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supercharged 5.0 true fire 98 explorer sport

The fuel pressure regulator should regulate the pressure to 39.15 with no vacuum. With vacuum the pressure should drop 1 psi for approximately every 2 inches of vacuum. (this is because the conversion from vacuum measured in inHg to psi is approximately .49 to 1)
So if you had 20 inches of vacuum you should have 29 psi fuel pressure.

If it really only went from 42 to 39 that would mean you only have 6 inches of vacuum. Something doesn't add up with those readings.
You should fix this before any more tuning. make sure that you don't have anything hooked up to the vacuum line going to the fuel pressure regulator, like the PCV valve.

aaaaaaaah ffffffffffffffffff.......iretruck........:mad:

should this also be on a line by itself? i would have to look again for sure but this line is shared by my bypass valve on the supercharger, and it also goes to my vac/boost gauge
 



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vacuum lines

aaaaaaaah ffffffffffffffffff.......iretruck........:mad:

should this also be on a line by itself? i would have to look again for sure but this line is shared by my bypass valve on the supercharger, and it also goes to my vac/boost gauge

It might work with just the FPR and the vacuum gauge hooked up providing there are no leaks, but the boost bypass has a moving diaphragm that might effect it and make it read wrong? Check and see what you actual vacuum is and them divide by 2 to see how much your fuel pressure should drop.
Example: 18 inHg vacuum = 9 psi drop
Fuel pressure 39 - 9 = 30 psi

And when under boost, psi to psi so every lb of boost equals 1 more lb of fuel pressure.
10 psi boost with base 39 psi fuel pressure = 49 psi fuel pressure under 10 lbs of boost.
 






tuning has been coming along. dono, and 4pointslow have been BIG TIME helpers.
first correction that i had to make (4pointslow figured this one out) was dropping the fuel pressure from 39lbs to 32lbs with the vacuum line on.
second one was (once again, 4pointslow figured this one out) was that the injector data in the base tune was not correct (nice catch john!). the funny thing was it was also wrong on dons as well, so he killed 2 birds with one stone.
third don found, and it was the rev limiter wasnt set correctly. the truck was shutting down at 5600 rpms. after that was found, she was able to spin much more rpms......which now brings us to a new found problem.
john had spotted something in the maf transfer that he questioned. he was seeing that the maf was getting close to being pegged. dangerously close. i made a call to don lasorta racing to see if he had any recommendation.
he recommended a sct ba3000 (http://www.summitracing.com/int/parts/scl-ba-3000/overview/).
dono also did some digging for me today while at work, and also found another maf that can be used. a pmas mh90 (http://www.pmas-maf.com/product/mh90-90mm-universal-1800kghr-maf-2/).
now heres the kicker. one of 2 things are happening with my lightening maf. either a, its doing something funny and not working properly (which i want to believe, but cant say because it is playing nice with don every time he has done something with the tune) or b. it is being maxed. which says one thing. a lightning maf is suppose to be good for about 450hp from what i can find (and i am assuming that is crank hp). that means at the moment, evils making close to 450hp at the crank :eek:
 






Maf size

With the mafs you listed, be careful, one is a BA3000, the other is a BA2400 which is smaller and may be too similar to the one you already have.
Also there is a value file for the SCT BA3000 maf, don't know about the other one.

With that program called Dyno Sim 5, I entered all your specs and came up with about 489Hp at the crank at 6,000
At 5,500 it came out to be 467HP
You can be pretty sure you are making 450 at the crank.
If you had drag slicks or auto 4wd I bet that 13.8 you ran could have been a 12.8
 

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With the mafs you listed, be careful, one is a BA3000, the other is a BA2400 which is smaller and may be too similar to the one you already have.
Also there is a value file for the SCT BA3000 maf, don't know about the other one.

With that program called Dyno Sim 5, I entered all your specs and came up with about 489Hp at the crank at 6,000
At 5,500 it came out to be 467HP
You can be pretty sure you are making 450 at the crank.
If you had drag slicks or auto 4wd I bet that 13.8 you ran could have been a 12.8


......you have got to me ****ting me.....
never...NEVER did i ever think i would be making that much!!!!! now the wait game begins.....what am i going to break lol.
i have to call pmas tomorrow and ask them if they have a valuve file that can be used with the proracer. don had pointed that one out to me. one part of me wants to go with the ba3000, and the other part of me wants the other one for obvious reasons.
 






maf

Tell the part of you that wants to be cheap to shut up. lol, hahahaha

There is a used BA3000 for 180 plus shipping on eBay.
I have not looked into the mafs so I am not sure what one you will need but the wording on the cheap one you listed made it sound like it was a direct replacement for the lightning maf, not an upgrade. You need one that can measure more than the lightning maf, since you are close to pegging it by reaching the second to the top box in the maf transfer function.
Don told me you hit 941 counts at 5,500 rpm. You will peg if you go any higher.
 

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the pmas maf I listed sounds like a direct replacement for the BA3000. Its designed for the same flow. The only reason I recommended it is that I couldn't find any one complaining about the pmas mafs. Some were actually recommending them over the SCT units. I really like the price point also.

PMAS also has the next step up (Which I think is the equivalent to the ba5000).

I have the pro-m slot maf in a 3" tube that is equivalent to the ba5000. What happens there is I loose some resolution as currently I'm using just under 3/4 of its range. If I get close to the full range, I'll be posting pictures of another motor pull with shots of the blocks lifter valley split in 2. I guess the ultimate decision will be based on what value files pmas suggests for their mafs in the pro racer package, and cash flow. We also need to remember that the difference between the two mafs in price needs to be multiplied by 1.4 to see the real difference in cost.

4pointslow, I'm guessing you pm'd the ebay link to the used one? That might be a great middle ground.
 






No link, be I did find a used ba3000 in Quebec the guy wants $300 for it however. I just spoke with him briefly a little while ago. I will get a hold of him again tomorrow ask him for some pictures and see if I can deal with him a little on the price
 






Tim, I have the BA3000 on my truck.

So backup a couple posts, explain to me again what the lower fuel pressure at idle does for you? When I set my truck up, I had read you wanted your fuel pressure around 39psi or a little higher to get the best atomization out of the injectors. So I checked mine after reading Jon's post and talking with Tim. Mine was set at 47psi at idle without vacuum. I turned it down 2 psi and now it is chirping the tires as it goes into second gear (if it was tuned to shift quicker, it would probably light them up). A/F ratios still look good on my wide band. My truck idles and runs great (maybe not making optimum power), so would I be messing up the tune if I reduce fuel pressure?
 






Fuel pressure

Yes, you are throwing your tune off any time you change fuel pressure.

In the tune there are things that have to be entered so the PCM can control A/F mixture under all conditions. The specs for the injectors are for a precise fuel pressure. If the pressure is changed, the injector data should be scaled to go along with those changes or the PCM will have trouble controlling A/F mixture.
Even changing the injector data may prove to be insufficient to give the PCM precise control.

So it is not that lower fuel pressure gives you better anything, it is that the data for injector characteristics are established under a certain pressure. On most older fords like ours, the fuel pressure was 39.15 with no vacuum line attached to the regulator. With the vacuum attached the fuel pressure gets lowered to compensate for the high vacuum sucking on the injector tips.
This keeps fuel pressure drop across the injectors balanced. In other words if you have 40 psi behind the injector, and the tip is in a 20inhg vacuum, the injector would spray the amount of fuel that another injector would spray if it had 50 psi behind it and the tip was not in a vacuum.
 






so would I be messing up the tune if I reduce fuel pressure?

YES.

When your fuel system is in closed loop (warmed up, and less that 1/2 throttle (probably, depending on where the tuner set it)) the long term fuel trims will even out the a/f ratio to what is being commanded as long as you haven't reduced fuel pressure too much.

Open loop (Cold start and wot) there is no adjusting of the a/f ratio being done. This means you are absolutely correct. The more you reduce the fuel pressure, the leaner your truck will run at wot.

4pointslow has a recent thread that goes in extreme detail that ultimately shows just how critical it is to follow specifications exactly. With fuel pressure above spec, it throws the injectors way off of their targets.

I further proved this trying to dial in Evil's maf transfer function. The symptom I was seeing is this:
At part throttle and seeing a air velocity of say.....500 I would see I was running 11% lean. Then at wot and the same maf transfer target of 500 i was a few percent rich. See the problem I had? Which target to I adjust for? This is when 4pointslow dug in to the issue. I don't pretend to be a tuning wizard, and am ok when everything is behaving as it should, but when it doesn't I am pretty much lost.

LOL ...4pointslow beat me to it....
 












Boost is around 6-7psi. I don't know what the maf counts are. I would have to do a datalog to find out.
 






Andrew, do you have an old wot log on your hard drive anywhere?
We are only looking to confirm what your maximum maf ad counts are. Your motor and cam are very close to Evil's.

The Next variable is...What if Evil gets an M122? More headroom will be needed. So, BA3000, or BA5000?
We are entering the territory of possible block splitting. Very few have split their block at the level we are at, and the numbers of split blocks keep going up from here. I tend to be a risk taker, but we need to know that the odds will increase with boost from here.

Do I hear a Dart block in Evil's future? lol
 






trust me, the dart block thing has been on my mind all day. hell, i was even having a hard time sleeping last night because the thought of reaching the point of splitting the block! i am even rethinking the m122 thing now!
i was able to call pmas today. i would need one of their pig tails, and he also said to go with their mh 90-3000. he had said if a am wanting something that will equal a ba3000, that would be the one i would need. also, he had said i could do one of 2 things for programming. either use the values for a ba 3000, or they have them on their site, and i can down load it. this is them

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Now we are back to being more cost effective building an engine from scratch in the first place!

By the way, I need to check my computer at home for the datalogs.
 



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