Rallyrcr

Oct, 1992 Ra 240ps
Jan ,1994 Sti 250ps: forged piston,solid lifters,cams
Oct, 1994 WrxRa 260: "
Nov,1994 StiRa 270: "
Aug,1995 StiRa 275: "
Aug 1996 StiRa 280: "

So what does a 1996 STi have under the hood???

I have found both kinds an STi RA and an STi for my rally car conversion

Gary

DARREN

I have a march 96 STi and i believe in standard form these put out 275 bhp
Log on to

submannz

Yep those HP figures are correct, the new 2000 impreza was droped back down to 160Kw from 205Kw for 1996-1999.

The biggest difference was the big roller bearing turbo, and bigger intercooler.

No Subaru's come out with forged pistons they are Subaru's cheap equivalent called hepolyte pistons they are a lot stronger than standard pistons but not as strong as a true forged type. The hepolyte pistons are good for 18PSI continuous boost.

Adam M

Do you mean the sti pistons are not forged?

including the 22B pistons which in subarus literature say they are forged?

Dont get me wrong, I know they are made of chocolate and have uprated them, but it doesnt mean the standard ones arent forged!

cant you tell the difference by looking at them? I am sure I have been told many times taht sti pistons are nearly always forged.

If they are actually hepolyte? Then what are the non sti pistons made from?

pat

submannz,

most subaru pistons are cast items, perhaps they are hypereutectic types which would indeed be stronger than a standard part, but having seen one in bits, the grain structure does not suggest that they are, also the crown thickness would indicate that they do not have nearly the strength of a forged item.

My old STi II lump was an open deck job with forged pistons. This was the second time I had ever seen forged pistons out of a Subaru engine, the first time being back in 1999 when Anders engine was in bits the first time. I have also seen forged pistons from an STi IV motor. Again the crowns are so thin that I cannot believe that anything but a forged item would not break.

I have also seen a cast piston which had a hole punched through it by a wayward conrod which had come out of an STi III, but this engine had previously been rebuilt and it's impossible to say whether the original pistons were or where not forged items. I have also seen the pistons from an STi V motor and these seemed somewhat lighter but still had the usual casting marks.

It would seem that it's a bit of a pot luck thing as to whether you do or do not have forged pistons in an STi

Rallycr,

Oct 1992 is not STi II, they were made in 1995 and 1996, in fact 1992 predates STi production cars. 1994 sounds like it could be an STi (as in STi one, the original, which never had a suuffix and are quite rare). I wasn't aware that there were solid lifters around then, perhaps this is a retrofit?

1995 sounds like an STi II and the figure seems about right too, 275PS is the nominal output of that engine. The 1996 unit seems like an early STi III which with its solid lifters was able to raise the RPM limit, and thereby naturally raise the power output (given good flow through the heads and a good turbo, there is no reason that power should fall off at the top end... my engine usually bounces off the rev limiter on the rollers, as they keep going until power falls off and it never does).

If you want to buy a good starting car for conversion into a rally car, then I'de suggest something like an early Type RA which will have the closed deck block, MAY have forged pistons etc... the bits on it are homologation bits, Prodrive got up to, maybe over, 400BHP out of these babies in the Group A days Alternatively, have a look at a Type R, you won't get the closed deck block, but you will get a stiffer chassis and you'll get adjustable centre diff for the loose stuff

Cheers,

Pat.

submannz

I have been advised by many people that certain cars have forged pistons only to find when stripping the engine down looking up the piston numbers to find they are not. The only time you will find a motor with forged pistons would be if some one has had them fitted after.

firefox

You can get forgies in STI's..

You can specially request them in the car from new, if required (option)

Meant to be good upto something like 1.8 bar (so I have heard).

J.

pat

submannz,

you haven't found any forged pistons in any stripped down engines yet, but that doesn't mean that they do not exist. If you would like I can take some photos of forged pistons which have come out of one of my engines, and out of a version IV STi, they have the Subaru / FHI logo on them so presume that they are not after market units.

Cheers,

Pat.

submannz

Yes they exist, but as an after market part. So finding them almost impossible.

stick

I've encountered the same problems when trying to find out what's what with regards to the STi. I own a '95 STi (version II) and according to Subaru Japan I had forged pistons. Upon cracking open the engine I DO NOT have STi forged, but in fact have STi cast jobbies. This is in contrast to a Version V longblock just sitting in a rack at my tuners which came from Japan with STi forged goodies.

It seems that the forged items are an optional extra. If you fork over the cash they stick in the forged items (or whatever has been requested). Makes sense right?

The same issue trying to find the stock HP figure for the Version II. All literature points to 275PS. On the dyno I got 285HP at the flywheel. This was with a busta busted clutch and broken headgasket. Mods for the dyno run were exhaust and FMIC (stock ECU).

Rallyrcr

thanks all thus far

sorry for the delay in my response as i have bee away racing.

i already have a rally car and am looking to upgrade the engine.

i have found both an sti II and an sti ra II engines in NZ and i believe the early sti and the ra's both had closed decks and forgies and that the power out put is the same....the ver 3 sti however had an open deck and the sti ra a closed deck and forgies and solid lifters

chassis is not my concern as i have a fully prepped car already it is just got a 1.8 non turbo in it.

Gary

stick

All STi's in NZ AFAIK are from Japan. Any NZ new STi would have been shipped over from Japan. Nothing done to them except cirtification for NZ. My Version II has an open deck block, while a friend's RA (same year) has a closed. YMMV.

I would suggest that you get someone you trust to confirm exactly what the engine has or get photos sent over

submannz

There are so many variations from the STI factory you never know what you are getting.

If you are after a closed deck the easiest way to find one is the 1989 Turbo and N/A engines ex NZ/JAP.

By the way if a vehicle had forgies in Japan they are most likely removed prior to shipping to NZ/AUS/UK as imports, as are sterios/rims and other bits and pieces.

[This message has been edited by submannz (edited 10 August 2001).]