3SGE turbo??

[Wiggy]

Evening all

Before posting this up in any technical sections of the forum I am throwing it out to all to see what your thoughts are. It would appear that most people don't have any taste and because of this I've had little interest in the ST162 being up for sale. So, seeing as its looks the part and now goes well having rebuilt the top end I may keep it as a daily run about...
typically, your mind soon starts to how to make it quicker? Looking at it when I had the head off, the 165 and possibly 185 turbo setup would bolt straight onto it. I could use everything thats there and just add a few bits such as Manifold, Turbo and down pipe along with 165/185 exhaust system. If I kept the boost very low, could I get away with no ECU changes? It would run the AFM, same deal as the 165/185 but the O2 sensor doesn't exist on the 162 but as far I can remember it doesn't really do anything for fuelling on the GT4 anyway?

For what it would cost me to do it could be a worthwhile mod? I could probably get all the parts except the turbo for free. I'd probably have to make some sort of front mount up but thats easy and I'll have a side feed manifold as standard then 

Any thoughts?

[silverspeed]

v6 it. 

[Wiggy]

I had cheap and easy in mind, just like me 

[cunning stunt]

im preety sure this has been done to a few mr2,s, cant think where ive read it possibly on two brutal website or a link from there.

[Wiggy]

It sounds plausable though right? Mechanically all I'd need is manifold, turbo, Down pipe, exhaust, oil feed and return sorting out and some way of getting water in and out. All quite easy to do. My main worry is the mapping on the 3SGE ECU and how it would cope with boost? Even low boost, say around 6-7psi, just enough to give it a bit extra 

Its quite nippy anyway with a stock 150(ish) so if I could up that to around 180-200, she would fly 

[Chris_de_Bear]

A few points off the top of my head, without knowing the answers specific to the 3sge:

1. Turbos generally need a lower compression ratio to avoid det. (may get away with very low boost)

2. Will the NA pistons take the extra heat, and does the 3sGE bottom end have the oil jets squirting up over the pistons to keep them cool.

3. A turbo will inherantly obstruct the exhaust and reduce power (off boost). Will make the car less drivable, and would you be able to run enough boost safely to gain an advantage. (Try driving a 4 off boost and see how gutless it is)

4. Does the ECU have the safeties built in such as knock control ? Does it make the top end rich enough to cope with boost ?


It is probably quite feasable, but I suspect to keep the reliability would need an awful lot of time & money spent. Would probably be less hassle & money to dump in a complete engine, loom & ECU from a 165.

[Wiggy]

couple of good points raised there, cheers 

I did think about stickin in a 205 lump like I've done in my 165. I could have one serious 2WD car then, much lighter than any 4 as well. If I did this though I'd have to go manual as well and the money starts to drain away...lol

options options.... Maybe I should just leave it alone and get the 4 sorted as well, best of both then 

[flyingtele]

Can be done, but not cheaply. Pistons and rods aren't as strong as those in the 'four, and it runs a considerably higher compression ratio. You would need a piggyback ecu, because as far as I'm aware (but may be wrong) most NA ecu's are only mapped up to 1 bar absolute pressure (regular atmospheric pressure, or 0 psi) as it would never see positive pressure.
I would imagine that it if it ever saw boost it would just ramp up the fueling, much like the st165/85 once you go past ~12 psi as a safeguard. And the gt4 does use the 02 sensor for fueling, when under boost or accelerating it uses the afm for fueling, but uses the 02 sensor when cruising, eg on the highway at a constant speed.
I think your best bet would be to but a 3sgte and trans out of an mr2, and it should all bolt up, there is a small mod for the gear select levers, other than that it should bolt straight up.

[Wiggy]

yep, sounds like its gonna get expensive so I'll leave it alone I think, keep it nice and reliable, hopefully...lol

Running like a charm now since the top end rebuild and dare I say it actually feel faster must have been the full on service it had 

Just need my wheels back from Jerry and the new lowering springs and it should look proper bow...

Wonder if a 165/185 back box would fit on it, needs to sound a bit nicer now