Tuning help, supercharged 96 4.0, sct tuners needed

[fishy2k8]

Okay I'm trying to figure out the issue of the wot going lean.

I don't have a datalog yet because I'm out of town, but basically when The truck hits wot the signal from the tps is telling the computer to go into a different fuel source. There are 3 fuel sources (tables I guess).. Source 0 is cold start, then there is a 5 and a 3.. 5 is what it needs to be in but when you go wot is changed to source 3 which causes it to go lean.

Does anyone know what perameter needs to be adjusted or what is going on with it?
Thanks.. I'll have a datalog up on monday

 

[Jakee]

Okay I'm trying to figure out the issue of the wot going lean.

I don't have a datalog yet because I'm out of town, but basically when The truck hits wot the signal from the tps is telling the computer to go into a different fuel source. There are 3 fuel sources (tables I guess).. Source 0 is cold start, then there is a 5 and a 3.. 5 is what it needs to be in but when you go wot is changed to source 3 which causes it to go lean.

Does anyone know what perameter needs to be adjusted or what is going on with it?
Thanks.. I'll have a datalog up on monday

Base fuel table is what it goes off in WOT. The MAF transfer function is what you need to adjust to get what you command in the base fuel table. The wideband reading is what you use to make the correction. I'm not sure I understand your question.

Fuel Sources

0 - Closed loop fuel control is active (keep it at stoich)
1 - Cylinder Cutout - stabilized - STFT at lean stability limit
2 - Some exhaust unit too hot - enrich STFT to cool exhaust temps
3 - Cylinder cutout - stabilized - STF controlled by torque control feature
4 - Cold Engine Startup Open loop logic - Cold startup engine table
5 - Stabilize Normal drive-ability logic
6 - Lean fuel error logic
etc...

 

[fishy2k8]

okay well we have the fuel table for WOT set and transfer function is fine, it's not a load issue..

3 - Cylinder cutout - stabilized - STF controlled by torque control feature

this is what it's going into at wot and i think it's because of the auto trans delete.. i think we might be missing something that we haven't turn off or changed for the auto not being there.

 

[Jakee]

Maybe. What all did you change for this? I have some info for doing this; I'll have to dig up.

 

[fishy2k8]

not sure what all he has to do for tuning out the auto but he did it the last time i had him tune, in feb... so i know he knows what all to turn off.

 

[Jakee]

Maybe not? just kidding

 

[phix-]

Who is your tuner? Maybe you should contact James. I am currently working with him on a m90 setup. I have not seen a dyno time yet, sorry I can't help much.

 

[fishy2k8]

i go to a guy that has a dyno in Kentucky and is an sct tuner

 

[jah81592]

Is this a ohv? If so then a lot of these have commanded stoich at wot and won't go into open loop. He needs to verify this is able to go into open loop during wot. If not he needs to change the scaler to allow it to. Your tuner should know this.-j

 

[fishy2k8]

well i'm not real sure what the open/close loop issues were.. i think it was a combination of old fowled o2's and a tune that was maybe a little goofy somewhere. but anyways, all tuning issues and running issues have been solves, just awaits a dial in on the dyno. i ended up getting a manual computer from a 97 that i got from another forum member, got a tune for that and have had it tweaked good enough that it's very safe to drive. no wot issues now. after the new year, if the snow stays away, i will venture to the dyno and get some numbers and a ironed out tune

 

[94Eddie]

Make sure your fuel system is delivering enough fuel too. What is the size of your fuel injectors and fuel pump? Are you using a boost sensitive fuel pressure regulator?

 

[fishy2k8]

had nothing to do with fuel delivery.. and everything to do with the tune. my fuel system is plenty strong with 190lph, 42lb injectors, and the stock regulator is already boost reference.

 

[94Eddie]

I should have read your signature before responding. My bad. Having the computer from a manual Explorer might make a difference. It does with the 5.0L Mustangs.

The 42 lb injectors are overkill on a 4.0L Explorer engine with the horsepower you will likely make. How much boost are you running? How do you know you are running lean? Is it based on wide band O2 readings or are you hearing detonation? Detonation isn't just caused by a lack of fuel. It can also be caused by a combination of octane level of the gas you are using being too low, timing being too advanced and/or the intake air the engine is receiving from the blower being too hot. Also, running a compression ratio of 10:1 on a blown engine is getting toward the high end without an intercooler and/or running higher octane gas. My advice is to make sure your tuner is experienced with tuning blown engines because an inexperienced one can toast a blown engine from detonation in the blink of an eye.

 

[fishy2k8]

Umm yes I have a wideband..

Yes my tuner knows what he is doing

42Lb is not overkill when e85 becomes involved

10:1 is not too high and it has never detonated

Thanks though.. It will make around 270/330

 

[94Eddie]

Actually the alcohol increases the octane rating of the fuel. It is why methanol is used in drag racers. I made 500 hp with 42 lb injectors on a Kenne Bell blown 5.0L at 16 psi with water/alcohol injection for air intake cooling and the car had great street manners. Believe me, 42 lb. injectors are overkill for 270 hp. Too large injectors can make tuning a little difficult because small changes in the fuel tables make for big changes in fuel delivery.

You never directly answered my question. What is the readings of the wide band and what is the brand of wide band you are using? Is the engine detonating? How much boost are you running? If you have an adjustable FPR then you can adjust it to richen the mixture if you have a good wide band to get feedback on the changes. Many a Mustang has been reliably tuned this way making far more than 270 hp.

I have a ton of experience with blown engines and tuning them. I have used a TwEECer on my Mustang way before SCT was a thought in a person's head. I see some red flags with your setup and my advice is to take them into account when tuning and running your engine. A tune you get in January isn't necessarily a safe tune in the blazing hot summer with a non-intercooled blower and a somewhat high compression ratio.

 

[fishy2k8]

E85 needs 15-20% more fuel delivery, hense 42lb.

It is tuned for 11.5 a/f at wot, pulied at 6#, dyno wideband, and innovate

Why would I mess with fuel pressure when I can fully adjust fuel delivery in the tune

Again..my tuner knows what he is doing, not sure why you are giving unneeded advice, only tuning issues I was having was the auto computer didn't like having the trans turned off.

 

[94Eddie]

Good luck with it.

 

[Jakee]

Actually, it is a little different with a V6. The same calculation is used but with 2 less cylinders which increases the LBS/hr needed.

Example size needed for a supercharged V8 at 300 HP: 28.125
Example size needed for a supercharged V6 at 300 HP: 37.5

This is with a MAX of 80% duty cycle and the B.S.F.C @ .6 for both

But for that HP, which I agree is not the highest, it may be a little large. 42's are not large enough to cause drive-ability issues, but I know the point. Go bigger than 42's and you start causing yourself a headache so you should only go bigger when needed.

oh, and if the tuner knows what he is doing, or takes the time to modify all needed spark tables, the tune in January will be good all year long. He'll take IAT's into consideration and have it pull timing as the temps rise.

 

[94Eddie]

I think you will be fine since you are running 6 psi. Have you considered running regular gasoline or E10? You might make more power since it has a higher specific energy compared to E85. You probably aren't running enough boost to cause detonation using gasoline with a 10:1 CR. If your chip holds multiple programs you could have one for E85 and another for gasoline.

 

[fishy2k8]

it made no sense to pay the same for 36lb injectors when you can find 42lb injectors for about the same price and have the capability to run e85

i am currently running 93 octane.. and anything will detonate with a bad tune.. doesn't have anything to do with boost.. everything to do with the tune. anyways, i will have a 93 tune and an e85 tune, i'm not using a chip, using a sct handheld.. obd2