ok so i have a b20 vtec on boost with dsm 450 injectors and it has a stock fuel pressure regulator right now and im wondering if i should get a aftermarket fuel pressure regulator or just use a stock one?

also what pressure should i be at?

 

I'd recommend and aftermarket one, and your fuel pressure is determined by how much fuel you need, which is determined by your AFR preference.

 

If the motor is tuned already don't touch it.

 

Stock one should be fine. I use a stock one on my car.

 

Stock

 

Yea its already tuned on it... but the one i had the fuel line broke so i just put a stock one on and im wondering if it would make a difference

 

The regulator isnt going to be phased by the injectors. What will require an aftermarket one is a high pressure fuel pump, like a walbro 255 hp. The stock one wouldn't be able to keep the pressure down with something like that. If anything larger injectors will make it easier on the stock one.

Also, injectors are flow rated at 43.5psig, but honda generally regulates them to ~39.

 

When I slapped a walbro on my stock unit the pressure at the fuel filter was roughly 55lbs...up from the stock 42ish.

I am confused, are you saying you had it tuned with an aftermarket regulator and then you went to a stock one or did you have a stocker on there at all times?

 

Had a aftermarket then went to stock...

I have a 255 fuel pump

 

Your best bet would be to ask your tuner where he set your fuel pressure at when he tuned your car