just put on some 42 lbers, can i ditch the FMU even without a tune??

[Foxfan88]

i have been running 19s and the FMU from my SC kit, just got a set of 42s with a pro-m 75mm MAF "calibrated" for 42 and for a blower application.

i have been told i can just ditch the FMU and let the computer learn and it will get the fuel it needs even without a tune.

i went ahead and took the FMU out.

so will the 42s compensate for the added air by themselves without a tune??
the sell the diaphram plates for different size injectors, i think 42s use 3:1 which isnt much. it seems like i dont need the FMU

havent started the car yet, so i can put the FMU on easy enough if need be (the car will run horribly rich due to it still having the 12:1 disc in it)

 

[zx9rrick]

I picked up 40 hp on the dyno just by blocking of the vaccum to the fmu.I'm using 30lbs injectors & putting down 425rwhp.If you what to trade your 42s for 30's lmk.My 30lbs are maxed out at 5400rpm & 425rwhp.

 

[Daggar]

The FMU HAS to come out with the 42s regardless of whether or not it will run without a tune (that ratio would be outrageous).

My Pro-M meter and 42 would start and run without a tune. I can even drive it. With boost (I have a wide band meter), I was still pig rich.

The whole setup ran like ass until I got it tuned.

Yours will likely run poorly as well. You take the life of your motor into your hands if you go out and boost and beat on it without at least having a wide band to get a reading from. Who knows... your particular combo may run lean.

 

[speedytang]

You don't need a FMU but then you don't need 42lb injectors so the car will be so rich from idle - 4k rpm it will drive like crap. You need a tuning device to cut back fuel and adjust your timing.

 

[PUNISHER RACING]

I have no fmu they are garbage. That injector size is a little overkill I am also running 30's with no tune no problems at all. Fox fan our cars are almost identical I am running a bone stock long block with an explorer intake and 30's I have a 255 intank no fmu and the fuel set at 44 psi. Car runs 12.2 @ 116 full weight with the a/c at 10 lbs of boost.

 

[bentley429]

Why not just get a tune. Get a a base chip from your local tuner and just drive it there with it in. Chances are its gonna still run like crap with the base chip in there but its better then nothing. I think my tune was $400 or $500 and it runs like stock.

 

[ninety15.0]

Well lets think of it this way. Stock 19# injectors with a 12:1 ratio disk in the FMU. Now you want to run an injector that is 2.2 times bigger and the recommended FMU disk is 3:1. That would equate to running a 5 or 6:1 disk if things were perfectly linear...i dont know if they are. But for some reason they suggest a 3:1...sounds like they know those 42's really move some fuel.

I think if you take the FMU off it will run...and if you mess with the FP enough..it may run alright for the time being. But a tune is necessary in the immediate future...especially b/c you upped that boost didnt you?!

 

[mustangdaren]

I have been running 42's for 3 years with no FMU and no tune. The car runs fine and has no hot start issues. It could still use a tune to get rid of a lean condition. Don't assume because you have big injectors without a tune it will run pig rich. Mine runs way lean at idle and part throttle and rich on full throttle when we tested it on a Mustang dyno.

 

[LordMustangGT]

I'm going to be running a T-70 with 42's and a 76mm blow-thru. I wont need a FMU so I dought you'll need it. It might run rich if you have low boost. I'm going to be running a 9lbs spring in my 38mm wategate.

 

[Foxfan88]

will the "blower calibrated" sensor help me out??

i am wanting to get a tune sometime but there isnt really anywhere local that does tuning. i am wanting to grab a tweecer and learn and tune my car myself.

the car makde 5-6 psi with the 6 " crank and stock 3.33 pullies, i upgraded to the 7 inch pulley on the crank.

i have everything on, all i have to do now is is put a blower belt on, i had to get a bigger belt and tried a few but the store didnt have the best size to use, i had to order one in. once i get that on i will fire her up and reset the FP to 40 psi like stock and get her warmed up and set a new idle and reset the TPS etc etc. then i will take her for a drive and see how she likes the new stuff. i wil let you know how it goes.

 

[Daggar]

will the "blower calibrated" sensor help me out??

i am wanting to get a tune sometime but there isnt really anywhere local that does tuning. i am wanting to grab a tweecer and learn and tune my car myself.

the car makde 5-6 psi with the 6 " crank and stock 3.33 pullies, i upgraded to the 7 inch pulley on the crank.

i have everything on, all i have to do now is is put a blower belt on, i had to get a bigger belt and tried a few but the store didnt have the best size to use, i had to order one in. once i get that on i will fire her up and reset the FP to 40 psi like stock and get her warmed up and set a new idle and reset the TPS etc etc. then i will take her for a drive and see how she likes the new stuff. i wil let you know how it goes.

The FMU HAS to come out with the 42s regardless of whether or not it will run without a tune (that ratio would be outrageous).

My Pro-M meter and 42 would start and run without a tune. I can even drive it. With boost (I have a wide band meter), I was still pig rich.

The whole setup ran like ass until I got it tuned.

Yours will likely run poorly as well. You take the life of your motor into your hands if you go out and boost and beat on it without at least having a wide band to get a reading from. Who knows... your particular combo may run lean.

I can't watch. Your story so far and seeming determination to just go out and run the car stinks like a Boosted87GT story. His stories almost always ended with the word "BOOM!".

Yes, you can get a TwEECer but you'll still need a wideband to tune it.
I've had the TwEECer and wouldn't give you two plug nickles for another one. I ended up selling it and driving 5 hours one way to get a dyno tune.

It's not to say that you can't do it but I'll tell you that all I got out of it was a bunch of headaches.

 

[Foxfan88]

yeah thats what i have thought also. i would really like to tune it myself. to learn and and its just good knowledge to have. i'd get a wideband, but alot of people say getting a tune from a shop is easier, seems like it. i may not have time to sit down and tinker around and getting it running right.

what would i do since i always tinker and upgrade my car alot. i dont want to get married to a tuner and spend more and more money.

i'll just have to see what happens

 

[mustangdaren]

Take it to a shop with a Mustang dyno so the car can be put under a load for tuning. It is more like rear world driving compared to a dynojet. I plan to put a 4 bank SCT chip in mine and have it dyno tuned. I was going to go with a PMS II but I'll come out way cheaper with the SCT chip. The dyno time, three custom tunes and chip is less than what the PMS cost, not including paying for dyno time and a wide band if you want to do your own tuning.

 

[PUNISHER RACING]

If you want to tune yourself get yourself a good wideband o2 and an Anderson Ford PMS or Motorsport X tender they can be had cheap

 

[mustangdaren]

Where can I get a Anderson Ford Motorports PMS II cheap. I would love to have one if I could find a good price. Everywhere I have seen them they are $800-$950 Hook me up if you see a good deal.

 

[Daggar]

yeah thats what i have thought also. i would really like to tune it myself. to learn and and its just good knowledge to have. i'd get a wideband, but alot of people say getting a tune from a shop is easier, seems like it. i may not have time to sit down and tinker around and getting it running right.

what would i do since i always tinker and upgrade my car alot. i dont want to get married to a tuner and spend more and more money.

i'll just have to see what happens

You don't have to be married to the tuner everytime you modify something. The tuner will get your MAF transfer correct, adjust for the injector size (Pulse width, slope, duty cycle vs. voltage, blah blah blah), fuel tables etc. and you'll be pretty much set unless you make some major changes. You don't have to retune it bucause you added a new cam or bumped the boost or changed manifolds or anything like that.

Now if you changed the type of power adder or changed the displacement or compression ratio, then you might need a retune. If you add an intercooler or water/meth injection then you'll need a retune. Minor changes though... not necessary.

Where can I get a Anderson Ford Motorports PMS II cheap. I would love to have one if I could find a good price. Everywhere I have seen them they are $800-$950 Hook me up if you see a good deal.

Ditto... I'd like to know where I can get a PMS "cheap". I've never seen one of those. My custom dyno tune was about $300 cheaper than purchasing a PMS.

 

[Foxfan88]

got it all going today!

started the car, started it up and it ran really good. usually it would die, i had to help it a little bit but it idleed really smooth and nicely compared to what it did.

set the FP back to 40 and work from there.
the car drive excellent, drove alot smoother than it ever did before. maybe my old stock injectors were just dirty or something (never replaced them since i had the car)

didnt get on it too hard. i eased into the throttle in second gear. i noticed the boost comes on alot faster. it was making 4 psi by 3500-3800 rpm and went to 8 psi on the top.

played around with it some in first didnt stay in it too long, spiked 10 psi once lol
the car just fries the tires alot more than it did before.

i did notice under WOT it had a little pop to it. nothing major just a little bit, is this rich or lean??

on the way back my idle was really high, the car got warmed up and i guess the New maf started messing with stuff. it was idling at 1500

i adjusted the idle to around 8-900 and reset the tps to .99 and took some FP out of it to about 36 to see the change. the car started getting a SMALL surge at idle. half the time you cant notice it. doesnt even do it all the time.

by this point the car would want to die, revving it up and letting the rpms drop it would die, but when it did idle it idled pretty good. drove it again, as far as driving goes it drives excellent, no bucking or anything it drives smooth. just when you press the clutch in the rpms will drop and the car will die. it you lug it down to around 1k in gear and press the clutch it will keep running but most of the time it will die.

the car is harder to start. i am guessing its putting in too much fuel.... it wont start by itself... you have to give it some throttle and even then it still takes a few extra cranks to get it going.

is the small popping at WOT over 3k a rich or lean condition???

overall i am impress i havent really got in it much the car just spins the tires like it did before lol but there is a difference it makes more boost and comes on sooner. it makes 8 psi consistantly.

one my second test drive i thought i blew a head gasket or even worse. after some WOT action, the car die and wouldnt start and start running i had to feather the gas. i was like "damn i did it now" but it was puffing out black smoke BAD, peglegged the car home and the inlet tube coming out of the blower was blown off due to the extra pressure. and the engine was running without the MAF and the 42s were DUMPING the fuel into the engine, looked like a diesel with all the black smoke rolling out.

i really need a tune now i think all my idle issues and such will be cured with some tuning.

next step is a wideband for sure, not going to risk anymore, i need to know what its doing. and either a dyno tune or a tweecer.

heres a pic! got the new valve covers on and a badass breather lol, i plugged off the PCV and run an open breather to vent the crank case, seems to have solved my problem with the dipstick coming off.

 

[Foxfan88]

we concluded the car is running horribly rich. friends were behind me and saw black smoke bellowing out the exhaust when i was under WOT

tomorrow i am going to tinker around and try to lower the FP and get a better idle and see if i cant get it to run a little leaner, still runs good just loads up and wants to die sometimes