550 injectors and fuel pump question

[ZUUHLSGSX]

do i need to buy a high flow fuel pump to feed the 550 injectors or can i just do the rewire of stock fuel pump? also should i aquire an adjustable fuel regulator too? thanks for any suggestions.

 

[gringoloco]

Honestly I would just upgrade to the walbro 255 lph pump, its a direct bolt on. Make sure you get the right one though there are ones for fwd, and awd. With upgrading the injectors and going above stock boost you will need a FPR. Make sure to get a fuel injector FPR and not a carb. one ran on the older v-8's. I would suggest the aeromotive one:

FPR

Fuel pump

 

[ZUUHLSGSX]

thanks for the advice bro.

 

[herostar]

If you're running anything less than 720's you can get along just fine with the walbro 190, which also means you won't have to run an AFPR. I ran the 190 on my current setup for a while with no ill effects, and it's making over 400 hp.

 

[gringoloco]

If you're running anything less than 720's you can get along just fine with the walbro 190, which also means you won't have to run an AFPR. I ran the 190 on my current setup for a while with no ill effects, and it's making over 400 hp.

How did you manage that. The 2G Turbo FPRs are rated at 43.6psi at zero psi, so what is the max fuel pressure you can run on it? You would need a FPR that regulates the pressure 1:1 with the boost rising. So if you are running 20 psi or higher, which is what im assuming you are running to get around 400 hp. That would make your fuel pressure 63+ psi at 20 psi of boost. How in the heck is your stock FPR pushing that? Im not saying your wrong, or anything like that. Im just curious as to why you were running a 190 instead of a 255 lph pump on your setup. Your profile says you are running a 60-1 setup. I was always told by trusting DSM members that a 190 lph is good for 16g setups and smaller. And that anything larger than that you would need a 255 lph pump. Along with an aftermarket FPR to keep up with the rising of the fuel pressure to make sure you are getting enough fuel. Can you post a pic of your dyno sheet I would like to see your fuel curve? I would think it would be quite sparatic and not a solid line due to the fuel system cutting out, from not keeping the right amount of pressure. I just cant see the stock FPR keeping up with anything above 50 psi, but like I said please correct me if im wrong. But if im wrong and it can keep up with 60 psi of fuel pressure. Why are aftermarket FPR's even needed, im confused now.

 

[herostar]

I ran the 190 for about 2 months, maybe 2k miles. Then I switched with a friend who had a 255 for the extra insurance. At 20 psi my egt's and timing were just fine. I know stockspyder dyno'd 421 whp in his awd spyder using a 190 lph pump too. The reason for the aftermarket FPR is that the 255 simply flows too much for the stock regulator to control, so the fuel pressure is not consistant. This problem is mainly at idle, but also occurs throughout the RPM range. I'm sorry I don't have a dyno sheet, but this estimate is taken from similar members running the same setup, as well as other DSM's locally whom I have raced and beaten. I plan to have a dyno sheet in the next month or som on race gas and about 23 psi... so it should be interesting to see what the stroker puts out

 

[kraka]

Yes, a new fuel pump is a must have before you upgrade to bigger injectors...IF you choose a 255lph pump, you will need a AFPR...Don't be fooled into buying the cheap FPR you see around ebay and the internet...You will need an ADJUSTABLE Fuel pressure regulator...just getting a new FPR won't do much for you.

Best Buy for you= Walbro 190lph -$90 and free shipping on Ebay!
You can do the re-wire on the 190 if you want but you are only going to be running 550cc injectors so you'll be healthy with out it!

 

[ZUUHLSGSX]

Yes, a new fuel pump is a must have before you upgrade to bigger injectors...IF you choose a 255lph pump, you will need a AFPR...Don't be fooled into buying the cheap FPR you see around ebay and the internet...You will need an ADJUSTABLE Fuel pressure regulator...just getting a new FPR won't do much for you.

Best Buy for you= Walbro 190lph -$90 and free shipping on Ebay!
You can do the re-wire on the 190 if you want but you are only going to be running 550cc injectors so you'll be healthy with out it!

thanks kraka.im kinda on a low budget right now and that will help take some of the pain out of buyin this stuff.