impreza82

Hi people

Just after some info, I keep reading about how prefacelift 2.0 WRX or STI engines being weak.

What does this mean? Are there probs with this engine? I am maybe looking at an early Impreza soon so would like to know what to watch out for if there are any weakspots. And if so is the tuning/risk worth weighing up?

Thanks

Impreza82

Davey96wrx

iTrader: (1)

You really really need to know your stuff if you want to push the earlier ones as the engines are getting on a bit.

In all honesty a late uk turbo ie '99-00 is a better bet as they have a stronger 754 gearbox, supposedly better flowing heads and ceramic coated pistons albeit still cast but a few have ran close to 400 hp moderately reliably with full supporting mods, it's also a little cheaper when you want to do a remap as the ecu can be unlocked and Ecu's remapped whereas the early ones need a different circuit board or standalone management which adds to cost.

TonyBurns

iTrader: (3)

The entire car is a weak spot, that is the biggest issue with the classic Subaru 2ltr engined cars.
To start with, the standard engine is good for around 330-350bhp max safely, some have run more bhp some much less before they have let go, its very hit and miss.
The big issues are (especially the early engines) head gaskets, the rods, issues with the oil pump, the standard ecu isnt that good, clutch/brakes/gearboxes are weak (this includes the so called stronger TY754 boxes which still eat gear sets), so all these need to be taken into consideration, especially the intercooler (slanty ones in particular), hence why alot go front mount.

The main point is what do you wish to achieve??

Tony

Jay m A

iTrader: (2)

The older engines are just as reliable as later engines, like for like - in fact the belt tensioner on the earlier ones are more reliable than some later ones etc.

The problem lies with how the engine has been looked after, of which it is a lottery, but unfortunately for the older engines they would have seen more mileage, and no doubt been in the cheaper cars which makes it more affordable to buy ty some that can't really afford to run them!

Basically the older engines are more likely to fail these days because they have more chance of being poorly looked after.

impreza82

I would be looking at 300 in a classic v1/v2. But I dont want to run a car thinking this can go bang at anytime. I really just seems so hit and miss with early cars, some can last and some can handle it, plus it would be a weel looked after model not a £1500 cheap import.

I think saving for a newage sti would be the way to go.

MattyB1983

iTrader: (51)

If your budget can handle it then buy a car that has either been fitted with a newage STI motor or has been rebuilt using better components.

My pals beautiful low mile and well cared for STI V2 shat itself at 305 for instance.

marcevs72

iTrader: (5)

there is nowt wrong with a cheap import classic.most of them are better condition than later classics.mine is a 93 and in better condition than most newage ones.just have to look around as loads out there.unless you get an sti all classic and newage scoobs engines are on borrowed time when you start tuning them.

impreza82

Its not the condition of the car that would be my concern, its the strength of a standard engine that has been well cared for. All tuned cars have extra stresses put on them when tuned but early classics seem to not handle the pressure that well compared to other models.

marcevs72

iTrader: (5)

you can have a newage car done 50k and the engine let go yet there are loads of early classics in 3 figures going strong.the only real weak point of an early classic is the gearbox.the other bits that will be on their last legs would only be stuff you would be upgrading anyway if you after more power (brakes,suspension etc...)there is no difference between a 93 wrx engine internally and a 99 one only the sti had forged internals so saying early classics dont handle the pressure is a bit wrong.

MattyB1983

iTrader: (51)

Remember some early cars got CDB

marcevs72

iTrader: (5)

like mine.handy for my stroker build at enginetuner next month.

TonyBurns

iTrader: (3)

Incorrect though, they changed the cranks, the rods are still crap as they were in all the classics, the sti and normal wrx/uk car all used the same ones, the only difference is that the sti had forged pistons and the others had cast, the original/v2 sti forged pistons were not as good as the later v3-v6 cars, improvements were made across the range over the years, the cdb engines are just if not more prone to letting go due to the "chocolate" internals.
As I said, the entire car is a weak spot, the composite HG's on the early cars are also not as good as the later classics, another point to make a note of.

Tony

marcevs72

iTrader: (5)

i like the fact that lately on here early classics are getting a right slating as being crap,cheap cars that are no good...

Essexdon

I own a 95 WRX that has been dynoed at 267bhp, I've decided to go against remapping and upping the power to 300. I have read and then re-read so much threads on here about these engines going "pop" so the finance and sence out way the risks in my book, plus my car is immaculate, 50k, fsh, service every 6 months or 5k miles, pulls stong in each gear, no turbo wine, no smoke and does not drink a drop of oil.

in my book if you want a faster car buy a faster car.

TonyBurns

iTrader: (3)

They are not crap cheap cars, just crap for tuning cheaply
We are talking about a car that was good in its day, that was 20 years ago, they have advanced quite a bit and the modifications they made during the run of classics was pretty good, but they still had a fair few problems of which most were fixed with the new age STI's (better brakes/suspension/clutches/gearboxes/engines etc).

Tony

marcevs72

iTrader: (5)

Last thing to be upgraded on mine is brakes and gearbox but havnt decided what to use yet as going to be running 400+.

rossyboy

iTrader: (8)

Original engine, headgaskets, turbo and gearbox on my '93. Been running 325 ish since 2006, albeit only about 10k miles done in that time.

I strongly believe that the CDB helps keep the HGs together longer on the early cars.

Totally agree that they are not a good base for tuning, but hell that makes properly modded ones incredibly rare.

Forgot to add - its mapped for 1.5 bar @ peak and I've seen 1.55 on the AVCR. Not bad for a crappy old unreliable engine

dj219957

touch wood. my 93 classic is still runnign on orginal box, gaskets etc 80k miles. they are a great engine if service, given mechanical sympathy and not badly tuned. no more worse than the wrx new age cars. how about comparing a classic wrx engine to a 2.5 new age engine lol. the 2.5 sucks!

impreza82

Sounds like going strong pal.

gazzawrx

iTrader: (11)

And forged pistons, my 1994 wrx has mahle pistons as standard and also a set of oil squirters in the block.

impreza82

So they come with Mahle pistons as standard on the V1/V2 WRX's?

MattyB1983

iTrader: (51)

No it doesn't chap.

gazzawrx

iTrader: (11)

Yeah it does, i rebuilt the engine myself and it was all there, theres a post on here somewhere showing my lump in bits

dj219957

some 93 94 cars had cdb

r6nick

Is there a nobody who is just happy with the power Subaru gave thier car be it a Classic or the Cosworth???
No mods on my car honest


https://www.scoobynet.com/group.php?groupid=82

Davey96wrx

iTrader: (1)

Right getting kinda sick of people slating the early engines, so I'm going to do a mega post.

First of all, yes you can tune the engine.

They are not as "chocolate" as some "specialists" on here say.

Once you have upgraded the gearbox to at least a 754 uk box, P1/ver56 Sti being a better option (TY754VBAAA) then your giving yourself a fighting chance, ultimately a six speed is better but also costs the equivalent of 4-5 of the above named gearboxes.

You'll need a good clutch, not a paddle plate though as it shocks the transmission too harshly and will break things.

Now onto internals. All this talk of them being made of chocolate is absolute bollocks spouted by people who think just shoving boost up its bottom is engine tuning.

The conrods are exactly the same as all uk and classic Sti engines, there are examples of a few uk turbos running 400hp, there was Harvey's ver3 Sti that was running over 400hp, lots of P1 impreza's running close to 400hp. The early classics run the same bloody conrods so make of this what you like.

The significant weak spot is the cast pistons in the early wrx, they are clearly not as good as a forged piston, but the space between the top of the crown and the first ring land is a decent measurement signifying plenty of material.

What you need to do on these is tune the engine slightly differently, clearly the piston is ok as cast pistons go but will not be happy with huge temps and very high boost.

In order to make power out of this engine I recommend getting a set if Ver3/4 Sti heads as they flow better than the early heads and the cams provide more lift and duration. Take these heads to a known specialist and get them correctly ported and polished, you will now make more horse power with less boost which will keep the pistons happy.

The early cars had fibre head gaskets, replace these with steel ones, research your particular engine though as some of the early classics had pistons that rise just above the deck.

While you have the engine out replacing the heads, it would be a good idea to replace the oil pump, only use a quality supplier I recommend Lateral or if you want to pay more for the exact same product RCM.

You next need to pick a turbo that is not running out of its efficiency range and pumping hot air.
Ideally this build would be to about 360-380hp, which in a classic flies. There are lots of turbos out there, for this build I'd say a TD05 18g billet from Andy F or a SC38 from scoobyclinic, its not about running mega high boost but running a turbo within its peak efficiency shifting more air whilst keeping the charge at a reasonable temp.

Next weakness are the coil packs, which crack and cause misfires, replace these with newage coil packs, there is a guide on how to do this on NASIOC in the EJ20 section. The guide shows how to wire them in by bypassing the igniter but you can also wire them in whilst keeping the original igniter, I'll do a guide for this as will be doing it on mine in the next few days.

Now the basics are covered, make sure you have a good FMIC, suitable injectors, a good quality FPR, an uprated fuel pump, a knock link would be a good idea, and finally a standalone management system or piggyback board like ESL you're good to go.

You can tune these engines, you just need to have a different approach.

Davey

MattyB1983

iTrader: (51)

CDB were introduced in 92 and were still being used in some imprezas until as late as 96.

MattyB1983

iTrader: (51)

The wrx would of left the factory with cast pistons, the sti came with forged pistons. In the early days when the first sti was released it was actually put together away from the main production line. They took a normal wrx and completely reworked it, this is why the applied model code is the same on the wrx and sti. One thing that got reworked was the pistons. Original cast pistons were swapped with forged ones along with a list of other things.
Maybe your car had some forged pistons fitted before you got it or maybe its actually an sti.

jayallen

iTrader: (31)

Try running that engine at a sustained RPM instead of a 5 second pull on a dyno and see how it fairs. Its ok tuning a stock classic engine to XXX bhp and driving it around at 30mph, its when its run under high load for long periods of time that the frailties are shown.

If someone is going to go to all the trouble of following your rebuild advice, for another 600 quid it would be worth fitting forged pistons/rods for piece of mind.....or bolt heads on a newage bottom end for the easy route.

There is a big difference to 400bhp for a dyno queen to 400bhp to someone who wants to use it.

Davey96wrx

iTrader: (1)

I disagree. One properly put together will last.

But I will add, the best option by far is to source a Ver7/8 Sti bottom end and fit the Sti3/4 heads. That's the road I've gone down as a low miles bottom end came up for a good price from a trusted trader on here.

£ per hp this is by far the best option, many have proven the Sti 7/8 bottom ends reliable at 450hp.