Issues with too small of a turbocharger?
 

Hey guys,

I've been looking into turbocharging my lancer and recently acquired a TD04HL-15T-7 (The OEM 09+ RA turbo with internal wastegate),its considerably smaller than the stock evo X one but I'm looking to achieve around 220 whp and guesstimating off the fact that a stock 09RA makes around that on a 2.0L engine so it should be possible with the 4G69.

Is it too small for our engine? and if so what issues would occur with a turbocharger that is too small?

I grabbed the OEM ralliart turbo because they're cheap and plentiful in case I need replacement parts, but now I'm wondering if its even worth making the manifold flanged for it because its TOO small.

Any insight would be appreciated

Well the advantage of using an oem turbo flange is that there are probably aftermarket turbos designed to work with oem manifolds and stock piping...

That being said there's lots of info out there about choosing the right size turbo, but in short, it could spin too fast, get too hot, leading to catastrophic failure of the turbo, which could then send pieces of itself trough your engine, it can also surge, or even run out of flow, ie. Engine trying to draw more air than the turbo is capable of moving...that being said the turbo you have will probably work, but I would be concerned about over revving the turbo at higher boost levels...if you wanna run 6 to 8 psi to make your 220whp, then it should be fine, but something properly sized, thus more efficient would be ideal.

It seems like most of the aftermarket upgrades for the 09' Ralliart turbo are simply "do the evo X turbo swap" haha

I remember reading that the stock wastegate actuator opens at around 9 psi(I'll have to check it myself) but I don't imagine going any higher than that.
As long as the wastegate is functioning properly then I shouldn't run into any issues regarding spinning too fast and potentially grenading my engine right?

False, if the turbo is too small, it'll spool up with the wastegate wide open...wastegate works on pressure, volume is a different story...however, that turbo I don't think is TOO small, but it is on the small side...

It will probably spool very fast and be fun to drive but will have no top end...and by that I mean a bigger turbo would have more top end at the same boost pressure...but it'll have way more top end than without a turbo obviously...lol

You'll see how quickly 9psi doesn't feel like enough, and you go buy a boost controller...