I am not expecting anything Adam, but that doesnt mean problems will not happen. I am raising important issues that need to be considered, going the 2.5 route is not the be all and end all of peoples issues now and it may not be suitable for some people out there for reasons other than the technical aspects, yet the impresion seems to be from all these recent threads, get a 2.5 and all your problems will be over. What are you going to say if the 2.5 supply dries up? I know SOA are already restricting sales of these short motors. I personally chose not to go the 2.5 route when my engine failed, because of the concerns with resale and insurance, i could have obtained a 2.5 short motor for a lot less than Mark is charging through my personal contacts in the USA, so cost wasnt the reason i didnt go down that route.

Lower boost but higher flow rates, you have an extra 500cc to supply air/fuel to, at the top end of the rev range even on lower boost you are going to be working the VF28 quite hard, is this extra flow requirement going to stress the stock turbo and over speed it? How is the offset in cylinder fuelling going to be affected by running a 2.5 with STi5 heads, injectors, plenum, fuel rail design? The USDM STi revs to 7500rpm, it's not that short of the STi5 2.0 at 7900rpm.

You dont know why it failed yet do you? It could be for any of the usual reasons, such as a faulty MAF sensor or knackered fuel pump. Mechanically the 2.0 engine is very reliable, they usually fail for good reason. Mechanical design wise the 2.5 and 2.0 are fundemantally identical. As yet we dont have any longevity stats on the 2.5 either, is the extra airflow/change in airflow requirement going to kill MY99/00 MAF sensors quicker, answers we as yet dont know.

Playing devels advocate, probably yes, but to be telling people in such an unresearched way that they should just forget about the 2.0 route and "you would be mad" to not take the 2.5 route is iresponsible, especially with people who arnt that technically competent or are not seeking to push the engine performance that much.

 

and just as a bit of useless info for most people, but what the hell. Having a 7500rpm limit on my car would make it slower at the nurburgring with equal power/torque. It will also make the 0-60 dash slower as you need an extra gear change.

7500rpm limit
Maximum Speed per Gear:
1st: 39.4 mph
2nd: 58.9 mph
3rd: 78.6 mph
4th: 105.6 mph
5th: 147.3 mph
8100rpm limit (they dont rev to 8200rpm, the tacho is out 250rpm at the top end)
Maximum Speed per Gear:
1st: 42.6 mph
2nd: 63.6 mph
3rd: 84.9 mph
4th: 114.0 mph
5th: 159.1 mph

I hit 158.4MPH at TOTB2 test day and exceed 150MPH in 2 places at the nurburgring so would spend more time in the high stress region/on the limit of the engine rpm range with a 2.5 litre.

[Edited by johnfelstead - 12/20/2003 12:45:05 PM]

 

And to give an analogy of my own experiece.

When My cars engine went in May.I got a new replacemet engine and a VF34 Turbo and fitted an HKS FMIC.Had car mapped and was getting 310 BHP.
This I ws slightly disappointed in as I thought the FMIC would have allowed cooler charge and more power over standard VF34 installation in Jap Spec "C". However it was Turbo that was limiting factor.
Now after fitting FMIC and realising it's cooling characteristics I wanted to utalise this After all it was "Daft not to". So New Turbo req'd and the rest.

What I am getting at is If a 2.5 is fitted and run to produce standard power? Mmmm. You may want to modify. The extra 500ccs(Youv've got them so why not use them "Daft not to") Will take you to higher stages of fuel/airflow issues and expense.
I guess if you are into that kind of thing. you would have the contacts and know what to do /pay.
But very few with blown engines have this knowledge(If they did their engines may not have blown in the first place).
That's why they come on Scoobynet to ask.
I feel a lot of answers that are given are based on hypotheticals and can not be taken as read for their specific needs /setup.

It's nice to be given options But it would be more helpful if it was more explained what these options will incur.

TVOTP. Steve.

 

cheers for all the advice, from it am i right in thinking the 2.5 option wouldnt be a good choice - in my case?

all i want is a new short engine to bolt straight on, with a oil pump if need be, and obviously a ECU remp (ECUTEK) which i will need with a standard replacement anyway to map for UK fuel.

before the engine went i did intend to keep the car standard and was satified with the power i had, i do not wish to start changing turbos, fueling, ecu's etc. 300bhp/torque will be fine.

the only expense id like after the car in back on the road, is just the usual running costs, servicing etc.

think im going to get a stock replacement then, or preferably a cost efficient repair on my current short engine...

 

you have to make that decision peccy, just look at whats involved for you personally. Going 2.5 will most likely alter your insurance costs, have you asked? Running costs in general mechanical terms should be the same (as long as you dont have to swap turbo etc).

You will quite easily achieve 300BHP on a 2.0 engine with an ECUTEK remap and decat, based on the fact you seem to want to keep this to low levels of tune, standard spec i dont see any benefit with a 2.5 for you and if you leave gearing the same etc then it may not suit your car as well.

Putting it another way, there are more unknowns going the 2.5 route. Do you want to be a guenea pig or go for what you know will work straight out of the box and give you what you are happy with already.

 

Agreed!

 

Hi Dave : Sorry to see your mishap and I am sure driving 20 miles on the engine will not have improved it. I would have thought your most cost effective option was to speak to David O`Brien at API Engines and I am sure they could incorporate some mods if that was the way you are going or do a good deal on a half engine if that in fact is what is required.
If you are going the high powered 2 litre route then obviously I would reccommend you speak to Roger Clark Motorsport.
Both of these companies have a reputation for reliable engines and they can build them properly first time.
If you want to go down the 2.5 American route there are a number of considerations. As John Felstead has already highlighted, these engines are not proven beyond stock output although as a short engine I am sure they will be a very useful tool. If you want to purchase either a 2.5 block or short engine let me know as I am sure I can be of assistance.

 

At the end of the day if you're happy with std power I think it would be a waste of time going 2.5

Get a decent builder to provide a refreshed std spec engine.

After all, don't forget, the reason your engine failed was not because it was a 2.0 litre.

Also I think the 2.0l rev's matching the Type R gearing, etc is a valid point made.



[Edited by jameswrx - 12/20/2003 3:38:08 PM]

 

Or you could have my STi 7 short motor or full motor for that matter. (under 10,000 km) Drop me a mial if youre interested.

Conrad.