Hi Guys ,

Could anyone tell me what is involved in replacing a WRX engine with an STI one , My current bottom end is knocking and have been offered a STI engine at a reasonable price so would like to know if i can get all the bits i need from an STI engine. Iv heard the word headers thrown around as a problem but dont really know what this is ( will speak to mechanic tommorow) but i am told my current engine has Magnex Headers if that makes any difference...

Hoping someone can help ?

 

The major mechanical difference is that the 2001> STi engine has AVCS (Variable cam timing) which the WRX ecu cannot control

The AVCS can be controlled if you are using an aftermarket ecu, with some slight wiring additions.

Alternatively, you could put your WRX cylinder heads on the STi short motor, and fit that without any mechanical changes. You should have the ecu map checked and altered to suit, if you decide to go down this route.

 

Thanks , Would there be any advantage of buying the STI motor and using the short motor over buying an uprated WRX bottom end ?

 

Afternoon bump

 

STI short engine has forged internals standard wrx doesnt, the avcs heads are a lot better than wrx heads in terms of mapping abilities etc, if you get the ecu from a sti also then you can use the avcs heads Basically use the engine loom and ecu from an sti and then you'll be fine.

 

Thanks ,

My current ECU has been remapped so dont really want to make it redundant . So could i buy the STI lump and just swap over the short engine ( is this the same as bottom end ? ) and oil pump ect using my existing heads to sort out my knocking bottom end issue ?

 

/\ Bump , Also , anyone know if i would need a STI head gasket or a WRX one ?

 

straight fit mate, and they use the same gasket

 

I really think if your going to the extent of changing the engine etc the redundant ecu could be sold as a package with your current engine. this ecu is mapped to your engine. only thing they will need a similar exhaust turbo etc but they would have an ecu that should be ok for your engine. selling the engine alone means the buyer will+ need to map anyway, i woudnt put your ecu to the sti engine and wrx heads either without mapping. IMHO either change the lot or you wasting a lot of money doing part of the conversion. Only my opinion but up to you

 

Thanks ,

Im only looking to use it for enough parts to repair my current engine rather than a conversion , then would probable sell what i didnt use.

Are things like the bottom end , Oil pump ect arnt different enough to need a remap ? It was mapped while it had an uprated pump and was running a steady 336bhp at around 1.3 Bar boost if that is helpfull in anyway

 

every engine is different, changing the short engine would still in my opinion need a remap. just to be safe

10 of the same engine same setup etc identical on build will all produce different bhp output

 

Delux1234 has more threads goin about the bottom end failing than ive had dinners. Look mate, basically you want to get the car back on the road as quick and as cheap as possible. Is this right?? If the answer is YES, then buy the sti bottom end and fit your wrx heads of your blown engine and refit to car. Job done. Then you should take the car to be checked by a competent mapper with a set of det cans (earphones), He will listen to your engine and make sure it isnt detting or making any strange noises. At this stage while the mapper is there you should have him tweak the map on your car. I know you have had it done before but it is a new bottom end and needs done again. So in easy steps you weant to buy sti bottom end fit your wrx heads and fit into car, contact mapper for tweak, JOB DONE.

 

Cheers mate ,

Would this be the better option over buying the WRX bottom end and fitting that as above ?

 

Yes WRX bottom end is weaker than the sti one

 

plot thickens , Been told the WRX bottom end with forged pistons comes with all the pumps , modine ect just needs cambelt and my heads.

 

thanks guys to all those who have helped ,

Im going to do it properly and replace all the oil pump, modline ect , Both options below include oil pump , Modline sump ect

Is there any advantage fitting the bottom end ect from an STI engine rather than fitting the wrx bottom end with the forged pistons , Bearing in mind the WRX bits are £900 delivered and the STI £1200 + post. Otherwise i think i may be best just getting the WRX one...

 

Bump

 

Reason i ask is because the WRX bottom end is a few hundred pound cheaper than buying the full STI Engine , and cant see any benefit in buying the STI over the forged WRX one apart form selling unused parts on... or am i missing something ?

 

The WRX bottom end is not as strong as the STi.......but it's all relative as I've run between 325 and 400 BHP on my Bugeye WRX since 2002/3.

Save pennies and get the WRX bottom end, swap over like for like, get car back on the road, sell off any unwanted bits then check map and put the rest in the bank for a rainy day

Shaun

Shaun

 

Cheers

 

Sounds sensible

Or buy the sti engine and sell the heads

I would recommend chamging bearings before building it up

 

Thanks , How much do heads go for ?

 

£300 to £500 last few sets I have seen depends how quick you want to sell them.. not a great deal moving at the moment so probably 300ish

 

JGM is right......from a money point of view if you sold the UK AVCS heads for £500 you would be ahead of the game

It's just the hassle of typing BTTT, saying you won't post to Denmark, no I don't want to swap for a fish tank........LOL

I've got a garage full of stuff which is just too much grief to sell

You don't fancy some 19" Kahn RSV's with Pirelli P Zero Nero's in Bright flitter or a carbon Bug WRX Scoop ?? ..... LOL

Shaun