Thread: 740cc injectors for t28

Would 740 cc injectors be too much for a t28 setup running around 20 psi from time to time??? most of the driving will be in the 7 to 10 psi range what does every one here suggest??? and i will have the ECU reflashed by Calum does he do Dual maps?? one for 7 psi and the other for 20 psi???
thanks for the help...

i think most guys running t28s are running 50lb or 550cc injectors, seems to be about the right range for that turbo, but if you plan on goin bigger in the future might aswell get 740cc now

Get 700+ccs to start. I have had my 50lbers on the car for less then six monthes. I bought them and they were brand new and they have less then 8k miles on them. Now they are useless because I already maxxed them out running high boost...

yeah might as well go bigger if your going to do it, im running 520cc subaru injectors on my t28 setup and it should be just fine to 20psi of boost, i dont plan to go bigger on the turbo any time soon, the 520's at 4 bar should be good to around 360whp farily easily. the 740's good to something around 480whp or so at 4 bar.

Nope they leave you room to grow if u want a bigger turbo later. Calum doesn't tune the ecu thats up to you to tune them.

The problem with going huge from the start is idle and low RPM suffers because of the lack of resolution from the ECU.

At least that is the case on standalone units.

its funny because my 520cc program from calum actually idles better than my 370's did with his 370 program, low rpm range is still about the same but i noticed that instead of having to crank 2 revolutions or so to start it now fires up usually within 1 revolution, and idles very well. Still have my nice lopey idle due to the s4 cams but that was the biggest difference i noticed between the two.

wrong adjusting the K value will get the injectors to idle like stock. Tho I guess it could depend on the brand of injector.

No I'm pretty sure I'm right. There are physical limitations to how small the pulse width can be and how much fuel is injected. I'm not saying 740ccs are too big, because I don't know anything about these ECUs, but I know there IS a limit.

Yeah there is but the 700-800 are ok. get into the 1000cc's and you might have a problem. All injectors are built the same some brands have a better spray pattern than others.