tw2

Hi

I am living in Switzerland and want to swap an STi engine into my 98 WRX (still the old one with lower spoiler an nonflashable ecu).
I am looking for a STi Version 4-6.
Since here in Switzerland there where no STi Versions 1 to 6 this is something totally new out here. So I need your help.

What parts to I have to replace?
Till now I cam up with:
-complete engine
-turbo
-header
-uppipe
-intercooler
-ecu
-gearbox
-rear diff
Is there anything else?

Did enyone do something like this before?
Advice appreciated.

Thanks

tw2

Does now one know the diferences between an STI 4-6 and an 98 WRX?
Need help.

What do I have to watch out for?

harvey

iTrader: (48)

Is your car a ver 4 WRX? If so the swap for an STi4 is not difficult. Putting a 5/6 engine into a 4 is a lot more work.

tw2

I guess mine is a version 4 wrx. It has the low spoiler and the nonflashable ecu.

What would be harder for a version 5/6?

Do I have to change other then the above mentioned things?

harvey

iTrader: (48)

From ver 4 WRX to ver 4 STi there is no need to change gearbox, diffs,headers and up-pipe. Nor is there any need to change these components if going to an STi 5/6.
Best to use a complete engine with turbo and ECU. Alternator, starter, A/C etc are all interchangeable.
Best to port the headers and up-pipe at the same time.
The ver 4 inlet manifold is different to the ver 5/6. The tick over valve,ICVS, is different between the ver 4 and the 5/6.
Although I have not done it, a swap from Jap ver 4 WRX to STi4 will be relatively straight forward. For a Euro ver 4 WRX there may be small differences in wiring/sensors but the differences will not be insurmountable.
Putting in an STi 5/6 will involve more work including some wiring harness changes.

tw2

Don't I have to change the rear diff due to different ratios in Japan (top speed).

Is 2400 reasonable for a complete v4 Set?

Wurzel

iTrader: (1)

The major problem you will find is that the STi4 is RHD and your car is LHD so the wiring loom will be the wrong way round and all the cables will be to short or to long depending.

Also the wiring loom for an STi is more complicated than that of a WRX/GT, and the STI ECU will not be a straight swap and will not plug on to the WRX ECU Plugs.

There are also a few other differences with regards to certain ancillaries fitted to the LHD and RHD cars.

That is about as much help as I can be.

As you are Swiss log on here and ask the question on there, there is a guy in Czech that has done this so ask him, sorry can't remember his login name.

harvey

iTrader: (48)

The rear diff has to match the front diff. This has nothing to do with the engine which is independant of the gearbox which houses the front diff.

tw2

Thank you very much for the information.

I already posted there but people know very little about a swap like this.
The czech guy, I already had contact with him about a year ago but he suddenly stopped reply?!?

I really do not know right now what I will do.
I would really like to have an STi engine in my car but I do not want to take out all the stuf and then not be abl to get it back to work.
Maybe I should only swap the gearbox and fit better haedgaskets.

Well, have to think about it.

harvey

iTrader: (48)

I have a ver 2 WRX running 380-400 bhp and it was not difficult to get it there.
Why not consider a bit more power out of your existing engine???

FB Tuning

iTrader: (30)

Why don't you just fit the V4 STi engine, and swap your V4 WRX Inlet Manifold and wiring loom onto it?

Surely that's the easiest way to get the engine in and running without any LHD/RHD wiring issues etc. - I've fitted a couple of Legacy engines into Imprezas by doing this.

Then you could fit aftermarket ECU, such as a PFC, to take advantage of the higher rev limit

tw2

Will that work with the original manifold and wiring?
I heard the sti engine has more sensors and there are different plugs.
What other aftermarket ecu's would fit?
What do you think about the power fc?

Yes I was also thinking about just swaping the gearbox & rear diff, changing the headgasket on my engine and put on a different turbo.
Thing is, the engine already has 155 tkm.

I am now running on a maximum of 1.3 bar and going to about 810°C ext. So if I want to get that amount of power I'd might have to change the internals and then it's going to be the easier way just to swap the engine.

harvey

iTrader: (48)

This is getting a bit convoluted.
I am not sure why you are changing the gearbox and diff.
Do one job at a time. Decide on your priorities and draw up a spec list and then do the mods in a logical well thought out order.
Look at the spec of an already successful car that has the performance characteristics you want to achieve and copy that spec or if there are areas for improvement then incorporate them.

Depending on model year, the advantages of the STi over the WRX are different pistons, exhaust valves/heads and cams. The ECU is different to take advantage of these changes.
To go circa 380+ bhp standard WRX internals are adequate in a properly treated and mapped WRX.
The Apexi Power FC is a capable ECU BUT equally important is the ability of the mapper. A good ECU and crap mapper could be an expensive experience.

810 deg C is a conservative EGT. I run to 910 regularly.

Here is a link to a 380-400 bhp (subject to map and octane booster) 1995 WRX Wagon. 80,000 plus miles. A relatively cheap and quick modification project. All the engine/under bonnet work was completed on an evening or week-end, over a three week period I think.

harvey

iTrader: (48)

Oops.www.geocities.com/harveysmith3000