i was talking to jim at ccs motorsports yesterday about chip burning.

in the conversation, he said i'd be much better off swapping over to an ecm from a late model tbi pickup. he said the communication rate on that computer was much faster and it would increase tunability, that the difference between the two was something like 6 pages of code in my ecm and 60 pages of code in the late model ecm.

does anyone know anything about this?

 

you know what,i think he may have a good point,i had an 88 tbi 305/700r4 from my neighbor,she purchased new after her divorce i bought it and did a much needed tune up,i went to the track with it and out of the 6 lo3s my 88 was the fastest stone stock with 3.08s at sea level it ran consistant 15.20 and the others ran from 15.8s-17.20s the other cars were 89-92s with mods,so i got on the band wagon,hedders,ex.,3.42s,ported tbi,5.7injectors next trip it ran 14.70s,blown trans(107,000mi.)fresh 700 w/2500 stall w/jet stage 3 custom chip 14.30s.the other guys followed my mods and still could not out run my lil RS,nor did i get any faster but i was still way ahead of the pack..i realize its a car ecu but there is a difference with the 88 ecu's,i put my ecu in my freinds 89 RS and his car picked up 4tenths,so he went and purchased one and got the same chip as me then we would be nearly even who ever left the best won the race..........there is a difference with those ecu's

 

Could you tell me what BCC chip that is and if possible, could you send me a spare ecm to test on my ecu bench? I've got lockers up and running and it would be really nice to actually compare the bins and see exactly what is going on during PE.
I'm reluctant to change my ecm for obvious reasons but I know there are code changes, I just wasn't aware of a hack released for the 88 ecm. If there is please let me know where I can find it.
Thanks for the heads up and maybe if other people get similar results we can conclude that stock, the 88's have a better chip/code for modded L03's. If the gains are as large as you suggest I'm excited.

 

Noone's actually addressed the question of a 92+ TBI ECU tho.. could you talk to Jim and see what year/model trucks he's referring to, specifically? If they're OBD-II I wouldn't go near it, but a quick 8192 baud OBD-I swap wouldn't be bad... if the pinouts weren't drastic.

 

i believe he was talking about 94-95 obd-1. he discussed pinouts and their being easy, but frankly, it was over my head.

here's his site and number.

http://www.ccsmotorsport.com/index.htm

jim paschall: 512.829.0227

he's a nice guy and will take the time to talk to you.

 

I believe there is a guy over on the 454ss board that has succesfully converted to a faster 7060 ecm, I would assume from a 7747. If this were the case, I would assume it would be possible to swap from the '89-'92 8647 as well. Though not near as simple as simply unplugging the harness and swapping in the ecm, it should definetely be worth it, the 160 baud rate of our ecms just plain sucks.

va454ss is also doing the swap and knows much more about it than I do, so hopefully he chimes in.

 

I can't find *any* info on that ECU.. methinks it would be a good time to start posting links to relevant data.. man, 8192 baud is tempting....

 

i hear the ecms out of the tpi cars are much faster than the tbi cars also. not sure though. but it looks like they can be had for under $50 on ebay.

http://cgi.ebay.com/ws/eBayISAPI.dll...&category=6763

btw, how hard is it to swap out a ecm?

-chuck

 

i don't think a tpi ecm will work on a tbi car, at least not with the factory chip tuning. tpi fires 8 injectors, tbi fires only 2

 

AFAIK there doesnt seem too be too much difference between the 88 and the 89+ ecms. The 88 ecm is a bit short on code. Seems to be like the 8746 but missing a few things. The actual calibration might be better and it seems to adjust the blms in PE. Other then that its neary identicle to the 8746. Shares many of the same things. There is one nice thing, about it, no speed limiter. Its set to 255 mph in the calibration.

 

duh, forgot about that. Does the ECM control that or is that in the Chip? oh well either way, im sure it'd be easier switching from a tbi vehicle to another tbi. like w/ the faster truck computer. anyone find out which year we're really looking for with that yet?

-chuck

 

The TPI ecus still only have 2 injector drivers.. they bank fire 4 high-impedence injectors each which are wired in parallel. The prom tuning and wiring would be the real problem. Does anyone have pinouts+wire colors for the TPI speed density ECUs vs 8746/8063? What about the later truck TBI ecus, which I can still find nothing for info on...

 

The tpi only has one injector driver instead of two like the tbi ecms. The 749, on the other hand, has two and all the features of the tpi ecm but with one extra driver so it can be used on a tbi system. There are some differences in the way it does the injector firing, like I hear its bank fire instead of full batch. There are some threads on this very topic. Go do a search. When it gets warmer out I may go see if I can pick one up myself.

 

yes, damn this cold weather.

 

Hey everone, I think I found what we were looking for. Swapping a 7060pcm for our 8746ecm. Here's a link to a decusion on the 7060pcm by Mike at www.GMPCM.com on the 454ss board that I found very interesting. Go here. Tell me what you all think about it.

Steve

 

I think we'll have some VSS issues.. but I think they can be overcome. Other than that, it looks like it may be a doable swap.

EDIT.. looked at some of the links on the GMPCM site.. haven't found any technical documentation on the 7060 yet.. however, I did discover that in 1986, the '2.0 L4 TBI “P” LQ5' application did use the 7165 (MAF TPI ECU).. perhaps we could snag usability of the 7165 or 7730 (MAP TPI ECU) ourselves... if we're going to open pandora's box, let's do it right, and make sure ALL the evil gets out this time... hope included. As long as it can yeild 8192 baud data, I want to be able to consider it an option.

8647 Pinout: http://www.cruzers.com/~ludis/1228746sheet4.gif
7730 Pinout: http://www.cruzers.com/~ludis/1227749sheet8.gif

Okay, I admit a crapload of tuning will be required.. but I think this is the case either way.
www.cruzers.com/~ludis lacks 7060 data.. we need to find this. We also need to find out the full advantages of switching ECMs. The ALDL data is nice, but higher resolution maps and tables would be great too, among other things which I know decidedly not enough about to even think of.

 

why not include the 749 as option for swaps, from what i can tell, with the injector driver from the quad 4 sunfires, it should run the TBI injectors just fine, the quad 4 uses 4 2.4ohm injectos.

the only thing i am not sure about is the firing scheme of the injectors. if it fires both at once, instead of alternating, would that cause some idle issues?

 

what scanning software are these guys using? This sounds like a good idea. I'm sure the extra tranny controles could come in handy.

 

AFAIK, the 7730 can only run one tbi injector. I was going to try one of the later tbi pcms in my truck so I could have tbi and still operate my 4WD 4L60-E but I dont have it anymore. Maybe ill do it with the camaro. Having an electronicly controlled trans could be interesting.

 

https://www.thirdgen.org/techbb2/sho...hreadid=221750

 

bbbRRRR. Wrong. Even my haynes manual distrinctly shows two drivers.. but here's an internal schematic of the ECU anyway.
http://www.cruzers.com/~ludis/1227749sheet7.gif

And I'm still fairly certain they alternate firing.

 

That's the 7749 ECM which Does have the extra injector driver but stock MAP TPI cars had a 7730 ECM which only has one.

 

Again, this is the program I'll be using:


http://www.efi-tuning.org/forum/inde...=ST&f=17&t=98&

 

Yes the '7749 is the one you want as far as ecms go. The '7730 wont work.

 

good ***! this has turned into the diy-efi board. i haven't understood a word of the last 9 posts!!!!

 

i really like the idea of having an algorithm to adjust the BPW as teh vacuum changes. Thats pretty sweet.

 

ok, what is "bpw"?

 

I see.. so.. hmm.. and the 7749 is the Syclone ECU? great. So where's info on the 7060 again?

 

the 749 is in alot more than the syclone. if you get the whole setup out of a sy/ty, i beleive you have to change injector drivers to the ones that came in the sunfires. i beleive grumpy did this swap on a CFI car, years ago, i did some research on it a while back, and IIRC the quad4 applictions had the correct injector drivers for our cars.

 

Unless your hellbent on running a computer controlled trans the 7749 would be the easier one to use. Has teh faster data rate your looking for, along with some other features. Im not sure you can use one of the PCMs w/o an electronic trans w/o having problems but I could be wrong. Probably want to visit the links above and snoop around in there. There seems to be more info available.