TWEECER FAQ's

sstock

Active member
This will be a new sticky for FAQ's on tuning with the TwEEcer.
I plan on compiling and listing as much info as I can with explanation to make it more attractive to individuals that want to try and tune their own Gen 1's. There is a lot written on the use of the tweecer, but unfortunately most is for EECIV and EECV mass air equipped vehicles. Although there are some similarities, many of the strategies are unique to the speed density. Besides what Raymond knows and has provided, there is not a lot of resource help for our vehicles.
If you plan on tuning your own truck, it is advisable that you buy a wideband to help you with your effort. Although much can be done without a wideband.
I hope to update this with info on a regular basis.

5-28-05
Sorry for the long delay lets see WFC, schedule change at work that is kicking my behind, and springtime chores, you all know the drill.
I guess I’ll start it off with a disclaimer, I am not a professional tuner, I don’t charge for tunes but I have spent 100’s of hours in the books and playing with my tweecer (sounds funny) evaluating cause and effect. The EEC 4, even though much less complicated on Speed Density trucks, is still a challenging endeavor. So with that said I’ll start on injector change strategies, seems like besides getting rid of the EGR and smog pump changing the shift points etc., people are wanting to change their injectors for one reason or another. On blown vehicles it is a must if you plan on reliably feeding your engine above what I would say 350rwhp. 19’s will take you a long way with a FMU but eventually your wideband is going to show you leaning at the top of your RPM. There isn’t much you can do with the tweecer to get more fuel to dump with 19’s so once you get to that 350rwhp, it is probably time to move up in injector size. The 24lb and 30lb Ford injectors are pretty much drop in changes with just a simple scalar change in the tweecer. They have no other issues, and will perform like stock; in fact you wont know you have made an injector change except you now have the ability to drop more fuel in your engine. I recently tuned a stock-blocked 351 Gen1 running a Powerdyne supercharger, 6lb. of boost with 30lb injectors and no FMU. He was probably making close to 300rwhp. Otherwise, seems like injectors above 30lb’s in size there are a few more tweaks to do. To tune these correctly you must start with a sequence similar to a high school lab experiment. It is not going to be an instant gratification thing to get it perfect. You will need to monitor the wideband through a few engine run cycles to get an idea of what is happening and what needs to be done. I might add that it is a real good idea to base line your engine with the wideband before you drop your bigger injectors in. Take notice on cold startup air/ fuel (A/F) ratios and the time it takes the motor to warm and the change in A/F during this time. Do this both idling and start and drive it immediately the next morning. If you have a wideband that data logs like the LM1 you can record these to overlay on your future logs after you change to bigger injectors. I might add it is extremely helpful to have a tach signal on the data logs. With bigger injectors (above 30lb), wide- open- throttle (WOT) is absolutely the last area and the easiest to tune for with a tweecer. The first areas to look to is the initial startup fuel, both cranking and cold startup enrichment. Getting it to start easily cold/warm is a must. Then being able to drive it cold especially you folks up north is another area to look at too. Getting the injector scalar value right here is the task. Just because you are running a 42lb injector, inputting the 42lb injector scalar into the tweecer is not going to be the answer. I can guarantee that you will be running lean through out the entire range both cold startup and warm operation and have issues. This needs to be correct or else you will not be happy. Recently, I saw a couple professionally tuned GEn1's that were tuned only for WOT with big injectors and ran like stank on the street. Horrible street manners and lean surging and idle hunt. That crap aint going to fly. Anyone who knows me, knows that I'm a stickler about perfect drivability. I’ll post up more later.
Steve

5-29-05

Selecting the correct scalar value for a given injector is, in my mind, the first order of business for starting your tune. Because EEC 4 speed density does not have a Lo Scalar input like EEC 4 mass air, The correct enrichment/drivability/decel must be a marriage of the injector scalar and the injector minimum pulse width scalar. The correct injector scalar will make sure the truck starts with the correct A/F in the cold startup open loop and after warming maintains the correct A/F in both cruise/part throttle and idle. The injector minimum pulse width scalar controls the correct A/F during decel and supplies the correct A/F during open loop warm up when the throttle is closed. All the idle surge issues can be attributed to an incorrect scalar value in the minimum injector pulse widths. I have some neat strategies to find the correct value but it will entail using a wideband.
For now though leave the injector minimum pulse width to stock setting which is .0004999 because it will get in the way of picking the correct injector scalar. With that said, I can tell you that if your injector change is 42lb or above, the "fuel crank pulse width function" must be changed or you will flood your engine while cranking because the bigger injectors are just dropping too much fuel. Try inputting the following "Y" values from left to right: .061,.049. .014, .013. .005, .005, .006, .008, .008, .008.
This should get your truck started. If it is still too rich and is loading up on crank then try reducing these numbers by no more than 10% at a time for the correct ECT(Engine Coolant Temp.). For instance if it starts good when the ECT is 70 degrees but not when its 180 degrees then only change the value for that temperature.
Now onto choosing the correct injector scalar value: I've played with the Ford injectors in 19lb, 24lb, 30lb, 36lb, 42lb. Also other brand names in 50lb and 60lb variations and my own which are 47.7lb Chris Johnson home made variants of the motorsport 30lb injector. The 19, 24 and 30lb injectors will be close at their own values. Keep in mind though that the number you input in the tweecer software is not 19 or 24, which is the amount pounds of fuel per hour but the number of pounds of fuel per second is the value you input. For example: a 19lb injector scalar will be calculated by taking 19 dividing it by 60 then again by 60 to get a scalar value of .005418. A 24lb scalar would be .0067. A 30lb scalar would be .0083. A good starting point for all other injectors would be a scalar value of the injector minus 4. So if you had 60lb injectors try inputting a 56lb scalar(.0156) to start things off.

More later,
Steve
5-30-05

On my 47.7lb injectors, I eventually finished up with a 41.5lb injector scalar value. The inputted scalar value was 41.5 divided by 3600= .01153. Once you get your value in then hook up your wideband and start your engine cold. Air fuel ratios should be in the high 11's or very low 12's initially and within a few moments should start leaning. Within 1-2 minutes the EEC should go into closed loop and the wideband should start seeing the 02 sensor switching around stoich (14.7). So you might see readings fluctuate from say 14.3to 15.1, back and forth. If your startup A/F's are too rich you need to input a higher scalar value, and if too lean a lower scalar value. Try dropping no more than 1lb/hr until you start zeroing in on the startup Air fuels. It may take a few mornings to get this close enough to move on to part throttle checks.
More later
5-31-05

Assuming you got the cold startup close, its time to check part throttle operation on cold startup. In other words start your engine wait 10-15 seconds drop it in drive and check wide band A/F's. At the start of your drive you should see A/F's in the low to mid 12's then as you get down the road a 1/4 mile or so those A/F's should lean into the 13's. Closed loop should come slightly later within 1-2 minutes after startup and then should be reading either side of stoich switching back and forth. Remember even though the open loop A/F's are governed by the fuel base open loop tables, it must be considered if you haven’t had a large displacement change these should still be very close and the change you should make is with the injector scalar input.

One warmed up and you continue to drive you will notice an idle hunt and or surge when you decel and stop. This will be apparent on all injector changes above 30lb'ers. The reason is a lean condition on decel and transitioning back to idle. The symptoms will be a hunting idle between 700- 1500 rpms most the time it is not as bad as this but it still exists and it may cycle many times before setting down to an idle. Stalling usually doesn’t occur but the reason this is happening is the injector minimum pulse width needs work. The stock scalar value is .0004999. By changing this scalar value it will allow you to enrichen the decel to eliminate this condition. On my injectors I ended up with a scalar value for injector minimum pulse width of .0009. Some guys running 42's have had luck with values as high as .0011 but if you get too rich here the open loop warm up can show real rich (richer than low 11's)and closed loop idle A/F's can show in the 12's which will fail your emissions and waste fuel. Again if you happened to data log your 19's , you can get a feel of what a stock injector does and you want to duplicate this with the bigger injector. One other thing with the injector minimum scalar inputs, it is perfectly normal to see A/F in the 11's to low 12's when you let off to closed throttle to coast or come to a stop. As long as these A/F's quickly lean to an acceptable A/F at idle, then it can be assumed that you have it dialed in.

More later
6-01-05

Another note on the injector minimum pulse width, your value scalar input would be different based on which brand injector you use and what size you use. I haven’t seen it though where a value greater than .0011 has been used. Once you get the idle hunt and surge taken care of, start leaning the injector minimum pulse width scalar value down in increments of .000025. Remember to keep a check on the items while doing this that were mentioned in the last post.
Oh and BTW, you need to know your math, don’t mess up a decimal point or bad things will happen when you start her up.
More later.
6-19-05

Part throttle and full throttle enrichment:

On speed density setups there is a function that is called "TP for open loop" that is rpm based and throttle position. Also there is a scalar that is called TP counts for wot (wide open throttle). Both do a little different job.

First the "TP for Open loop" function, on a stock truck this function will transition a truck from closed loop to the fuel base open loop tables. Basically, anytime the truck goes to wide open throttle it will go open loop by default, but more importantly, it can be changed to go open loop at a set rpm point and throttle position. This is great for adding part throttle enrichment. For instance, the default setting, an engine must reach 2810 rpms and a tps setting of 350 (about 1/3 throttle) before allowing open loop. On my truck, for example, I have that set at 2010 rpms and 225tps because with a blower you need far less throttle angle to get into the power region. This 225tps setting equates roughly to about 4" of vacuum in all gears, which I feel is a great transition point from cruise to power. This is the one area where many supercharged trucks have suffered broken pistons as a result of not adequately fueled during onset of the transition between cruise and power. Most supercharger kits available do not sell you a chip to control this and limit their kits to 5-6 psi which with a centrifugal blower it really isn’t a big deal because you are not making much boost at 2800 rpms. Kenne bell kits make good boost at these rpms so I would expect their chip they sell, changes this or maybe not??? Also, Cammed and headed applications can really benefit from changes in this function.

The second is the TP counts for wot open fuel scalar and this will control at what point the computer will command more fuel through the wot fuel multipliers. To simplify, it is basically a switch point that comes into play after the truck has been switched to open loop and it again is tps based. On a stock truck at about 650 tp counts (or 5/8 throttle) the computer will command additional fuel over the open loop fuel tables. This is a great way to get more fuel in the motor for blown applications. With proper sized injectors, you can eliminate the fmu all together by massaging this switch point. Mine is set at 350tps, which is about 1/3 throttle or 2psi of boost. Again for cammed and headed applications this will also help you nail down that perfect air fuel ratio.

I might also add , all of this will lead you to the fuel for wot multiplier function and after the above two have been set, this is where you can actually adjust how much fuel can be added. In other words, this is a very powerful function within the EEC. This function will allow you to enrichen or enlean wide open throttle air fuels. It is RPM based and you can adjust at what rpm you can either add or take away fuel. Good manipulating in this function will allow a nice smooth air fuel line. I might add that it is very realistic for your engine to be rich at wide open throttle right off idle then go lean at a certain rpm in the mid range then back rich again at shift. This is where you can really cut the ET by spending time with a wide band and getting the A/F just right. On my truck, I ran an 11.67 with a perfect A/F line.

What is a perfect A/F line??? Everyone that has raced or tuned will give you a slightly different answer. And of course it will be different for normally aspirated and blown or even turbo'd setups, and different on street tunes or race fuel tunes.
I can tell you on my supercharged truck, it is not a straight line. And to be perfect it shouldn’t be a straight line. For instance on my latest race tune, it is good to start off at Stoich(14.7to1 A/F), then as you go full throttle, the A/F richens, by the time I get to 3500 rpms, I make about 5 pounds of boost and am looking for a target A/F of about 13.25 to 1. That is considered lean and mean and is making best power at that point. From there, I will want to richen as the rpm's raise to the peak torque point of about 4200 rpms. At this point, I like an A/F of about 12.25 to 1. From that point, it will again begin to become increasingly leaner to the shift point of 5600 rpms, where I like to be 12.8 to 13.0 to an A/F.
Now this is a race gas and 1/4 mile tune only. This tune is all wrong for the person that gets on the freeway with street octane mashes the throttle to the floor and holds it for a minute or two for a top speed run.

More later on street tunes with N/A and blown setups.
Also, how to make changes in the "fuel for wide-open throttle multiplier.

Here is another update, sorry been few and far between.

Move up the "ADAPTIVE CORRECTION_1_MAX" scalar to .99
and "ADAPTIVE CORRECTION_MAX_" scalar to .99

This allows for a wider margin of computer learning. It cured a coast vacuum throttle transition lean issue I had.

Another scalar to change is the "minimum ECT for stabilized fuel table" Change this scalar to 250. This will keep the engine enrichment based of the "fuel base open loop table" and out of the stabilized fuel tables8-17-05
Here is a tweek for the blower and turbo guys.
This is not recommended for use on street octane fuels but at the track running race octane will prove beneficial, especially for the kenne bell guys and people not running an IC.

It has to do with timing that is pulled automatically when dealing with elevated ECT (engine coolant temperature) and ACT(air intake temperature).

As a general rule of thumb, intake air temperatures raise when air is compressed. A general rule of thumb is 10-13 degrees for every lb of compression. So if ambient temp. is 100 degrees outside and you are making 10psi of kennebell boost(non IC), then your intake charge temps are going to be in the neighborhood of 230 degrees. That is enough for the EEC to pull 12 more degrees timing out of the base spark table. If you are running with 20 total then you may end up with only 8 degrees total assuming your coolant temps are 180 degrees too.
Ever wonder why your truck does not run as fast at the track after you hot lap??? Well there is a pretty good reason there.

There are a couple of tables to play with to turn this off but again , I throw caution that it is a race gas exemption, you may be able to tweek them down but don’t eliminate them on street octane.
The first table is the SPARK REDUCTION FOR OCTANE, all values should be zero'd out.
The second table is the SPARK ECTvsACT MULTIPLIER, this basically multiplies a coefficient in this table against a corresponding value in the spark reduction for octane table, the product of the two is the amount of timing pulled from the base table.

I'll give you an example, Mark was flogging out his kenne bell truck at the drags tonight. He said it was an easy 90 degrees outside(Texas evening), Mark makes about 8lbs of boost and he was hot lapping it so the ect was 180 degrees if it was anything. We set Marks tune up with 20 degrees of total timing including the 10 base. This is considered safe with 93 octane. If we look at the table for spark reduction for octane you will see the maximum retard is 8 degrees for wide-open throttle but then you look at the ACTvs ECT multiplier table and plug in 194 degree act and 180 degree ect and you get a multiplier of 1.2. So total pulled timing is 1.2 times 8= 9.6 degrees. So total timing is around 10.5 or so.
Now you can see why this truck can pick up 3-4 tenths is he was racing with 112 octane and these tables zero'd.
Don’t give up on the Kenne's they can make good power(even on a 427 stroker) but it takes a tune to do it.

Steve
Here is another tweek for you hot lappers at the track.
First, I'll start it up with a little story. Awhile back, I went racing on a Friday night at the local track, I put my Dot race tires on at home so when I got to the track, I could start racing. It was a warm afternoon and as soon as I got tech'd, I pulled up to the staging lanes, switched the tweecer to the last race tune I made and staged. I imagined it launching real slow and soft and about 100' out the truck nosed over and coughed and lost power, I thought I blew my discharge tube off and went rich. When I got back to the pits, I learned the tube was on and went to the data log on the wideband to see what the story was. The log showed extremely rich A/F's. I pulled up the tweecer file and looked over the fuel trims and they seemed right. Why was my truck suddenly overly rich today and not the time before?? Scratching my head, I could only account for 1 issue, and that was the fact that my truck was pretty warm under hood when I made my pass.
Here is what I found out that evening: There is a scalar that is called the"minimum ECT for stabilized fuel table". Its use is basically a switch that works when the coolant temperature reaches 204 degrees, it switches all fueling to the stabilized fuel tables. Well one look at these tables told the story, the tables were set up to enrich A/F's in event of possible elevated coolant temps. I guess Ford's strategy was to enrichen to prevent issues with longevity of engines, my guess only. The reality of it is the stabilized fuel tables are marginally richer than the base tables with "stock" injectors. With larger injectors the enrichment becomes profound. Now if one doesn’t want the tedious task of designing a new stabilized fuel table for your individual injector, you can set the scalar value for the minimum ECT for stabilized fuel to a figure of 250 degrees. This will insure the fueling to be consistent and remain on the base fuel tables. Now you can hot lap away and not drown on the track from over fueling.

More later!

Steve
Some more talk on spark timing for LHBLO processors:

There is a scalar called "Spark initial retard tip-in", this scalar has a factory value of -5 degrees. What this does is removes 5 degrees of timing at the moment you open the throttle from the closed position (either idle or coast). Try setting this value to "0" and you should be able to tell a difference on throttle response. I noticed on my truck, it really smoothes out how the engine transitions from a coast to back on the throttle, especially light throttle transitions.
For adjusting wide open throttle fuel air-fuel ratios:

If you choose to adjust A/F with the Fuel Wide Open Throttle Function, they are rpm based when the throttle is fully depressed. The X values can be changed to reflect different rpm points, just make sure they are ascending from lowest to highest.
The "Y" values are numbers that directly reflect enrichment either leaner or richer.
It is important to remember the lower the number the richer the A/F will be. Larger numbers mean the A/F's will go leaner.
Numbers less than .500 should be avoided; if you still are too lean then the base fuel tables will need work. That’s another topic.
I haven’t used any numbers greater than 1.2 either, so don’t know what effect it will have above that constraint.
Remember to get the decimal point correct or damage to the engine could result.
Example: Your truck is running an A/F of 14.0 at 3500 at wide-open throttle and your target is 13.0. The Y value is set at .9, try inputting a value of .800 and make another pull to see the effect. Lets say the A/F drops to 12.6, then try inputting a value of .82 to see if you can get it back a bit. Keep working systematically to you get the A/F cornered. Then make the next pull to 4000, then after that is dialed in try 4500 and so on. I like to drop it in second and do all my tuning there. From a rolling start with full tanks works great for me. Remember baby steps and creep up on it. Try working from rich towards lean, not the other way.
Another important point is to pull timing before you do wot tuning for a/f.

More later.
 
Thanks for posting this back up Steve!!!!!! Hope you are feeling better!!!

Jamie R.
'93 Vortech'ed Lightning
 
I read Steve's FAQ section, but I have some confusion. I'm using Cal Edit 1.30A9 Beta 3 with LHBLO Strategy.

-Cannot find "TP for Open loop" function referenced in FAQ.
-Cannot find "TP counts for wot" scalar referenced in FAQ.
-"Spark Reduction for Knock Table ECT/ACT" same as "SPARK REDUCTION FOR OCTANE" referenced in FAQ?
-Cannot find "SPARK ECTvsACT MULTIPLIER" table referenced in FAQ.
 
I read Steve's FAQ section, but I have some confusion. I'm using Cal Edit 1.30A9 Beta 3 with LHBLO Strategy.

-Cannot find "TP for Open loop" function referenced in FAQ.
-Cannot find "TP counts for wot" scalar referenced in FAQ.
-"Spark Reduction for Knock Table ECT/ACT" same as "SPARK REDUCTION FOR OCTANE" referenced in FAQ?
-Cannot find "SPARK ECTvsACT MULTIPLIER" table referenced in FAQ.

The TP for open loop function is omitted in the beta software version. I have brought this to the attention of STKR (makers of the Tweecer) repeatedly and this problem is still unresolved as well as many others such as the displacement multiplier, etc.. The Tp for open loop is a huge player for SD EECs especially for blown and turbo applications. Try the alpha version without the beta update it might be in there. I use the old 120RT software version with the LHBLO updated DAT file for all SD tuning. My believe is SD lightnings are such small potatoes they dont want to dedicate the time to fix the new software ills. You can add the calcon software to this as well, it is totally ineffective for SD processors with numerous issues unresolved for so many years now. Too bad it is such an effective tuner with the old software.

The TP counts for wot" scalar is the WOT Breakpoint voltage, even though it states voltage in the units it is in counts. Anther software glitch.

Spark reduction for octane is the same in the new software as spark reduction for knock.

Spark reduction for knock ect/act is the same as the spark ect/act multiplier.

The fact that the TP for open loop function is omitted in the beta software version renders this software not usable for SD EECs. Try removing the beta version in the control panel and re installing the 130A9 version without beta and see if that will work for you.
 
Last edited:
Got it. Descriptions match in 1.30A9. You probably get tired of hearing it, but Thank You. I'll keep clicking the buttons!
 
Maybe a silly question, but..........?

Hey guys, I'm new here, and I dont have a Lightning, BUT I do have a '94 F150 with a 351W, and an E4OD. My question is, since these trucks are so similar, will a "tweecar" for a Lightning work on my truck? I know full well that it wont magically transform my truck into a Lightning, BUT what I really want to do is "tune" my trans more than anything else.

Please help!:cr1:
 
Hey guys, I'm new here, and I dont have a Lightning, BUT I do have a '94 F150 with a 351W, and an E4OD. My question is, since these trucks are so similar, will a "tweecar" for a Lightning work on my truck? I know full well that it wont magically transform my truck into a Lightning, BUT what I really want to do is "tune" my trans more than anything else.

Please help!:cr1:

Yes your truck will use the same strategy, so it is compatible. You can drop a Lightning tune right into that EEC and it will work fine, regardless of your computer catch code.
 
Cooooooooooooool

Hey thanks man!! Do the Lightnings hold the truck in low gear long enough to wind it up? Mine shifts to 2nd around 15 MPH. I am goin to change my rear gears to 4:11 like the Lightnings ASAP, right now it has 3:55's and 29" tall tires plus it's a king cab with a stepside. So its HEAVY! It could really benefit from the gears, but I'd love to "tune" the trans and some other stuff.


Thanks again!!!:eek:ldtu:
 
I am currently building a 393w stroker for my 1996 Ford Bronco and will want to tune my own vehicle. Although I have no real tuning experience I am willing to learn and the Tweecer\RT looks like it may work for me. Listed below are some of the main components I am using for the build, will the Tweecer work for me from what you see? Also could anyone explain what the key differences are between the Tweecer and the Quarterhorse from Moates. Oh btw some really great stuff from Super Glide for the first time reader.

Tks nsasanas

Welcome to www.moates.net! : Moates.Net




1996 F4TE Roller Block
Edelbrock 61cc Heads
Edelbrock RPM Truck upper and lower Intake Manifold
Camshaft (Still Undecided)
Edelbrock 56mm or 61mm Throttle Body (I have them both)
1.6 Scorpian Rockers

19lb or 24lb injectors I have a set of each, but would just as well put 30lb injectors in when I put the new engine in the truck

Probe Rotating Assembly: 3.85 4340 Forged Crank, 5140 Forged Connecting Rods, 19.3cc Forged Pistons

BBK Shorty Headers with the EGR emissions tube
OBD II with factory Mass Air (I'm thinking with larger injectors this will have to be upgraded as well, tell me what you think)

TIN3 EEC-V Computer (One of my friends also gave me a BIO0 if that makes a difference)

E4OD Automatic Transmission
 
Last edited:
Back
Top