OBDI Tuning

[PhantomGTZ]

Hello,

I wanted to shoot a question out there for you guys. The car is not a Sy or Ty, BUT I wanted to ask an expert on GM OBDI Turbo cars. I'm not an expert but I do know a bit. Here we go:

I want to tune my car for a turbo application.I bought all the necessary forged internals, now I'm stepping to tuning.

1. I've always been told that you should not surpass 80% duty cycle on your injectors. Does this hold up in real-life turbo applications? Do people push the envelope safely?


2. Will pushing 80-100 psi of fuel pressure compromise the functionality of an injector? (The car uses low impedance injectors if that makes a difference). I will be installing an after market fuel pump that is capable of doing this.

3. Would you suggest running 10% larger injectors than stock with an
-SAFC,
**or**
-an FMU + APFR (to cover richness at idle) ?

What be the limit to this idea? 20%? 30%? I still want the car to idle.

4. Is the MSD DIS-2 the best way to control spark? besides a stand alone of course. Could you suggest another option?

5. I keep tossing numbers into a BSFC calculator, and I keep getting a value of (.52)-(.54). I know a turbocharged car should see a value of around (.60) . But does this case only apply to larger displacement vehicles?

Realistically the engine should make about 300 horsepower at the crank. Thats using a small T3 (.60 compressor / .63 exhaust) and 15 psi and the setup will have a front mount intercooler.

Thanks for reading,

-Joel

 

[PhantomGTZ]

Re: OBDI Tuning

As you can tell, I'm trying to do everything I can to avoid a stand alone.

 

[JSM]

Re: OBDI Tuning

Looks to me like your trying to find a bandaid fix.

Do you even know what ECM you are using, part #, code it is running, how to edit a chip?

I would suggest heading in that direction first, learning how a computer works, not how to put external pieces in place trying to make things work.

 

[PhantomGTZ]

Re: OBDI Tuning

I'm well aware of what ECM I'm using, and the chip.

I do not know how to edit a chip. Is there software available? As far as I can find, nobody has bothered to try editing this chip. Even if I had a decent understanding, I'd rather have a professional do it who has more experience.

The car was never available from GM with a turbo. The computer does not have the fuel maps for a turbo application. Like I said, I'm not a whiz when it comes to FI turbo cars.

-Has anyone here had an OBDI car dyno tuned?

 

[leroy]

Re: OBDI Tuning

I would recommend using a syty ecm for boosted applications. I think a 730 ecm can also be used with the $58 code. There are aftermarket engine management systems available also, including megasquirt.

I would also suggest going with big enough injectors, instead of raising fuel pressure or an fmu.

Stock ignition with a tighter plug gap may work for you.

There's a diy-turbo group on yahoo that would be good to join.

HTH,
Jim

 

[JSM]

Re: OBDI Tuning

I'm well aware of what ECM I'm using, and the chip

and

I do not know how to edit a chip. Is there software available? As far as I can find, nobody has bothered to try editing this chip.

Not trying to be sarcastic, etc. But those two statements conflict.

What you need to find out is what model ecm you have, get a wiring diagram, see what tables are available for your stock ecm. Find the software to edit chips, learn how to do it, etc. (hints, tunerpro, tunercat, datamaster)

Then as Jim just mentioned, if you want to stay with GM ECM the syty for boosted application is probably the best. Now you gotta figure out how to wire it all up (hence wiring diagram from above)

I see you mentioned paying prof. to do the above. If your going to do that, you will be cheaper to get a standalone system. By the time you pay a shop $40+ (cheap shop at $40/hr) you will have more money in the converstion than to buy a stand alone (FAST, Bigstuff, etc)

I personally don't like to tune on a dyno. I have found it doesn't load the motor the same as the street does. Unless you plan to be racing dynos, best is to tune via road.

You will find the high boost wide open tuning is easy. Drivability is the part that takes weeks, months.

Tuning is the most important part of any engine build. 5 years ago people were throwing thousands, bowtie blocks, etc HOPING to run 10's. Phil long did a bunch of tuning and ran 10's on a stock motor. Skimp on tuning and you might as well throw away any money spent on the engine.

 

[PhantomGTZ]

Re: OBDI Tuning

Thanks, I appreciate the info.

The engine is a quad 4. in 1988 I believe they used the same ecm as the sy/ty and turbo sunbird, but that year the the crank had a 15 degree difference I think.

Here are the possible ALDL definition files:

A089 1989 LG0 vin A
A092 1990 LD2 vin D, LG0 vin A
A144 1991 LD2, LG0

I was given this website from a friend. What do you guys think about this software? http://www.techedge.com.au/vehicle/aldl160/aldl_sw.htm

This is what I found as far as a datastream for my engine. Open the zip, and find one of the ones I listed above. I scanned it over, but what can I do with this info?

ftp://ftp.diy-efi.org/pub/gmecm/ALDLstuff.zip

I don't have any software to create a chip, or edit a chip. Is there one in particular that you could suggest? How much did you pay for it?

I have a burner/copier though.

Is there any tutorials, or helpful websites out there that could help me out instead of posting all my imbarassing statements on here? LOL

thanks,

-Joel

 

[JSM]

Re: OBDI Tuning

I suggest Tunerpro.

Tunerpro RT is $30 to register.

Has editors built in, with some searching on sites, etc you can build your own def. files. Isn't that hard, just requires you to play with things a bit and figure them out.

 

[PhantomGTZ]

Re: OBDI Tuning

Do you truly believe it will cost $2000+ for a dyno tune? Thats how much a Tec3 would cost me. You could tell the dyno tuner to optimize the timing, and A/F for safety and not peak horsepower. Just throwing it out there...

When you begin editing,

are you only editing the MEMCAL? Do people on this site tune their own chip/ECM with good success? I apologize in advance for how stupid that question sounds. I'm almost done with my mechanical engineering degree, not computer engineering. I'm wondering how deep I'm getting myself into.

I would love to see a screen dump if possible to show the software editing ease.

 

[JSM]

Re: OBDI Tuning

Again I hate dyno tunes, unless that is what you plan to use your car as a dyno test mule. Most of the dynos are roller setups. The only load to motor is by acceleration of that known fixed weight. You can't set car to drive at 35mph and have the same load as you would on the street.

#1 finding someone with a dyno and gm ecm editing knowledge will be tricky.

#2 yes it could cost $2k if you pay that person to wire up a stock ecm also. If you do the work yourself different story.

So many people want to tune the boost first then fix drivability. It doesn't work that way very well. You must first get the car to run, be very close drivability before tuning the high throttle position, boost tables. This is more truck on stock GM ecm probably than aftermarket. IMO you won't get good drivability on a dyno.

I tuned a locals syclone here, had 11.9's AFR on street, very nice curves. Put it on chassis dyno, AFR was 9ish:1. Drove it home back to normal.

Had we tuned on dyno, on street probably be 13:1 AFR, engine last about 1 good boost then be destroyed.

Tunerpro is free to download, then you can see the screens yourself.

 

[Turbo6]

Re: OBDI Tuning

Again I hate dyno tunes, unless that is what you plan to use your car as a dyno test mule. Most of the dynos are roller setups. The only load to motor is by acceleration of that known fixed weight. You can't set car to drive at 35mph and have the same load as you would on the street.

#1 finding someone with a dyno and gm ecm editing knowledge will be tricky.

#2 yes it could cost $2k if you pay that person to wire up a stock ecm also. If you do the work yourself different story.

So many people want to tune the boost first then fix drivability. It doesn't work that way very well. You must first get the car to run, be very close drivability before tuning the high throttle position, boost tables. This is more truck on stock GM ecm probably than aftermarket. IMO you won't get good drivability on a dyno.

I tuned a locals syclone here, had 11.9's AFR on street, very nice curves. Put it on chassis dyno, AFR was 9ish:1. Drove it home back to normal.

Had we tuned on dyno, on street probably be 13:1 AFR, engine last about 1 good boost then be destroyed.

Tunerpro is free to download, then you can see the screens yourself.

I'll agree with the AFR difference. I went to the dyno Saturday and my AFR was 10.8/1 and at the track it was 11.7-11.8 with the same settings. I did lean it wout some and get it to about 11.7/1 on the dyno. It didnt make as much boost either and only made 500.4 rwhp.

 

[dgoodhue]

Re: OBDI Tuning

1. I've always been told that you should not surpass 80% duty cycle on your injectors. Does this hold up in real-life turbo applications? Do people push the envelope safely?

Yes

2. Will pushing 80-100 psi of fuel pressure compromise the functionality of an injector? (The car uses low impedance injectors if that makes a difference). I will be installing an after market fuel pump that is capable of doing this.

It depends on injector, I have heard about some injectors no liking much more than 70-80psi. Unless your using a FMU you should see that much fuel pressure.

3. Would you suggest running 10% larger injectors than stock with an
-SAFC,
**or**
-an FMU + APFR (to cover richness at idle) ?

What be the limit to this idea? 20%? 30%? I still want the car to idle.

Those are all bandaid solutions.

4. Is the MSD DIS-2 the best way to control spark? besides a stand alone of course. Could you suggest another option?

ECM control is best, again that is a band aid solution.

5. I keep tossing numbers into a BSFC calculator, and I keep getting a value of (.52)-(.54). I know a turbocharged car should see a value of around (.60) . But does this case only apply to larger displacement vehicles?

Its generally applies to all engines, what is this going in? A V6 berretta? If you have the patience the stock syty ECM and scan tool can be programed to run this application, if the stock SyTy injectors were able to fit your fuel rail (sometime the height of the injector varies) they would provide enought fuel and the intitial tuning wouldn't be horrible to start off with. Though, this DIY ECM tuning isn't for everyone and maybe over your head. Most of us don't have tuning experience with the signal inteceptors such as the SAFC. Our ECM do it already (boost control can be done in the ECM as well)

 

[dgoodhue]

Re: OBDI Tuning

what is this going in? A V6 berretta?

Never mind about that question as I reread your post. You may want to attempt to use the Sunbird Turbo bin as a base its a 4 cylinder Turbo.

 

[dgoodhue]

Re: OBDI Tuning

I'm almost done with my mechanical engineering degree, not computer engineering. I'm wondering how deep I'm getting myself into.

I would love to see a screen dump if possible to show the software editing ease.

Goto Tunercat, you can download free version of the their software with the 747 TBI v8 mask, I have a 747.bin somewhere if you can't find one. Try looking around http://www.diy-efi.org/

 

[PhantomGTZ]

Re: OBDI Tuning

Never mind about that question as I reread your post. You may want to attempt to use the Sunbird Turbo bin as a base its a 4 cylinder Turbo.

Well,

keep in mind that my cylinder head flows about twice as much, has 2 cams, and makes about 40 more horsepower without a turbo in stock form. The firing order is the same, but the wiring is different. The turbo 2.0 uses a distrubuter, the 2.3 does not. That means making an ignition table.

thanks for all the replies guys. I need all the ideas I can get.

 

[Tooky]

Re: OBDI Tuning

I don't have the answers but wanted to offer my opinion. I think what you're talking about is a HUGE project and way over the heads of even a lot of experienced tuners on this board. I know I would not have the guts to attempt such a project yet and I have been racing my Syclone for 4 years now. What you're talking about is basically an engine transplant or conversion, I mean something completely outside what the factory provided functions for.

I was daunted by the ECM chip tuning for my Syclone and 90 Turbo Grand Prix for the longest time, eventually I finally got into it and I still can't beleive how much you can change and how complicated it actually is. I mean it's not "quite" as bad as what I had imagined but in other ways it's even more so. I guess what I'm saying is, if you have never even tuned chips for a stock/mildly-modified application, you're in WAY over your head trying to do an ECM transplant for a frankenstein project for which their is no precedent. Very few people have the skills to accomplish something like that. You very well may become one of them, but I doubt these skills would be acquired in a very short period of time.

In summary I'm not trying to talk you out of it, I just want to make sure you understand how difficult an undertaking this actually may turn out to be.

PS: Dave's advice on the Turbo Sunbird BIN sounds good to me, tuning for your head flow and camshafts is insignificant compared to the fact that it's a 4 cylinder turbo engine that at least is based in the same ballpark (compared to say a 5.7L N/A V8 chip). The DIS ignition compared to a distributor could be a problem but I think a solution can be engineered. I know TurboTony said he got the SyTy ECM to control a distributorless application. Also - even Distributor ignition motors still have a full ignition table..

 

[dgoodhue]

Re: OBDI Tuning

The turbo 2.0 uses a distrubuter, the 2.3 does not. That means making an ignition table.

That could be an issue with synchronizing. We have an ignition table though. Look/search through the GM DIY email archives to see anyone has done this before, a lot of stuff has been attempted.

 

[PhantomGTZ]

Re: OBDI Tuning

I was trying to imply that the 2.0 turbo motor bin was a bad idea.

What is wrong with the "bandaid" ideas? alot of these items (injectors, Adjustable Cartech FMU, AFPR) are mechanical and really won't be unreliable. The only programming that would be needed would be the MSD boost retard.

If these items are installed and working properly, the car would not differ from the stock ECU programming unless boost was applied. This is pretty standard practice for supercharger kits for the V8 guys.

I could also look into a J&S Safe Guard for knock protection.

 

[PhantomGTZ]

Re: OBDI Tuning

I'm going to alot of research on the sunbird ECU/chip when I get home tonight.

 

[dgoodhue]

Re: OBDI Tuning

I was trying to imply that the 2.0 turbo motor bin was a bad idea.

What is wrong with the "bandaid" ideas? alot of these items (injectors, Adjustable Cartech FMU, AFPR) are mechanical and really won't be unreliable. The only programming that would be needed would be the MSD boost retard.

If these items are installed and working properly, the car would not differ from the stock ECU programming unless boost was applied. This is pretty standard practice for supercharger kits for the V8 guys.

I could also look into a J&S Safe Guard for knock protection.

FMU changes with barometric pressure, so they aren't consitent. The SAFC is intercepting the MAP or MAF signal tricking the computer, the problem is this sometime put the ECM in unwanted condition (ie changing the timing due to perceived additional load)