Aftermarket MAF and chip install for 1989 3.2 need help

[vinyl_tien]

I got the kit for a pelican member about 6 months ago. Finally I have chance to install them, but I find a lot question about it.
The original 4K ECU rom is 28 pins, but the auto Thortty is 24 pins. The instruction said should install like the third picture. Is that correct????

[Quicksilver]

To go back to a 24 pin chip requires that you switch a jumper on the the circuit board. It really is a step backward. The 28 pin chip allowed the programming of the processor to be overridden.

The choices I see for you here are:
- Contact Steve Wong about a 28 pin chip as he might have one for that MAF.
- Change the jumper back to 24 pin and run with it.
- Don't go with the MAF.


I would be surprised if the MAF produced any power unless you run it at various altitudes where the barn door and the altitude switch can't cope. (I would be REAL interested in what it would do on a drive up Pikes Peak.)
A lot of people diss the stock AFM but it isn't a restriction. A very well respected race engine builder when asked to test the MAF discovered that it produced a 5 HP loss in power.

[SilberUrS6]

Originally Posted by Quicksilver

I would be surprised if the MAF produced any power unless you run it at various altitudes where the barn door and the altitude switch can't cope. (I would be REAL interested in what it would do on a drive up Pikes Peak.)
A lot of people diss the stock AFM but it isn't a restriction. A very well respected race engine builder when asked to test the MAF discovered that it produced a 5 HP loss in power.

I think the only benefit to running a MAF is if your AFM is completely shot, and you can't get a good, used one. Since they are NLA new, there will come a time when folks running Motronic won't have much of a choice about how to solve AFM problems.

[175K911]

I had the first production MAF that the old Autothority ever produced. Was in exchange for them using my car on their dyno to develop the installation and software. Still have it.

First, I've never known any of the Autothority 24 pin proms to be used in the 28 pin socket of the '87+ cars. They produced the software in both 24 and 28 pin configurations.

Second, the MAF did produce some extra HP but it was all above 5000 rpm. Dyno results showed little if any gain below that. and the gains above that weren't but 3 or 4 hp more than just a chip.

However, that's on a stock engine with stock everything. Once I went to headers, C2 cams and sport muffler, the MAF began to show better breathing than the stock barn door. In back to back testing at Summit Point, the MAF allowed the engine to pull better from about 4000 up, and pulled smoothly to 7100. And with increased displacement and a bit more compression the MAF really showed it's worth.

But as I told Al Collins back in the day when he asked what I thought it was worth, I said $995 which wasn't that much more than the 495 or 595 he'd been charging for just his software for stock engines. But at $1995 it wasn't worth the money. And certainly not for a stock engine.

[vinyl_tien]

Thanks you guys, I think the best way is moving 24 pins software to 28 pins. Maybe install it after I convert my 3.2 engine to 3.4 with c2 cam.
Really appreciate!

[vinyl_tien]

Does any one know, which EPROM rom porsche using? I mean EPROM model, I find a friend who can copy 24 pins software to 28 pins rom, but I have no ideal what kind black rom I should buy.
Need you guys help!
Thanks!!!

[Chuck.H]

27c32 (4k) and 27c64 (8k) from memory.
There is no benefit of copying though, as you only have 4k worth of data - yes you can copy it twice, but what you really want is the 8k image that replaces the in-CPU maps.

I've had this MAF on my car for over 250k miles, for me it's been great - agree, maybe it really woke up when I replaced B&B with SSI+M/K, but all and all the butt dyno says "lets go". I just wish this MAF was compatible with later Ford models that are all over junkyards, but I do have a spare so I'm not too concerned. One day I'll put a newer Ford MAF inline and compare the voltage curves side by side.

HTH,
Chuck.H
'89 TurboLookTarga, 347k miles

[vinyl_tien]

Thanks Chuck
So if I copy 24 pins software to 28 pins rom, that will work right? or I just get a 24 pins DME ECU?

[Chuck.H]

You can use the 24pin in your 28pin DME; I've gone both directions in the past, here are the pinouts for the two chips, and the conversion notes.

2732
4kx8 EPROM.

+--------------+
A7 |1 +--+ 24| VCC
A6 |2 23| A8
A5 |3 22| A9
A4 |4 21| A11
A3 |5 20| /OE VPP
A2 |6 2732 19| A10
A1 |7 18| /CE
A0 |8 17| D7
D0 |9 16| D6
D1 |10 15| D5
D2 |11 14| D4
GND |12 13| D3
+--------------+

to use a 2764 in a 2732 socket:
1) put chip in, pin 1 overhangs.
2) connect 1,2, 27 to 14 (ground)
3) connect 28 to 26 (vcc)

to use the 2732 in a 2764 socket:
1) insert chip leaving pin 1 open
2) connect 28 to 26 (vcc)

2764
+--------\/--------+
1 -|Vpp Vcc|- 28
2 -|A12 /pgm|- 27
3 -|A7 (A13) nc|- 26
4 -|A6 A8|- 25
5 -|A5 A9|- 24
6 -|A4 A11|- 23
7 -|A3 /OE|- 22
8 -|A2 A10|- 21
9 -|A1 /CE|- 20
10 -|A0 D7|- 19
11 -|D0 D6|- 18
12 -|D1 D5|- 17
13 -|D2 D4|- 16
14 -|gnd D3|- 15
+------------------+

Chuck.H
'89 TurboLookTarga, 347k miles

[vinyl_tien]

Thanks Chuck.H, appreciate !!!