Let's talk computers for a minute

Stang_ROTY · 06-04-2001, 12:00 PM

I have a 93GT with comp. code A3M. Can this computer be modified with a chip to accept a C4 tranny and a larger 393 stroker w/ 30lb injectors AND be effective? The reason I asked is because I talked to a buddy of mine who said that he installed a custom Superchip and he lost 16HP!!! The last thing I want to do is pay$$ to lose hp but if it'll help me pass emissions than I'll try it.

Unit 5302 · 06-04-2001, 06:04 PM

It should accept your mods without a "chip." The computer doesn't care what size displacement you have, or if you have a C-4 tranny. Only an electronically shifted tranny will have problems with a manual computer.

As far as the Superchip goes. Save your money, they are junk. The only chips worth money are custom burned when you dyno, or computers that allow you to reprogram your parameters.

Stang_ROTY · 06-05-2001, 06:26 AM

But what about the stock CPU being calibrated for 19lb. injectors? Doesn't that make my investment in the 30 lbs. injectors useless since they won't achieve their full potential. I would think that I'd be running very rich without letting the CPU know that the injectors are larger than the originals (Do you agree?). It's so hard to tell the truth about these products from the vast amount of info (true or not) out there. It's not like I'm eager to drop the 250 bucks for the thing but I need all the help I can get passing emissions which means a good air to fuel ratio. I heard somewhere around 14/7 is good.

keen · 06-05-2001, 07:58 AM

You can run the stock ECM if you buy a MAF meter calibrated for 30# inj's. The 30# MAF has a lowered output voltage to make the 19# ECM think it has less air going in so in turn the inj. pulse is lower. Call Johnson Motorsports about a custom chip they may be able to alter the MAF transfer curcuit w/o going to a different MAF.

Stang_ROTY · 06-05-2001, 11:50 AM

keen-

I just received the Pro-M 75MM Mass Air Meter that I ordered and it was calibrated for 30lb's. I'm a little confused. R you saying that my mass air meter lowers the ouput of the bigger injectors??? If so, what is the point of spending the money on the injectors and how does that MAF sensor increase HP?? Instead of "fooling" the CPU, what I want is for my computer to understand what I mods I have.

SHaFT7 · 06-05-2001, 01:12 PM

i believe he's saying that the 30# MAF makes the comp think its not sending the full load of fule thru the 19# injectors, so it sends more, when in fact it is sending the normal 19# load thru the 30#'ers, so it ups it to what the 30#'ers are supposed to use

------------------
SHaFTed

91GT, Flows 2chambers, dumps, 70MM BBK TB, K&N conical, Robert Shaw tstat, Hurst short throw, T5, 17" Lexani Roma wheels, 235/40/R17 on front, 255/45/R17 on back, mach1 hood, LX tail lights, bright red!

Capri306 · 06-05-2001, 01:52 PM

Stang_ROTY: what you're asking for is a completely customized electronic engine control computer. If you have all of the resources of Ford Motor Company at your disposal, by all means go for it. The computer Saleen offers appear to be the best so far, and they're the only ones making a totally aftermarket computer control box.

Getting back to reality, you're not fooling or tricking your computer into anything. Your stock MAF unit is calibrated to 19 pounders already. Substituting a 73mm calibrated for 30 pound injectors and installing 30 lb/hr injectors, as long as they are matched to the demands of the engine and to each other, will do the same job. The only thing the computer is doing is proportioning the weight of fuel to the weight of air entering the engine, and then making fine adjustments to that. The computer isn't fooled by any means, and it only interprets the signals it gets from sensors anyway. To modify the actual innards of an EEC-IV unit is a big no-no, as the chips are all soldered to the 'board.

When keen said the modded MAF lowers the output, he's right, it has to! 30 lb/hr is the MAXIMUM flow rate for those injectors. If you didn't trim the flow rate, especially at idle and cruising (95% of your driving conditions), you'd be blowing raw gasoline out the tailpipe. Think about the flow rating as WOT conditions only. The rest of the time, the computer is trying to keep your a/f ratio stoichiometric (14.7:1 by weight) and still carry out its functions to control emissions. When you go to WOT, the computer shuts down all emission control functions and goes into what I like to call "kick-azz mode". EGO signal is ignored, timing lookup tables shift, and so on.

On the emissions side, anything more than stock 19 pounders (other than a factory original Cobra Mustang setup with its factory 24 lb/hr system) is not going to pass emissions sinply because everything you add on to the engine control system (injectors, MAF, computer) has to be granted a CARB E.O. or have a 49-state certificate if you're not in Cali. In this case, a bigger MAF calibrated for 19 pounders (with an E.O.) and an adjustable fuel pressure regulator are your best options. A C4 transmission wouldn't cause the computer to throw a fit, it'd just act like an AOD in 3rd gear. I'm not sure what the legality issues are attached to this though. Guess you could tell them, "my tranny won't shift into overdrive." Hehehehe

On a final note, chips are absolutely the biggest waste of money and pieces of junk on the market today, and actually cause a loss of fuel economy, higher emissions (in most cases), and problems with driveability on the low or high end. Unless you can have one custom burned by someone with a full-blown dyno setup and the resouces to make sense of the info he gathers, steer clear of chips.

------------------
Capri306, Moderator, The Mustang Works Online
1979 Mercury Capri, 5.0L -- C4 -- 2.73
1987 Mustang LX Notch

Stang_ROTY · 06-06-2001, 09:40 AM

Capri306,

Thanks a lot for explaining that to a "rookie" like myself. I need all the help and advice I can get. First, let me say that almost every part I've bought has a EO or CARB # issued. This goes for the heads, EFI upper and lower, MSD distributor, headers & h-pipe, etc. the only thing that doesn't have an EO number is the bigger fuel rails I bought from Cartech to match the fuel system that came with the car and possibly the 30lb. injectors(which is an emissions issue). Virtually everything else Secondly,
Let me ask a question about the reference you made to "custom" chips. Superchips sent me a spec. sheet asking everything from my combustion ratio to injector size to my quarter mile times (which, of course..I don't have yet). Is this a "custom" chip they are going to program specifically for me (since I give them all the parameters that need be changed) and do you include Superchips in the category of "junk"????? And also, what would you do if you were in my shoes as far as modifying the CPU?

Thanks again for the help.

Quote:

Originally posted by Capri306:
Stang_ROTY: what you're asking for is a completely customized electronic engine control computer. If you have all of the resources of Ford Motor Company at your disposal, by all means go for it. The computer Saleen offers appear to be the best so far, and they're the only ones making a totally aftermarket computer control box.

Getting back to reality, you're not fooling or tricking your computer into anything. Your stock MAF unit is calibrated to 19 pounders already. Substituting a 73mm calibrated for 30 pound injectors and installing 30 lb/hr injectors, as long as they are matched to the demands of the engine and to each other, will do the same job. The only thing the computer is doing is proportioning the weight of fuel to the weight of air entering the engine, and then making fine adjustments to that. The computer isn't fooled by any means, and it only interprets the signals it gets from sensors anyway. To modify the actual innards of an EEC-IV unit is a big no-no, as the chips are all soldered to the 'board.

When keen said the modded MAF lowers the output, he's right, it has to! 30 lb/hr is the MAXIMUM flow rate for those injectors. If you didn't trim the flow rate, especially at idle and cruising (95% of your driving conditions), you'd be blowing raw gasoline out the tailpipe. Think about the flow rating as WOT conditions only. The rest of the time, the computer is trying to keep your a/f ratio stoichiometric (14.7:1 by weight) and still carry out its functions to control emissions. When you go to WOT, the computer shuts down all emission control functions and goes into what I like to call "kick-azz mode". EGO signal is ignored, timing lookup tables shift, and so on.

On the emissions side, anything more than stock 19 pounders (other than a factory original Cobra Mustang setup with its factory 24 lb/hr system) is not going to pass emissions sinply because everything you add on to the engine control system (injectors, MAF, computer) has to be granted a CARB E.O. or have a 49-state certificate if you're not in Cali. In this case, a bigger MAF calibrated for 19 pounders (with an E.O.) and an adjustable fuel pressure regulator are your best options. A C4 transmission wouldn't cause the computer to throw a fit, it'd just act like an AOD in 3rd gear. I'm not sure what the legality issues are attached to this though. Guess you could tell them, "my tranny won't shift into overdrive." Hehehehe

On a final note, chips are absolutely the biggest waste of money and pieces of junk on the market today, and actually cause a loss of fuel economy, higher emissions (in most cases), and problems with driveability on the low or high end. Unless you can have one custom burned by someone with a full-blown dyno setup and the resouces to make sense of the info he gathers, steer clear of chips.

06-06-2001, 04:17 PM

Superchips are fine....just over-priced. They're a big name and you're paying for their advertising. They are custom burned for your applicaion. If I were you, I'd contact Chris Johnson over at JMS and have him burn one for you.....less $150 (unless $$$'s no issue to you and you want to make Superchips richer

)

------------------
'90 LX 5.0; 12K original miles (no sh*&); 3.55 gears; pulleys;Edelbrock Performer Heads; BBK shorties; MSD 6AL box w/ blaster 2 coil; Motorsport E303 cam; Pro-M 75mm MAF; BBK 70mm TB; Eibach spring kit; Southside welded subs; K&N cone filter charger; Hurst shifter; fiberglass turbo hood; A/C-less; rear seat-less; cat-less; 2 chamber Flos; Corbeau racing seats (fronts);
30# injectors; JMS Chip; 190 lb fp; TFS track heat Intake (12.299 @ 113)

andy669 · 06-06-2001, 04:35 PM

Hey Stang_Roty, I'll give you a second opinion. Bada$$lx is right! Hell, even our local tuner (with chassis dyno) says Chris is one of the best tuners in the country! Capri306 is also correct!! "Box" (one size fits all) chips are garbage! of course thats just my opinion, i could be wrong.
andy

red82gt · 06-06-2001, 04:42 PM

With a bigger motor will come a bigger air demand (you're going with the 393, right?) If your going to fail emissions its going to be a visual inspection failure (no EO # for the injectors, 351W in place of 302-this will depend on the laws in your area).
The computer will make the correct A/F ratio in closed loop regardless of what size injectors you have and what size of motor as long as the MAF sends the right signal to the computer. If the A/F ratio is correct and you have all your emissions gear and are not running a camshaft that's too radical, your #'s should pass. Usually when a car fails because of injectors it is because it is badly over injected (too big of injectors)and the computer cannot pull out enough fuel, with a 393 you will need the extra fuel.

I guess what I'm saying is that unless the guy at the emissions place recognizes the 30lb injectors, and fails you because of them, you should be able to pass the tailpipe test.

[This message has been edited by red82gt (edited 06-06-2001).]

Stang_ROTY · 06-06-2001, 08:29 PM

Guys,

Thanks for the advice. I just got home from my engine builders shop and I'm really getting excited. Seeing him place the rods and pistons in the block and watching him install the cam really got my heart pumping. I WILL take you advice and do appreciate it!! First thing tomarrow after work I'll call Chris and tell him my buddies from Mustangworks.com highly recommended him. The hell with superchips. As far as the laws go around here...no one will fail me for the visual. I have some contacts at a few of the local testing garages, and hopefully everything will work out. I'll keep everyone posted as to when things really get going. Unfortunately, I can see a delay coming as the Flaming River Quick ratio manual rack is out of stock everywhere and on backorder. Just to verify things, I am running the 393 stroker and a semi-mild Comp X-treme energy cam. Thanks again!

------------------
Almost done!
93 GT, Dynamic C4, 8 pt cage, chute,
Sothside Machine bars & Sub-frames, 3.73's
'69 393 stroker w/SRP pistons, Edlebrock Performer heads, Performer RPM Upper & Lower Manifold..Crane Gold 1.6 Rollers Comp Cam..BBK 70MM TB, ceraminc shorties & H-pipe w/cats..30lb Injectors..Cartech Fuel System

06-04-2001, 12:00 PM	#1
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	Let's talk computers for a minute I have a 93GT with comp. code A3M. Can this computer be modified with a chip to accept a C4 tranny and a larger 393 stroker w/ 30lb injectors AND be effective? The reason I asked is because I talked to a buddy of mine who said that he installed a custom Superchip and he lost 16HP!!! The last thing I want to do is pay$$ to lose hp but if it'll help me pass emissions than I'll try it.

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06-04-2001, 06:04 PM	#2
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	It should accept your mods without a "chip." The computer doesn't care what size displacement you have, or if you have a C-4 tranny. Only an electronically shifted tranny will have problems with a manual computer. As far as the Superchip goes. Save your money, they are junk. The only chips worth money are custom burned when you dyno, or computers that allow you to reprogram your parameters.

06-05-2001, 06:26 AM	#3
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	But what about the stock CPU being calibrated for 19lb. injectors? Doesn't that make my investment in the 30 lbs. injectors useless since they won't achieve their full potential. I would think that I'd be running very rich without letting the CPU know that the injectors are larger than the originals (Do you agree?). It's so hard to tell the truth about these products from the vast amount of info (true or not) out there. It's not like I'm eager to drop the 250 bucks for the thing but I need all the help I can get passing emissions which means a good air to fuel ratio. I heard somewhere around 14/7 is good.

06-05-2001, 07:58 AM	#4
keen Registered Member Join Date: Jul 1999 Location: berk.,ca.usa Posts: 93	You can run the stock ECM if you buy a MAF meter calibrated for 30# inj's. The 30# MAF has a lowered output voltage to make the 19# ECM think it has less air going in so in turn the inj. pulse is lower. Call Johnson Motorsports about a custom chip they may be able to alter the MAF transfer curcuit w/o going to a different MAF.

06-05-2001, 11:50 AM	#5
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	keen- I just received the Pro-M 75MM Mass Air Meter that I ordered and it was calibrated for 30lb's. I'm a little confused. R you saying that my mass air meter lowers the ouput of the bigger injectors??? If so, what is the point of spending the money on the injectors and how does that MAF sensor increase HP?? Instead of "fooling" the CPU, what I want is for my computer to understand what I mods I have.

06-05-2001, 01:12 PM	#6
SHaFT7 Registered Member Join Date: Jul 2000 Location: Lawrence, KS, USA Posts: 169	i believe he's saying that the 30# MAF makes the comp think its not sending the full load of fule thru the 19# injectors, so it sends more, when in fact it is sending the normal 19# load thru the 30#'ers, so it ups it to what the 30#'ers are supposed to use ------------------ SHaFTed 91GT, Flows 2chambers, dumps, 70MM BBK TB, K&N conical, Robert Shaw tstat, Hurst short throw, T5, 17" Lexani Roma wheels, 235/40/R17 on front, 255/45/R17 on back, mach1 hood, LX tail lights, bright red!

06-05-2001, 01:52 PM	#7
Capri306 Moderator Join Date: Sep 1998 Location: Grand Rapids, Michigan, USA Posts: 1,001	Stang_ROTY: what you're asking for is a completely customized electronic engine control computer. If you have all of the resources of Ford Motor Company at your disposal, by all means go for it. The computer Saleen offers appear to be the best so far, and they're the only ones making a totally aftermarket computer control box. Getting back to reality, you're not fooling or tricking your computer into anything. Your stock MAF unit is calibrated to 19 pounders already. Substituting a 73mm calibrated for 30 pound injectors and installing 30 lb/hr injectors, as long as they are matched to the demands of the engine and to each other, will do the same job. The only thing the computer is doing is proportioning the weight of fuel to the weight of air entering the engine, and then making fine adjustments to that. The computer isn't fooled by any means, and it only interprets the signals it gets from sensors anyway. To modify the actual innards of an EEC-IV unit is a big no-no, as the chips are all soldered to the 'board. When keen said the modded MAF lowers the output, he's right, it has to! 30 lb/hr is the MAXIMUM flow rate for those injectors. If you didn't trim the flow rate, especially at idle and cruising (95% of your driving conditions), you'd be blowing raw gasoline out the tailpipe. Think about the flow rating as WOT conditions only. The rest of the time, the computer is trying to keep your a/f ratio stoichiometric (14.7:1 by weight) and still carry out its functions to control emissions. When you go to WOT, the computer shuts down all emission control functions and goes into what I like to call "kick-azz mode". EGO signal is ignored, timing lookup tables shift, and so on. On the emissions side, anything more than stock 19 pounders (other than a factory original Cobra Mustang setup with its factory 24 lb/hr system) is not going to pass emissions sinply because everything you add on to the engine control system (injectors, MAF, computer) has to be granted a CARB E.O. or have a 49-state certificate if you're not in Cali. In this case, a bigger MAF calibrated for 19 pounders (with an E.O.) and an adjustable fuel pressure regulator are your best options. A C4 transmission wouldn't cause the computer to throw a fit, it'd just act like an AOD in 3rd gear. I'm not sure what the legality issues are attached to this though. Guess you could tell them, "my tranny won't shift into overdrive." Hehehehe On a final note, chips are absolutely the biggest waste of money and pieces of junk on the market today, and actually cause a loss of fuel economy, higher emissions (in most cases), and problems with driveability on the low or high end. Unless you can have one custom burned by someone with a full-blown dyno setup and the resouces to make sense of the info he gathers, steer clear of chips. ------------------ Capri306, Moderator, The Mustang Works Online 1979 Mercury Capri, 5.0L -- C4 -- 2.73 1987 Mustang LX Notch

06-06-2001, 04:17 PM	#9
bada$$lx Guest Posts: n/a	Superchips are fine....just over-priced. They're a big name and you're paying for their advertising. They are custom burned for your applicaion. If I were you, I'd contact Chris Johnson over at JMS and have him burn one for you.....less $150 (unless $$$'s no issue to you and you want to make Superchips richer ) ------------------ '90 LX 5.0; 12K original miles (no sh*&); 3.55 gears; pulleys;Edelbrock Performer Heads; BBK shorties; MSD 6AL box w/ blaster 2 coil; Motorsport E303 cam; Pro-M 75mm MAF; BBK 70mm TB; Eibach spring kit; Southside welded subs; K&N cone filter charger; Hurst shifter; fiberglass turbo hood; A/C-less; rear seat-less; cat-less; 2 chamber Flos; Corbeau racing seats (fronts); 30# injectors; JMS Chip; 190 lb fp; TFS track heat Intake (12.299 @ 113)

06-06-2001, 04:35 PM	#10
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	Hey Stang_Roty, I'll give you a second opinion. Bada$$lx is right! Hell, even our local tuner (with chassis dyno) says Chris is one of the best tuners in the country! Capri306 is also correct!! "Box" (one size fits all) chips are garbage! of course thats just my opinion, i could be wrong. andy

06-06-2001, 04:42 PM	#11
red82gt Sober voice of Reason Join Date: Nov 1998 Location: Kelowna, B.C., Canada Posts: 1,514	With a bigger motor will come a bigger air demand (you're going with the 393, right?) If your going to fail emissions its going to be a visual inspection failure (no EO # for the injectors, 351W in place of 302-this will depend on the laws in your area). The computer will make the correct A/F ratio in closed loop regardless of what size injectors you have and what size of motor as long as the MAF sends the right signal to the computer. If the A/F ratio is correct and you have all your emissions gear and are not running a camshaft that's too radical, your #'s should pass. Usually when a car fails because of injectors it is because it is badly over injected (too big of injectors)and the computer cannot pull out enough fuel, with a 393 you will need the extra fuel. I guess what I'm saying is that unless the guy at the emissions place recognizes the 30lb injectors, and fails you because of them, you should be able to pass the tailpipe test. [This message has been edited by red82gt (edited 06-06-2001).]

06-06-2001, 08:29 PM	#12
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	Guys, Thanks for the advice. I just got home from my engine builders shop and I'm really getting excited. Seeing him place the rods and pistons in the block and watching him install the cam really got my heart pumping. I WILL take you advice and do appreciate it!! First thing tomarrow after work I'll call Chris and tell him my buddies from Mustangworks.com highly recommended him. The hell with superchips. As far as the laws go around here...no one will fail me for the visual. I have some contacts at a few of the local testing garages, and hopefully everything will work out. I'll keep everyone posted as to when things really get going. Unfortunately, I can see a delay coming as the Flaming River Quick ratio manual rack is out of stock everywhere and on backorder. Just to verify things, I am running the 393 stroker and a semi-mild Comp X-treme energy cam. Thanks again! ------------------ Almost done! 93 GT, Dynamic C4, 8 pt cage, chute, Sothside Machine bars & Sub-frames, 3.73's '69 393 stroker w/SRP pistons, Edlebrock Performer heads, Performer RPM Upper & Lower Manifold..Crane Gold 1.6 Rollers Comp Cam..BBK 70MM TB, ceraminc shorties & H-pipe w/cats..30lb Injectors..Cartech Fuel System