onequickseven

if i get my boost to level out at 15 pounds my injector duty is at 92% at 7000 rpm i have 1600/550 set up dont know if i need bigger fuel lines or injectors? On top of my injector duty to high i can not get my boost to level out dont know if turbo is to big ,gate to small or what is going on. Its a half brige,3mm,motor with a 62-1 .96ar ,46 mm gate,AEM boost controler .but i am having spikes in the upper 30s so at this rate the motor will not hold together for long .

Marcel Burkett

#1 What fuel pump ?
#2 A 0.96 a/r is wayyyy too small for a half bridge . Most likely your back pressure is through the roof.

onequickseven

fuel pump was a Bosh but the guys at rotor sports in NC thought that was my fuel prob so the put in the pump that they use on all ther set ups.and it helped my duty like 2% at 7000.they had no clue what the fuel prob was just told me to shift at 7000.as far as the a/r i get about 8or9 pounds tell around 5000 5500 then baaam to much boost .my gate spring is a 9

classicauto

iTrader: (3)

Something is extremely wrong.

Any damage to i/c piping? Torn couplers?

How's the wastegate lines, any leaks?

You should be hitting 10psi much much much sooner the 5K on a HBP. More like 4K, full boost by 5.

Also, the .96 should be fine. I ran a 1.00A/R on a monster halfie, it was perfectly fine.

onequickseven

just went thru and checked all the pluming and its all good so about like me no clue what is going on

classicauto

iTrader: (3)

How's the boost solenoid hooked up?

And what type of wastegate/manifold?

onequickseven

the boost solenoid is hooked up like it said to with the boost controler . its a tiel 46mm gate.manifold no clue

classicauto

iTrader: (3)

"like it said" is kinda vauge, if its hooked up properly and funcitoning properly you shouldn't have this issue.

Which port on the solenoid is going where? Where's the boost signal taken from?

Also, some setup info from the EBC would be good. What type of crack pressure is set in the unit? What duty cycles are you running on the current setting? Are you using scramble boost?

onequickseven

port 1 is turbo pressure port 2 top of gate.as wher the boost signal guess the one going to the BC is what you ment .its in the back of the manifold.my crack pressure in set at 8.8 and it is set at 77%, and no on the scramble boost.

AnthonyNYC

iTrader: (3)

I would also advise to check for leaks but you did that already. To properly check I would block the piping from the turbo and pressurize the system, you will clearly hear any air leaks. Next thing to check is fuel pressure, what are you using for a fuel pressure regulator and what is your pressure without the vacuum line hooked up?

Anthony

Busted7

Im running a 62-1 with large street port and it starts boosting hard at 3500/3800 so theres one problem you have. Im running two walbros and two 5/16 fed lines and at 20 psi im getting 80% dutie cycle. Im running 850/1680 inj.

At 15 psi on the 1/2 bridge i would think you need more fuel available!
I would put a 12 lb spring and check and make sure everything is perfect.


Good luck!

onequickseven

its a a fuelab regulator i will have to check on the psi unhooked thank its around 35 to 38 hooked up.as far as a leak i just got new 4 ply coplers and tbolt clamps .but as for the air to air they is no holes that i can see i will check it, its a new greedy 2 row

sk8world

iTrader: (5)

as far as duty cycle goes how are the Afr's? Could be dog rich. I run 1680's and 1000's and when I see mid 10's my duty gets in the high 80's to low 90's..

on, the gate being too small.. I doubt it being the issue at such low boost but as above it could be the vac source as I am trouble shooting the same issue on the same gate now.. mine controls boost but has 2-5 psi creep. I will post up what I find if you have not got it taken care of by then.

My old set up with 1600's and 550's started to run high duty at 20psi but a tad rich. So depending on what your plans are you may need to upgrade. I am not sure how the bridge likes fuel thu..

onequickseven

my afr is a bit rich at first its in the 10s but it starts to lean out .it dont help i have not got a data log yet i got my duty nums from rotor sports.but my wide band from what i can tell my afr creeps up to around 14.5 at 7500 but i have to use my foot as my boost controler its hitting 30+ if i stay in it, but it dont start to make good boost tell 5000 to 5500

dregg100

iTrader: (34)

you are hitting 14.5 at 7500 and the engine still runs? this seems like you have a major issue somewhere obvious. and when you say "good boost" what does this mean?

also, 30 psi on a half bridge with that smaller turbo, and small hotside seems a bit off. it shouldnt be able to produce that much boost.

onequickseven

ya the 14.5 is not good that be why its parked in my shop.it is slow to spool up i am getting 8 to 10 pound tell like 5000 to 5500 then the turbojumps up (spikes) it is not the same all the time some times its 24 some times it is not that high but the last time i took it out it hit 34.at around 8000 and thats when it went lean. at 30 + pounds i no its going to lean out . but i cant get my boost to level out my injector duty might be ok if i can get my boost under control.i can hear the gate open but the boost still goes up.

Dudemaaanownsanrx7

iTrader: (23)

Have you tried disconnecting the boost controller to see if it will do just the stock spring pressure in the wastegate? What size spring are you running? on the one hand it sounds like your wategate isnt opening because it has such high boost, but on the other hand it sounds like its wideopen until 5000rpm because of all the lag.
with that setup you should be getting boost ALOT sooner then that. even sooner if the wastegate is stuck closed or somthing.

onequickseven

my spring is a .6 bar i thank thats around 8.8 pound . is holds about 9 pound if i turn my controler off thats if i creep in to the boost but it spikes bad if i just floor it. it may just be the controler is junk.i am going to go thru evey thing once more next week.

sk8world

iTrader: (5)

Are you sure its spiking that high? Are you running a GM 3 bar ? or what other map sensor? Sure its computed right? (correct info put it to read correct boost)?


Who did the work? The shop you took it to could not fix it?

onequickseven

Its the stock map . The boost gauge has peak hold i have a manual boot gauge to check it with. just have to run line to it. the place i took it to told me to just drive it and to have my injectors checked maybe thats whats is wrong.I got them from rx7.com so i am sure they are 1600 cc.

onequickseven

ok went thru and checked for leeks found none. hooked gate up with no controler and it is still spikes around 15 , my fuel psi is 42 with vac and 46 with out vac . so with that much fuel its still got high inj duty.

Marcel Burkett

High exhaust back pressure , caused by a poor manifold design or an undersized turbo will cause your boost to spike . If the placement of the wastegate isn't ideal , it would be difficult to get the exhaust gas to change its initial direction and "turn a corner" to get to the wastegate . Because of the small size of the turbo , it to cannot pass enough gas out the exhaust . Because an insufficient amount of gas gets through the turbine the pressure in the manifold builds as the rpm's rise , this high pressure would then act on the turbines blades , causing the turbo to accelerate quickly resulting in an uncontrolable boost spike.
What you would need to help you fix this problem could be one of three things , or a combination of them all , these being , a better designed manifold , a larger wastegate or a larger turbo .

ErnieT

iTrader: (2)

Make sure that your FPR is a 1-1 ratio and not higher. If it is, thats where your problem is.

Dudemaaanownsanrx7

iTrader: (23)

that bridge port must be putting out too much exhaust 62-1 is a pretty big turbo so i dont think he needs a bigger turbo. what a/r hotside is it running? is your wastegate plumbed into the rest of the exhaust. Maybe your gate is sticking shut, or is just too small. What is the rest of your exhaust system? DP size, cat/midpipe, catback?

The injector duty cycle isnt related to the boost spiking, and the spiking definitely needs to be delt with first. Those duty cycles while high shouldnt cause the injector to stick unless they are staying that high for a sustained amount of time. Your fuel pressure probably needs to be higher under boost to get your duty cycle lower.

BluRR

iTrader: (1)

Check your fuel pressure man. I had the same prob where i would lean out 10psi with the same 550/1600 setup. The problem was my fuel pump was not switching over from low speed to high speed. So i connected the pump straight to have full power all the time...ran 17 psi after that with no issue at all. Try connecting the pump straight to the battery or acc and give a test run and see what happens. Also check your FPR and make sure you dial setting is starving the injectors of gas when you go up on boost.