well...in my quest to build my car right, i am debating between spending the loot for a Haltech EK6 or just do it cheap with an AFC and lower fuel pressure. Right now, i still have stock internals, so boost isn't gonna go above 13 lbs. I have emailed Haltech and they said that you don't use the stock ECU at all when you put this system in... that sounds all great and dandy to me, but, doesn't our ECU control other functions in the car besides just fuel and spark? Such as gauges, A/C control, and don't even like the wires for door locks go through there? or am i just smoking crack, and the only thing i need to worry about is the A/C control, and guages?

As for the wiring issue...how hard could it honestly be? i got a damn good knowledge of how wiring works, how circuit works, where sensors go on cars, etc. so...i should be able to figure that out pretty well. It honestly looks like it would be easier to wire than how the factory harness is run.

Tuning: that is the next issue. I want to have an EGT, and a quality A/F meter. Like the modded ones wyatt has on his site. Gettin a laptop to use is not a problem either. And...there is like 2 dyno's in my area...so i should be able to get some good dyno time to get it done. But, i should be able to get it running just by tuning the closed loop mode with the A/F meter, and the WOT with the EGT and the A/F meter...then get some dyno time to really fine tune it.

Injectors: 550's would be what i would use for now...but what kind i need to use i am not sure of yet..whether it would use saturated or Peak and hold's. This i ain't sure about yet...but shouldn't really be a problem. Just need to talk to RC and Haltech on this.

Hmmmm...what else am i forgetting about guys? I know that Hahn is the only one who has done this yet...but you guys said it is a piggyback setup they use? i thought the Accel DFI was a standalone? Nowhere on accel's site do they have anything about how you can hook it up as a piggyback...if you could, this setup would be so much better. That way you could retain the stock ECU to control the little things that will cause problems.

I guess i should write to the DSM mailing list as well..i know there is some people on there that have put the EK6 on their 4g63's.

Is there any other systems that any of you have looked into? I know SDS makes some...but they look kinda cheap, and The MOTEC ones are hella expensive..but probably the nicest.

Let me know what you guys think? i would really like to get some discussion going on this topic.

Jason
95 GS-turbo

where is our voltage regulator on our cars? isn't that inside the stock ECU??? that would be another on of my concerns.

also, what kind of differences do you think there are with between the OBD1 and OBD2 computers. One thing i know of is the fact that of course it doesn't cut fuel when the MAP sensor reads boost. Also, i believe the main plug is different..I think the 95's are one plug...where i hear everyone say that the OBD2 has like an upper connector. So, i guess it is more than 1 right?

If i did decide to go with the AFC...would it be possible to use a map sensor from another car? A turbo one that can read boost...like a 2 bar map sensor that you use with the haltech? As long as it is a 5 volt sensor...i would think it would work. That way...you could have the SAFC read the boost, the cut the value to the right amount...which would be 4.7 volts right? that is where it sees 1 bar of pressure...or 0 lbs. of boost. So, if at 15 PSI...it puts out a voltage of around this 4.7 volts...you could now have more room to tune the AFC.. correct? So...if at this value of 4.7 volts, the injector duty cycle is high like 80&, you would be about where you need to be for that amount of boost? right? If anyone has thought of this...or tried it, let us know...

jason
95 GS-turbo

I know you're exaclty right about how "nice" it would be to use a multi-bar map sensro. Wyatt and I talked ourselves about how nice that would be, but it goes back to the same problem that you were initially trying to solve. A CPU that would agree with the upgraded tuneable map sensor. Our current cpu would go bonkers over seeing a map sensors that isn't the spec one.

However, with a better one, liek you said, that would give us that much more flexibility for tuning for a better, more leaner formula under boost that's above the 4.7 volts. Right now at low boost, the boost-dependent FPR is a pretty nice alternative, but it would be nothing compared to electronic tuneablility.

Jason
98' Eagle Talon ESi-T
Mitsu Super 16g Turbo(HRC)


http://springfielddsm.homestead.com/JasonsPics.html

_____________________________________
Jason ESi-T

04' BMW 325Ci
91' Nissan 240SX
98' Eagle Talon ESi (sold)

I have no real idea of how the HKS VPC works (in terms of the ECU and the old sensor)but 4g63 guys use them to replace their MAF's with a MAP. So could we use it to replace our MAP with another MAP (which I would assume is better) and somehow make our ECU read the boost and have control similar to the S-AFC. Just a thought that someone who knows more then me can run with, or shoot down just as fast as I wrote it

If you decide to go with a "stand-alone" system, the haltech seems like the best way to go right now for several reasons..
first its afully programmable dfi ecm, and you retain your stock ecu in order to control less vital functions such as a/c, your fans, guages, etc..

If any of you read turbo magazine, they put in the haltech system into their turbo 2.5rs impreza...


later!

-= RS Turbo=-

>I have no real idea of
>how the HKS VPC works
>(in terms of the ECU
>and the old sensor)but 4g63
>guys use them to replace
>their MAF's with a MAP.
> So could we use
>it to replace our MAP
>with another MAP (which I
>would assume is better) and
>somehow make our ECU read
>the boost and have control
>similar to the S-AFC.
>Just a thought that someone
>who knows more then me
>can run with, or shoot
>down just as fast as
>I wrote it

That sounds like a nice idea but unfortunately it will never happen simply because our ECM does not have the program to run while under boost. For example the 4g63 ecu will read boost and adjust injector pulse and duration according to boost. Even if you accomplished not getting a check engine light while under boost with our ECM.. it still would not know what to do with it.


Hope that helps !

You should look into a Pro EFI unit like Mike Simon, John Shepherd, and now Sean Glazer and Brent Rau are using. It plugs directly into the factory harness, and all of the factory accessories still function. It is a full stand alone engine management system with complete datalogging. Call 402-731-7301 and ask for Jason.

if you are not going to change your internals, and only going to run 13 lbs of boost, just get a s-afc, and save yourself the headache. there is a LOT of stuff that goes on in the fac. ecu (emmisions crap, ignition control, fuel control, and other functions) that is pretty necessary for daily driving. I would reccomend using a stand alone computer if you are building a "race car" something that is NOT street driven AT ALL. even Hahn uses the Accel DFI as a piggyback on teh stage 5 kits. the ignition is mainly controlled by the ecu, with a little help from an ignition amp. With stock internals, and 13 psi, you really won't see much benefit using a stand alone. our map sensor goes from 0to 5 volts at -15in. hg to around 7 psi (not exactly sure if it is -15 or -30 'though). the voltage is linear with the pressure as far as I know. putting a bigger map sensor on it would mess up the fac. fuel curve. I explained this to Murix a few days ago, but this is basically how I see it. Most all MAP sensors are 0 to 5 volts. if you put a 3 bar map sensor (reads -15in.hg. to 30 psi) then it won't hit 5v until 30 psi. So at....say.....15 psi, your computer would be getting a voltage that it normally gets when it is around 2 psi, and would mix the fuel according to that (which is not a lot). and usign a vpc isnt' the answer because it's main purpose is to eliminate the MAF sensor (which is a BIG restriction on most cars). we dont' have a MAF sensor, therefore we don't need it. even if it would work. the s-afc and bigger injectors will do the trick in most average turbo setups.

Have fun!

well, like i have said before, the reason i want to go with an enigine management system is because i plan to do rods and pistons in the future, possibly this summer. Hopefully not any sooner cus of a blown motor, that would suck. But, for right now, i want to get the fuel system in order. There is no need to have rods and pistons unless you have fuel that can support it. I understand what you are saying about how our stock ECU controlls alot of the daily functions on our cars. Thats my whole point behing this post. To see if any one knows how the haltech will interact with our stock ECU. According to haltech, you still continue to use your stock ECU to controll the normal functions, but you use the E6K system to controll the spark and fuel. How exactly it gets hooked in is something i have yet to find a serious answer on. A friend of mine from my area is having a haltech installed on his turbo del sol, so i am going to try to get a hold of him over the holidays and see what he has to say about it.

As for the accel DFI that hahn sells, i am actually looking more towards this setup, just for the fact that it comes preprogrammed for the car. Total on the ECU, harness, sensors, 625 cc injectors, and 1:1 regulator is 1500. Which i guess is not a bad deal. It is enough to put them into the 11's...so anyone out there that has their rods and pistons done already, maybe you should get a hold of them and see what they can do for you.

But, like i have said, i would rather destroy my motor with a bent rod, or cracked piston from too much pressure than blow it up cus i ran out of fuel and detonated.


jason
95 GS turbo

Hey Jason,
I'm really curious about this 1:1 regulator. I'm guessing the Bell adjustable can't go to a 1:1 ratio of fuel?
Or are they givign you this because they are thinking you don't have an adjustable regulator to begin with?
I am also thinking of the DFI system, simply because all it does is control fuel, and doesn't get into any of the other crap the ECU does already.
I'd like to see someone put some 440+ injectors in our cars with stock bottom ends and see how much boost our cars can really take given the rigt amount of fuel.
I'm tempted to buy a junker motor and blow it. Any takers?

Wyatt Leras
http://www.turbogs.dsmpower.com
98 Eclipse GS Star Stage 5,000 Turbo kit

Well..that is basically my plan. I wanna bend a rod in half. That would be the shit.


As for the 1:1 regulator. I think you need that with the accel and 625's because the bell or even the super FMU doesn't adjust that low. I think i have read the lowest they go is 3:1 ... I would imagine that if you got 550's and used like a 3:1 ratio you could theoretically run that..but what i was thinking, is with something like a 3:1 ratio, and 20 lbs. of boost, you will be pushing close to 100 PSI through your injectors still. 47 base plus 60 in additional pressure. And why i wouldn't want to run that is because it is still not 100% reliable...not that anything really is. At least with 625's and a 1:1...fuel pressure is not as important as with our setups now and even with a 3:1. This just basically gives all the controll to the injector pulse width. Which is the way a car is supposed to run. Pushing higher pressure through injectors works, but it can't be good for them. I have read how they can be stuck open.

And as for worse gas mileage with 625's...that might not be the case. As long as the accel could shorten the pulse width enough, the car will still run in closed loop, bouncing back and forth between rich and lean. So, i don't see how larger injectors will make a difference. a larger injector would just use a shorter pulse width and a smaller one would need a slightly longer one, but it would still be delivering the same amount of fuel.


jason
95 GS turbo

By the way wyatt...i need to get in touch with you about getting that new downpipe...I don't wanna screw around with gettin this one welded again...

The factory computer in a non turbo eclipse controlls all engine functions, and that is pretty much about it. The cruise is seperate, a/c has input to the ecu but is not needed to for the a/c to work (it just lets the ecu know it is on and that is where the extra drag on the engine is coming from so it can kick up the idle and prevent stalling on deceleration). The guages are all seperate, the tach gets its signal from the stock ignitor. So properly done the stock ecu can come out, and an aftermarket can be plugged directly in. This is why I would recommend the Professional EFI System. They have precalibrated maps, and automapping of the fuel and timing tables so any modifications made can easily be re-tuned.

Jason.

This is where you are wrong, I have ran a completely stock all wheel drive 92 talon at the track, and ran a 15.3 at 89 mph. Then I plugged in the pro efi unit(which takes about 5 minutes) and ran a 14.2 at 95 mph. The factory has a completely different goal when tuning a stock production car. They are looking for smooth driving, emission, and general appeal, so the average person (anyone from 16 to 60 years old male or female) can get into the car and get smooth appealing drivability. When tuning for performance this is not possible to achieve. When obtaining maximum performance gains, transition between gears and throttle response is more immediate, and therefore less "smooth". Milage can also be increased with a stand alone. 14.7 is ideal for emission output, but a car at cruise can easily run at 17 to 1 air fuel. I have seen cars go from averaging 19 mpg to 24 with a properly tuned stand alone system.

So with all this talk of a system, which is the one to go for?

group buy? =)


l e o n

the difference in changing the mapping from a stock 1g awd is one thing, but changing a modified 2gnt that has a turbo to something else is a different story. the way the turbo kits are set up, they aren't exactly designed to bring out the "economy" in the cars. that kind of goes otu the window when that boost needle goes past 0 . I also may be wrong, but from what I remmeber, our cars don't hav ean igniter. the tach signal comes straight from the ecu. the ecu also controls the egr valve operation, and evaporation canister solenoid operation. the ecu also controls the 2 coil packs on the car. Now, I know the emmissions stuff is not exactly "manditory" everywhere, and you can get individual coil packs per cylinder with the haltech, but it makes it that much harder to pass emmissions with people that have emmissions laws, and obtain the maximum performance from the motor at the same time, while still retaining streetability. It's a lot more of a hassle than a piggy back setup is.

Have fun!