Differences between '84 and newer 911's electronics and engines?

[Dadofour]

I have rebuilt an '84 and '85 911 engine and the mechanicals are identical. The distributors are shared, but the wire sets are different.

Can anyone shed some light on what the differences are?

What makes the '84 so unique?

Thanks

[KNS]

The routing of the spark plug wires, the earlier steering wheel and the non-powered seats - last part is the best. Not sure if there is anything else...

[scarceller]

The 84 DME box is different than the 85 car. In the 84 DME it uses a 2716 (2K) UVProm chip that contains the maps. Then the 85-88 cars the DME changed and uses a 2732 (4K) chip. Then in 89 they switched to 2764 (8K) chip.

In 84 the Bosch DME was state of the art for the time and large chips where very expensive if even available I think this is why they used the small 2716 (2K) chip. But as the years moved on bigger chips became more readily available.

One more thing is that the 84 cars had fuel and timming maps that where VERY conservative. This is why the HP on the 84 car is less than that of the 89 cars. By 89 the factory really found how far they could safely push ignition in the 3.2L. The simplest upgrade is to put a 89 DME in a 84 car, instant factory power gain. You'd be surprised to learn that some after market chips are simply 89 chips slightly altered if altered at all.

Read this:
http://911chips.com/ignition.htm
Steve goes to great lengths to explain these details here, BTW Steve is one of the few tuners that really understands these DME systems and how to improve them.

[Joe V]

So the connector and harness is identical between an early production '84 and a late production "89??? Fantastic! Thanks for the info. I've always wondered if I could "upgrade" the ECM on my '84.
Well now I'm going to get greedy!!! What about a chipped '89 ECM on an '84? Will it provide even greater HP gains over a stock '89? Who's on first? What's on second...

[scarceller]

Most aftermarket chips are 4k or 8k chips have have yet to see a 2k aftermarket chip. So it may be hard to find a aftermarket chip for an early 84 car.

But any DME with 4k or 8k chip would work just as well. The best aftermarket chip for these cars comes from Steve Wong, period! I'm not just saying this I have looked at the maps in great detail on Steve's chip compared to others out on the market. I own several different type chips and the Steve chips not only make power but are very well designed for throttle response.

Contact Steve.

[911st]

Ya, just contact Steve at 911chips.com.

I belive he noted once that even though the later 911's are quoted to make more HP, when hot they pull things back more and actually may make less HP.

Some or most of the 84's had the chip hard soldered on the board I suspect. I think Steve adds a socket and puts a bigger chip in w his performance programing. If is good for about 15hp over the best stock chips.

Add a cat bypass or euro muffler - and -a sport muffler or add a second tail pipe to the other side of the stock muffler on top of the chip and gain a total of about 25hp, better part throttle response, and better gas mileage.

Enjoy!