Flowforce 640s
 

So after what everyone said on here on my last post, I decided to get the flowforce 640s. I plan on pulling the engine soon to do the turbo kit. Should I try to tune the new injectors soon before pulling the engine and doing the turbo, or just try to run as little boost as possible? I believe with the setup I'm putting in, I can get 3 psi at the max. I just want to avoid the chance of detonation, as I know it's higher when boosted.

It is less difficult to tune a NA vs FI application. Although running low boost 6-8psi would be fairly straight forward.

Doing them before the turbo means you can get idle and off boost response correct before adding another variable in.
however you will need to redo most of the fuel map anyway when the turbo goes on, so you are kind of doubling your work if doing it before.

having said that, if it was me, I’d put the injectors in before and tune if so I know it’s right before I add the turbo and then tweak the map to suit.

this is assuming you are doing the tuning yourself? If paying to get it done then just do it once after turbo, save paying twice..

fwiw, I fitted and tuned my 640s before I fitted my rotrex. Just adjusted the injector size and deadtimes and the ecu did the rest so an injector change can be quite simple dependent on which ecu you have and what method of tuning.

I may be the odd person out, but I'm a fan of letting the computer auto tune on wastegate - an hour will get 90% of your fuel map done - then its fine tuning. Boost away!

did you use an aftermarket fuel rail? Trying to make sure everything will be good to go

Nope. Completely stock everything (lines, rail, hoses, etc) The only things not standard were the injectors themselves, and I threw in a DW200 for safety whilst I was there...