Topfeed conversion on the 1jz-gte


ShoarmaTeam Member
I'm in the process of converting my 1jz-gte to single turbo.
A while ago, I already converted my ECU from the stock 1j ecu to 2jz-gte JDM to accomodate my 440cc injectors a bit better and it's been running like a champ.

Now with the larger turbo the quest for some more horsepower arrives and again I'm looking at upgrading my injectors to 550cc-ish as I will never go above 450hp with my mk3. I'm not fond of the drop-in bigger injectors like sard and therefore I'm looking at upgrading by changing to a radium topfeed fuel rail with topfeed injectors. The 525 BOSCH EV injectors that I'm looking into are the larger 48mm style injectors. There are also the smaller ones, but they are more expensive and not that easy to source where I live.

And here's my question: will the 1JZ be able to accommodate the larger 48mm injectors with the radium rail without modding the intake? Keeping the stock intake is a must for me.

Please let me know if you've done it and know that it does or does not fit.

The radium rail:
The larger style injectors: