I'm just about to get the 2.5 conversion! just want to know wot people think of it and how it has performed for them! I have f con pro managment so should be able to match her up well fuleing wise.

 

2.5 is the only way to go m8 , FREE torque....

 

wot about everything else

 

Speak with Ron at Axis power racing in the States if you want detail on what a 2.5 can and should do.

Mark A

 

depedns on your budget, if you have 10k, go see scoobylcinic and the sc450 will see you right

 

I think tidgy is dead right.

You can use a 2.5 from Axis or several others as a simple cheap short engine replacement, add a slightly bigger turbo and injectors and with a re-map have a sweet engine that will last a lifetime.

Alternativly you can use that same engine for a 2.5 high output engine for a lot more $$$$$$ and can shatter the transmission!

I think that is the attaction of the 2.5 short engine out of the box, mild to wild, bhp/torque and costs to match.

 

i think its roughly 15k ish for the gearbox, clutch and engine package. sounds expensive, but to get same from else where your gonna be talking same money or more.

and heres the plus, the sc450 has been developed over a number of years and the origional development engine is still going strong after 18months in the gaffers car, so your getting performance and reliability

 

From my own personal experience, with a std 2.5 bottom end and supporting mods, expect no more than 370 bhp, and 390 lb/ft torque, to remain safe.

Whilst you can get more power, the std pistons/rods seem to be the limiting factor.

Sure you could get more outright power from a 2.0, but you will never see the amount of torque you get from 2.5.

As has been said before, this will give you a strong engine, which is great to drive, and should be relatively trouble free as regards drivetrain on a later year car especially, and is cost effective.

I had this set up in a 93 WRX though, and destroyed 2 gearboxes, although I think the earlier boxes were made of chocolate.


If however you decided to go the 2.5 with uprated internals etc ( ie SC 450 bhp) route, be ready to spend more and more,as other parts of the car start to fail....

 

to be honest 350 bhp is mega power for me! its the torque that impreses! wot sort of figures are people getting!?? and wot has it cost all in?

 

What car do you have?

Rough costs

Short engine £1500
Parts (gaskets, oil / water pump, cam belt / (tensioner?), seals, running in oil / new oil, filters etc) £500
Labour to fit it all £???
Remap /ECU £ depends on what you have

Is the basics, then if you're going for more power then consider turbo, injectors etc etc etc

 

pennie subaru are the nuts for these converstions

 

There's a group buy on for Axis Engines at the moment....

 

I have a type r v5 sti. my engines gone and 2.5sti short block seems attractive, i have hks mangement and yellow injectors, td05 turbo down pipe, nur spec, air filter, and heavy duty double cluch! so hoping the 2.5 will slot in with only a remap! and I'm looking at doing the job myself!

 

There are 2.5's and there are 2.5's in you get what I mean.

My Cosworth 2.5l engine is an awesome bit of kit on the road and track. Ok.. it was'nt cheap but then the good things in life never are.

It all depends on intended use and available budget really.

It makes my old twin scroll Spec C set-up look slow. I have the same response as the old twin scroll set-up, even with a single scroll turbo and what is reported to be the largest FMIC on the market for a Subaru. Best thing I ever did! Smooth and quieter than my old 2ltr and revs just as easily.

Building engines for power is easy..... keeping them together and reliable is something else. It's all about the complete package.

 

i would just be going for the standard sti bottom end! with my v5 heads and matching my engine management to wot i have. i need it to be strong but i'm happy with 325-350 bhp! as long as i get that torque!!

 

will be great ,give mark at lateral a ring for advice and parts , to get right compression ratio right with head gaskets. got any questions during the rebuild drop me a pm might be able to help done a few now and they work really very . ( one question what has happened to your engine ?) if its bottom end failure you need to get a new oil pump and have heads etc cleaned out well to make sure no swarf left lying around in oil galleries , oh and if you can spare 600 ish gbp more get the custom pistons mark sells. gazza

 

Thanks! i'm getting a new oil pump as i think that failed!! and a new oil cooler, a new sump (spec c as its deeper for track use) On the gaskets do i need the 0.7mm or the 1.1mm ? wot about the injectors? will they do?

 

If you are keeping to a std bottom end, due to the economics of the job, then I reckon your injectors should be fine, although you might want to consider a fuel pressure regulator in order to increase the potential of these.

As said before, ring Mark at Lateral performance regarding the head gasket size.

 

Standard 2.5 bottom end ECUTEK Map leave the 440cc Injectors and buy a fuel pressure regulator. The Ver 5/6 gearbox seems to be the best of the 5 speeds so that should be fine. Id like an 18g on it and hope for 350-350 ?????

Renno

 

Don't you think a 20g would be better?
Hope so as mine is intended for a 2.5 later.

 

sorry but wots 18g /20g???

 

Oh for sure but im just thinking ultimate safety first. He's happy if he gets 335 - 350. If he runs the 20g to the limit he could get 385 395 ( depending on other mods ) of each and with standard ej257 pistons which from what I hear MAY not be reliable at that level.

So he could get a 20g and run it at lower boost or an 18g at normal boost ??. Im sure there are people running 400 with standard 2.5's but I reckon 350 350 would be ideal and allow for that extra little bit of safety he wants. If it was my engine id go for 330-350 and if I wanted more id at least put a set of forged pistons in.

Id say injectors would be maxed out around 350ish aswell.

Renno

 

dont wanna hijack guys but what costs are involved.. from lets say out the box into the car.. for a 2.5 turbo engine into a classic rb5. not brand new im guessing just want a rough idea how much it would cost to get it to run....

 

give paul a call at pr development PR Developments and he will tell you how much and advise.

 

Best talk to one of the tuners or engine builders who do this sort of thing. Lateral supply bottom ends as do Zen among others im sure. I reckon it can be quite tempting to start adding bits and then you start thinkg I better do the clutch because there's no labour to do it while the engine is already out blah blah and then your tempted by a slightly bigger turbo ECU and kinda goes from there. But if you set a target and stick to it your laughing. All my opinion so talk to others to.

Renno

 

Renno, take your points above, and certainly I think the 440's will max out very quickly. Mine did @ 315 bhp.

As to approx costs for a drive in sick, drive out rebuilt kind of project you would be looking to sign a £3500 cheque.

As a DIY task a 1000 less at a guess.

That would be using your stock parts.

Gregory:

The 16g/18g/20g are codes given to a very popular range of turbos based on the early Mistsubishi TD series used on the WRX Imprezas.
Good solid no frills turbos. The 20g is the 380 maybe 400 bhp capable turbo, 18g a bit smaller @ 350 ish and the 16g smaller still.
They are all cheap compared to the new generation MT 321's

Many people have got very good results on 2 litre engines with the 18g, hence Renno's comments.

 

It’s always good to set yourself a budget and try your dam hardest to stick with it, however it often fails and we spend more to gain those few extra horses.

Gregory, from what you wanting from the build and what existing parts you have i wouldn’t think it will be as expensive as some think. You need to make a detailed list of what you have on your existing set up and what can be used for the new build and what cant.

I would defiantly look into larger injectors, 550 will be fine and a decent fuel regulator and pump, your turbo can be used and will changeable in the future if you decide to go any further, or if costs are an issue you can keep your existing set up for the time being and see where this maxes out then plan a change for a later date.

You don’t say what base model you are using, this would be good to no as for the gearbox and its limitations as this can be a costly part if needed, but assuming you stick to the 350 you should be fine with the existing clutch and box.

 

I think he said it was a Ver 5 Type R Un-ink.

Renno

 

Example price for a 2.5 direct swap, from one of the more reputable Subaru specialists... Zen Performance - Engine Builds

But as has been said, the costs can escalate once the engine is out, if you let them....

And once you do, you will become a very poor man, with a quick Scoob

 

I've just ordered some more stuff! In the post is a new 255lph walbro and turbosmart regulator. i've ordered new pump, sump, and oilcooler! i think my turbo is a v28 roller bearing! so wot does this mean!! good/bad news for 2.5! I think the gearbox is up for it and has a double plate hks cluch! and then that should just leave me with fitting and a remap!! so should'nt have much left to spend!! lol