I had a couple questions in regards to fuel pressure/volume

1. I understand NO TUNE is not reccommended
2. I understand there is major diff between Fuel Pressure & Fuel Volume


In general, if you were running lets say 5 psi of boost regardless of the size of the turbo. Would you be better off using the Walbro pump with the stock injectors? Would the Walbro give the stock injectors the capability of handling more boost / flowing more fuel? Any information in regards to fuel pressure/volume to help me understand would be appreciated.

 

so you have absolutely no engine management? i say get a wideband and find out im curious to see it this wouldnt just floood your engine with fuel.

 

I am going to do this lol - just wanted to see what people thought first...I have an LC1 so ill let you know in a few weeks

 

I dont care if you have a 1000lph fuel pump - if its connected to the stock fuel system with stock regulator - you will still get stock fuel flow from the injectors. Look at it this way, the fuel pump has to maintain the regulator's requested pressure, stock is 45 psi I believe. Running a larger pump will simply result in a lower pump duty cycle. You only need a larger pump if youre moving enough fuel through the injectors (larger than stock) that it causes a drop in pressure on the system. See what I mean? Say you run the walboro 255 - you still will only be at 45 psi - so your stock injectors will still flow the same amount of fuel

 

what if you change the regulator and pump and keep the stock injectors?

 

At what size of injector would you need to upgrade the fuel pump?
Stock is 380cc?
Upgrade at 500cc?

 

stock is 370cc n i dont remember anything bout 500cc maybe u ment 550cc

 

The stock fuel pump seems to handle 550cc fuel injectors very well. Anything bigger than 550cc and I would suggest upgrading the fuel pump. Also as far as upgrading the fuel pump and using the stock injectors, I would say that it really will not have a huge impact on the fuel system but the only way to find out is to try it.

I would suggest trying this before you install the turbo kit. I would record your fuel trims before you install the pump and then check your fuel trims after. If it seems to make things richer then the stock computer will know it and it will try and take away fuel.

 

I believe I am going to run a rising rate FPR with the return system I have the walbro and stock injectors at 7psi no tune. Ill let everyone know how it works out...I also have a wideband LC-1 to monitor the AFR.

 

even with the rising rate, it will run at 14.7 afr. at least get a dezod black box. lucky you, i have one for sale soon and safc-2.

 

the amount its going to cost you to run a fpr you can just buy 550 injectors and call it good.the stock injectors maxed out at 6 psi on my car. running perfect 11.5 till about 5k then it would lean out to 13.

dont boost on a budget.

 

nah, let him boost on a budget, ive got parts to sell ;)

 

what were the specs on the turbo you were using

 

And I forgot I already have the whole return system! at WOT and boost the FPR should add fuel in open loop

 

Your forgetting a MAJOR part in tuning TIMING!!!! fuel isnt the only thing you need to get the car to run safe. Plus injector trim size and response time all change with larger injectors. Just because you throw more pressure behind the injector doesnt mean the injector is going to be efficient enough. get your self a piggy back and get the car tuned.

 

54 trip .63ar



do what ya want man. just be prepared for the after effect

 

update - going to run 440cc injectors walbro and NO TUNE! whewww

 

*turns head and hold nuts* ok, fire it up!

 

lololol

 

LMAO@!