Hey guys,

Doing the SD swap (unfortunatly from an 85) So is it the 730 ecm I want? There are what are the 344 and 262's for? I only want to do this once in my life, so gotta get it right the first time

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1985 IROC-Z, nuff said :P

 

Yep, the 730 is the way to go. Just did the update and after messing with my VE tables, she drives just peachy. -Matt-

 

Cool

Whats the first thing to tackle when burning a performance chip?
Spark tables, A/F ratio?

What does "ED" do to his chips that makes him so popular?

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1985 IROC-Z, nuff said :P

 

You will want to start on the Volumetric Efficiency tables first(PE tables).

 

Definitely the VE tables mentioned.

Quote:

<font face="Verdana, Arial" size="2">
What does "ED" do to his chips that makes him so popular?

The same thing bottled water companies do. He gives them a high price and everyone thinks they are great. They might be good, but they will never the best. -Matt-

 

Generally start with the VE, but you have to work back and forth with VE and timing. You can tune the VE to a poor timing table, and be forever lost with what to do. That's why testing is soo important.

Also, the base cal you start with has alot of where you'll be doing the most changes.

Smooth stable idle, min PTSv for cruise, low ETs, and MPG will pretty much fill in your tables, but the mid to high load areas just take time to futz with

For a 3rd gen FBod the 730 is the way to go

 

Yea thats basically the direction i've been PUSHED

I was going to go to a 165 (from the 870) but after getting flamed up the wazoo.. I decided SD.

I just got alot of repinning im not looking forward too

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1985 IROC-Z, nuff said :P

 

get the wiring diagrams, get organized, and in a none rush mode take your time and just do it. I've done a bunch of ecms swaps, and getting the info ahead of time, and getting organized are the keys. First time took me 3 days to do, and nowadays 4-5 hours.

 

SH*T! THREE DAYS?????

*second thoughts*



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1985 IROC-Z, nuff said :P

 

3 days? That isn't that long. Try sending a "custom" prom back and forth to formato or ed wright. I did the 730 swap, it was pretty straight forward since Mike Davis already had all of the information layed out.


Brendan

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1987 IROC-Z L98,SR,EB 6085's,LPE 219/219 SR Cam, Crane 1.6RR, EB TPI Base, 58mm TB, Stock T5, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, Aluminum DS, 94 Disk Rear, Adjustable Prop Valve, Precision 3.73 Gears, Weld in Sub-Frame Connectors, Hotchkis LCA's, KYB Shocks/Struts, Poly Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm, Big stereo, 730SD Conversion.

To see the ROC, Check out the webpage Here

 

This is my one and only car and mode of transportation

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1985 IROC-Z, nuff said :P

 

Ok, one thing to note when doing ALL of the research. Get all of the things needed BEFORE you take anything out of your car. You can make the adapter harness on your kitchen table where there is light/plenty of workspace/and possible beer/pop what not. WITHOUT even touching the car. I'm not extremely familiar with the 85 ecm setup so you will need to do alot of cross referencing but it shouldn't be too hard.
If done correctly you should be able to swap ack and forth from the 730 and 870.


Brendan

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1987 IROC-Z L98,SR,EB 6085's,LPE 219/219 SR Cam, Crane 1.6RR, EB TPI Base, 58mm TB, Stock T5, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, Aluminum DS, 94 Disk Rear, Adjustable Prop Valve, Precision 3.73 Gears, Weld in Sub-Frame Connectors, Hotchkis LCA's, KYB Shocks/Struts, Poly Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm, Big stereo, 730SD Conversion.

To see the ROC, Check out the webpage Here

 

Im not looking for the swaping back and forth

I just want a programable prom

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1985 IROC-Z, nuff said :P

 

As to your other question, I'm using a '262. It's essentially an updated '730. The pinouts and programming are virtually the same.

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408cid 1985 Corvette
http://www.mojosgarage.com

 

I don't know how 'modded your car since the signature doesn't describe much, so thats why I brought up the "swapable" idea. Because if you have a "not so stock car" like mine, you can't just do the swap and plug a chip in. I left my 165 setup in temporarily until I could get the VE table close or to where I thought driveablity was good enough and not throwing codes or using like 10gallons of gas for .5miles.


Brendan

 

Well its moded enough to need a chip..

And I can't do anyhing with the 85 so thats why i decided the ECM change....

I figured I'd burn a chip i was very comfortable with (hell a stock bin will work) and then plug 'er in and tune from there. I just dont want my car out of commision for 3 days

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1985 IROC-Z, nuff said :P

 

I understand what your saying, even though i have a "beater" that i can almost go back to. I can't stand not driving my car.
But what I was saying is that the SD setup is NOT as "forgiving" so to speak, The tables are coded to work for the stock motor, the chips do run a little rich and you may find that it won't run very well. Since you have a different cam and all. Best thing to do is just swap it and give it a try.
Your car is CLOSE to stock, same heads and what not, so you shouldn't need a LOT of tuning. Just alot of patience and testing.


Brendan

 

So would you recommend another MAF then?

I was originally just going to go to a newer MAF, but after virtually being cussed out by this board of unforgiving SD only supporters I was turned that direction. I'm NOT making 400hp, so I dont necissarily NEED SD, I just wnat to burn my own proms damn it

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

You can do whatever you want. You didn't get cussed out. You were told what we have all went through and the pro's and con's. MAF would probly work for you. But thats your decision.
We are just trying to help and show both sides. And me for one have been the 165route. I wasted alot of time/money doing that.
If your having second thoughts, email me, I still have almost all of my 165 stuff left over that I will sell to you if you want to give the 165 a try(sorry guys, not meaning for a classified ad here).

Brendan

 

Blah

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

If you want to burn your own PROMs then just contact TunerCat and buy the '85 1F TDF file along with the TunerCat program, a programmer, an eraser, and some spare PROMs. Bam - now you have everything you need in order to program PROMs for your '85. If you want to save some money then buy Flash PROMs instead of regular PROMs and then you don't need an eraser.

Blah.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

[This message has been edited by TRAXION (edited July 18, 2001).]

 

Let me clarify things a little. My first one that I did was like 10 years ago, and there was NOONE around to ask any questions. The only info I had was from several GM schools I'd been to. Also was rooted in 20 years of carbs, and distributor weights. You however get to cash in on lots of others work.

It's real easy to hit reply and go na, the idea of being able to swap ecms has lots of merit. You can make some really nice Plug N Play ecm stuff.

 

The 85 ecm has a slower baud rate, and i believe less memory.

blah

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

That shouldn't matter if your only interested in writting your own prom.

 

!#$!%

For some reason i can just imagine you guys running through a pit yanking peoples spark plug wires just so you can come out on top.


First its SD only, then its SD/MAF swapable, then its stay with 85......whatever, i'll figure something out.

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

You don't seem to understand where most of us are coming from and I know damm well Grumpy has alot of time in this stuff.
You can't get everything in this world without time and effort, maybe even some thinking.

We are giving you a hard time due to your lack of respect for the opinions and facts we have given you. Along with all of the negtive feedback and unwillingness to learn is just wasting our time.

I don't know if i'm making any sense here but i'm sure a few guys would back me up on this.

Brendan

 

Thats just the thing, this board isn't intended for "backing people up"
Its intended for sharing facts/thoughts/opinions/ and knowledge.

I started this thread with a very specific question. Because of your influence I was heading the SD route, I asked about a 730, and the topic stemed from there, which is good, the more info the better. And dont make it sound like im unprepaired, or underqualified to work on my car, it has come along way. Time isn't an issue, but it just happens with this one if i need to go somewhere, i can't untill the car runs. I've started threads concerning the ECM change to a later MAF and got an overwhelming response making my decision sound bad, so being flexable i considered SD. Now im just going to have to make a call on my own. Which will probalby come soley from the parts most readily availiable in my area.

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

Have you considered an aftermarket ecm like Haltech or Accel DFI?

p.s. I think you can make some minor changes to the stock '85 chip and be happy (especially with MAF).

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-Greg

'85 Trans Am - WS6,TPI:
Original owner, original paint/engine/interior, plus the usual bolt-ons

 

No haven't really considered it...

Only because i haven't heard anything about them.

I guess the only draw back i can think of immediatly is tunercats support?
maybe?
Are they for MAF or SD?

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

I don't think there are any aftermarket MAF ecms , just SD.

 

Ok back to getting technical

Can someone maybe explain to me what the ECM difference is between MAF and SD?

You say less forgiving, how is it less forgiving? Is it the sensitivitiy difference between MAP and MAF sensors? Or the way the tables and values are designed? More controll over SD proms? What is the tuning and HP aspect difference between the two.

 

Go here to check out both. Both will convert MAF to SD. With the Haltech, you can use the stock harness with only a few re-pinnings. You will lose emissions stuff with both -


http://www.force-efi.com/

 

Wow..

Well looks interesting, i guess they dont have prices on the site though?

As so many of the rest of us I'm on a tight budget, one thing that captured my interest is the money SAVED in burning your own proms with the adition of the controll you have over your engine, the biggest inconvinience is the repinning (naturally)

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

Get ready to puke when you find the prices. It is not a cheap alternative.

 

Ok,
MAF sensor actual meter or measure the incoming airflow, by that, the computer can adjust things much more precisely(to a POINT). Each prom maf or Sd have predefined tables but since the MAF sensor can measure the EXACT amount it can put out better results with less fine tuning, BUT, you compromise alot of driveability and fine tuning. Some guys I know swear by the MAF and it works great. But with SD you can fine tune just about everything have a perfect chip if you get extremely **** with it(glenn )

For SD,
the MAP sensor measures engine vacumm directly and does its calculation from there, since the measurement is in a static vacumm measurement you may run VERY lean or VERY rich unless your chip has been tuned for your specific engine combo.
say your STOCK engine idles at 40kpa(vacumm measurement) and the VE table(or fuel table) has a setting of 20, that may be correct for a stock motor but a modified engine may require more or less fuel at that load range(vacumm measurement).


That is generally WHY it is said that the SD is less forgiving.. Now, to a point the SD system will work on a mild modified engine, if the chip is already a big rich and vice versus...

Another thing to think of, the older MAF sensors(pre 89 GM sensors) could only support 255gm/s for airflow, which is ok for a stock motor but even a mildly modified 350 will exceed that and trip an engine code. There are ways around that but you would be lieing to the computer and it could get a little complicated in that aspect.

Another thing I look at when doing this comparison and it has been beaten to death.
The ecms are readily available, MAP sensors are cheap, and its rather simple to tune once you get into it.

 

Chill...

With regard to GM ECMs you have 2 main options...

1) Convert to SD. This is the best option. Period.
2) Stick with your current ECM and use TunerCat.

We are giving you options - not telling you what to do. YOU have to weigh all the options and pick what you want to do. You have the information giving the Pros and Cons of each ... .. . now you need to make a choice.

Tim


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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

 

Leirch, Thank you very much for that last post, helpfull, and to the point.

I basically knew about the hardware element (map/maf) but its the way the ecm deals with what the two sensors feed it thats the gray area for me.

Im going to just chase down a 730 ecm and call it good. (assuming the pin swap goes well) Thanks guys

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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.

 

Yea no problem. Things can be dealt with with the correct attitude(I do tech support all day unfortunatly).
Let us know whats going on with the swap.

Just as a reminder, you don't HAVE to have a 730, you can use any that are mentioned in the ECM interchange article that are compatable with the 730.

Brendan

 

Yea im using that interchange to find my doner


and im a system admin so I know the attitude thing all to well



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1985 IROC-Z
TPI 305, 700R4 with shift kit, richmond 3.73's, auburn pro series posi, crane compucam 2030, ported plenum, gutted air boxes, all the little insignificant stuff.