engines have ran 450-500bhp..... but this entails an element of risk and is dependant on type of use expected.

As already highlighted.... whilst achieving these types of figures for a dyno or being used to pop down the shops is one thing (which I believe get's lost in some of the sales bull****). Getting it to maintain reliability on track, competition and hard use is entirely different. The likes of Rob North (who ran a 490bhp Spec C on standard 2tr internals) who used his car for competition had a proven reliability record..... but that does not mean it would still be the same in another 10k miles. The likes of Rob, myself and others accept these risks because at these kinds of levels nothing is bullet proof or guaranteed..... no matter what spec you have.

People are constantly trying different things and the game is continously moving on.

On my latest 2.5 build we decided to go high compression. Along with the increased response and better burn, it also meant we were able to achieve more power with less boost. In low boost mode on VPower my engine is still making circa 480bhp at a paltry 1.4bar on a standard position AET GT30 turbo. Not a lot of boost. Even 600+bhp only required 1.85bar at peak power (on the same AET GT30 turbo), admittedly on race fuel.

Certainly headgaskets are an issue. Moreso on the 2.5's. Mine decided to pop at just over 9k miles after continued use at well over 2bar.... the final set of 2.5bar run's seemed to fuel the demise of the HG's! :D However, the engine did have a fairly hard life.

In my opinion a lot of what success you have, is who you work with to reach your goal! Having said that, no one can overcome the laws of physics...... but it's fun reaching goals that were not long ago, thought impossible. :)

Westwood2006 09 May 2010 05:54 PM

Dam, all that money I spent on a new block, uprated oil pump, forged pistons, steel conrods and uprated bearings etc etc etc (and etc) was a complete waste of time!

/s

jd5217 09 May 2010 06:07 PM

define "proper" forged pistons

Westwood2006 09 May 2010 06:13 PM


Originally Posted by Shaun (Post 9388788)
some OE 2ltr engines have ran 450-500bhp..... but this entails an element of risk and is dependant on type of use expected.

I think the key part of this post is "have ran" as opposed to "are running"!!! :thumb:

jd5217 09 May 2010 06:16 PM

Mine has been running at 450bhp for in excess of 3 years now.

Westwood2006 09 May 2010 06:26 PM

Lets both do an afternoons worth of 1/4 mile runs with a couple of high speed runs thrown in for good measure and see how we both get on!!!

IMHO you have been lucky.... so far.

jd5217 09 May 2010 06:27 PM

done a season of drag racing in the 3 years

Westwood2006 09 May 2010 06:30 PM

Like I say. Very lucky.... good for you mate. This isn't the norm though.... unless you were doing 16 second runs or something?

jd5217 09 May 2010 06:33 PM

I put it down to the parts being well chosen / fitted and the mapping being spot on.

Westwood2006 09 May 2010 06:39 PM

What mileage you on / how many miles at 450+? What model? What year?

jd5217 09 May 2010 06:41 PM

2004 sti uk. would have to check mileage.

Shaun 09 May 2010 06:51 PM

Westwood2006,
Why have you wasted your money?

Whilst I am not advocating 450-500bhp from a OE 2ltr engine, the fact does remain (whether we wish to state it is by fluke or not) that these do exist and some have taken a right beating. However, I do think this level is pushing it a bit. Luck goes a long way and even spending cash on buying the bits you think can cope, does not always mean such. There are plenty of stories out there to prove that one! :D

At the end of the day when you start to use these cars under the remit that has been mentioned on this thread, let alone when you start to increase power and modify as well, you will always have an element of risk. This is a simple fact that I do not think is really understood by many.

There was an element of risk that when we ran race fuel in my engine and increased the power by the factor we did, something could of let go. The risk was assesed and accepted (however small, but you need to be realistic). To a degree I think fortune really does favour the bold (or is that stupid)! :D Go in to this with your eyes wide open and it certainly helps dealing with whatever happens as a consequence.

jd5217,
I believe the term "forged" as regards to OE piston's is somewhat different to the actual process that is undertaken with aftermarket "forged" pistons.

Westwood2006 09 May 2010 07:47 PM

Why have I wasted my money? :lol: Dude, that was waaaaay below the belt :nono:

Started writing a loooong reply, but just can't be bothered to discuss costs TBH. No disrespect.

I'm not interested in luck. I have 1 daily driver that I rely on for work and I have had 2 OE engines pop. That gets old real quick.. My philosophy now is build something strong and run it under what it should be able to cope with. Looking at my costs the engine was actually only 25% or so of the total project cost.... I'm at 450 /485 on my current build and this year I'm doing some tuition and a couple of events. So we'll see how she holds up.

I think encouraging others to push OE engines to these limits is a little irresponsible. People are going to get caught out. Yeah a handful have "got away with it for a while" but it depends on so much. age, mileage, driving style, mapper etc etc. Not to mention that missed gear or what ever in the heat of the moment.

But each to their own. You have your experience and I have mine. And I suppose your tag line should count for something. What do I know? I'm just some guy.

I'll run my car the way I think it should be and you run yours. Same applies to everyone else. It's all good.

That's the way life is.... and we'll all be here to share it. Bottom line? You pays your money and takes your choice.

TheVoices 09 May 2010 08:42 PM

I think Shaun was refering to your 'tongue in cheek' statement in post 32 !

He isn't having a go, actually agreeing with you.

Shaun 09 May 2010 09:21 PM

:D As TheVoices has just said. Don't worry I to have misread things before... it happens. :)

Westwood2006 09 May 2010 09:37 PM

Ah I see what's going on. "/s" in my post 32 means "sarcasm".

All good here... I think I misunderstood you as well :thumb:

Shaun 09 May 2010 09:40 PM

I thought you were just signing off with the "/s". :cry:

Anyway... at least that one is sorted. :D

Westwood2006 09 May 2010 09:47 PM

:norty: Just in case you think I'm Bull****ting http://en.wikipedia.org/wiki/Sarcasm

FTA:

"It is common in online conversation to use a pseudo-HTML element: <sarcasm>You are such the internet tough guy.</sarcasm><sardonicism>Yeah, that's really going to work.</sardonicism>[10]. Many times, the opening tag is omitted, due to the HTML tagging often being an afterthought. Similarly, and common in social-news-based sites is a single /s placed at the end of a comment to indicate a sarcastic tone for the preceding text. A "rolling eyes" emoticon is often used as well, particularly in instant messaging".

:D


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