So I have my Greddy TT kit coming in next week and unfortunately i am getting the kit without injectors. I have all bolt ons but still stock internals so im not planning to run high levels of boost (for safety issues obviously). Prolly8-9 psi tops for high boost, and i'd say about 6 for low. Im not really looking to exceed 400whp. With that said, im looking to figure out what size injectors i should run. I was told either 440cc or 550cc. Which would be the better route to go with? This car is a daily driver as well so i dont want it to be dumping fuel, but when I need the extra fuel i want it to be there. I dont really plan on running return lines if i dont have to and i dont want to run into idling issues either with large injectors. Does anyone have this set up on their daily driver? and if so what size injectors did you use? Also what would be the best place to order the injectors? I found some 440s for about $475, but im not sure if that is the "usual" price for what they would be. Any input would be appreciated.

Thanks

 

Have you decided who and how you are going to tune? I would decide that then ask the tuner.

Good Luck!

 

^^like EZG said. Your turner's skill with your tuning system will help with drive-ability and smoothness



I think 600-750 injectors will be good. fuel is something you want to have some cushion with. Check with Dynosty or Forged for some injectors. They've done a lot of different builds with different brands and sizes.

Just as a reference I have 1000cc low impedence HKS tuned on built block with no idling issues. Smooth from stop light to stop light.

 

This is the best advice that you could be given OP... once you decide on a tuner and what he is going to tune with it will make it that much esier for him, and lighter on your wallet, if you used the injectors that he suggests and is familiar with. 440's will get you what you want, but they may be hard pressed to do it, it is advised that you keep your injector duty cycle below 85%, keeping that in mind i would go with either 550's or 600's for saftys sake. GL and let us know what happens.

 

I would use the DW600cc injectors. they are good to about 500whp with a walbro and stock returnless fuel system. Also with a Greddy 18g kit at 8-9 lbs you will almost certainly be over 400whp is it is tuned right. Let me know if you are interested in having us tune it. We can get you everything you need and also send ya a base map to get here.

Thanks, Vince

 

I was planning on going with Uprev for the tuning. If not that then it would be Utec, but it will most likely be uprev (oops forgot to add that info lol). I've heard of people with idling issues on stock internals with anything over 600cc. Its obvious i wouldnt ever want to be running lean, but i dont want to be strait dumping fuel either seeing it is a daily driver. So you think i would be fine with 550s, without fuel return?

Also Vince....where are you guys located? And what systems are u mostly familiar with when it comes to tuning? I'm located in Connecticut. Also if you'd like to pm me ur pricing that'd be good too.

Thanks

 

Vince is currently working on my car - Greddy TT 18g using UpRev (its got a few more mods now but I basically started with your setup). Having gone through some nightmare issues with my first builds I would highly suggest you base your decision on two key factors:
1. Stock Internals
2. Fuel flow
That said 550s will likely give you enough room to max out the available fuel and strength of the internals. I went to 9psi on stock internals (with approx 50K miles on the motor before the build) and an upgraded walbro (non return setup)... after about 10K I had serious knocking and ring damage... All due to improper tuning (car ran lean under WOT) using UpRev (Not Vince... another shop and my own ignorance).

Having had the motor rebuilt (twice) with forged components and finally did what I should have done in the first place... Take the car to a REPUTABLE tuner. I can't stress enough the importance of this, in my opinion the cost is high but if you want to go FI its a must and (in my experience) its nothing compared to what you will spend if its not done right.

 

DW 600's /thread

 

DW600's would be fine, or go larger for E85. Get a fuel return, nothing fancy, but worth the $400.

Vince knows what he's talking about, but be careful how many people you ask for opinions. Seems like a lot of bad information on this forum lately.

 

Thanks. Yes, i am spending a good amount of time and research on tuning shops. I've learned to not just go anywhere and use a shop that specializes in VQs as well as the EMS ur tuning it with. So far I narrowed it down to Perfomance Motorsports in Long Island (not sure is anyone else on here is familiar with them) I hear their an authorized Uprev dealer and specialize in VQs. I'm still open for other suggestions as well, as long as im not shipping my car halfway across the world lol. When you had this issue with the knocking and ring damage, what size injectors did you use? The more i hear about things like this, the more it pushes me towards the 550s. And yes, i'll have the Walbro fuel pump as well.

Any other recommendations for this setup on stock internals? Im already thinkin about going with 4-6lbs springs on wastegates for added safety. Last thinh i need is a horror story.

 

im selling a deatschwerk 300 lph pump for $110 if your interested, outflows the wahlbro. has 4 hours use on it

 

I have a Greddy TT 18g kit, ran it on my stock block for 2 years hard with ZERO issues. You MUST have cushion with your injectors IMO. I ran RC750cc's for 2 years and had zero idling issues. That with with a returnless system and just a walbro 255 pump. I made 430 and daily drove the car.

I firmly believe you should be looking at alot of extra room on your injectors should you need it in the future and two, you don't want to be pressing the limits of the injectors all the time.

Have you talked to Chris at EFI logics about uprev? He is a licensed dealer of uprev and in your back yard, he has done a number of Nissan's and might be worth talking to. Both EFI and PME have tuned a number of cars in my area and all run very well.

 

One message that was resounding above all others when I went through my "thing" was "DON'T SKIMP ON FUEL."

With that being said, when I was on all stock internal "stuff" the guys I trusted put me into DW600s and judging by what you're saying your goals are and how they matched up with my original goals... that was what I was thinking too.

I'm uprev as well... mind you I was DW600s for about 3 pulls on a dyno and then magic happened and I transitioned slowly to a built short block and bigger goals. I'm running DW850s with 0 idling issues. Okay granted there are some warm-hot start issues that can be resolved with a simple feathering of the gas... but nothing operationally concerning.

My answer would be DW600s from my experience (at least, in what I was told) but I'd pay some attention to the suggestion for FRS.

 

Just like vince said DW600's + walbro and a high quality Uprev F/I tune. Not all tuners are made equal... I've seen far more **** poor F/I tunes than good ones which is why you hear stories about startup, idle and drivability issues. Just because someone knows uprev and does a bunch of tunes means zip for F/I. Uprev done correctly and your car will start, idle, and drive just like stock except for 150 more HP regardless of injector chioce. He is one of only 2 tuners I truely believe 'does it right, 100% of the time' with F/I on uprev. Make the drive to Vince it'll be worth it.

 

^^^ thanks for the good words Randy!!!

OP, shoot me a PM with what you are looking for injectors and fuel wise, and maybe anything else you need. Chances are I can get you a good package deal that will get ya everything you are looking for. We areloacted just north of Philadelphia and we have done dozens and dozens of F/I VQ's on UPREV


^^^ chances are you were tuned before UPREV refined the starting enrichemnet tables. Since them I have been able to get 1000's to start perfectly with no hot start issues. If ya have you ROM I can look at it and make some tweks for ya if interested. ...

 

Who is the other one, hal?

 

Frank Smith @hills garage in Baltimore. Higher pricing and locked ROMs @hills steered me to Vince@RTT. Still don't understand why some tuners feel the need to lock all their ROMs, for most it's a non-issue but for me it's a deal breaker. But I've watched Frank do meticulous work, sometimes spending hours just on startup and idle. He even took time to help me with my own tune checking out my logs and offering Uprev advice (before I went to Vince for my final power tune). A++++

 

Hey man! Im running DW600 with stock internals (until i build this winter, parts are all here!) and 255walbro pump no issues. As stated before, most important to have your tuner look into this with you also. Even if you dont plan to max them out, its better to have the part running comfortably than maxed out. Goodluck!

 

When did UPREV refine the tables? I've been having start-up issues for awhile. Cold starts are perfect, but with warm starts it takes a few seconds...