Why would replacing DME result in slight reduction of power?

[movin]

'87 DME died a while back and the replacement was the newer version with 28 pins. The old DME's chip had fewer pins. Thing is I noticed a slight reduction in power. Puzzling. BTW, both had S.Wong chips, same parameters. The old DME just made the car more powerful in the top end.

[DW SD]

odd issue. I'd venture that they are not the same parameters. Did you double check with Steve?

Any chance your car gained weight? How much difference? Any other changes?

Doug

[Por_sha911]

Dumb Question: Did Steve custom program both chips for you? Is it possible that one chip was programed differently than the other?

[ewave]

The extra weight of the 28 pin part over the 24 pin part is slowing the car down.

[johnnyo]

Any possibility one DME was from a ROW and the one you have now is US ? Just a stab in the dark

[livi]

I will be very interested to hear Steve comment. I have zero knowledge of course (so why don´t I shut up?), but could it be that the newer 28 pin is designed to go with a bit different input parameters so although "programmed" identically with the old chip, it does not produce identical output ?

OK, I should have shut up..

[ewave]

Originally posted by livi
I will be very interested to hear Steve comment. I have zero knowledge of course (so why don�t I shut up?), but could it be that the newer 28 pin is designed to go with a bit different input parameters so although "programmed" identically with the old chip, it does not produce identical output ?

OK, I should have shut up..

It's just an EPROM... It contains the code that the cpu (an Intel 8051) runs. So if the eproms have the same programming, the output would be identical. I think my pin weight theory is correct. Try driving back to back experiments with your eyes closed to see if you can still tell the difference between the two DME's.