Questions for mitsi turbo guys

[gibbon]

Hi guys just a couple of questions about the turbo on my starion. Spoke to a previous previous owner who said the turbo had been chopped and changed but couldn't remember exactly how. So I'm trying to work out what I've got, what's been done to it, and because I'm bored, what I could potentially do with it.

The compressor housing is marked td05-12a, can anyone tell me the visual difference between compressors with suffix a, b, c, g etc?. And can a 12a comp housing be milled out to accept a bigger wheel? Previous guy said it might have a 14g wheel in it but the cover doesn't agree. Also the compressor blades are uniform which I dont think is the g wheel pattern?

The turbine housing is marked 060 which is physically small but I think some 90s onwards turbos had it so it's not necessarily an early 80s tc05 relic? IIRC the 060 pertains to max exhaust flow, so would it be a bottleneck if I were to increase compressor size 

I was considering putting a small 16g td05 on it, but not sure if the turbine housing has the same orientation etc as the old turbos... could get around this by using the existing housing but not sure if itll fit, or if it does, if itll just be a big bottleneck as previously stated  

[ajg193]

@ProZac @fuel

[fuel]

Hard to tell without pics but it sounds like it's mostly stock with perhaps a wheel upgrade from a later model TD05.

14B is early E39A Galant VR- compressor wheel, and the blades are uniform. 

16G is late E39A Galant VR-4 and Evo1-3 compressor wheel and they have a staggered blade arrangement, with the Evo 3 16G wheel being slightly different again (more curved).

Then you have the TD04 series of turbos from Lancer GSRs, Saabs, Volvos, Subarus etc which can come with 13G, 15T, 16G, 19T etc which introduces another bunch of wheels into the mix.

I would just fit a TD05H-big16G complete on your existing exhaust manifold (will need some porting) and then clock the compressor housing (requires drilling out locating pin) and relocate wastegate actuator mounting bracket or weld up internal wastegate and use external wastegate. Will need a different downpipe made up too.

[gibbon]

Thanks for that, yes it sounds like it might well be a 14 wheel. What blade configuration would a td05-12 (no suffix) have? That's the only other thing that might be in there

 

On the turbine side, you say I'd need a new downpipe if I fitted a 16g, by that I assume the housings are different. Does that mean I couldn't fit the 16g cartridge into this 060 housing? 

I've still got the factory starion downpipe which is pretty restrictive so it would solve two problems by fitting the 16g and changing it 

[fuel]

I don't believe you can fit a TD05H cartridge to a TD05 turbine housing. You would want to use the H turbine housing as it separates the wastegate outlet for more flow.

[ProZac]

Can you put up some pics?

I don't think any of the later intercooled Starion front compressor covers had the TD marking embossed into them, they usually had a spot on the casting where it was supposed to be, but usually not stamped, so they just read '05-12'. They were TD turbos though. If yours had TD embossed into it, its probably not a stock starion compressor cover.

060 refers to the exhaust housing size, it has a 6cm^2 passage measured radially at some specific angle. It's mitsies way of indicating what garret calls the A/R ratio. 060 is the smallest, there are also 070 and 080. 070 Seems to be the sweet spot for a modified SOHC 4g63.

Yes, you can machine out a 12a compressor cover for a 14b wheel, not sure about all the way out to a 16G, but it'd be worth a shot.

Years ago I had all the compressor maps for this stuff, did the calcs and came to the conclusion that for a worked SOHC 4g63 an EVOIII big 16G was where you wanted to be, should be smack bang in the meat of its efficiency range at around 1 bar of boost. I bought a stock evoIII turbo, rebuilt it with a mitsy rebuild kit, and bought kinugawa housings for it, 070 exhaust and a big front cover. The front cover is machined for the EVOIII big 16G wheel, but is the same casting they also machine out for 20G and 25G wheels, so looks externally much bigger. Gotta have the aesthetics, yeah? ;-).

Early non-intercooled stuff is the TC range, hopefully that'd not what you have, not a lot can be done with them.

[gibbon]

Pics up, a little hard to get in there but you get the idea. Correct that the "TD" wasn't embossed, whether it was etched at the factory or after the fact I have no idea. I think from the shape of the compressor wheel (uniform blades) we have ascertained that it's a 14b wheel, the turbine side is the real mystery, I'm not sure what turbo it came with originally, is the tc05 exhaust housing the same as a td05?

Car is a factory sirius dash intercooled model, so worth playing with I reckon. Previous owner rebuilt the engine, VR4 internals, balance shafts out etc. I used to play with starions a decade ago but I've forgotten pretty much everything. Went to the Starquest forums after buying it, the scene sure has changed. Starions used to always seem to be a but of a poor cousin to the popular cars, not anymore, some serious love and attention going into these things nowadays

There's a small 16g complete item on Trademe at the moment, I was thinking of swapping the compressor wheel and housing onto what I already have, just not too sure if it'll end up being a bit choked up, 060 is that little bit smaller. Then again the whole thing may be moot, if I'm aiming for under 300hp I wonder if the 14b wheel wouldn't be a better option anyway.