Un-performance Chip
 

I have an 87 924S that had a performance chip installed (not sure which one) by the PO. I'd like to find out more about what it takes to change, swap, or even revert back to the factory chip.

I imagine the chip is installed in the ECU, but haven't come across any details yet in the books that I have. Anyone BTDT?

TIA,

on the later DMEs, I believe that the chip just snaps into place on the ECU. On the early cars, I know for a fact that you need to desolder the old one and solder a new one in. Not sure if the 924S used the old style DME (it does use the early 944 dash, after all), or the later one.

The 924s uses the later DME as the engine in a 924s is the exact same as my 86' 944. I think its a plug n' play type thing.

yup On my 87 924S it was plug and play, Just remove the old and install the new. Why are you changing back to stock???/

If you open the DME there are two circuit board inside. If you remove one (the face each other like a clamshell) you will see that one has a larger chip in a socket. It just swaps out with the other chip. The DME is held under the steering columb by 4 screws and it attached to a large cable. You pull back on a retaining clip and pull the cable off, and the DME just comes out. It's very simple. There might be a brandng or sticker on the chip installed, google it and find out what type it is. It's hard telling but it may not be a bad thing, allthough stock is good and safe and to some people desireable, and I understand this.

Have fun!

http://www.clarks-garage.com/ has a good procedure for chip replacement. See "DME Control Unit Removal and Installation" and "DME Control Unit Chip Installation" in the Garage Shop Manual.

Tech-Session.com also has a detailed description on how to remove and install the chip. Thats what I used. Tech -Session also has about 58 different technical jobs posted by random people. ;)

Thank you all very much.

My reason for wanting to back down to the factory chip (temporarily) is to allow my sons (new drivers) to drive the car. Once they've had some time behind the wheel, completed a couple of PCA driver training events, then we can consider the perf chip.

Best regards,

You might be over stating the effect of the perf chip...
Some people can't even tell the difference...

It might not even be worth removing & changing it for that reason...

Have fun though at the driving events.

i agree with doug...
i'm afraid once you get the chip removed, you'll be 'disappointed' (if that's the right word) with the level of change..

Wanna trade chips? :D

I was wondering how long it was going ot take for someone to ask that. :D

:bump:

ferseriously... I would be glad to trade :D

Brando,

If my intention was to elliminate the perf chip completely I'd be glad to trade. I just want to mellow the car a little till they get used to it more.

Actually I still need to locate a used factory chip as it didn't come with the car.

Thanks all,

Is yours an auto? Did mine and only real change was flatened out the performance. My stock used to have a large acceleration increase at 3.2K rpm. Now it's flat.

Its not worth your time and effort to remove the chip, its not going to effect it that much. If you really want to slow the car down, just remove the 1st and 4th spark plugs... that should do it.

lol
i think the guys here are right... you *really* will be going through a lot of effort for a very minimal loss...

Well that's curious . . .

I hear on the one hand about how slow these cars are, and I'm assuming that's with the factory chip. Yet I know for my own case - with a perf chip - these cars are not slow at all. I think mine kicks butt!

That's in part why I figured the factory chip would give my boys a chance to build up to the performance level of the car.

This should be interesting . . .

The 924 is slow, but a 924S is lots faster. The 924S engine is 25% larger than the 924. The S compared to todays standards is slow.

i'd find someone else with a 924S with a stock chip and ask to drive their car and see for yourself.