GC8 STI v7 conversion?

[freshboyss]

Hey dudes, I have purchased a 1999 gc8 v5 STI with a blown ej207 motor. I was looking at a version 7 complete engine to replace the blown engine which comes with all the goods ECU, engine loom, turbo etc. I've been told that the v7 motor will bolt straight in but have also been told that the v7 ECU will have trouble working with the car without some auto electrical work. I'm not the most familiar with subies so I'm a bit lost with knowledge but I know the v7s came with AVCS and the v5/6 doesn't. What are your thoughts? Will everything be plug and play or am I better off rebuilding the blown motor? 

[94 Leone]

You can use the V7 STi engine, but you need to either run an ECU that supports AVCS, or de-AVCS the engine, I reckon your best option is getting the heads on your current 207 checked, and buying a brand new shortblock from winger subaru, then getting it all assembled- providing your camshafts, and heads are all good.
Will be the most reliable way of rebuilding.

[freshboyss]

The complete motor comes with its v7 ECU. How about the wiring side of the conversion?

12 minutes ago, 94 Leone said:

You can use the V7 STi engine, but you need to either run an ECU that supports AVCS, or de-AVCS the engine, I reckon your best option is getting the heads on your current 207 checked, and buying a brand new shortblock from winger subaru, then getting it all assembled- providing your camshafts, and heads are all good.
Will be the most reliable way of rebuilding.

The complete motor comes with its v7 ECU. How about the wiring side of the conversion?

[Guest]

2 questions that need to be asked. How much are you willing to spend total? And how capable are you or is a shop doing the whole job?

[freshboyss]

10 minutes ago, evowrx said:

2 questions that need to be asked. How much are you willing to spend total? And how capable are you or is a shop doing the whole job?

 

All labour will be done by myself and my old man in his workshop, I've already bought a new clutch for the next engine and have a budget of around $3.5k. This can either pay for the v7 motor or to rebuild the blown v5 one. I'm honestly looking for the fastest and most cost efficient solution as I want this thing on the road asap. I would absolutely put a v7 engine if it wasn't such a long and expensive job, which is why I'm asking.

[Kiwi_Fozze]

Most effective way of doing the swap is to take ecu, motor loom, body loom and dash from a v7 and do a total rewire. that way everything works.

 

Cost effective? no, not if paying someone. time consuming, yes very. worth it? oh hell yeah imho

[Dairusire]

6 hours ago, kwi_fozze said:

Most effective way of doing the swap is to take ecu, motor loom, body loom and dash from a v7 and do a total rewire. that way everything works.

 

Cost effective? no, not if paying someone. time consuming, yes very. worth it? oh hell yeah imho

 

Right, not to crap on that parade, but you don't NEED to do the body loom, and dash, as doing the dash and all that isn't easy at all.  

You can do it, with just the engine loom and motor ecu etc, and everything will work. It will take a bit to splice it all in correctly, but this way you don't need to change a whole S*** load.
It'll just take time and patience to do it right.

 

[ginganinja]

Just rebuild engine. Heaps easier. Remove engine yourself and strip to shortblock, have someone rebuild the short block then assemble long block and install again yourself.

[Dairusire]

^ also definitely that.

[freshboyss]

Cool, thanks guys I'll have a think about it but will most likely just rebuild my motor. 

[Guest]

Yep rebuild. If you want it bigger and better grap a v7 sti- semi shortblock or cases and use v7 sti rods/pistons. Use genuine bits and do the timing while youre in there. Grab the parts from partsouq its waaay cheaper than local and genuines best. Will work for your budget...the v7 sti swap wont.

[ginganinja]

can get forged Mahle Pistons for decent price. chances are you may have to go 0.5mm oversize. use no less than V7 rods. and i second what evowrx says re using genuine parts for everything else.

[Scoobydoo]

And get the heads ported & polished, and the exhaust side flow matched to the headers. A few extra gains here and there all add up.