86' mustang gt p600 need help

Let me tell you guys about my car:
1986 mustang gt 5 speed, 5.0 HO engine.
mods:
STOCK ENGINE, intake, injectors (19's pounds), stock heads, stock computer.
BBK equal lenght headers into 2 1/2 exhaust, NO CATS, flowmasters 2 chamber.
3.55 gears, centerforce cluth, T5 with world class kit. M6L ignition, 2F blaster coil, sunpro boost guage, autometer electrical fuel pressure gauge, autometer pyrometer.
P600B, 2 core intercooler, ATI FMU, aTI 255 LPH in line fuel pump.
i am running the stock 8 rin crankshaft pulley with the 2.70 inches blower pulley.
I see about 10 pounds of boost at 5,200 rpm.
My car has the stock speed density system, with the check valve on the MAP sensor to eliminate the boost pressure to the MAP.
Still I feel the car strong, but not all times, sometimes I press the pedal to the floor and the engine would rev up very slow with no power, still I see bost but not that much, no black smoke from the back, so Guess I dont have a rich condition, I also have low exhasut temperature less than 1200 F degrees so I guess no lean condition either.
My best guess are:
1) I did not calibrated my plugs lower than manufacturer specs, so it might be posible the boost is making the sprak go off, but still I dont feel like a missfire on my engine.
2) I need to change my speed density to mass air flow system, maybe A9L or A9P computer, 30 pounds injectors and calibrated 70 mm mass istr flow sensor, along with trick flow intake and 70 mm throttle body.
So that is my story, I really need the help guys, all sugestions are very welcome.
Thanks.
Pablo

PS: By the way, those p600 sure make a lot of noise at idle, they sound like a bad steering pump, but when you rev it up ...ahh that sweet whistle.

so what was your question?

how much fuel pressure you running and whats your timing set too.. I think your gonna need bigger injectors to be safe because you're probably running those 19's at 100% duty cycle most the time which means they wont last long.. you might be running lean up top.

When I just put my p600b in a month ago I felt like I lost some of the instant torque I had below 3,000rpm like your describing but as soon as the boost kicked in it moved! I think it just takes more horsepower to get the blower spinning fast enough to start making boost at the lower rpms. maybe thats just what your feeling in your car.. still dont understand what question your asking though...

ohh and about the plugs.. I got msd 6al and coil and have one range colder plugs gapped to .05 and haven't had spark blowout yet so you might be alright with that.. dont know if you have colder range plugs though...

K.C.90gt
My questions:
1) What combination I shoud use for INTAKE, INJECTORS, THROTTLE BODY, COMPUTER and ROCKERS.
I was thinking of a computer A9L with the addition of a tweecer or the Ford EEC Memory Adapter. what do you think?
I also have my timing set at 10 BTDC wit the spout off.
Fuel pressure art idle is 38 pounds, and at full bost is about 85 pounds.
I will try to get colder plugs, amybe 1 or 2 degrees colder.
by the way, I just gap the spark plugs at 0.040 and a noticed an improvement on accelaration, but could not test a lot because I blew my blower belt..ughhh...number 2 this past week, the first one becasue missaligment, and this one I think I over reved the baby to much.
So please give me your advice.
By the way, you have a killer web page, and I really liked your car..NICE WORK!!!!
I will try to send you some pics of my car, send me your e-mail and I will send them to you.
I live in costa rica, central america, and we do have a lot of stangs around.
Thanks for the help.
Best regards.
Pablo

You definitley need to get bigger injectors and convert to mass air! You could get it running with speed density but it will take ALOT of tuning! I would start with the A9L and get the lightning or a Pro M mass air meter and get 42# injectors to be safe. Then you will have plenty of fuel and the motor will be safe. I wouldn't gap your spark plugs no more than 0.35" with a blower, and use 1 or 2 heat ranges cooler plugs. You will notice great improvment by getting mass air, it is so much better then speed density.

I would suggest the A9L computer as well for sure, but if you are going to get a lightening meter or new style plug meter... make sure that the conversion harness that you have has the newer style plug on it... the older style is oval, the newer style is rectangle shaped. Anyway, there are a lot of ways to go about what you are doing, but I would like to see you spend the extra money in the meter as opposed to a tweecer... get yourself a Pro-M Univer and it will save you dollars and your tuner headaches. You can tune it yourself, but unless you are willing to spend consideribly more money on the tune by doing it yourself (tweecer + LOTS of dyno time), then you are much better off having it professionaly custom dyno tuned by a good, reputable tuner which is going to end up costing you probibly around 400-500 for a good tune.

BTW, how much money are you planning on spending... seems like you want to do a whole lot at once... do you have a budget? It may be easier for people to recomend different combinations to you with a speciffic budget and speciffic goals for the car.

SnakeIs and WA2FAST :
yep, the 42 injectors sounds a lot of fuel, but using them would affect my idle? to much fuel...how about 30's injectors?
PRO M...sounds good too, but what size? remember I would use the trick flow intake ( idle to 6,500 rpm).
and throtle body size? does it have to match the PRO M size? 70 mm PRO M and 70 mm throttle body? how that sounds to you guys?
WA2FAST : the reason I want to use the tweecer is becuase I can tailor the fuel needs of my engine with the supercharger, but now you got me thinking...does it means if I use the PRO M mass air meter with the A9L computer I would not need to touch the computer because the computer can do all the job and suplly the extra fuel at 14 psi?....I thought the A9L is good for stock engines...but with supercharging?
WA2FAST , so far I spend about 3,500 dollars, so money is not an issue since I come this far, but for sure I dont want to spend my hole income on it...I think a few 1,200 dollars more would get me OK...Injectors, computer, pro m mas air flow sensor, intake and throttle body...what do you think?
Thanks for the help guys.
Pablo

Like I said, #42's would more than likely suit your needs... #30's more than likely will not, your still going to end up needing the FMU with #30's probibly, so if you are trying to get rid of the FMU (like we are suggesting), then you are going to need more than likely #42's... they are not too big if thats what your car demands. The size injector does not effect idle at all on a car that is properly tuned... the injector pulse-width is determined by the computer which gets its information from the O2 sensors and various other sensors. A 70mm t-body would probibly be a good idea, but you definitely want larger than a 70mm meter... infact, you won't be able to find one. As suggested above, a Pro-M Univer is going to be your best bet for meters. Any stock computer is not going to be able to properly compinsate for boost... because it can't determine boost... it reads airflow and air temp and final A/F ratio, not boost, that is why it is best to have the car tuned... to 'help' the computer out in doing what is best both to be safe, and to make power. All of the suggestions are above, just as before. If you want my shopping list for you, here it is:

A9L computer
Pro-M pigtail MAF conversion harness w/wiring directions
Pro-M 3.5" Univer callibrated for #42
#42 FRPP injectors (green top)
70mm Holley throttle body (I have been through many, this is the best quality if you ask me)

As far as your tune goes... like I said above... if I were you, I would just get your car tuned and be done with it, don't get a tweecer. If you plan on changing your combination regularly and/or have pretty much unlimited access to a dyno for free, then go for it.

WA2FAST, got it, the list you gave me sounds good to .
But when you say "tune" the car and "help the computer" once the boost comes on, does it mean to have the A9L computer modify internally? or externally? with a special chip?
If so, is like having a tweecer atached to the J3 port at the back of the computer, so that is why I consider the option of the tweecer to start doing the mods to the sotck program and change the air fuel ratio when the boost comes on, this could be done with the voltage signal of the air flow meter, throttle position signal from the TPS and with the RPM value, at list that is what I expect fromm the tweecer, then I can add some more fuel.
Or maybe go with the combination you just told me and keep the FMU and adjust it to increase the fuel pressure gradually up to 100 PSI depending of the boost pressure...this is the the cheap way to supply more fuel to the engine.
Please give me your input, expand a little your idea of have the car tuned with the combo of parts you sugestted me.
Thanks for the help friends, all the input you are giving me is great!!!
Pablo

It's not just about fuel. Your computer makes certain decisions with timing and fuel based on a factory N/A application. It can compinsate to a point, but what needs to be done as far as fuel and timing when you have a power adder completely changes. Call up a tuner and they will explain everything to you, but it is MUCH, MUCH more complicated than that.