Choice of turbo

Hi, I need some advice as to which brand and size of turbo would fit best on my Toyota Glanza 4efte. It is a 1.3L engine. I currently have a TD04L from Subaru but would like to upgrade to reach a bhp somewhere between 350 and 400. Any suggestions pls?

Depends a bit on your budget, what local supply is available and preference on response or top end power. In terms of Garrett frame sizes, GT30 or GTX30 turbos should get you there, given the relatively low displacement, and assuming a conventional rev range you will need to be a bit careful with compressor selection to achieve the required pressure ratio at high flow without overspeed if you want somethingthat is still responsive. In the newer garret line G25 models would probably be the pick. Borg Warner, probably SXE257 or EFR6758 or EFR7163 are probably suitable. I haven't seen that much done on small stuff with precision, they don't publish compressor or turbine maps and I know there were some historic failures, although the north American drag scene love them for large frame stuff. There are several IHI/Mitsubishi/Hitachi models that would probably do ok but the Japanese turbos seem to have been left behind a bit technology wise. There are some reverse engineered copies of Garrett and BW models as well as Japanese turbos which have gained a reputation for high build quality at much lower prices. Pulsar and Kinugawa being popular at least in the Australian market.

There are still turbo calculators online, the not2fast one was good but appears to have been pulled down. The Borg Warner one isn't bad, you obviously have to make some educated guesses on what VE and exhaust temp the system will achieve amongst other things. www.borgwarner.com/matchbot

I can email a Microsoft Excel spreadsheet I have made to simulate engine air/fuel/power requirements with a rough injector latency/fuel pressure compensator if you would like.

Thanks for all the information. Here in Malta the most popular brands are Garrett, Borg Warner and Turbonetics (however I've come across some negative reviews regarding oil leaks for Turbonetics). As regards the size I was considering TD05 18g or GTX28, however, from the information you gave me it seems I should aim a bit bigger, right? I've been doing some research but I'm still trying to get my head around all the numbers. I would like something with minimal lag, obviously. I would really appreciate any help :) here's my email address corinnecoleiro@gmail.com. TIA

What manifold flange are you using, that may affect your choices?

Edit: Are you looking for crank power or wheel power? I usually assume people are talking wheel power.

A lot of those small turbos struggle to make the pressure required within speed limits or have a narrow power band, Assuming your setup will peak power around 7500rpm you need around 2.5 bar boost, if 7k or just under you really need around 3 bar boost. If you are only talking crank power you can step back a bit and it gets easier. I'm assuming you will be running an ethanol blend or water injection? Not familiar with that engine package, individual sequential fired coils is ideal. If looking for 400hp+ wheel power G25-550 would do it really easy.

If you are only looking at crank power, favouring response the new GBC22-350 looks like a really good option and will likely have much lower boost threshold and better response than anything similar available. https://www.garrettmotion.com/racing-and-performance/performance-catalog/turbo/garrett-boost-club-line-gbc22-350/

For 350-400 hp Evo 9 turbo would be perfect.

This is the manifold flange. A 3 bolt from the TD04L Subaru model.

Around 350 whp is what I was thinking. So far I'm using pump fuel but I'll be talking to some people about fuel blends that I can get here. Yes I will be installing the individual coils as well.

Sorry I took a while, I have emailed the calculation sheet I made and a few comments on use.