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View Full Version : GM "749" (syclone/typhoon, quad 4, 2L turbo) ECU... anyone usin' one in a volvo?


dhallilama
12-31-2007, 05:55 AM
pardon me if what i write below is confusing or is a haze of complete and utter incomprehensibleness... i'm pretty tired, and kinda just thinking out loud...

the ECU is GM part number 1227749 (now has a Delco PN, too)... they were used in quite a few vehicles... all OBD1... syclone/typhoon, turbo sunbird, quad4 vehicles, etc...

the ECU can be had pretty easily for ~$50. they're actually available from NAPA and GM dealers as well (although i have yet to verify the price there).

i've been thinking about it for a while... lots of openly available information on 'em. lots of people seem to be using them in other applications... 4cyl turbo dodges, porsches, misc V8s, etc... pretty commonly hacked.

high resolution, fuel and spark, use a 2 or 3 bar MAP, built in "limp" mode (guessing if the injectors are sized ok), wastegate control, knock detection (with the sensor of course), fan control...

possibility of 16 multiple maps with a multi-bin switcher... ~$65 new, with the dash mounted remote... switch binaries on the fly. low boost, high boost, ethanol, valet mode... damn... possibilities are endless. ok, so there are 16... and 16 isn't exactly endless... but more than i can think of uses for at the moment.

tune-able by laptop.
a lot of commercially ($) available ECU tuning software, some freely available also.
tons of diagnostic/logging software out there.
with an eprom emulator, can be tuned on-the-fly (then later burned to eprom)

ok, so you would need to pull/burn/replace the eprom when doing changes...

base maps, well... you'd likely be f'ed with getting something ready to run off the bat... maybe pick a map from one of the diy-efi guys as a start?

lots of tuners are familiar with the ECU and the tuning software... meaning if you were so inclined, it probably wouldn't be that difficult to find a good shop to dyno tune it for ya.

these ECUs have been used in performance apps for a while, so plenty of software/hardware is out there... meaning it can be found used for pretty cheap... even the damned thing which i can't remember it's name, but holds multiple maps/programs and can be switched on the fly. damned brain... the more beer i douse it with, the less it remembers.

as a side thought, the GM cruise control would be an easy implementation with this...

Motorola 68HC11 processor, so no... not the fastest (8mhz??? i forget), but should be easily enough for anything thrown at it.

i've got an eprom eraser and burner, an eprom emulator... ALDL (GM OBD1) connector... a few of the things that'd be needed.

if ya had to buy everything, it probably wouldn't be a cheaper option than megasquirt... but it's another option, and one that's pre-assembled and easily available should you need another one because you spilled your beer on it.


more to come when i've rested and re-beered myself.

PetesDustyVolvo
12-31-2007, 11:23 AM
Sounds great, aside from the whole "oh wait we already have megasquirt so why bother" part.

dhallilama
12-31-2007, 07:57 PM
Sounds great, aside from the whole "oh wait we already have megasquirt so why bother" part.

just another possible alternative for those who want another option besides MS...

nothing against megasquirt, just thought the 749's cost/availability and higher resolution would make it interesting...

500dollar744ti
12-31-2007, 08:01 PM
just another possible alternative for those who want another option besides MS...

nothing against megasquirt, just thought the 749's cost/availability and higher resolution would make it interesting...

i was on that boat trying to think of every way to avoid megasquirt but that was because people made it sound like it is difficult to set up... you would have 10x more trouble setting up what you are talking about here than megasquirt... MSnS is rediculously easy to setup and if you are going to rewire for new management why not start with the best bang for the buck.

the poi
12-31-2007, 08:14 PM
theres no real time tuning with a prom-burned ECU. This is a huuuuge problem.

MrBill
12-31-2007, 09:10 PM
theres no real time tuning with a prom-burned ECU. This is a huuuuge problem.

+1 to that. My roomate had the turboedit for his honda, man was it a pain to change numbers and "try again"

God damn...

dhallilama
12-31-2007, 10:19 PM
^ real time tuning can be done with an eprom emulator...

i was mostly just thinking out loud.... 'cause i've got eprom burners, an eraser, at least 2 emulators... and every other part sitting here (many in multiples), save for the 749 ecu.

on the other hand, i've also got an MSII sitting in my desk. not trying to avoid MS by any means... just bench racing options :)

plantto
12-31-2007, 11:52 PM
I dont know if this would be a problem, but the syclone/typhoon is a V6 turbo not 4 cylinder turbo.

dhallilama
01-01-2008, 12:08 AM
^ same ECU was used on the quad4 (a 4cyl), and the 2.0L 4cyl turbo sunbird (along with a few other vehicles)....

i got a line on a 749, should be here sometime next week. dunno if i'll give it a go in my volvo or not, but i'll post about it either way. the 740 is not only a daily driver, but right now it's our only car (unless you count piles of parts as a "car"... then i've got at least 2 more :) )


the other car forum i'm on is pretty anti-technology (traditional hot rods/customs only)... a few megasquirted cars there, but the vast majority are carb'd. any that are EFI keep quiet about it.

Lord_Athlon
01-01-2008, 01:17 PM
i thought about this for a year or two, then i bought a ms box and totally forgot about it till the other day.

JohnLane
01-01-2008, 02:44 PM
Interesting.

16 maps to switch through.....
Hmmmmm.....
A map for economy with low boost and 87 octane....
A map for 92 octane....
Another for 100 octane.....
Adjustable naughty (almost) on the fly.... Hmmmmm.....

dhallilama
01-01-2008, 04:28 PM
ok, looking a bit more into the 749.... the tables are all 16x16, and the fuel control is to 1 µsec...
so larger maps and the same fuel resolution.
dual tables across the board... so in a V engine each bank can have it's own set of tables... or in a straight motor configuration dual injectors could be used with separate maps.


it's not open source, but has been reverse engineered pretty heavily so it may as well be.
i do think MS is FAR better documented, and far more people using them...

how many maps can you switch through with MS? i could be wrong, but reading through stuff the most i see is 2. multiple maps would surely sway me more in one direction or the other...

again, not arguing one way or another, or trying to start a pissin' match between ECUs... just trying to fuel (no pun intended) my curiosity.

JohnLane
01-01-2008, 08:02 PM
Well I'm interested.

wennstroma
01-01-2008, 08:33 PM
The newer ms-2extra betas have optional 16x16 fuel maps, still 12x12 on ignition. They have three switchable tables now but I don't know if it is fully operational yet, I've never used them.

Lord_Athlon
01-07-2008, 12:26 PM
http://www.diy-efi.org/gmecm/