ok i just intalled my new turbo kit and it seems to be running a little rich , my kit includes , t3 turbo in a 60 trim , wastegated at 7 psi , 89 ford probe injectors, 3 in intake pipe& down pipe back is also 3 in, 12:1 fmu , walbros 255 fuel pump, type rs bov,and a costome mount side intercooler, i have all the other little thing for the kit as well, i retarded my timming by 6 degrees and it just wont smooth out what would you guys think the problem is . i thank you for any help

This post has been edited by trd94: Apr 11, 2006 - 2:46 AM

you retarted your timing WAY too much..
that FMU is a VERY bad idea...under just 2 lbs of boost, your gonna be raising your fuel pressure 24lbs. thats nuts...your fuel pump and injectors will never be able to keep up with the demand.

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yeah man, are you using a safc or something to regulate fuel?

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why is this fmu bad ,i think nik used a 12:1 on his 7afte with no problems , by the way your dyno # are awesome

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i dont have a safc yet but i do have a fuel managment unit (fmu)

12:1 is an extremley high rise rate...for every pound of boost, your raising fuel pressure by 12lbs.
id REALLY get away from the fmu, get a set of properly sized injectors and a 2 bar map sensor from an alltrac or mr2T, and somthing like the SAFCII or even better emanage or SMT6 or 7 to control them.
thanks for the props =)

:edit:
the probe injectors are what 330cc or somthing?
thats actually pretty close to what you need.
what are you doing about your stock map sensor?
if you were to go to a 2 bar map, you could get rid of the FMU, and use somthing like the SAFCII to tune out your fuel curve.
with the option of using a better matched turbo to the car, you ST guys should really be looking into maximizing everything else in the setup to make it more durable, and bulletproof.
the FMU is really old school stuff, and really should be abandoned for our setups IMO.
there are much better, safer, more controlable ways to do it.

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the map sensor i used check valves to bypass it (i know very old school ) i will look in to a differant map sensor thanks again

i think that you should be fine with the 12:1 fmu, that is what i am using. and i am using check valves (i haven't heard of a 2 bar map used on a 7afte successfully without a code) I think that you should get a safcii to manage those injectors, i think thats the problem.

*shakes head*

so you have a 1 bar map, 50% larger injectors and an FMU ?

are you still running oil in the motor ? or is your oil all fuel ?

you're throwing in 50% more fuel at idle, and 250% more fuel at 7psi

so unless you have a 3.0 litre, making 420 crank hp @ 7psi then your fueling is incorrect.

Throwing a code doesn't mean the 2 bar setup is wrong... it depends what the code is...

if you put a 2 bar sensor on and 800 cc injectors you may get a 'rich code' ... if u put smaller than needed injectors on with a 2 bar you may get a 'lean code' ...

so unless you're actually getting a code for the map sensor ... and have verified that is the code that you're getting on a 2bar setup... then the problem would be the tune and not the use of the 2bar sensor

-nuke

thanks for chiming in on that nuke, i dont know the figures, so i dont like to quote amounts...but yea, thats the genral idea i was trying to get across to him.

and,
just be cause the check valve/ FMU thing WORKS, dont mean its the best way..trust me, the 2 bar map and properly sized injectors will go ALONG way to helping your car run better.

so you are saying that a 2bar map wouldn't throw a code at all if you are running correct ratios? what about the ecu seeing pressure??

like nuke and cheesy said:

it runs like **** because you need to turn those injectors down at idle.

get a safc. i have the old school five knob kind and it works well. the new ones you can adjust for TP and that will be really helpful.

what 2bar would work for the 7afte?


also TRD94 posts some pics of your set up.

This post has been edited by southwest2118: Apr 11, 2006 - 11:42 PM

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since the ST and the GT have the same stock MAP sensor, switching to an all-trac or MR2 turbo (both 3sgte) 2 bar map would work just fine for a 7afte build like Manny (presure2) is saying.

ok guys i thank you for all your help. right now i went back to my old set up stock injectors ,12:1 fmu idle is back where it belongs i turned the boost down to around 4 psi ,i am just going to wait until i get my safcII and look in to this two bar map sensor, i plan on making good hp but in the same time i dont want to blow a piston out the side. thanks again for the help and please keep it coming

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i do not know how to post pic but i do have a couple in my profile , if any one would like to post them for me go ahead by the way new paint job coming very soon!!

This post has been edited by trd94: Apr 12, 2006 - 2:36 AM

Some simple math... example

stock hp = 100hp.... target hp = 400hp
stock injector = 200cc/min ideal injector = 400/100 * 200 = 800cc/min

roughly: cc/min = desired wheel hp *1.5
200whp = 350cc/min
300whp = 450cc/min << the figure most 3sgte guys quote
400whp = 600cc/min

This is all for 4 cylinder cars

Fuel pressure example

stock fuel pressure = 40psi
new fuel pressure = 80psi
fuel pressure ratio = 80/40 = 2.0
flow ratio = square root ( fuel pressure ratio) = square root (2.0) = 1.41

1.41 is 141% so 41% more than stock ...

so if you had 200cc injectors @ 40psi, and you got a new fuel pressure regulator set @ 80psi then you effectively now have 200*1.41 =282cc/min injectors

282cc/min /1.5 = ~188whp worth of fuel

FMU example.

you have 300hp stock, you want to put on a turbo (that according to the compressor map) says that you can make 520hp @ 8psi (according to the chart)

fuel flow ratio = horsepower ratio
fuel flow ratio = 520/300 = 1.7333
fuel pressure ratio = fuel flow ratio ^2 = 3.0044
say your stock fuel pressure is 15psi.
new fuel pressure = 15*3.0044 @ 8psi of boost = 45psi fuel @ 8psi boost

FMU rate = (high pressure - base pressure ) / boost pressure
FMU rate = (45psi - 15psi) / 8psi = 3.75:1 FMU

The max pressure you want to reliably pump through your injectors is 85psi

Domestics run low psi fuel injections (8-20psi sometimes) so FMU's are great for them becuase you can double your fuel flow going from 20 to 80psi ...

but on an import where you already start at ~43psi of fuel pressure at atmoshpere... then you're limited to adding 45% fuel flow with an FMU Setup (or a dry nitrous setup because it works on the same fuel pressure rise concept)...

so with a 12:1 FMU you are limited to 4-5psi while still being considered 'safe'

so that's what i was saying...

@ 8psi , with a 12:1 FMU you run some 124psi fuel pressure
base is ~45psi
pressure ratio = 2.75
flow ratio = 1.65 =+65%

from your injectors
stock injector = 200? cc
new injector = 330cc/min
flow ratio = 330/200 = 1.65 = +65%

so at idle , the FMU isn't active...so you only have the increased fuel from the injector upgrade which is the 50-65% i quoted you at idle...

under boost you have to multiply the flow rates
new flow rate = 1.65*1.65*stock = 2.72 * stock
so 200 * 2.72 = 540cc/min injectors
540cc/min /1.5 = 363 wheel hp worth of fuel

if you're actually making 250 hp instead of 363 then your a/f ratio should be around

250/363* (12:1) = 8.3:1 << rich

-nuke

thanks nuke this is a big help keep it coming

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can't... i'm all out of info on this topic

This post has been edited by NuclearHappineS: Apr 12, 2006 - 6:03 PM

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I have a very similar problem. I`m running probe injectors, 255 fuel pump, and a safc2. I`ve got it turned down -50 and it still idles at around 11 to 1. Useing a AEM wideband guage. Am i missing something? What can i do to get this thing to lean out some? Also have check valve and stock preasure regulator, could that be the problem?

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yes.

[quote name='presure2' date='Apr 13, 2006 - 1:04 PM' post='421091']
[quote]Also have check valve and stock preasure regulator, could that be the problem?[/quote]
yes.
[/quote

What would more than likely be the main problem the regulator or not haveing a 2 bar map. Are just both

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the timing i retarded on the dyno also do you have one step colder plugs?

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i dont have colder plugs no one at my autozone knows how to look this up , do you have a part # to help me ,thanks again

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i dont know the part # off hand they should know how to look it up i would do this get new plugs then set timming to normal get you t-gun out turn it back 3 degrees see how she runs keep the boost at 4-7 psi

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I have the same setup as there and i have NO problems (except i have stock fuelpump, works fine at 7psi), so i don't that thats the issue. make sure that you have your safcii set for "pressure." how are those probe injectors impedence? maybe thats the issue... i just know my fuel system works fine, i run perfect with 550cc injectors, fmu, checkvalves, safcii (-50 low tp, -25 high tp) and EVERYTHING else stock for fuel.

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So i guess the 255 fuel pump puts out so much preasure that it is overloading the injectors with fuel. I need to get the fuel preasure back down closer to stock. There high impedence.

even with a bigger pump and a stock FPR the stock FPR should keep the pressure the same at idal

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Its running extremely rich at part to closed throttle. Especially going down hill. Im getting fuel in my oil. I cant lean it out any more with the safc. -50 at low throttle. turbo probe injectors shouldnt be to big. Right? I think im going to put my stock injectors back in. Running 7psi they should be ok right? Maby ive got a injector sticking open or something. Could i have wired them wrong? Anyone no which wire goes to which side of the injector. i just went by the way the stock ones were.

i got new plug and i set the timming back she runs good but still seems a little rough at idle but that could be my plug wires still stck size i will have to get a little bit bigger soon i am going to the dyno in a couple of weeks so we will see what happens thanks again

wire size doesn't effect the performance that much...?

i ran brand new denso oem plug wires the whole time i was 7afte

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stock wires here too.