terps

iTrader: (2)

I got the aps single kit which has the RFS and was under the assumption that the injector were basically 380s under higher pressure making them like 440's. when i search i found people maxing them out between 350-450 but alot of the info was wrong like 3bar vs 4 bar after rfs, etc

However the aps website says they flow like 500's @4bar or 58psi and are good for up to 600hp.

Whats the story with this and more importantly how far are these good for powerwise. im getting a retune soon and would rather not drop another $700 on 600cc injectors and install if these are good for 450 and not pushing the limits. thanks

Mike@DW

It can be hard to know the true flow rate on many injectors and what fuel pressure being ran directly effect the flow amount of the injectors. Most injectors are rated at 3 bar, the 350z stock fuel system runs 3.5 bar, why APS would rate them at 4 bar I do not know. Even 500c @ 4bar is almost surely not enough fuel to support 600whp.

I do not see the APS injector in our data base, but we would be happy to flow test them (at different fuel pressure too) so you know exactly where you stand.

Zivman

iTrader: (19)

On a stock compression motor, they will make into the 500's... on a lower compression motor, they will make up to 500. obviously keep in mind all dynos read differently, all built motors are not the same, and there are other factors not taken into account

Cass007

iTrader: (34)

Mike - is it possible to send terps some loaner injectors so he doesn't have downtime and you can still flow test these. The info would be good for the community.

Zivman

iTrader: (19)

This info is already known... I completely maxed them on on my car, and have experience with them on another built TT. And as far as I know, someone has flow tested them before. These kits have been around for years what more is needed to be known?

terps

iTrader: (2)

^zivman so i should be good for 450 dnojet hp on a stock block, excluding weird factors. just a ballpark number

yah i just said f-it and got a set of deatsch werk 600's incase the aps arnt up to par, if they are ill give someone a hell of a deal on them bnib

aps, has a "unique" pressure system that makes the calc more difficult

Zivman

iTrader: (19)

Most definitely. 450 at stock compression should be no problem for the injectors.

The chart is easy to understand. With the return system, you have rising pressure 1:1 with boost pressure; this is the number on the left column. so you take the 58 psi and say your are running 5 psi of boost, your rail pressure is = 58 + 5. The numbers in the right column show constant pressure at the injectors vs having a drop in pressure as boost increases like you see with the oem style fuel system. the only difference is with the APS fuel system they run a base pressure at 58 psi, or 4 bar, vs the US standard ratings at 43.5 psi , or 3 bar.

Here is my dyno chart with the APS base fuel system. This is on the base TT setup and an 8.8:1 (stock cams) motor running 14 psi of boost to around 4500 rpms and then tapering to around 11 at redline. This the very most power my tuner could make on my setup with the out of box base APS fuel system. As you can see, this chart is from 2005..... so for those that are looking, this info has been available for 3-4 yrs now



this is my dyno chart from 2007... 9:1 motor with GTM stage 1 cams running 15 psi to redline- APS Extreme fuel system



boost graph

terps

iTrader: (2)

thanks man, i appreciate it i called gtm, z1, and AAM and got competely differnt responses. i feel like they had more in them since i am running rich, and extremly rich in my opinion and am putting down atleast 400hp and felt they could handle more but alot of people said i would need 600cc.

venders need to brush up on what there selling for real, i got answers that 400 would be max, and another one said i was good for 500.

BTW im going to be running meth, so i feel like that will help me with not needing to up the injectors, but i could be mistaken. from my understanding you pull fuel slightly with the addition of meth.

Zivman

iTrader: (19)

The other thing to note is that if you run the 600cc injectors paired with the rest of the APS base fuel system you might have issue controlling them with the unichip. The 600cc will flow considerably more due to the 4 bar FPR. I have a buddy running a G35 with a built setup and APS TT that upgraded to the 600's and actually had to put in an adjustable FPR to lower the fuel pressure in order for the unichip to control fuel properly..... this was at 16 psi tapering to around 13 making just over 500

terps

iTrader: (2)

i got the utec but am more consired about hot start issues and all the other hassels that go along with large injectors

Cass007

iTrader: (34)

Expect hot start issues with the 600cc injectors, I had the same problem with the 650cc. I hated my Utec, I always felt like I had to "drive around it", it just did not suit my driving style at all.

txshldm

iTrader: (4)

I had the hot start issues with old tune and no RFS, but with the new tune and RFS I have not experienced the hot start issues.