I have seen an complete AX1.4GT injection front asking for RM2.5k negotiable and I think that is a good buy. You might say is has only 75hp but don't forget it is using fuel injection system that capable for a TURBO ADD-ON.

This kit are refered from a specialist in  turbo MOD for TU series engine, 

 with a low-boost of 6psi will increase your GT into a 120HP little monster. You do not need to lower your engine compression at this level. Additionally,  you need a improve your suspension, brake and clutch. These parts are gather by myself are I am still new in these stuffs. Do correct me if I am wrong. I knew there are somthing better but I need to balance the cost and safety issue. A sports gasget (RM300/=) is optional, you can add it if you want a peace of mind.

If you really care about your rear suspension, get a set a of Saxo, 106 or 205 axle (if you meet one please inform me) instead of lower the torsion bar alone. As the higher model not only came with thicker torsion bar also rear anti roll bar.

Most of the patrs I quoted here are based on new parts' price, that's mean if you can get a used or reconded turbine or ECU controllerso that the cost can be more economical. 

If you want to devide this project into stages my recommendation are:

stage 1 : Engine, transmission, fron axle, suspension and brakiong system transplant.

stage 2 : Upgrade of suspension system and brake pad.

srage 3 : add in turbo kit.

If you are intersted in add in a turbo into you Tiara/AX and 3rd party engine such as Starlet 4E is not an option for you. I will be glad to hear from you for any form of participation. For those who has technical background and experienced turbo specialist are welcomed in giving us in any adivice and correction. I believe that we can work together and build a standard package for all the members as I know the kit that I mentioned can have some alternative which cost lower.