413 DME and 2.5L Chip With S50?

[MX339]

I recently picked up an S50 swapped car that has a 413 DME installed. I'm not sure whether or not it actually has an S50 chip in it as I've been unable to find any info on what the chip numbers for the M50 and S50 are. I know it's not too much of an issue to run it around on the street as it's running in closed loop and shouldn't have an issue hitting AFR targets.

My question is, do these newer ECU's with variable TPS still run open loop at WOT? I'm planning on taking this car down to Roebling this weekend and I'm concerned it's going to run lean if it's still got an M50 chip in it while running almost entirely at WOT in open loop. I'm sure the best solution would be to just buy an aftermarket S50 chip from somewhere, but I don't really have time at this point.

Dave, if you happen to see this, do you have any S50 chips on hand?

Thanks.

[M3PO]

Which 413 DME is it? Red or Silver? Almost all of the S50 DMEs had EWS1 and were 413 silver. If you have one of those and it runs, it has been retuned. S50s without EWS1 are very rare, it's safe to assume you don't have one of those.

If you have a red, it could be anything besides an OEM S50 chip with EWS. I have an Evosport tuned S50 chip with EWS and the car won't start in ANY 413 DME. If the chip "looks" OEM, it's probably M50. Can you post a picture of the chip in it? And I think you are correct that these engines run in open loop when the WOT switch on the TPS triggers.

[MX339]

It's a red label DME. I'm actually positive it's got an M50 chip in it as I ended up replacing ECU's to chase missing spark, and the replacement DME is unopened. Unfortunately I can't get a picture of the chip in the original DME as I don't have the car with me.

[M3PO]

It's a red label DME. I'm actually positive it's got an M50 chip in it as I ended up replacing ECU's to chase missing spark, and the replacement DME is unopened. Unfortunately I can't get a picture of the chip in the original DME as I don't have the car with me.

Aw, I see. Well if you are positive that it is an unopened red label DME that clears that up. I am 99% sure the car goes into open loop at full throttle. In terms of the dangers of that, I can't say for sure but I think you are fine. From what I understand, what the DME "learns" in closed loop is used to adjust the WOT open loop operation. Since both engines use the same size injectors, I would think that this amount of "learning" is well within the capabilities of the DME but hopefully a tuner will chime in. You might PM 328ijunkie and ask him.