Hey guys I'm normally over on the maxima forums, but so many of those guys are running VQ30s with their F/I (return system stock) that most have no clue what to do with fuel on my car.

I have a VQ35DE on a 03 max and I'm looking to start kinda easy on the boost and I'm looking at low expense fuel system options. As far as I can tell, I can run the 255 walbro I have + a FMU on stock injectors, and at least run a few pounds of boost (i'll put it on the dyno and raise the boost until I see where the stock fuel injectors limit me, and correct me if i'm wrong!), but what are you guys doing when you need to use bigger injectors?

In the next few months I'll have a 350z UTEC rewired to hook up to my ECU and I should be able to tune pretty well for bigger injectors, but are you guys still running a returnless system like this or are you converting it to a return system?

If you are converting it, what is the normal process?

Thanks, and sorry for noob questions

 

its recomended after 400whp to run a fuel return system. most people just buy fuel return kits from either CJM or AAM. as long as your injectors can fit the stock rails there isnt really a need to get new fuel rails because the rails arent the limiting factor.

 

You will find it rather difficult to add a FMU without a return fuel system. My advise is put a set of larger drop-in-fitment injectors (such as these Deatschwerks ones) and some form of engine management to control them. Your UTEC will do for the 440cc injectors, but beyond that I would recommend a standalone due to the UTECs downfalls with larger injectors. I have all of the wiring information ready if you need help with that.

 

Thanks for the info. I was hoping to be able to do like the return system guys and just get it running 5-6lbs on a fuelpump/FMU/SAFC with stock injectors for now then do more serious upgrades when I get the UTEC hooked up. Is that a possibility?

 

Your car is returnless correct? If so, fitting a FMU will require a return fuel system, which I thought you were trying to avoid. Personally I would not waste time on that, and go straight for a solution in the first place. In your situation, it sounds like 600cc injectors, walbro, and management would work quite nicely and not require a return fuel system. This would give you room to grow in the future as well.

 

Thanks, I'm pretty sure on the UTEC for now (greddy EU doesn't work well with my car) and most standalones are way out there in price. I'll go with some smaller injectors since you say the UTEC doesn't do well with large ones.

 

Sparks...I was running 440 injectors on my TT and it was not necessary to have a RFS. I was at 425whp if that helps and also a UTEC...car ran great!!

 

awesome, my goal before i build it is 375-425 whp. So the utec and 440's should run it great!

 

I'm running the UTEC with 650's and no issue. Daily driver too.

 

are there many people with problems with UTEC and 550cc+ injectors?

 

UTEC and 750's here..... RC's at that

 

650's and Utec...stumbles a little, but it's because of my big cams

 

650's and Utec, no issues.

 

FCon Vpro, 460whp, no RFU.

 

550cc and utec with no issue here.

 

i agree with just a lil exception, id bump the 440 to 550 based from from personal experience