Jump to content
SAU Community

Difference Between High Flow Injectors

Pal

By Pal,
in Engines & Forced Induction

 Share

Recommended Posts

Pal Veteran

Pal

Posted
Posted

hey all,

had a set of high flowed sr20 injectors (flowed to 600cc) fitted to my car a few weeks back. since then i've noticed black carbon on my rear bar and chewing the fuel. i haven't been doing alot of boosting but am still getting just under 15l/100. to me this is too much so thinking its maybe to O2 sensor (was replaced about 1 year ago). got in contact with my tuner who is adamant that its the high flow injectors are causing the problem (bad spray pattern due to being drilled) not the tune. i got a power fc and high flow turbo.

STATUS Grand Master

STATUS

Posted
Posted
hey all,

had a set of high flowed sr20 injectors (flowed to 600cc) fitted to my car a few weeks back. since then i've noticed black carbon on my rear bar and chewing the fuel. i haven't been doing alot of boosting but am still getting just under 15l/100. to me this is too much so thinking its maybe to O2 sensor (was replaced about 1 year ago). got in contact with my tuner who is adamant that its the high flow injectors are causing the problem (bad spray pattern due to being drilled) not the tune. i got a power fc and high flow turbo.

we have no dramas using high flow injectors providing they are done properly. Get an independent dyno check.

PM-R33 Grand Master

PM-R33

Posted
Posted (edited)

I'm a bit curious on this. Lately i swear my car is using more and more fuel. $30 of BP Ultimate gets me about 100-150km's driving to and from work, im pretty sure it used to get me around a lot more.

I was thinking maybe the oxygen sensor is f**ked from using antilag every now and then, however i'm not sure whether Microtech's and other non Power FC ECU's use the standard oxygen sensor.....?

Edited by PM-R33
Fastrotor Proficient

Fastrotor

Posted
Posted

My moneys on the injectors. Getting them to flow a certain rate is easy.... getting them to atomise like std ones once modded is the problem. You can get a certain afr your aiming for, but theres alot more fuel going in than required , as the unatomised stuff goes straight out the pipes.

Case in point, bout 5 years ago i wired and dyno'd an SR20 for a mate, against my advice he got the stocker's flowed to 550cc ... and said the guy promised they atomized perfectly...... Anyway i maxxed them out, 100% ..... ok, car still ran fine, except once small transition area off boost, i could not get rid of a small hiccup, no matter what i tried.... anyway left it there.

Month later i did another SR20 but this time guy used some factory 550cc injectors, made the same power, same fuel pressure (i always fit a gauge). ....... however............ only using 70% duty cycle. I was expecting a difference but not that much ! It opened my eyes quite abit.

Gary

PM-R33 Grand Master

PM-R33

Posted
Posted

Gary do you know much about the Microtechs and O2 sensors? I know the older models couldnt run them in closed loop, but i read somewhere the LT12S does. I hooked the laptop up and had a flick around to check if it was running in closed loop but i cant seem to find a setting anywhere. I'm pretty sure my O2 would be rooted (i've never replaced it since owning the car) however i dont know whether to replace it or not considering the Microtech might not even use it. You know anything about this? I might go ask Pete when i get a chance.

Sydneykid Grand Master

Sydneykid

Posted
Posted
My moneys on the injectors. Getting them to flow a certain rate is easy.... getting them to atomise like std ones once modded is the problem. You can get a certain afr your aiming for, but theres alot more fuel going in than required , as the unatomised stuff goes straight out the pipes.

I've seen that on an N/A engine, especially with individual lambda sensors in the primary pipes, but never on a turbo engine, with a single sensor after the turbine . My theory has been that the hot exhaust turbine spins up the unatomised fuel, so it becomes atomised and hence shows up as richness on the F&W lambda sensor. Maybe I've just been lucky.

Pretty soon we will all be running on E85 and then it won't matter what the injector spray pattern is like, ethanol has such superior atomisation.

Cheers

Gary

bozodos Grand Master

bozodos

Posted
Posted

PM_R33 my LT10S has the O2 sensor physically disconnected, and yeah I get about the same fuel economy as what you're getting :) effing shite ECU's they are, can't wait to get rid of it.

back on topic, is there any advantage to say getting standard RB25 injectors high flowed, or would it be better to get say S15 ones?

PM-R33 Grand Master

PM-R33

Posted
Posted

I don't mind the Microtech at all. Maybe mine is still tuned a lot richer than what a lot of you guys run, i dunno. I'm going to find out if it uses the 02 sensor, could have something to do with it. That fuel has to be going somewhere...

EFI Performance Enthusiast

EFI Performance

Posted
Posted

I would be looking toward the tune in the ECU, remembering microtech's have poor timing control for light throttle cruising, there injector control is also poor.

The injector spray does play a part in this also, and I will honestly say this

WHO THE f**k HIGH FLOWS INJECTORS.

Do not use them and do not sell them.

My 2c

PM-R33 Grand Master

PM-R33

Posted
Posted (edited)

Well let's just all jump on the "Payout Phil's ECU Train" lol. Yeah i know they aren't the best ECU. But when i put my foot down my boost gauge needle fly's really fast and car's in the mirror get really small...... I still smile :iluvff:

Edited by PM-R33

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Erelyes
      Ceramic turbine damage to engine - what did yours do?

      By Erelyes · Posted

      Ha, well, it's been.... a bit of a journey. Things have taken much longer than I'd hoped. I'll probably put up a thread at some stage. Hopefully soon. The car's not done any kms since my update in June though, put it that way.
    • Dose Pipe Sutututu
      M35 Aftermarket Fuel Pump

      By Dose Pipe Sutututu · Posted

      Here's the chart for fuel pressure vs. current draw, assuming your base fuel pressure is 3 bar and you run like 0.5bar boost on WOT, you should only momentarily hit 9amps here and there. (Ignore my prev post, I cannot read a chart these days it seems)
    • GTSBoy
      RB25 Drama's

      By GTSBoy · Posted

      Those comp test results are not hideous. Whether they are accurate or not (ie, when that comp tester says 140 psi, is the real pressure120, 140 or 160?) is unknown to us. The state of the battery used to crank it over is unknown, etc etc. Many people around here would say that the absolute values and the spread are perfectly fine to just add boost and keep going. I personally would be happier with a narrower spread than that, but even the diff between 125 and 145 is not terrible. That one cylinder at 125 though, has probably copped some damage relative to the others. You should inspect the valves seeing as you've got it open. Do you know how to measure installed ring gaps? That, and an inspection of the rings themselves, is how you will determine whether they need to be replaced. If you're not good to do these things, take the block and the pistons and rings to a shop that is, and ask them for the go/no-go on them. Do the bores need a hone at all? If so, you might well be justified in getting some different pistons in order to get away from the ring supply problem. Whether you're happy to spend a lot more money right now, on more gear, rather than less money, but an amount that looks stupid given that you will only get a handful of rings in exchange for that money, is for you to decide.
    • iain_ST44GA
      M35 Aftermarket Fuel Pump

      By iain_ST44GA · Posted

      also possibly backed up to my filler and shat down it! 🤣
    • Julsmadrid
      RB25 Drama's

      By Julsmadrid · Posted

      Ok so i would love some advice here please, i purchased an R33 a few months back and its had a few mods done to the engine, its an RB25det running a Master ECU, 1200cc injectors, bigger turbo, oil cooler, oil filter relocation kit, Spool H-beam rods, acl/ross pistons. When i removed the motor from the vehicle (as its getting a respray) i thought i would compression test it and these are the following results. Cylinder 1-145psi, Cylinder 2-143psi, Cylinder 3-125psi, Cylinder 4-145psi, Cylinder 5-140psi, Cylinder 6-135psi this test was done with the motor on the ground and powering up the starter motor. I dropped the sump and found broken oil squirters on cylinder 3,5 and 6. I was told my rings are probably worn so i stripped the motor completely to get a new set of rings for it. The trouble is no one has these rings anywhere and they have to be custom made by Ross over in the states and will cost about $600+$200 delivery. My question is how can i tell if my rings are at fault and if they are still ok and is this price ok for a set of rings?
×
×
  • Create New...