Mongo

Wow that might actually work. You're doing a transmission swap too right?

FLYVMO

Yes I'm doing the 6L80E swap. I am using the OBDII version (STA-1000)of the unit but it does the same thing.

Cheers!
Carl

Mongo

Got a PM from someone in a different forum who had a similar issue on an LS and 4L60E swap. His solution was to use some sort of GPS-Pulse converter for the speedometer. I will look into that also, but I believe that may resolved the speedo issue.

Looks like the Microsquirt TCU will be the software of choice to get the 4L60E to jive with the 928.

RicardoM

Any of you guys know why an '87 S4 would have a GTS rear bumper on it?
someone told me the factory put GTS rear bumpers on some of the cars, but kind of weird explanation considering the GTS didn't come out till 92

jcorenman

Welcome, but this may not be the most relevant thread to post this question to.

The rear bumper has been replaced. Obviously there were no GTS bumpers in '87, but in '91 when GTS production started the factory modified the S4 tooling to create GTS bumpers. Replacement parts from then were all GTS-style.

Koenig-Specials 928

You mean this one from Summit?

Mongo

Yes that's it! The next determining factor is the PPM the factory speedo puts out for compatibility.

Koenig-Specials 928

I think I read somewhere that it is 9 pulses per wheel rotation. So do the math for 1 mile and that's the number.

Petza914

When I had Carl do the C5 Z06 6-speed transmission swap into my '79 Spyder he also installed GPS based speedo signal converter that works perfectly with the stock 928 gauges. Maybe ask him which device he installed in my car. He had temporarily placed the GPS antenna behind the windshield on the dash since it needs a clear view of the sky, but I relocated it to the rear deck just behind the convertible top (right in the center) as the receiver is pretty small and weatherproof. Looks like it might be the same one someone else posted the photo of.