How much boost are you running with factory headbolts/gasket

[SuperTurboD24T]

Originally Posted by Slobodan

The Hitachi turbo is actually just Garrett parts that hitachi threw together. I just used the compressor backing plate, comp wheel and housing. The rest is the stock centre cartridge, turbine unit. I noticed it taking a little longer to build boost up to 6psi then after that it just bolts towards 12psi like no other.

As is the case with a larger turbo It is a trade, but if you have the hardware to support it, a good trade. Turn up the fuel, fit a charge cooler, and you will get back some of the losses you noticed. Of course, a compressor with more suitable pressure characteristics would be best, and it seems you are searching for such a combination (less total flow, greater pressure ability).

This information *should* be true, if Mazda's engineers spec'd the turbo for the 13B properly. Normally, they are very good at this.

I would probably try to increase the boost in stages, with a commensurate increase in fuel, and see how the engine responds, whilst watching the EGT. It might work well for you.

Yes, a T31 style turbine housing will fit the downpipe flange directly.