Hi I am looking fore some advice \ knowledge about my my95 wrx 260ps. When I got it it had a gc8c open deck engine but the bottom end barring was gone.
The replacement engine is a closed deck short block ej20 engine that I assume came from a 92-94 wrx or wagon.
After the engine was fitted I took if to a rolling road to check it over, they found it only produced 224bhp (I will post the graph below).

I’m trying to finger out why only 225bhp, I know the wrx engine came in a variety of power ratings but from what I can see the only difference is mapping and boost but as the ECU is still the 260 ECU and the boost is producing the 12 - 12.7 psi that the 260 expects im thinking there must be internal differences inside the engine to help produce this extra power or something is not setup right

I forgot to mention the wrx has a cone induction kit, dump valve and cat back exhaust. I did not do this its just the way it came

So basically I have got 2 questions

1: are there internal differences inside the 92-94 and 95 engine to produce extra power

2: from the power, AFR and Boost graphs below dos any one see any obvious problems with it

I took it to the rolling road to find out the answers to these questions to witch they said every think is as it should be but after reading the graphs I realised the guy on the rollers could not even spell Impreza lol. So I thought id asked people who might be able to help

Apologies for any mistakes or stupid assumption if im wrong but this is my first Scooby and I’m learning fast

 

engines lose power over time as things wear.
also 260ps is not 260bhp.
Only losing about 25bhp over 13 years isnt that bad.

 

Thanks for the reply
I did forget to mention that I do know that 260 ps is not 260bhp
And 260ps is on 100ron and that engines do lose power over time but I was expecting a bit more as i seen a standard 95 wrx pulled a 254bhp

Am I expecting to much?

anyway my main concern was just that it is setup right and was hopping someone could tell me if the power graphs were normal or showed a problem

 

If you've bought an engine without any history that could be 16 years old then you are expecting too much.

I seem to remember that WRX wagons had a slightly higher compression to run on a TD04 variant for more low down pulling power but lower power - 240 PS?

Nick

 

The engine was meant to be a 60,000k jap import wrx engine from a MY95 but its clearly not as 95 engines were open deck except for 95 RA’s

I have looked on Which engine do I have and other sites for info in the engines a have seen that early wagons produce 220ps on about 10 - 11 psi but iv not seen any confirmation of different compression ratios.

But this is the exactly sort of info im looking for thanks Nick

Also does any one know if there are engine number stamped in on the block and where you can fined them. I did look but all I could see was the ej20 stamp and the closed deck hatching

 

was the car rolling roaded at wallace performance in aberdeen? or somewhere else? (not sure if there is one other than aberdeen??)

 

yes wallace performance in aberdeen It was just up the road from the garage that fitted the engine that’s why i went there

 

wallace performance isn't really a popular place in aberdeen but i hear its under new managment but still not keen on them personally. best place to go would be japerformance out in ellon, it is a short drive but worth it in my opinion.

my cars out there tomorrow for its mot

 

I wanted to go to japerformance and all the sidc boys go there and recommend it but like I say I just had a short drive along from the garage that put in the engine .

Im going to give it a good going over check everything out. I will run a few tanks of good fuel through it and maybe take it out to Ellon for a run. I did about 40 miles in it after Wallace and it seemed to run better I was thinking that the old fuel in the tank (I put in vpower but it had some old fuel left in it ) or ecu being reset had anything to do with the run numbers

 

was it just the block that was replaced or was it block, heads and inlet manifold?

 

Are you using the turbo off you're old engine?

 

block heads and inlet manifold it was a complete replacement engine. I still have the old engine that I am debating rebuilding

 

That link nick posted was pretty interesting:

Which engine do I have

According to that Wagon engines go from 220hp to 250hp depending on type A, B, C etc, how do you tell which type someone has? We are running a TD05 on ours with Saloon ECU, it's a 1995 Wagon so what should it have come with power wise originally?

T

 

As far as I know the replacement engine did not come with a turbo so there was only one. But not confirmed I will definitely be checking that it is still the td05 turbo

 

thats your problem mate, the compresion will be different more than likely!

what you should of done is used your old heads and inlet manifold. (just replace the block)

that way you could of made it the same compresion ratio as before and the injectors may be different buy doubt it much.

 

dale ken's site is full of information but that’s a similar question to what I wanted to know the only difference I know of is standard boost. all the compression rations seem to be 8.5 but the wagons are not listed.

According to kens site if your car is a 95 then it’s the GC8C it looks like 220ps standard what is it actually putting out

 

Yeah that's a pain, I am sure stock classic Wagon imports were supposed to run 240ps with the TD04 at 0.7 bar. We have a classic wagon but it has a TD05 and saloon ECU so not sure if they are compairable.

What ECU are you running with the new engine? W6/U8?

T

 

take her along to japerformance and ask simon

alot easier lol

 

The standard boost target for the various Impreza are as follows :

UK 1993 - 1996 : 11.47psi

WRX 1993 - Sept 1994 : 11.47psi

WRX Sept 1994 - 1996 : 12.7psi

WRX Wagon 1993 - 1996 : 10.8psi

WRX RA 1993 - 1994 : 11.47psi

WRX STi 1993 - 1994 : 13.64psi

WRX STi RA 1993 - 1994 : 13.64psi

WRX STi RA 1993 - 1994 : 13.64psi

WRX STi 2 1994 - 1996 : 13.64psi

WRX STi 2 RA 1994 - 1996 : 13.64psi

taken from Frequently Asked Questions

 

i don’t know about the ECU it is on my list of think to check but it’s at the garage getting something non Engine related fixed before I get it back
I am also going to check that there is not a rubbish £20 eBay remap chip in it. If you look art the graph it says that the barometric pressure hit 1003mBar that’s 1 bar I think, but the PSI graph does not go above 12.5 - 13 PSI it sort of contradicts itself

 

After a bit more digging around, It looks like there are are all sorts of engine compression variants for 92-95, depending on WRX or Sti, saloon or wagon.

I really think that the age of the engine is going to be the main factor in your lower output rather than what model it was pulled from.

Nick

 

Thank nick if you have different information on compression rations and models I would appreciate the links

that’s why I wanted to know if there is some way of telling what engine I have by numbers, markings ect ect

 

Info is mainly from a book - Subaru Impreza by Brian Long but with other info I've hoarded over the years.
In general, compression varied from 8.0 to 9.0:1 and turbos would have been TD04 L and H variants, plus the TD05.

The lower boost target wagon ECUs would be combined with the TD04L (Lower power) turbo and higher compression engine to give a more torque at lower revs.

Nick

 

Ok thanks so if iv got a 9.0 to 1 CR engine with say a td05 running 12.7 PSI am I going to blow the engine

What should I do to

1: not blow my engine
2: sort out the power

If it is a 9.0 CR wouldn’t I get an aggressive Knock correction value

 

Ours seems to be okay and it's the same engine you have, running a TD05 and 1.1 bar of boost with a U8 chipped ECU by Polar. It has a sticker saying 294hp on the ECU but how realistic that is I don't know as like you not 100% sure what it originally came with power wise.

It should have come with a TD04 so I guess it is similar to you, slightly higher compression but as long as you don't get det then happy days really what was the AFR like on the dyno?

T

 

Ours seems to be okay and it's the same engine you have, running a TD05 and 1.1 bar of boost with a U8 chipped ECU by Polar. It has a sticker saying 294hp on the ECU but how realistic that is I don't know as like you not 100% sure what it originally came with power wise.

It should have come with a TD04 so I guess it is similar to you, slightly higher compression but as long as you don't get det then happy days really what was the AFR like on the dyno? We will get her on the dyno again once we have sorted the niggles and report back so we can at least compare as sounds like a similar setup.

I'm not at all sure of the differences between inlet manifolds, injectors and the other engine ancillaries you mentioned but if they were not designed for that engine then there could be variables that are not weighing up against one another which could be effecting the performance.

T

 

I would be very interested in the output or you wagon because the setup does sound similar
I don’t think thay changed over the manifolds because the even used a different power starring pump that came with the replacement engine.




The original engine used the round reservoir but the new engine used the flat metal one.
Pictures are not from my car before anyone starts telling me iv go an STI

Do you recommend polar for a chip? Did you get a live map or fixed map version?

The AFR is the graph on the bottom left of the second picture but I don’t know what the standard figures should be and iv got no means of comparison

 

If you are not sure where the engine 'came from' it is not unheard of for some places to sell Legacy engines as WRX ect as to most people they look the same.
Not sure what to look for but someone here will give you some pointers.

 

Yes that fact has not escaped me. I just want to know what’s going on so I can plan accordingly

 

No matter what age an engine, if its running right and isnt knackered it will still produce decent power, in fact I find that older engines tend to be better, dont know about Scoobs but on all the cars i have had, well looked after old ones seem to be as good as new ones.