Well, I installed a new 730 ecm & put the 749 on the bench, TC sent me $58b, loaded a stock BBZB 1580, set some const. Well it runs a whole lot better. I don't know why, perhaps wishful thinking but I can tune idle for a solid steady vacuum at idle. So then I went for a beat run obviously to get more gas. Datamaster showed me some stuff I need a little help with.

RPM-5175
Map-277 kpa
Boost-19.6
BPW-17.91
INJ DC-154.5
VE-82.7
KS RET-11.1

A few questions.
1. Do I need to go 3bar or are these boost numbers a byproduct of a bad tune?

2. VE is low, it seems that my last entry in F29 is 54 and F30 is 27.7 for that rpm, so VE must be derived from F29+F30 not F29 getting doubled at last enrty (yes/no?). Is the bad VE calc causing high duty cycle or do I need bigger injectors? Running 30lbers 383ci. All data runs have similar trends.

3. Is there a way to scale my VE based on the numbers I listed. Is there a formula to apply the corrections?

I love those cogs, no belt slip.

 

I don't use datamaster but judging from those numbers without the physical units included I would say that it is scary lean.
Was it detonating like crazy?
Did the boost gauge read 19PSI?

When I installed the boost setup on my rig I tuned the part throttle VE tables before bringing it up to 5000 RPM. I normally rev it to 6000 RPM but don't have the tables good enough for that yet. That was all at 6PSI.

I would take it easy and get the part throttle worked out first and go from there. What is you horsepower goals? What is the cubic inch, injectors, & max. RPM?

From the looks of it that thing was in trouble at that RPM. At 20PSI you would need around 65#/hr injectors at the stock fuel pressure.

EDIT-read it is a 383ci with 30#/hr injectors. If you really have 20PSI then it is VERY lean at 5200rpm. At 20 PSI you would need a min. of 50#/hr or 55#/hr injectors. Do a search for "gncalculator.xls" on the power adder board. It will give you a rought idea of what you need for fuel.

 

Not sure about the boost gauge its a damn 2 1/6" gauge on the pillar, left hand on steering wheel rt hand on shifter, holding on for a hell ride, didn't get a good look at gauge. I don't doubt the number. The cogs work!

I know the lower VE tables need work. I hate to think about 60lbers, I just got the 30's to idle.

It probably was detonating come think of it, I thought at first it was too much water/methanol, still might be.

But is there a way to scale the VE tables? Is F29+F30 my true VE or is PE in control? Or PE + F29?

HP goals are 500-550 crankshaft. Or really just making the best of what I have, tuned good able to drive to work on pump gas.

 

So are you saying you have a 2-bar MAP sensor? and your getting MAP readings of 277kPa?

 

Yes, I have quite a few entries well over 200kpa. I know its at least a 2bar.

HMMMM makes me wonder now that you point that out. I had to modify the connector to fit the sensor, it reads 2.34 volts key on engine off. I've seen the boost guage flash beyond 15 psi. Maybe a 2bar can read beyond 14 psi.

I would upload my DM run if I knew how (hint). I would like to show anyone who may have some ideas on better VE tables.

 

Ha ha, yeah the cogs work. Boosted rigs are fun.

I know what you mean. I was in the process of trying to get crappy Ford 42#/hr to idle. There are a few members on the DIY PROM board that have very good idle results with 60#/hr injectors. I can't remember which, but do a search for "60#/hr" and "60pph".

It was probably detonating. Your BPW was 17.xx ms, at 52000rpm the max. BPW you can have is 11.5ms for double fire batch. That means it wanted 17.xx ms but you gave it 11.5ms of fuel. So, 17.xx/11.5 = 1.52 and that means it wanted 1.5*30#/hr injectors or 45#/hr injectors. That is with whatever AFR you were trying to achieve. Don't take the 45#/hr as that is what you need for injectors. It is a very rough estimate. It kind of sounds in line with the high boost. If it did have 45#/hr at 5200rpm it would have put you in the 500 FWHP range.

Look at the fuel multiplier table it multiplies the BPW with a table value when under boost.

With 30#/hr injectors you can get a max of about 400-450FWHP with the stock fuel pressure. You could use an adjustable fuel management unit (FMU) or big injectors for more HP. You could reach 500 FWHP with either 42#/hr or bigger injectors or increasing the fuel pressure (FMU) with the 30#/hr injectors to make them flow enough fuel as 42#/hr injectors.

 

sounds like you have a 2 bar MAP sensor and a 3 bar patched bin. A 2 bar can only read up to 200kPa (absolute pressure) depending on atmospheric pressure, that could read just over 15 psi gauge pressure. the 2 bar sensor has orange plastic inside where the green harness connector plugs into it. I've never seen a 3-bar but have been told by a friend that its black inside.

email me your DM file. I'll post it. you have to have your own web storage, i think. ttypecamaro@jhu.edu

 

Yeah, he could have a 3bar bin. The 277kpa would be roughly 277*(2/3) = 185kpa or 12.5PSI. This puts it into the 40#/hr range and still about 500HP when tuned properly.

Not all 2BAR maps have the orange inside. I have a new GM 2BAR that is completely black.

Post the part number of the MAP sensor you are using.

 

With the key off, the MAP will read atmoshperic pressure (approx. 100Kpa) and a 2BAR map would read 200kpa with a 5v signal. Since you have approx. 2.5v then it sounds like a 2bar map. I could be wrong.

You can only tune the VE tables so much. You are exceeding the fuel supply of those injectors. The BPW you listed shows that. You can have a max of ((120/5200)/2) = 11.5ms for 5200 RPM. The ECM wants them on for 17.5ms. It ran out of time.

 

Email me the scan and the bin I can take a look at it.

Tune the car without the belt on first. adjust spark and fuel up to 100kPa before you do the rest.......

I think 30lbs on a boosted 383 is to small........


/N.

 

As far a MAP part #, I'll pull it off car and look but the inside connector filler piece is black. As far as bin, I don't have a patch, so it should be 2bar.

I think I may go P&H injector 60pph, Grumpy has got em running on his 231, so my 383 should run them, of course I can't tune like him so I won't get the full benefits of them.

ttypyecamaro & gta324 PM me your email and a "how to" attach a Dm file and I'll send it to you.

I do have two fuel pumps in car, stock one in tank and walbro 255 under hood. Starting with 45psi running,vacuum hose on, jumps to 55-60 if I snap throttle.

Is it possible the $58b is is giving these numbers? Reported that the $58b is scaled differently for V8 apps. Is this param possibly scaled differently? Maybe I should try $58 again.

Do I need a patch to run the new hardware in a 749 for P&H injectors?

 

Watch out for running the Bosch style 42#'s.

Not a real linear type of injector. Turbo Buick guys dont even care for them and have even run a ton of supporting tests on them to prove it if u go hunting at turbobuick.com or gnttype.org.

The 60/65(depends on who u talk to) seem to be pretty linear and very consistent from batch to batch.

I know Bruce and I both have ours idling at/around 1.3ms but we are running sequential 148 setups(thanks bruce). Can literally sit at idle with little or no change in PW.

So they shouldnt cause you any real problems as far as idle repeatability goes, although I havent any experience with them at smaller PW at idle.

later
Jeremy

 

My email is in the sign..........

If you are going to run P/H injectors with the 749 you need to modify it.

Dont think the $58B is the problem, I have used it with no problem.

Email me the bin and a log from Datamaster...

/N.

 

If your referencing what I said ,the Motron 60/65#'s are high impedance type injectors, just for clarification.

later
Jeremy

 

Ok. I am about to order some 60lbers. Should I just use High Z or go low Z, I can do either one. I just want best result. lookin at racetronics, all prices about the same. It would seem low Z is better for idle. Or have the high Z's gotten better. Racetronix has 60lb high Z at 12 ohms. Is 12ohm too low for stock hardware?

 

Also keep in mind on the $58 style bins you MUST get vacuum fueling CORRECT not just somewhat close BEFORE you tune for boost.

Get bigger injectors though, 30's are way to small for your app.

 

87tpi7749

I think your lucky to still have pistons and rods according to this datalog file. You're detonating like crazy over 3700 rpm. And a little between 1300-1600rpm. after 4200rpm(8spi) your injectors go static when your O2 voltage was already low and your BLMs are really high. you need to take the belt off that supercharger untill you get some injectors!!!! by the way... thats a beast!

you have a problem with the spark, you're detonating at low boost(4-5psi) and 3 degrees of total spark. This is probably from being lean, but could be from compression or fuel octane. your intake temps seemed really high (150-162F). Is the weather hot where you live?

I wouldn't waste time doing too much tuning without those new injectors, unless you need to drive the car.

the idle PW are steady around 1.80-1.85ms. seems to idle fine. it stays within 75 rpm and 3kPa, which is probably all due to electrical error. the ecu is taking out 3.9% at idle

the stuff:
DataMasterfile 87tpi7749's.bin file

 

Detonation is kind of expect with a 383ci, 30#/hr inj. and boost....and it probably caused some pre-ignition. I would check what is left of the spark plugs.

Also, notice there was no mention of re-wiring when swapping out the 749 ECM to 730 ECM. Without re-wiring, the grounds and other things were messed up. Maybe it works better now with the 730 ECM because that is what it is wired for.

 

I guess good hard parts and machine work pays off. I assembled the best rotating assm I could reasonably afford (~$5000.00 incl machine work & balancing) with a Bowtie block.

I have been stumped on the 749 driver mod for low Z injectors, as the link from the stickies show a jumper wire used, I can't tell where one end connects. The other issue is do I wire the harness as a Sunbird or a SY/TY?

 

edit: nevermind

 

I had already wired for the 749, I just swapped out the 749 to the 730. As I understand the 730 gets wired the same to run a $58 code. Right? Maybe? AHHH crap. I probably F'd up.

I think I need to look at what I did. junkcltr you have me thinking about the wiring now. I've gotta look at the prints. I'll update with what I find.

 

I love GM. I just looked at the prints. No problem running it the way I was aside from some vss & a/c stuff, the connections are the same. Power feeds and grounds, sensors, etc all the same. The only connection the 730 did not have on my pin scheme was D6 a ground, but it looks like its shared a D7 anyway. As dumb luck would have it I was pinned correctly.

Come to think of it, I already had it wired to 730, then swapped the pins to run 749, so to run $58 on a 730, there shouldn't be a difference.

Any help for the 749 inj driver mod jumper wire?

 

That sounds like a nice engine. Good machine work & parts are always the best way to go.

Check out this thread for the 730 ECM with $58 code:
Third Generation F-Bodies > Tech Boards > DIY PROM > 4kb nvram expansion board for 730/749
Look at the bottom of the thread. It is sort of hi-jacked thread info.

Check out the stickies for the (730 ECM with $8D) to (749 ECM with $58) swap. It is listed under the 730/749 ECM info.

 

After looking at the 749 ECM wiring, you are correct.

I found that I didn't have to re-wire anything when going from (730 with $8D) to (730 with $58). By the looks I wouldn't have to re-wire to drop in the 749 ECM. The only thing that makes me wonder is the D6 ---> C13 ground. I would have to ohm out the 730 ECM and 749 ECM to see what the difference is. That is, if there is a different connection point or inductor on the ECM PCB.

The jumper wires are used on the 749 ECM to enable the P&H circuit for P&H injectors. You need the jumper wires for P&H, you don't need them for saturated injectors (12-16 ohm).

 

So I guess we will wait to talk about my VE stuff until I get some bigger injectors. I was thinking 65 pph P&H. Or how about 75's.

I'm itching to order some injectors tomorrow. Suggestions please. I thought 30's would do it last time, I don't want to waste any more money.

 

really? what about IAC motor?

 

87tpi7749,
Go here http://www.megasquirt.info/, then click on the left hand "Injectors and Fuel Supply" link. You can use the little calculator with your crank HP goal and number of injectors. I would use that injector number and go 10 to 20% bigger. They use .50 BSFC (how efficient the engine is). Using 10 t0 20% bigger will but you into a .55 to .60 BSFC range. Don't skimp on the HP you put in. With a tough engine like that with boost I would probably always want to push it more knowing it can take it.


ttypecamaro,
Yes, I did not re-wire the IAC in the end. Actually, I tested out all of the possible combinations to see how the IAC responded. I found that there are multiple ways to wire it to make it work properly because it is just a stepper motor. One of them was leaving the wiring alone so that is how I left it. The ECM sends a pulse out on the wires to make the IAC turn in a direction and then another pulse on another wire to make it turn some more. There are four wires to turn it 90 degrees each time. It is the matter of the wiring and which signals are pulsed at which time. I even messed with changing the code to reverse the polarity of the bits that control the IAC. What I learn was to just leave it alone. There is more info on this at:

Third Generation F-Bodies > Tech Boards > DIY PROM > Keeping the $58 running?

 

Here are the pins I moved 730->749
A8------------->A9 (ALDL data - Not needed to move though)
C1------------->B12 (VSS output for cruise - Not needed)
C11------------>C12 (Injectors 1,3,5,7)
C12------------>C11 (Injectors 2,4,6,8)
D6-------------->C13 (Injector ground)
E3-------------->E4 (IAC coil A high)
E4-------------->E3 (IAC coil A low)
E5-------------->E6 (IAC coil B high)
E6-------------->E5 (IAC coil B low)
F1-------------->F4 (shift light) for manual trans
F2-------------->disconnect (AIR pump solenoid)
F6-------------->F4 (TCC) for automatic trans

And for running P/H injectors
1. Wire up the 749 like sy/ty
2. Change inj drivers and sense resistors
3. Add a "internal" jumper between C10-C14

Injectors connects to
1,3,5,7 to C11 and C12
2,4,6,8 to C10 and C14

jumper wires between D5-D6 and C13-C15

Pictures is on my website.........

/N.

 

ttypecamaro, I know about the IAC wiring but it didn't seem to matter swapping ecm's back & forth, IAC counts were normal, idle was steady. I dunno? One more reason I love GM.

Why does the 730 ecm injector output wires swap pins for a 749 ecm? Isn't the engine batch fire anyway? Both banks fire at the same time. The ecm doesn't know if its firing an odd or even numbered cylinder, so why swap the wires? I'm sure there is a good reason, I just wonder.

 

Wow, nice info and pictures, couldn't be any clearer than that. Thank you. Going P&H for sure.

How about isolating two injectors per ecm output wire, would it make a difference? 1&3 to C11, 5&7 to C12, so on?

I was also thinking about a 30amp relay with alternator power to provide a better power feed to injector B+ side and switch the relay with the stock key on power, maybe even do the same with the fuel pump, should be easy to do and give a stronger power supply. If it's unneccessary and a waste of time, please tell me. Its just a thought.

 

I don't think you really need to upgrade to PnH injectors, if you don't want to. You can get hi impedance injectors in the 60-65lb range, from racetronix. I beleive they are fairly linear, so you shouldn't have much problem at idle.

I could be wrong, but from what I've read here with guys running big injectors, alot have used them with success.

bear in mind, 12 ohms is considered hi impedance. anything from 12-16 ohms. 2 ohms and lower is considered low impedance and require injector driver upgrades.

someone else chime in here if I'm way off?

just to let you know where I'm coming from, if you ever fry the ecm, you would be stranded until you upgraded another ecm, if you went that path. with the hi impedance injectors, you would just need a new ecm, and swap the prom.

 

Yeah, it couldn't get any clearer than that, but you are doing a fair amount of re-wiring for no reason.

Two inj. per wire wouldn't really make a difference. Make sure they are twisted pairs if you do it though.

Using a relay would be worse than the factory wiring. The factory wiring is pretty much direct to the battery. A relay introduces a failure point and possible inductance. Leave the positive side wiring the way it is.

What did you decide on for injectors??

 

Yes, after looking at the prints you are right. I'll leave the positive side as-is. I went with the Delphi 65 pph Low Z. Its not that I prefer these, but I wanted to try Low Z and I felt like I was up for the challenge. After finishing my DIY-WB, I was itching to do some more electronics work.

Now I'm thinking about upgrading my fuel supply system. My thoughts were sump the tank and use a pump from racepumps.com its a mechanical efi pump capable of 204 gal per hr @ 75 psi, -8 feed line, branched -8 output to feed both rails seperately, a return is not required with this pump, regulator is on supply line. Feedback is welcomed. My ideas are sometimes crazy.

 

Good choice on the injectors. That was my personal choice for injectors until I saw the price and then cheaped out. I will probably get a set of them late this year. The P&H are better for your application because they give better adjustability at idle and provide a good amount of fuel for WOT.

I never heard of the pump you mentioned. I need to check it out.
In general, a boosted app. runs about .60 to .65 BSFC. That means it takes about .65 lbs of fuel to make 1 HP.
As an example, say you want 500HP. That means you need 500*.65 = 325 gals/hr of fuel. A gallon of gas weighs 5.8 to 6.5 lbs. If you use 6.0 lbs/gal, then 325 gals/hr / 6.0 lbs/gal = 54 lbs/hr. You would need a fuel pump that flows at least 54 gallons/hr for 500HP with a BSFC of .65. A Walbro GS307 255 ltr/hr fits the bill when using stockish fuel pressure and even when the battery voltage is low.

You can do the math on the pump you are interested in to see how much HP it can provide fuel for. I don't think you will ever exceed the capicity of that fuel pump

 

junkcltr - your math is a bit off, hehe. Imagine buying a fuel pump that flows less than one injector!

I'll let you find the mistakes (hint - look at the units).

 

Good catch. The final result is correct, but the units are a mess.

Try again:

As an example, say you want 500HP. That means you need 500*.65 = 325 lbs/hr of fuel. A gallon of gas weighs 5.8 to 6.5 lbs. If you use 6.0 lbs/gal, then 325 lbs/hr / 6.0 lbs/gal = 54 gals/hr. You would need a fuel pump that flows at least 54 gallons/hr for 500HP with a BSFC of .65. A Walbro GS307 255 ltr/hr fits the bill when using stockish fuel pressure and even when the battery voltage is low.

 

Thats the same injectors that I have...... But I will probably go a bit bigger this year...

/N.

 

Well, I know how to use datamaster with a 730 ecm with Autoprom. Problem is after I repin the connectors on the ecm to be a 749 the car appears to be running ok. I did get all the flags tripped and the Check Engine light isn't on any more as I removed the EGR because I run a TPIS mini-ram. I can't get my snap-on mt-2500 or datamaster to connect to the ecm through Autoprom.

The wiring guide says the 749 reads the aldl on A8 or A9. So on the 730 I had it on A8 and switched to A9 on the 749. The nothing.. No connection, No Nothing.

I have been told that the 730 is almost 100% identical to the 749 as long as you run the $58 code. Problem I get there is I can't get the XDF & ALDL file to be compaitble.

Where in the $58 code can I adust the idle? I am idlig around 1200 in park.

 

Look for 58_RR_V14 on moates.
go to the bottom of the tables section and there are your idle tables.
You might want to try lowering your TB blades and see if the idle follows.

 

Do you have a 10k resistor between A-B In your ALDL calble? That forces the Idle to 1200 rpm, either remove the resistor or change the ALDL mode desired rpm at 69E in the chip..........

/N.

 

I am using a Moates Autoprom so the 10k resistor isn't needed. I went into Tunerpro and the idle is set at 750. I didn't adjust the Throttle blades on the BBK throttle body as it was already set and running on the 730 ecm @ 750rpm

Car didn't make any noticable change on the dash. So, I did convert the 7 wires to switch from 749 back to 730, reburned the chip back to a $8D and checked my settings again. Tunerpro and Datamaster were sucessful in datalogging. I don't get why neither can connect when the 749 is hooked up. If Mangus ever gets this fixed I know there will be alot of happy people. Something else that I have been trying to get to work with no success is..

Leaving the 730 ECM hooked up

Burning the BBZT?? 749 Eprom into the 29c256 chip
Using the $58.xdf file from NWSTP.Com
Using the $58.adl file from same site.

Installing into the 730 and getting that to run.

I figured if I could get that to work, I could use the 2 bar map, Datalog, and Emulate and live tune. But, Alas, It doesn't like that.

I can't repin the ECM like the 749 as the car does really funky stuff.. Like Runs only on Left bank for a short period of time. (10 Seconds)

I don't understand the 749 ALDL connection either. The 730 says to put in A8 and the 749 says not necessary as it pulls data from A8 & A9..

So becuase I haven't driven this car with the S/C on it yet and it has been 1 year since I last drove it. I am installing the MSD boost timing master on it tomorrow using the 730 ecm and driving it a little bit.

With around 100 hrs run time on the engine while in the garage, I figured the engine should almost be broke in. LOL

 

Yes the Autoprom on $58 currently will not log and emulate at the same time. You can do one or the other but not both simutaneously. Magnus is aware of it and is working on a solution. We are also trying to figure out how to correct this in the $59 code we are working on. If the solution works, we should be able to make a patch for $58 so Autoprom mode will work. Otherwise it is up to Magnus and Craig to figure it out.

 

I have for the 1st time in 2 1/2 years was able to take my car for a ride today. Started and ran good. Car runs very rich at idle enough to kick on the check engine light after 5 minutes but will go out once you get it above idle. Cruising around city either 30 - 60 mph the blm's are at 128. Have to problems that I need help with.


Would like to pull fuel from VE-Tables on the $58 @ idle

If you stomp on it in drive it is bucking and snorting like I need to add fuel in PE.. Other than that, Car is running fine.

1. in the $58 what tables do I use to pull fuel from idle and
2. add fuel in PE to stop it from bucking and snorting..

 

Usually the table used for idle is the close throttle table (f31E)

If you stomp on it and it bucks it might be AE not PE. If the bucking is occuring right off the bat try AE. There are 3 AE tables : AE vs tps AE vs MAP and RPM Multiplier for AE.

If it is PE use the PE vs AFR table and lower the numbers to richen

 

Idle fuel is F29c Cruise fuel (not under boost) is f29

When you get into boost then F77 comes into play with F29

F29 and F29c need to be good before you can truly tune AE or PE.