What's the A63 chip telling my motor??

[MirageMark]

I'm wanting to know some particulars on the differences between the A48 and A63 drag chips. I know the A63 runs leaner at mid-range rpm's, but what, if any, other differences are there between these chips. Does A63 equal more rpm's than the A48? ect.....

Thanks guys,
Mark Screen

[daytona]

A63 chip is good only if you are drag racing,{going thru the midrange quickly}If you try to cruise at 5k to 6.5k it's too lean there and will likely burn . been there. A48 is my choice. rick

[daytona]

A63 chip is good only if you are drag racing,{going thru the midrange quickly}If you try to cruise at 5k to 6.5k it's too lean there and will likely burn . been there. I dont think there is any top end difference. A48 is my choice. rick

[T-REX]

Or I jus ain't never got it to hit it!!! I have turned my 48 box to 9600 and not hit no limit...I thank I did remember when I bought the box that U could git limits at 2 differnt rpm's 8600 and 11,600...I could be wrong...MMMM, maybe not...Nope, I probably ain't wrong...Naw, I ain't wrong, jus ask me!!!...REX

[MirageMark]

The A48 is a non-rev-limiting chip, but the A63 is as well. I'm just wondering if there are any differences besides leaning out at mid-range rpm's.

Thanks,
Mark

[MERCMAN]

the a48 is the original drag chip in the 11350 a series ecu.(39 lb system) (1996) the a63 replaced the a48 also going up to 56 lb regulator. the key was to shorten the pulse width on the injectors. with the higher pressure and shorter pulse width the motor will react slightly quicker. the a 63 was replaced with the a6 in the newest 849849 ecu. the pros an cons? the a48 has a better midrange for riding , the a63? if you are needing a split second advantage in drag racing the 63 or 6 is the way to go. the motor is alot crisper at and off idle. if you are doing anything besides strictly racing , i would advise the a48 chip. you will not notice that much of a diffrence.i recommend te a48 to ANY lakeracers. neither the a48 ,63 or 6 have a rev limiter or at least not one that you would ever exceed.

[Balzy]

lake racer and cruiser chip. It is a lot fatter at idle and 4500 to 5500. So far I like mine. Looking for your opinion...............

[Bill Gohr]

It's telling it it's a S3000 with 26cc heads if it's not don't run it.........in all actuality neither one of those programs were for lake driving. The A63 has a lean spot in the middle for clean accel in a race. Hey but guess what so does the 48. Everyone always forgets thats a drag chip too. The A48 originated on the 1995 drag engine. Most people just seem to like the 48 with the 39psi better. Thats what I use on my 280. The 48 has a higher injector volume at WOT but runs the lower pressure. We have a speed limit here at night and you always seem to be at 4500 to 5500. I've never had anyone stick it at that RPM. I think eveyone just talks about it cause Mercury brought it up in a service bulletin that said don't run the engine at that RPM and clean your pistons regularily cause they were having other problems. Bottom line is if you're not drag racing don't use Drag calibrations. It's a compromise. Any questions call me, See ya later.....

[MERCMAN]

OPTION #2 WOULD BE TO HAVE THE REV LIMITER REMOVED FROM YOUR CHIP BUT THE A48 IS NOT AS LEAN AS THE A63.

[MERCMAN]

BILL IS VERY KNOWLEDGEABLE IN THIS FIELD AS WELL.AS FAR AS THE A10 GOES FOR ANY KIND OF LAKE RIDING THERE WILL BE NOTHING AS RELIABLE AS THE 39 LB SETUP WITH THE REV LIMITER REMOVED. I HAVE ALWAYS RAN THE A48 ON ANYTHING THAT WAS DOING ALOT OF CRUISING THAT I WANTED PEAK PERFORMANCE OUT OF , IM FIXING TO GET THAT MAP PROGRAMMED IN AN 849 849 SERIES. BILL CAN REPROGRAM THESE BOXES TO JUST ABOUT ANY OF THE CHIPS SPECS. HE HAS DONE ONE FOR ME AND IT WORKS GREAT. I WOULD TELL ANYONE CONSIDERING IT TO CALL HIM. HES A GREAT GUY. I WOULD/WILL ALWAYS DEAL WITH THE LIKES OF HIM AND JAY AS WELL AS OTHERS ON THIS BOARD (YOU TO JOHN MARLES) IF I HAD TO TELL YOU EVERYONE I THOUGHT WAS GREAT ON THIS BOARD THEY WOULD HAVE TO ERASE IT FOR LACK OF SPACE ON THE SERVER.

[Way2Fast]

I have the new 2001 drag motor that came with an A13 chip. Does anyone know anything about this box? Merc Racing told me that the other chips are not interchangeable on my motor. The motor will turn up some dangerously high EGT when run above the mid 4,000rpm range. Seems like I'm stuck running 40 -42mph if I want to keep the temp. down. I guess I asked for it as this is a "no crusin'" motor.

[Firestarter]

Richard

I would think that you could use an A-8, it is last years european F1 chip. It is designed for the S3000 with tight heads and an SVS. It has a rev limiter at 9500ish. It is a very smooth box, and for lake use a real nice box, with a plenty high limiter. Just keep in mind that you MUST use a "Z"plug.

RT

[Way2Fast]

"8" should be luckier than "13" anyway !!

[MERCMAN]

way 2 fast , you can have a dash mount pot added for cruising. it lets you really fatter her up while your playing and then you can lean it out for the racin!

[Bill Gohr]

Thats probably true you really can't hold it there. Send me your box. Call me at 847-274-9378.....Depending on the rpm,s you want to turn I would suggest the A8 or the A10.....

[Craig Knight]

Tell me more about how to fatten my motor for cruising,
Dash Mount???

[captcarb]

The dash mount is a modification to the ecu that adds a wire bundle and a potentiometer that is mounted on the dash to adjust the mixture the same as can be done at the ecu. You might want to also add a good digital egt to monitor what you are doing.
CC

[Craig Knight]

Is there a catalog or web page where you might buy the parts and how to hook it all up.

[MERCMAN]

the newer ecus have to be sent off. i have been an electrical guru for years and have done a few but i sent my last one to rapair to have it done because they have a trick dash mount piece with a numbered adjustment on it that works great! i have a box with the dash mount pot you can buy or swap for another regular one as long as is the newer 849849 series , i sold my stv and got a skater so im running a diffrent fuel curve and dont need the mount up front. WARNING DO NOT TRY THIS AT HOME!!!!! you can permanently damage this unit trying to remove the pot and installing a wire in the unit. if you own an 11350 a series digital box you can buy a harness and the pot and install it yourself (just plugs in)

[MirageMark]

Hey Craig, If you're serious about that modification, you need to go see Steve Taylor at Taylor Marine in Orange,TX. I know you're pretty close to him. I was in Steve's pit crew for a few of the ODBA races this year and he has a trick setup in his boat that allows him to adjust the ECU. After every round, he checks his temp and determines how rich or lean to run the next race. It really is a neat setup. I've been in and out of his boat and still have not figured it all out! It's the only way to run like they run without blowing it all to pieces. Good Luck. See ya at the River!!!

Mark Screen

[BarryB]

I just bought an A48 chip to replace an A49 from Mark at perf plus. He said there is a limiter on the A48 chip but most will never hit it because it is at 10500 rpm. This is what he told me a few weeks ago.
Barry

[steve]

Just a bit of info. The A42 and the A48 have the EXACT same curve. The 48 is non rev limited, the 42 has a limiter. The A48 is NOT a major change from the std A42 box. The 63 is a drag box with a different curve AND a different fuel pressure. It is made for racing. The 48 works well for racing also but is simply a 42 w/o limiter. CALL Sean at Rapair for the actual curves if you doubt it. This is FACTUAL info. Just FYI. Also the A48 and 63 have a major defect--the chips are inserted into a socket. They wiggle loose and lose contact and the whole box goes bad after a while. The early analog and newer boxes , A6 etc are soldered onto the board . Much better solution. Lastly the A6 and A63 have the exact same curve. No difference. Some racers say the A6 can be leaned one more number but they probably have a box thats got a sensor off 1% or something. Exact same curve and no loose chips. Again FYI . Check for yourself . Lots of guys selling boxes on this board. Steve

[Bill Gohr]

Where did the A42 originate? I don't have my sheets here with me. The stock 2.5 box is an A49 there were a couple of roundy round boxes in the low 40 numbers and an A40 is a digital box for a 2.4 BP. The A48 was built for the 1995 drag motor.

[Bill Gohr]

Ever had the cover off your A6 box? Take the cover off grab the chip, and pull it out. The difference is that the old box functions on one chip and the new ones on 2, and both chips are just pushed into a socket.......

[LakeRacer99]

I just bought a used 260 with a digital box. I am not sure which box I have, It has no decals other than 11350 on the back of the box and 847619-9 on the plug in style EEPROM. Is it Mercury or Rapaired Mercury?
Thanks.

[steve]

The A42 is the same box as the A49 and may have been used for roundy rounds , not sure. Exact same curve.
847619-10 on the chip with the same base program. The A48 is also the same except it has the limiter removed or moved very very high.
The early Drag motors that used the A48 were basically 260's with tight heads and a few minor changes internally . The A48 is my favorite all around box.
The EEPROM on the A42,49,48,63 boxes is socket mounted . This chip carries the fuel map , rev limit and other important functions. The EEPROM on an A6 or an old analog box is SOLDERED to the board. Some of the other less important chips may be removable, I never gave them much attention. The reason the A42-63 series goes bad is generally attributable to the EEPROM wiggling loose and frying the board. The A6 doesn't have that problem. Also this saved Merc from warranty claims --Guys were swapping the chips and blowing 260's up and then swapping the chips back. Steve

[Bill Gohr]

Again my memory is failing me, probably has something to do with tumbling an F-1 boat at 110 on Thursday. I don't recall a "9" chip but I'll look it up. You sure it's not a 19. That's an A63. The 96 and 97"s came with a dash 10 or a dash 20. Those are both stock limited units for the A49. The real A48 is a dash 11.


Steve, the map chip on the 849849 box is covered in potting if you cut the potting you can pull it right out. The uncovered chip is the program chip. It pulls right out.

[LakeRacer99]

Thanks for the help...
I just checked the EEPROM and it has 847619-9 on the first line and below that is an *. It is a paper adhesive label like you could make on your laserjet printer, nothing too fancy.
Is this chip the only difference between these boxes? Same chip in all of them-just different programs, hence the different labels on the chips?
Sorry this is kind of confusing to me.

[steve]

Thanks for the update Bill. I've been wrong before and I'll check on that chip being able to be removed. Are you sure Merc didn't make some of them unremovable? Last time I looked at mine it was soldered right to the board under the gel. There were other chips on there also. I would guess one to be a voltage regulator, but they are usually 3 pin TO-330 packages. I'll double check the numbers and see whats what on my A6 boxes.
I thought you were supposed to be strapped in a harness in the F1 boats?? Sounds like a bad day! I went out last night to make a run at dusk and puked a brand new fuel pump ( never had one go bad before) . Lifted the cowel to see what was up and dropped it in the drink. Had to jump in ( river current) and save the cowel, climb back in , and paddle to shore, by now in the dark. The 2001XR was not meant to paddle! You have to practically lay down on the deck or hang your leg over the side . At least mine was a low speed problem . 110 sounds pretty hairy! Glad you are OK.

[LakeRacer99]

Hey steve...You appear to have a little expertise in components. I have a question. Have you ever heard of a manufacturer or any specs for the pressure transducer that makes up the MAP sensor. I have one that is bad in my ECU and would like to replace. Has anybody seen a schematic diagram of the digital ECUs. What does that cost or who do you got to know to get that info?
Always tinkering...

[steve]

I'll check on the schematic.
I am thinking of updating the drivers and also using some of the better componants the we use for High End audio amps for the board. Most have faster settling time, lower temp coefficient and are more precise. Should help, can't hurt. Also they are generally less RF sensitive and generate less of there own noise.
The MAP sensor should be readily available too.
HiRel that builds ECU's for Holley might be a source, Kinsler may be another.
When they screw up , they can cause all kinds of curve problems.
Have you tried some of the larger electronic componant companies on the net? Try Summit Electronics in Boca Raton Fla. Scott seems to find odd stuff pretty easily.

[Bill Gohr]

Yes I was and thank God for cells. When the chine peeled off the boat it turned left and I mean NOW. Tumbled a couple times and landed upside down. Boat's ok except for a couple missing pieces.......



Lakeracer, I can replace and recal that map sensor if you you need one. How do you know you need one?

[NPW]

just one more question on the ECU's ..whats the A 4 and the A7 used for

[H2Onut]

any info on schematics ?

[madmike1968]

Hey just wondering if you figured out the -9 ecu chip . I have the same one and nobody can tell me what it is thanks