installing Colby Transmission soon. Any suggestions with what else to consider?

[rallytaff]

Damn, I got 197whp and 271wtrq with the stock turbo on the same dyno! I guess Raffi knows what he's doing!

 

[ronmcdon]

They did dyno with a SAE dynojet. figures were pretty much what I expected. Sadly not a whole lot more can be done other than fueling.

btw added more a few more parts.
threw on another Anti Gravity lithoim battery.
Vic @ FSWERkS may have figured out why my previous litium battery kept dying on me.
wiill report more. Will throw on some ricey Verus canards and vents.

At this point pretty much done modding the car. I may look into installing my m2 fenders and finally throwing on the Braid 17x9 +35 (or +30 I forget) wheels Ive had sitting in my garage for past years, but that will be something for next year.

maybe should do a build thread because this thread really got off topic

 

[Grsemky]

They did dyno with a SAE dynojet. figures were pretty much what I expected. Sadly not a whole lot more can be done other than fueling.

btw added more a few more parts.
threw on another Anti Gravity lithoim battery.
Vic @ FSWERkS may have figured out why my previous litium battery kept dying on me.
wiill report more. Will throw on some ricey Verus canards and vents.

At this point pretty much done modding the car. I may look into installing my m2 fenders and finally throwing on the Braid 17x9 +35 (or +30 I forget) wheels Ive had sitting in my garage for past years, but that will be something for next year.

maybe should do a build thread because this thread really got off topic

Not even going to try the 30% injectors on a stock HPFP? I know the pumps are a pretty penny but uprated/port injection would definitely utilize that 280 more... Maybe used would be a viable option...

 

[ronmcdon]

would the injectors work with 91 octane?
what additional gains might and/or other benefits might come with that?

 

[Grsemky]

would the injectors work with 91 octane?
what additional gains might and/or other benefits might come with that?

The larger turbo is flowing more air, you now need more fuel to match, 30% is the volume flowed so yes it would work with 91... Ethanol needs more fuel but burns cooler hence why uprated injectors/pump are recommended

 

[ronmcdon]

Ah good to know. searched some threads and could never quite get an answer on that. sent Adam at Tune Plus a message and see what he offers. He also sells said injectors. Hope dont have to upgrade hfpf

 

[Grsemky]

If you go port injection the HPFP isn't an issue, but you you have the expense of additional injectors, if you go larger DI then you may run the risk of exceeding the pump... Definitely talk it over with the tuner, they should give you the pros/cons of each

 

[ronmcdon]

Ah definitely will check and waiting on what he has to say. either way pretty happy with what I got. will definitely see what gains the injectors get.

 

[MrMann]

very cool

 

[ronmcdon]

Just got a reply from Tune Plus (mind you who is also selling the injectors, so you can see if he is a totally honest guy). Sadly some bad news.

Adam Brunson
Sent September 1st, 2025 8:47:59 AM GMT-7
It (the 30% injectors) works with any fuel but you aren't limited buy injectors on 91oct, so unless you plan on running ethanol mix there would be no benefit to upgrading injectors at this time.

So, unfortunately this seems like this is pretty much the full potential of the Fiesta St engine at 91 octane. Fuel seems to limit more than airflow. Hopefully I'm wrong and we see gains from stuff like the WOR exhaust manifold. maybe cams, but I'm not optimistic.

It's the same deal for one of my other cars, my '19 honda civic si, with 1.5l turbo (incidentally doing transmission work on that as well soon). Even with a larger drop in turbo it still bottlenecks around 260-280ish. Thankfully these cars are more about finesse and handling.
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